JP4718126B2 - Sediment mud recovery device and method - Google Patents

Description

  The present invention deposits sediments such as excrement and dead bodies of animals and plants in aquaculture fisheries, or fine substances flowing from rivers, etc., and COD values deteriorate due to the influence of microorganisms, etc. The present invention relates to an apparatus and a method for treating sedimentary mud such as sea areas and lakes that have an impact on water. Furthermore, the work hardly causes water pollution such as pollution, and does not perform chemical treatment of the treated water discharged from the solidified liquid separator or the physical solid-liquid separator, and further in the course of treatment. The present invention relates to an apparatus and a method for treating sediment mud that drops into a drilling hole formed in the bottom of a seabed or a lake in the state of being on the bottom of a seabed or a lake without causing a foul odor.

  In fishing grounds where aquaculture facilities are installed, food residues given to cultured seafood, seafood excrement, animal and plant carcasses, etc., accumulate on the ocean floor and lake bottom. In addition, sludge is accumulated by components such as domestic wastewater flowing into rivers, livestock manure, and organic fertilizers contained in water flowing out from cultivated land. As a result, the COD value, total nitrogen amount, total phosphorus amount, sulfide, etc. exceed the reference value. This deposit is called “bottom sediment”.

  In these sea areas and lakes, the living environment has deteriorated remarkably, such as the formation of anoxic water areas or increased COD values due to the occurrence of red tides due to eutrophication and oxygen deficiency due to abnormal growth of micro-organisms.

  The development of technology that treats sedimentary mud by low-cost and less impact on the surrounding environment encourages the improvement of the aquaculture and lake environment, and improves red tide and COD reduction. In addition to encouraging, fisher producers and the like are desired to keep the cost of maintaining and restoring fishing grounds low and to prevent environmental degradation associated with processing operations.

  Techniques related to the treatment of sediment mud have been widely proposed, and problems will be clarified by listing them.

  1. The method of physically removing dredging with a general dredger such as grab dredger, dredger type dredger, and conveyor type dredger with bucket is the cheapest and can be processed in large quantities. However, when processing sediment mud containing a large amount of fine particles such as organic matter in aquaculture fisheries, etc., a large amount of suspended matter such as floating mud is wound up. Therefore, it is necessary to perform a treatment such as charging a large amount of sedimentation material in order to prevent contamination of surrounding water areas due to work. In addition, environmental impacts such as bad odor at the disposal site of dredged mud and water pollution due to drainage are inevitable.

  2. The suction dredge device is also a technology based on physical treatment, but the amount of floating mud to be rolled up is smaller than that of a general dredge device, and the influence of water pollution on the surrounding water area is small. In addition, since the amount of mud that can be treated at a time is small, it is possible to deal with a limited construction area. However, the sediment mud discharged from the suction device becomes a soft mud liquid having a high water content, and a large amount of processing materials such as chemicals and solidifying materials are used to treat this (see Patent Document 1).

  In addition, dewatering treatment is carried out at facilities installed on trolleys or on land, and the dewatered mud is treated with chemicals and discharged to collect mud soil with a reduced water content. It was inevitable that a processing apparatus such as a liquid separation machine was required and the cost was high. Furthermore, in the process or processing equipment for pressure-feeding to a trolley or land, the influence on the environment such as generation of bad odor due to the contact of organic substances with air cannot be avoided. Alternatively, in the method of dehydrating by temporarily standing on land for several years, there are only a few places for temporary storage, so this method itself is difficult, and the only post-dehydration processing method is landfill, which can be processed The small amount of earth and sand is also a problem.

  3. The method of spraying sand etc. and directly covering sediment mud has the advantage that it can be constructed in large quantities at low cost. However, when the soil to be coated is sprayed, the bottom mud is rolled up or the surrounding waters are polluted by scattering of fine particles contained in the coating material. In addition, shallower water depths cause significant changes in environmental conditions such as rising water temperature. Therefore, it was unsuitable for water areas intended to obtain biological resources such as fishing grounds. In recent years, natural destruction due to sand collection has become a problem, and it is difficult to obtain a large amount of coating materials at low cost.

  4). The guide pipe is driven into the sand layer below the ground surface below the bottom mud layer, the jet injection pipe is suspended in the guide pipe, the sand of the sand layer is pushed up by the jet water flow, and the bottom layer is reversed so that the soil layer is reversed. There is a technique to cover the mud layer. This technology is effective when the soil below the surface of the ground does not contain fine soil particles that cause floating pollution, but when the soil layer below the ground line is soil with a lot of fine soil particles, The surrounding water quality is contaminated during the coating process. In addition, when the soil layer is a soft rock or a gravel layer including a rake having a large outer diameter, a technique for covering the soil layer in a state where the soil layer is reversed by being pushed up cannot be applied.

5. A technique is also being studied in which the sucked earth and sand are guided to the processing equipment of the trolley, and then discharged from the tip of the pipe inserted into the earth under high pressure and sealed in the earth such as the seabed. However, when the ground strength is not uniform, the pumped earth and sand penetrates the weak ground strength and diffuses into the surrounding water area, causing water pollution. In addition, in the case of sand layers, gravel, rocks, etc., where the ground is consolidated, it is a well-known fact to engineers with experience in ground improvement methods that the pumped mud can hardly be enclosed in the consolidated sand layer, etc. If you try to pump it to the ground, it may break out of the ground due to the damage of the inserted pipe or the reaction of the pressure, which may spread a large amount of mud. Therefore, the pumping method is a technique that is not effective except for a place that satisfies extremely limited conditions.
Japanese Patent Laid-Open No. 10-499

  As described above, the conventional technique has a certain effect in terms of removing sediment mud. However, many of these technologies are intended to conduct sediment-liquid separation processing by mechanical equipment by guiding sediment mud on land or on a trolley equipped with processing equipment. In addition, it is necessary to use treatment materials such as chemicals and solidifying materials. Therefore, depending on the chemicals and solidifying materials used, it may contain harmful components directly or affect ecological systems such as environmental hormones.

  Even in cement-based solidified materials that have been widely used, many problems remain, such as fear of water pollution by the hexavalent chromium contained. In addition, in the case of sediment mud with a lot of organic matter, a bad odor is generated by touching the air, resulting in a new environmental problem.

  On the other hand, the method of reversing the soil layer or covering with sand brought in from other places has a limited application range of the soil layer. Moreover, it can be said that the technique of sealing the sucked mud into the ground at a high pressure is effective only under extremely limited conditions.

The problems of the conventional technology are summarized as follows.
1. It causes pollution such as diffusion of floating mud in processing processes such as excavation of sediment mud.
2. Odor is generated by contact with air in the process of sending to equipment on land or on a ship.
3. Injecting materials and chemicals containing chemical substances such as solidifying materials and coagulants to purify mud after solidification or dehydration of the mud may cause environmental hormones and other environmental problems.
4). There is a case where a processing method after dewatering the collected sediment mud is not established, and a countermeasure that does not generate a by-product that requires processing and disposal after construction is desired.
5. Even if the technology is effective under limited conditions, there are technologies that cannot maintain their effectiveness in sea areas or lakes where there is a soil change in the bottom sediment.

  An object of the present invention is to provide a bottom sediment mud recovery apparatus and recovery method that can solve the above problems.

The invention according to each claim that can achieve the above object is as follows.
(1) The invention according to claim 1 is a bottom sediment mud recovery device for recovering sediment sediments deposited on the ground surface of the water bottom, and is a type having a “shutter-type recovery port”, and has the following configuration Have
(a) a trolley that forms a fixed scaffold on the water;
(b) a casing pipe that can be built into the ground from the carriage,
(c) a casing rotary excavator that is installed on the carriage and supports the casing pipe and can be driven to rotate around an axis and move axially;
(d) In the state where the casing pipe is penetrated, the fixing means can be suspended from the carriage and can be attached to and detached from the outer peripheral surface of the casing pipe and fixed to the outer peripheral surface of the casing pipe. A recovery fan part that scrapes sediment mud on the ground surface while rotating and moving in the axial direction together with the casing pipe;
(b1) The casing pipe has a recovery port portion in an axially intermediate portion, and the recovery port portion includes an upper end portion of a lower casing pipe and a lower end portion of the upper casing pipe which are separated from each other in the upper and lower directions. A double-pipe structure portion that is rotatably fitted is formed, and a plurality of shutter holes of the same size are opened at equal intervals in the circumferential direction at corresponding positions of both the upper end portion and the lower end portion, respectively. In addition, the upper end portion and the lower end portion are relatively rotated by the rotational drive by the casing rotary excavator, and the corresponding shutter holes are in a shifted position, and the corresponding shutter holes are in the same position. Can be switched between open and
(d1) The recovery fan part supports a plurality of blades extending radially to scrape the sediment mud on the ground surface, and supports the upper edge of the blades and a through hole for the casing pipe And a cylindrical side plate that extends downward from the peripheral edge of the top plate and supports the tip portions of the plurality of blades.

(2) The invention according to claim 2 is a bottom sediment mud recovery apparatus that recovers sediment mud deposited on the ground surface of the water bottom, and includes a “slit-type recovery port”, and has the following configuration Have
(a) a trolley that forms a fixed scaffold on the water;
(b) a casing pipe that can be built into the ground from the carriage,
(c) a casing rotary excavator that is installed on the carriage and supports the casing pipe and can be driven to rotate around an axis and move axially;
(d) In the state where the casing pipe is penetrated, the fixing means can be suspended from the carriage and can be attached to and detached from the outer peripheral surface of the casing pipe and fixed to the outer peripheral surface of the casing pipe. A recovery fan part that scrapes sediment mud on the ground surface while rotating and moving in the axial direction together with the casing pipe;
(b'1) the casing pipe has a recovery port portion in an axially intermediate portion, and the recovery port portion is provided with a plurality of slit holes of the same size at equal intervals in the circumferential direction, and
(d1) The recovery fan part supports a plurality of blades extending radially to scrape the sediment mud on the ground surface, and supports the upper edge of the blades and a through hole for the casing pipe And a cylindrical side plate that extends downward from the peripheral edge of the top plate and supports the tip portions of the plurality of blades.

(3) The invention according to claim 3 is the bottom sediment mud recovery apparatus according to claim 1 or 2, wherein the fixing means of the recovery fan is a "wedge fixing type" and has the following configuration.
(D2) A plurality of the fixing means of the recovery fan portion are arranged at equiangular intervals inside an annular wall erected on the top surface of the top plate coaxially with the casing pipe, and each of the fixing means,
(d2-1) a clamping plate having a surface capable of pressing the outer peripheral surface of the casing pipe;
(d2-2) a vertically moving rust that can move up and down along the inner surface of the annular wall;
(d2-3) restraining means that can be fixed at a predetermined position in the vertical direction to restrain the vertical movement of the rust that moves up and down
(d2-4) a horizontally moving rust that abuts on the inclined surface with the vertically moving rust and is horizontally movable in the radial direction of the annular wall in accordance with the vertical movement of the vertically moving rust;
(d2-5) connecting means for connecting the horizontally moving rust and the clamping plate;
(d2-6) elastic means for urging the horizontally moving rust radially outward of the annular wall;
(d2-7) When the vertical position of the restraining means is moved in a direction against the elastic force by the elastic means, the vertically moving rust moves up and down and simultaneously the horizontally moving rust moves radially inward. Thus, the holding plate presses the outer peripheral surface of the casing pipe through the connecting means.

(4) In the invention according to claim 4, the fixing means of the recovery fan part in the bottom sediment mud recovery apparatus having the shutter type recovery port part of claim 1 is “air fixing type”, and has the following configuration.
(D2 ′) A plurality of the fixing means of the recovery fan portion are arranged at equiangular intervals inside an annular wall erected on the top surface of the top plate coaxially with the casing pipe, and each of the fixing means
(d2'-1) a clamping plate having a surface capable of pressing the outer peripheral surface of the casing pipe;
(d2'-2) An air cylinder fixed to the inner surface of the annular wall, comprising a connecting rod that can expand and contract in the radial direction of the annular wall, and the tip of the connecting rod is connected to the clamping plate The air cylinder
(d2'-3) a hole for air piping for supplying compressed air to the air cylinder is formed in the casing pipe above the shutter hole of the recovery port; and
(d2′-4) When compressed air is supplied to the air cylinder, the sandwiching plate presses the outer peripheral surface of the casing pipe by the connecting rod extending in the radial direction.

(5) In the invention according to claim 5, the means for fixing the recovery fan part in the sedimentary mud recovery apparatus having the slit-type recovery port part of claim 2 is an “air fixing type” and has the following configuration.
(D2 ′) A plurality of the fixing means of the recovery fan portion are arranged at equiangular intervals inside an annular wall erected on the top surface of the top plate coaxially with the casing pipe, and each of the fixing means
(d2'-1) a clamping plate having a surface capable of pressing the outer peripheral surface of the casing pipe;
(d2'-2) An air cylinder fixed to the inner surface of the annular wall, comprising a connecting rod that can expand and contract in the radial direction of the annular wall, and the tip of the connecting rod is connected to the clamping plate The air cylinder
(d2'-3) A hole for air piping for supplying compressed air to the air cylinder is formed in the casing pipe above the slit hole of the recovery port, and
(d2′-4) When compressed air is supplied to the air cylinder, the sandwiching plate presses the outer peripheral surface of the casing pipe by the connecting rod extending in the radial direction.

(6) The invention according to Claim 6 is the bottom sediment mud recovery apparatus according to any one of Claims 1 to 5, wherein the blades are curved as much as possible in a flat shape or a surface on the rotational traveling direction side of the recovery fan part is concave. It is characterized by having a shape.

(7) The invention according to claim 7 is characterized in that, in the sedimentary mud recovery apparatus according to any one of claims 1 to 6, the top plate has a slope that gradually descends radially outward.

(8) The invention according to Claim 8 is the bottom sediment mud recovery apparatus according to any one of Claims 1 to 7, which is detachably attached to the lower end of the casing pipe, and the casing pipe is connected to the ground surface from the bottom sediment mud surface. It has a tip cap that is used when building up to
The tip cap portion is composed of a lower tip cap and an upper support fixing means,
The lower tip cap includes a disk, a cone continuously provided on the lower surface of the disk, and a plurality of spiral mud scraping ridges protruding from the surface of the cone,
The upper support fixing means includes a columnar cylinder fixing frame that extends upward from the center of the upper surface of the disk, a plurality of cylinders that can be moved forward and backward from the outer periphery of the cylinder fixing frame to the outside in the radial direction, and the cylinder And a fixed leg attached to an arm projecting from the tip of each of the first and second casings and capable of contacting the inner surface of the casing pipe.

(9) The invention according to claim 9 is the bottom sediment mud recovery apparatus according to claim 8, wherein the upper support fixing means is further supported by a plurality of pillars extending upward from the peripheral edge of the upper surface of the disk. A guide roller frame and a plurality of guide rollers mounted on the guide roller frame at equiangular intervals, each of the guide rollers being axially rollable along the inner surface of the casing pipe. A wire hook that supports the suspension wire that is supported and suspends the tip cap portion is provided.

(10) The invention according to claim 10 is a sediment sediment recovery method using a sediment sediment recovery apparatus having a “shutter-type recovery port” and has the following configuration.
A casing pipe having a recovery port portion in an intermediate portion in the axial direction, wherein the shutter hole provided in the recovery port portion can be switched between a closed state and an open state by rotation around the axis of the casing pipe And sediment mud on the surface of the ground while being able to be suspended from a trolley with the casing pipe penetrated and rotating and axially moving together with the casing pipe in a fixed state on the outer peripheral surface of the casing pipe In the bottom sediment mud recovery method for recovering bottom sediment mud using a bottom sediment mud recovery device having a recovery fan section
A first step of installing a tip cap portion for preventing sediment intrusion at the lower end of the casing pipe with the shutter hole closed, and building the casing pipe vertically to the bottom mud surface;
A second step of building from the bottom mud surface to the ground surface while rotating the casing pipe;
A third step of removing and collecting the tip cap portion from the lower end of the casing pipe;
The shutter hole is built in the ground while rotating the casing pipe while the shutter hole is closed until the lower side of the shutter hole reaches the ground surface, and the earth inside the casing pipe is excavated and taken out, and then the lower side of the shutter hole A fourth step of pulling up the casing pipe until the bottom reaches the bottom mud surface,
The recovery fan is suspended to the bottom mud surface and fixed to the outer peripheral surface of the casing pipe, and the shutter hole is opened, and then the casing pipe is rotated until the recovery fan reaches the ground surface. A fifth step of scraping the sediment mud and dropping it into the casing pipe from the shutter hole;
A sixth step of releasing the fixed state of the recovery fan and lifting and recovering;
A seventh step of covering the surface of the sediment mud dropped into the casing pipe by introducing the earth and sand from the upper end of the casing pipe after the shutter hole is closed; and
And an eighth step of pulling up and collecting the casing pipe.

(11) The invention according to claim 11 is the bottom sediment mud recovery method according to claim 10, wherein after performing the first to eighth steps in one bottom sediment removal target region, the sediment moves horizontally. And a ninth step of repeating the first to eighth steps after moving.

(12) The invention according to claim 12 includes the tenth step of filling the ground surface from which the bottom mud has been removed with the earth and sand after the ninth step in the bottom sediment mud recovery method according to claim 11. It is characterized by.

(13) The invention according to claim 13 is the bottom sediment mud recovery method according to any one of claims 10 to 11, wherein the casing is excavated and taken out in the fourth step as the earth and sand to be introduced in the seventh step. It is characterized by using earth and sand inside the pipe.

(14) The invention according to claim 14 is a sediment mud recovery method using a sediment mud recovery apparatus having a “slit-type recovery port” and has the following configuration.
A casing pipe provided with a recovery port portion having a slit hole in an intermediate portion in the axial direction, and can be suspended from a trolley with the casing pipe penetrating and fixed to the outer peripheral surface of the casing pipe In the sediment mud recovery method for recovering sediment mud using a sediment mud recovery apparatus having a recovery fan unit that scrapes the sediment mud on the ground surface while rotating and moving in the axial direction together with the casing pipe,
A first step of mounting a tip cap portion for preventing invasion of earth and sand at the lower end of the casing pipe and erected the casing pipe in the vertical direction to the bottom mud surface;
A second step of building from the bottom mud surface to the ground surface while rotating the casing pipe;
A third step of removing and collecting the tip cap portion from the lower end of the casing pipe;
A fourth step of digging and taking out the earth and sand inside the casing pipe while building the casing pipe while rotating the casing pipe until the lower side of the slit hole reaches the bottom mud surface;
After the recovery fan part is suspended to the bottom mud surface and fixed to the outer peripheral surface of the casing pipe, the bottom sediment mud is scraped by lowering the casing pipe while rotating until the recovery fan part reaches the ground surface. A fifth step of dropping from the slit hole into the casing pipe;
A sixth step of releasing the fixed state of the recovery fan and lifting and recovering;
A seventh step of covering the surface of the sediment mud dropped into the casing pipe by introducing the earth and sand from the upper end of the casing pipe with the earth and sand;
And an eighth step of pulling up and collecting the casing pipe.

(15) The invention according to claim 15 is the bottom sediment mud recovery method according to claim 14, wherein after performing the first to eighth steps in one sediment sediment removal target region, the sediment moves horizontally. And a ninth step of repeating the first to eighth steps after moving.

(16) The invention according to claim 16 is the bottom sediment mud recovery method according to claim 15, further comprising a 10th step of filling the ground surface from which the sediment mud has been removed with soil after the ninth step. It is characterized by.

(17) The invention according to claim 17 is the bottom sediment mud recovery method according to any one of claims 14 to 16, wherein the casing is excavated and taken out in the fourth step as the earth and sand to be introduced in the seventh step. It is characterized by using earth and sand inside the pipe.

  In the present invention, a method of forming a drilling hole to a predetermined depth by repeatedly inserting a casing pipe and excavating the inside, which is widely used in the field of pile driving work or the like, is used for collecting sediment mud. The method is combined with a trolley equipped with a spud generally used in marine operations. In addition, a technology that moves the casing pipe up and down by a known casing rotary excavator or rotates the casing pipe in any direction around the axis is combined with a relatively simple new structure. . Thereby, an inexpensive apparatus and method are realized.

  The tip cap portion at the time of erection of the casing pipe has a function of extruding and removing bottom mud immediately below the casing pipe around the casing pipe.

  Further, the blades of the recovery fan section have a function of scraping the sediment mud underneath to the center. In particular, the recovery efficiency is high when the top plate of the recovery fan has a slope that gradually decreases toward the outside in the radial direction. The sedimented mud that has been scraped is dropped into the interior through a shutter hole or slit hole in an open state of the recovery port. The rotation of the casing pipe and the recovery fan when building in the bottom mud is sufficient as the rotation required to move the bottom mud quietly laterally. Thereby, winding up and spreading | diffusion of sediment mud by rotation are avoided. Moreover, since the casing pipe is pulled out after the surface of the dropped sediment mud is capped with earth and sand, this also prevents the sediment mud from being rolled up and diffused. In this way, since it does not have an adverse effect due to water pollution, it does not cause a decrease in productivity due to environmental changes around the treatment area, and is suitable as a method for treating sediment mud such as aquaculture fishing grounds.

  In the present invention, unlike the conventional method, it is not necessary to dig up the sediment mud up to the surface of the water or on land with the excavator or suck it up with the suction device, and the processing can be completed as it is at the deposit site of the sediment mud. Therefore, there is no process for introducing the sediment mud on land or on the trolley, and the sediment mud does not touch the air at all. As a result, no bad odor is generated in the treatment process.

  In addition, since the bottom sediment mud solidification material and chemical treatment materials used in many of the conventional methods are not used at all, there is no impact on the ecosystem due to water pollution due to components contained in the treatment material or environmental hormones. Absent.

  Regardless of the degree of consolidation of the bottom of the water bottom, the present invention excavates and removes the sediment in the casing pipe with a hammer grab or the like while penetrating the casing pipe into the ground to form a drill hole, This is a method of slowly dropping sediment mud into the soil. Therefore, the effect is not limited by the local conditions such as the strength of the ground and soil constituents, unlike the submerged pumping method.

  In particular, instead of collecting sediment mud on the water, it is dropped into the excavated hole excavated in the local ground, and more preferably, the excavated soil is used to cover the excavated hole, or after the sediment mud is collected Since it can be backfilled to the ground surface, no by-products that require treatment or disposal after construction are generated. This is one of the most important effects of the present invention.

  If the excavated soil is not suitable as a backfill after capping and capping, such as when the soil under the bottom mud contains a lot of fine particles, it is of good quality to a level with the ground surface. The backfilled and excavated earth and sand are collected on a trolley, etc., and the remaining earth is treated at the land facility. This avoids polluting the surrounding water area. In addition, even though such ground excavated sediment does not contain sludge like sediment mud even though it contains fine particles, there is no risk of water pollution without chemical treatment or consolidation treatment. It can be used as landfill for construction managed under conditions.

  In the present invention, it is possible to perform a considerable amount of work in one cycle by utilizing commonly used construction machines and excavation methods, and continuous work because it does not require time due to complicated processing such as solid-liquid separation. And the cost per unit processing amount is low. In addition to excavation work and removal of casing pipes, noise such as mechanical noise and vibration can be suppressed.

  In the present invention, since it does not disturb the area other than the circular area directly under the recovery fan part, and does not perform the input of processing materials, the load on the ecosystem such as useful microorganisms and animals and plants existing in the vicinity is small, and production of fishing grounds It is possible to purify only the part where the sediment environment has deteriorated while maintaining the nature, and the economic effect is great.

  In particular, the sediment sludge recovery apparatus having a shutter-type recovery port portion according to the present invention has a casing pipe partially having a double-pipe structure, a casing rotary excavator installed on a carriage, and is detachable. Other than the cap part that can be mounted and provided with a spiral protrusion on the surface of the cone, and the recovery fan part that can rotate and move up and down together with the casing pipe, it does not require a special processing device and is generally widely used. By preparing the casing rotary excavator and the casing pipe, the carrier, the excavation soil temporary loading carrier equipped with the excavator for excavation and backfilling operations, all the steps of the preferred example can be completed. Therefore, it can be implemented at low cost.

  Furthermore, the sediment mud recovery apparatus including the slit type recovery port portion can simplify the structure of the casing pipe, and can be easily controlled because there is no opening / closing operation like the shutter type, and can be implemented at low cost.

  In the casing pipe having both the shutter type and the slit type recovery port portion, the recovery fan portion can be rotated and moved up and down together with the casing pipe by being fixed to the casing pipe. It is not necessary to provide the driving means, and it can be carried out at a low cost.

  Furthermore, since any sediment mud recovery device can be applied to various grounds with the same device, it is not necessary to prepare a plurality of devices even in areas where ground changes are large, and it is highly economical. .

  The bottom sediment mud recovery method of the present invention can be carried out only in the area where sediment sediment is deposited, and does not affect the area where sediment sediment does not matter. In addition, since the wastewater treated with chemicals and other treatment materials is not returned to the water after dehydration, the degree of change in the surrounding biological environment is extremely small, and useful microorganisms and animals and plants are maintained as they are. The economic effect of sustaining productivity is great.

(1) Outline of sediment mud recovery equipment (related to claims 1 to 9)
(1-1) Overall Configuration First, a description will be given of parts common to each embodiment of the sediment mud recovery apparatus according to the first invention. In addition, this bottom sediment mud collection | recovery apparatus is used suitably for the bottom sediment mud collection method which is the 2nd invention mentioned later.
FIG. 1 is an overall configuration diagram of a sediment mud collecting apparatus 1 that collects sediment mud 22 deposited on the ground surface of a water bottom. The main components are a spud 11, a carrier ship 2, a crane 3, a work table 5, a casing pipe 4, and a casing rotary excavator 6.
Please refer to FIG. The trolley 2 is used as a fixed scaffold for installing the sediment mud collection apparatus 1 on the water. At the rear part of the hull of the carrier 2, a spud 11 that is a support column for fixing to the water bottom ground is equipped. Two to four spuds 11 are used according to the necessary supporting force, and the spud 11 can be moved vertically by a lifting device. A work table 5 for performing main work is continuously provided as a part of the carriage 2, and a casing pipe 4 that is a hollow tube is installed on the work table 5. The work table 5 is formed with a combination of section steel and the like so as to secure a strength that allows the casing pipe 4 to be built. A crane 3 is mounted on the carriage 2. The crane 3 hangs the casing pipe 4 when the casing pipe 4 is erected, and digs out the earth and sand inside the casing pipe 4 that has been erected and takes out or backfills the hammer grab (see FIGS. 36 and 40). It has the ability to attach and work.

  A casing rotary excavator 6 that supports the casing pipe 4 and can be driven to rotate and move up and down around the axis is also installed and fixed on the work table 5. The casing pipe 4 is supported by being connected to the casing rotary excavator 6 and is built through the casing rotary excavator 6 and the work table 5. For the casing rotary excavator 6, for example, a model corresponding to the casing pipe 4 having an inner diameter of 3 m, which is widely used as a known technique, is selected and installed on the work table 5.

  Further, a recovery fan portion 9 having a circular outer shape is suspended from the carriage 2 so as to be lifted and lowered. The recovery fan unit 9 can be suspended from the work table 5 in a state where the casing pipe 4 is penetrated.

(1-2) Outline of Casing Pipe and Recovery Fan Part FIG. 2 is a side view showing an outline of portions of the casing pipe 4 and the recovery fan part 9 which are main components of the present invention. A recovery port 40 for recovering sediment mud is provided in the axial intermediate portion of the casing pipe 4. As examples of the recovery port section 40, there are two types of “shutter type” and “slit type” which will be described later, but FIG. 2 shows a shutter type.

  The recovery fan unit 9 is suspended from the carriage 2 by a suspension wire in a state where the casing pipe 4 is penetrated. The recovery fan unit 9 is provided with fixing means that can be attached and detached on the outer peripheral surface of the casing pipe 4, so that it can rotate and move in the axial direction together with the casing pipe 4 while being fixed to the casing pipe 4. By the operation of the recovery fan unit 9, sediment mud on the ground surface is scraped toward the casing pipe 4. As examples of fixing means for fixing the recovery fan 9 to the casing pipe 4, there are two types of "wedge fixing type" and "air fixing type" which will be described later, and details will be described later.

(2) Configuration of the collection port (2-1) Shutter-type collection port (related to claim 1)
The shutter type recovery port portion 40 has two deformation modes that are partially different in configuration depending on which of the two types of fixing means (wedge fixing type or air fixing type) of the recovery fan unit 9 to be described later. Hereinafter, each aspect will be described.

(2-1-1) When combining a shutter-type recovery port with a wedge-fixed recovery fan (related to claim 3)
3-6 is a block diagram which shows one Example of a shutter type | mold collection | recovery opening part at the time of combining with a wedge fixed type | mold recovery fan part. FIG. 3 is a development view of the collection port 40. As shown in FIG. 3, the casing pipe 4 includes a recovery port portion 40 at an axially intermediate portion thereof (not a central portion that bisects the length). The recovery port 40 can be switched between a closed state in which the internal space and the external space of the casing pipe 4, which is a hollow tube, are blocked, and an open state in which the recovery port portion 40 is communicated by a rotational drive around the axis by the casing rotary excavator 6. is there. The specific configuration is as follows.

  The casing pipe 4 includes a lower casing pipe 4A and an upper casing pipe 4B that are separated from each other in the vertical direction. Since the lower casing pipe 4A and the upper casing pipe 4B each require a considerable length, they are usually formed by connecting short blocks having an appropriate length. The upper end of the lower casing pipe 4A is welded and fixed with the upper end 4A1 protruding upward. The upper end 4A1 is fitted to a lower end 4B1 provided at the lower end of the upper casing pipe 4B so as to be rotatable from below. By fitting the upper end portion 4A1 and the lower end portion 4B1, a double pipe structure portion is formed in the separation region of the casing pipe 4 separated vertically. In this portion, the upper end 4A1 is an inner tube and the lower end 4B1 is an outer tube. That is, in the double pipe structure portion, the outer peripheral surface of the upper end portion 4A1 and the inner peripheral surface of the lower end portion 4B1 can be relatively rotated while sliding with each other. The recovery port part 40 is formed in this double pipe structure part. In the upper end portion 4A1, a plurality of shutter holes 4A2 are opened at equal intervals in the circumferential direction. On the other hand, a plurality of shutter holes 4B2 having the same dimensions are also opened at the lower end portion 4B1 at positions corresponding to the plurality of shutter holes 4A2.

  Furthermore, a notch 4B3 is formed in the front and rear surfaces of the lower end portion 4B1 of the upper casing pipe 4B at a position below the shutter hole 4B2. On the other hand, protrusions 4A3 project from the front and rear surfaces of the upper end portion 4A1 of the lower casing pipe 4A so as to fit into the notches 4B3. The notch 4B3 has an effective movable width that gives a slight allowance to the sum of the width of the shutter hole 4B2 and the width of the protrusion 4A3. The protrusion 4A3 and the notch 4B3 are formed by the shutter holes 4A2 and 4B2 when the lower casing pipe 4A and the upper casing pipe 4B (ie, the upper end portion 4A1 and the lower end portion 4B1) are relatively rotated around the axis. It is a means for stopping the collection port 40 in the open state or the closed state, and is provided at a position suitable for this function.

  4A and 4B are sectional views of the shutter holes 4A2 and 4B2 of the casing pipe 4. FIG. In the closed state of the collection port portion shown in FIG. 4A, the shutter holes 4A2 and 4B2 are in positions shifted in the circumferential direction, and the internal space and the external space of the casing pipe 4 are blocked. On the other hand, in the open state of the collection port portion shown in FIG. 4B, the shutter holes 4A2 and 4B2 are in the same position in the circumferential direction, and the internal space and the external space of the casing pipe 4 communicate with each other through both shutter holes.

  As an example, the casing pipe 4 has an inner diameter of 3 m. When the penetration depth into the ground (distance from the ground surface to the lower end of the casing pipe 4) is 14 m, the casing pipe 4 is separated up and down at a position of 13 m (penetration depth -1 m) from the lower end of the casing pipe 4, An upper end 4A1 having a length of 3 m is welded and fixed to the upper end of the lower casing pipe 4A, and a lower end 4B1 having a length of 3 m is provided at the lower end of the upper casing pipe 4B. Thereby, a portion having a length of 3 m upward from the separation position becomes a double tube structure portion. In the double pipe structure portion, the upper end portion 4A1 of the lower casing pipe 4A and the lower end portion 4B1 of the upper casing pipe 4B are fitted.

  Further, a plurality of shutter holes are formed at equal intervals so that the lower sides of the shutter holes 4A2 and 4B2 having predetermined widths and heights are located about 1 m above the lower end of the upper casing pipe 4B. The width of the shutter hole is preferably about 50 cm as a dimension that can be applied regardless of the soil quality, but in the case of sandy soil or viscous soil, the width may be narrower. Anyway, it is not limited to these numerical values. The height of the shutter hole is, for example, about 1 m, but is not limited to this value. An interval between adjacent shutter holes 4B2 is, for example, about 68 cm. The position is set so that the bottom side of each shutter hole is the ground surface position when penetrating to the penetration depth. Further, a notch 4B3 having a height of 20.5 cm and an effective movable width of 75 cm is formed with respect to the lower end 4B1 at a position slightly below the shutter hole 4B2. A steel projection 4A3 having a height of 20 cm and a width of 20 cm, which is slightly smaller than the height of the notch 4B3, is attached to the upper end 4A1 by welding or a bolt nut so as to fit into the notch 4B3. Therefore, the effective movable width 75 cm of the notch 4B3 is calculated from the shutter hole width 50 cm + the protrusion width 20 cm + the margin 5 cm.

  In the above example, the welding position or the mounting position of the protrusion 4A3 is such that the lower casing pipe 4A and the upper casing pipe 4B can be rotated relatively by 55 cm in a closed state of the recovery port portion 40 shown in FIG. 5A. A position where one side of the protrusion 4A3 comes into contact with one side of the notch 4B3 and stops. The closed state of the recovery port portion 40 shown in FIG. 5A is realized by rotating the upper casing pipe 4B, that is, the lower end portion 4B1, in the direction of the arrow in FIG. 5A. In the open state of the collection port portion 40 shown in FIG. 5B, the other side of the protrusion 4B3 comes into contact with the other side of the notch 4B3 and stops. The transition from the closed state in FIG. 5A to the open state in FIG. 5B is realized by rotating the upper casing pipe 4B, that is, the lower end 4B1, in the direction of the arrow in FIG. 5B.

  The total length of the casing pipe 4 is such that the upper end of the upper casing pipe 4B is positioned several meters above the upper part of the casing rotary excavator 6 with the lower casing pipe 4A penetrating 14 m into the ground. Determine in consideration of

  FIG. 6 is a cross-sectional view of the distal end portion of the casing pipe 4 in a state where the casing pipe 4 having the shutter-type recovery port portion shown in FIGS. 3 to 5B is built up to the penetration depth in the ground 20. In the illustrated example, the collection port 40 is in a closed state. In the casing pipe 4, a tremy tube 10 used for supplying earth and sand for forming the coating layer 20b is inserted. The tremy tube 10 is suitably used in the seventh step of the bottom sediment mud recovery method of the second invention described later. Here, the tremy tube 10 will be described. For example, it is a pipe having an outer diameter slightly smaller than the inner diameter of the casing pipe 4 and substantially the same length as the upper casing pipe 4A, and its upper end opens upward. Use a funnel with a ring attached. In order to reduce weight and facilitate handling, the rigid pipe portion may be about 1 m, and a cylindrical hose having a length reaching the ground surface formed of a high-strength sheet material or the like may be connected to the lower end thereof. . The hose to be connected is attached by tightening with an annealed iron wire or the like on the outer periphery near the lower end of the tremmy pipe.

(2-1-2) When combining a shutter-type recovery port with an air-fixed recovery fan (related to claim 4)
7 to 9 are block diagrams showing an embodiment of the shutter type recovery port portion when combined with the air fixed type recovery fan portion. FIG. 7 is a development view of the collection port 40. The recovery port portion 40 of FIG. 7 is common except that the recovery port portion 40 of FIG. 3 includes an air piping hole 4B5. That is, the shutter hole opening / closing mechanism is common.

  Air piping hole 4B5 is a hole for letting through air piping 9C8 of air fixed type recovery fan part 9 shown in Drawing 27 mentioned below. A plurality of air piping holes 4B5 are formed at equal angular intervals in the circumferential direction upward by a predetermined distance from the upper side of the shutter hole 4B2 in the upper casing pipe 4B. The number of air piping holes 4B5 is appropriately set according to the number of necessary air pipings. The recovery fan portion 9 is fixed on the outer peripheral surface of the casing pipe 4 between the lower side of the air piping hole 4B5 and the upper side of the shutter hole 4B2. Details will be described later.

  FIG. 8 is a view showing a cross section of a portion of the air pipe hole 4 </ b> B <b> 5 of the casing pipe 4.

  FIG. 9 is a cross-sectional view of the distal end portion of the casing pipe 4 in a state where the casing pipe 4 having the shutter-type recovery port portion shown in FIGS. 7 and 8 is built up to the penetration depth in the ground 20. In the illustrated example, the collection port 40 is in a closed state. Except having the air piping hole 4B5, it is the same as the configuration of FIG.

(2-2) Slit-type recovery port (related to claim 2)
The slit-type recovery port portion 40 also has two variations in which the configuration is partially different depending on which of the two types of fixing means (wedge fixing type or air fixing type) of the recovery fan unit 9 described later is combined. Hereinafter, each aspect will be described.

(2-2-1) When combining a slit-type recovery port with a wedge-fixed recovery fan (related to claim 3)
10 and 11 are perspective views showing an embodiment of the slit type recovery port portion 40 when combined with the wedge fixed type recovery fan portion. The casing pipe 4 provided with the slit type recovery port portion 40 shown in FIG. 10 is not a structure separated vertically at the recovery port portion, but a single pipe, unlike the shutter type recovery port portion described above. In the recovery port portion 40 of FIG. 10, a plurality of slit holes 42 are opened at equal intervals in the circumferential direction at the axial intermediate portion of the casing pipe 4. Therefore, the slit-type recovery port portion 40 does not have an opening / closing mechanism and is always open.

  FIG. 11 is a cross-sectional view of the tip portion of the casing pipe 4 in a state where the casing pipe 4 having the slit-type recovery port portion shown in FIG. 10 is built to the depth of penetration in the ground 20. The slit collection port 40 is always open. The configuration other than the recovery port portion 40 is the same as that of FIG.

(2-2-2) When combining a slit-type recovery port with an air-fixed recovery fan (related to claim 5)
12-15 is a block diagram which shows one Example of the slit type | mold collection | recovery opening part at the time of combining with an air fixed type | mold recovery fan part. The casing pipe 4 having the slit-type recovery port portion 40 shown in FIG. 12 is common except that it has an air piping hole 45 as compared with the recovery port portion 40 of FIG.

  The air piping hole 45 is a hole through which the air piping 9C8 of the air fixed recovery fan unit 9 shown in FIG. A plurality of air piping holes 45 are formed at equal angular intervals in the circumferential direction upward by a predetermined distance from the upper side of the slit hole 42. The number of air piping holes 45 is appropriately set according to the number of necessary air pipings. The recovery fan portion 9 is fixed on the outer peripheral surface of the casing pipe 4 between the lower side of the air piping hole 45 and the upper side of the slit hole 42. Details will be described later.

  13 is a cross-sectional view taken along the line A in FIG. 12 and shows a cross section of the air piping hole 45 of the casing pipe 4.

  FIG. 14 is a B cross-sectional view of FIG. 12 and shows a cross section of the slit hole 42 of the casing pipe 4.

  FIG. 15 is a cross-sectional view of the distal end portion of the casing pipe 4 in a state where the casing pipe 4 having the slit-type recovery port portion shown in FIGS. 12 to 14 is built up to the penetration depth in the ground 20. Except having the air piping hole 45, it is the same as the structure of FIG.

(3) Configuration of the tip cap portion (related to claims 8 and 9)
FIGS. 16-19 is a block diagram of the front-end | tip cap part 7 used by attaching to the lower end of the casing pipe 4. FIG. The tip cap portion 7 is used in a process of lowering the casing pipe 4 from the bottom sediment mud surface to the ground surface, and is mainly attached to prevent the bottom sediment mud from entering the inside from the lower end of the casing pipe 4. Accordingly, the tip cap portion 7 is detachably attached to the lower end of the casing pipe 4.

  FIG. 16 is a side view of the tip cap portion 7. 17 is a view taken along the line CC in FIG. The tip cap portion 7 is composed of a tip cap 7A in the lower portion and support fixing means in the upper portion. The lower end cap 7A has a disk 7A1 having a diameter slightly shorter than the inner diameter of the casing pipe 4, a cone 7A2 continuously provided with the bottom surface of the disk 7A1 as a bottom surface, and a protruding surface on the surface of the cone. It comprises a plurality of spiral mud scraping ridges 7A3.

  The upper portion supporting and fixing means includes a cylindrical cylinder fixing frame 7B1 extending upward from the center of the upper surface of the disk 7A1, three cylinders 7B2 extending radially outward from the outer periphery of the cylinder fixing frame 7B1, and each cylinder 7B2. And a fixed leg 7B3 attached to an arm protruding from the tip of the arm. The cylinders 7B2 are arranged at equiangular intervals in the circumferential direction of the cylinder fixing frame 7B1. The number of cylinders is not limited to three as long as a plurality of cylinders are arranged symmetrically. By supplying a gas or liquid medium to each cylinder 7B2 from the pair of supply pipes 7B5, the arm protruding from the cylinder 7B2 is driven to move forward and backward. As a result, the fixed leg 7B3 can also move forward and backward. The pair of supply pipes 7B5 is connected to the rotary joint 7B4. The plate constituting each of the fixed legs 7B3 has a curved surface that can contact the cylindrical inner surface of the casing pipe 4.

  The supporting and fixing means are further mounted at three positions at equal angular intervals on the guide roller frame 7C2 and an annular guide roller frame 7C2 supported by three pillars respectively extending upward from three positions on the upper surface periphery of the disk 7A1. And a guide roller 7C1. Each guide roller 7 </ b> C <b> 1 is attached in a state where it is axially supported so as to roll in the vertical direction along the inner surface of the casing pipe 4.

  Furthermore, wire hooks 7 </ b> D <b> 1 for connecting a suspension wire that suspends the tip cap portion 7 are provided at three positions on the peripheral edge of the upper surface of the disk 7 </ b> A <b> 1. The number of support columns, guide rollers, and wire hooks is not limited to three, and a plurality of columns need only be arranged symmetrically.

  FIG. 18 is a partially cutaway side view showing a state in which the tip cap portion 7 is attached to the lower end of the casing pipe 4. FIG. 19 is a BB arrow view of FIG. The tip cap portion 7 has three suspension wires 7D2 connected to three wire hooks 7D1, and one suspension wire 7D4 connected to a swivel joint 7D3 that converges and connects these three suspension wires 7D2. Therefore, it is suspended horizontally in the casing pipe 4. When the tip cap portion 7 is attached to the lower end of the casing pipe 4, the tip cap portion 7 is inserted from the upper end of the casing pipe 4, and the three guide rollers 7 </ b> C <b> 1 are lowered while being in contact with the inner surface of the casing pipe 4. As a result, the tip cap portion 7 descends while maintaining a coaxial state with the casing pipe 4. When the tip cap portion 7 is lowered to a predetermined position at the lower end of the casing pipe 4, the medium is supplied from the medium supply pipe 7B6 to the supply pipe 7B5 to each cylinder 7B2 via the rotary joint 7B4. As a result, the arm of each cylinder 7B2 is advanced to press each fixing leg 7B3 against the inner surface of the casing pipe 4, thereby fixing the tip cap portion 7.

  The tip cap part 7 is integrated with the casing pipe 4 by being pressed and fixed in this manner, and can rotate as the casing pipe 4 rotates. The mud scraping ridge 7A3 provided on the cone 7A2 of the tip cap 7A pushes the bottom mud around the casing cap 4 when the tip cap 7 is rotated in one direction in the bottom mud layer. There is an action to scrape towards. The bottom mud is scraped off by slowly rotating the casing pipe 4 while gradually lowering the casing pipe 4 without rolling up or stirring the bottom mud.

  In FIG. 18, a cutting blade 4F is formed on the lower end surface of the lower casing pipe 4A, and has a function of cutting the ground when the casing pipe 4A is built in the ground while rotating.

(4) Configuration of the Recovery Fan Part The recovery fan part 9 includes a fixing means that can be attached to and detached from the outer peripheral surface of the casing pipe 4, and rotates and rotates together with the casing pipe 4 when the casing pipe 4 is driven in a fixed state. Work to scrape sediment mud on the ground surface while moving in the axial direction. There are two types of fixing means for fixing the recovery fan 9 to the outer peripheral surface of the casing pipe 4, a wedge fixing type and an air fixing type.

(4-1) Wedge fixed type recovery fan (related to claim 3)
FIG. 20A is a schematic cross-sectional view showing a state in which the wedge fixing type recovery fan portion 9 is fixed to the outer peripheral surface of the casing pipe 4. FIG. 20B is a schematic partial cross-sectional view showing a state in which the wedge fixing type recovery fan unit 9 is released. The recovery fan unit 9 is suspended from the carriage 2 by the suspension wire 9A1 in a state where the casing pipe 4 is penetrated, and can move up and down with respect to the casing pipe 4 when not fixed.

  The lower half of the recovery fan unit 9 is provided with a plurality of blades 9D2 extending radially to scrape the sediment mud toward the center. The surfaces of the plurality of blades 9D2 are flat surfaces or curved surfaces, but in any case, the surfaces are perpendicular to the horizontal plane. The top plate 9D11 supports the upper edge portion of the plurality of blade plates 9D2 and is provided with a through hole 9D3 for the casing pipe 4. The peripheral edge of the top plate 9D11 is circular, and a cylindrical side plate 9D12 that extends downward from the peripheral edge and supports the tip portions of the plurality of blade plates 9D2 is provided.

  In the wedge fixing type fixing means, an annular wall 9B11 is erected on the upper surface of the top plate 9D11 of the blade plate 9D2. The annular wall 9D11 is installed coaxially with the casing pipe 4. A plurality of fixing means are arranged at equiangular intervals in the circumferential direction inside the annular wall 9D11. Each fixing means has the same structure. In the example of FIG. 20A, four fixing means are arranged at intervals of 90 degrees, and two fixing means facing each other among them appear. Each fixing means includes a clamping plate 9B3. The sandwiching plate 9B3 has a surface that can press the outer peripheral surface of the casing pipe 4. The holding plate 9B3 of each fixing means presses the outer peripheral surface of the casing pipe 4 toward the axial center of the casing pipe 4, thereby bringing the recovery fan portion 9 into a fixed state. Hereinafter, a specific mechanism of each fixing means will be described.

  Each fixing means uses a combination of two wedges. One is a vertically moving rust 9B7 that can move up and down along the inner surface of the annular wall 9B11, and the other is a horizontally moving rust 9B6 that can move horizontally in the radial direction of the annular wall 9B11. A restraining means for restraining the vertical movement of the vertically moving rust 9B7 is provided. In the illustrated example, the restraining means is a wedge adjusting screw 9B5. The wedge adjusting screw 9B5 is screwed into the through screw hole of the fixing unit upper plate 9B10, and the tip of the wedge adjusting screw 9B5 comes into contact with the upper surface of the wedge 9B7 that moves up and down. By screwing the wedge adjusting screw 9B5, the vertical position of the tip of the wedge adjusting screw 9B5 changes. Accordingly, when the wedge adjusting screw 9B5 is screwed in, the position of the vertically moving wedge 9B7 is lowered, and when the wedge adjusting screw 9B5 is loosened, the position of the vertically moving wedge 9B7 is raised. Thus, the wedge adjusting screw 9B5 has a function of restraining the vertical movement of the wedge 9B7 that moves up and down and fixing it at a predetermined position in the vertical direction.

  On the other hand, the horizontally moving rust 9B6 abuts with the vertically moving rust 9B7 on an inclined surface. Accordingly, when the position of the vertically moving rust 9B7 is lowered, the horizontally moving rust 9B6 moves in the radial direction toward the center. Further, when the position of the vertically moving rust 9B7 is raised, the horizontally moving rust 9B6 is movable toward the radially outer side. The central side of the horizontally moving wedge 9B6 and the back surface of the clamping plate 9B3 are connected by a connecting rod 9B2 which is a connecting means. Accordingly, the horizontally moving rust 9B6 and the sandwiching plate 9B3 are horizontally moved integrally in the radial direction.

  Further, since the release spring 9B4, which is an elastic means disposed around the connecting rod 9B2, is held between the horizontally moving wedge 9B6 and the fixed portion inner wall 9B12, the horizontally moving wedge 9B6 is always in an annular shape. The wall 9B11 is biased outward in the radial direction. As a result, the horizontally moving rust 9B6 presses the inclined surface of the vertically moving rust 9B7 radially outward, so that in the illustrated example, the vertically moving rust 9B7 receives a force that is always displaced upward. At the same time, the clamping plate 9B3 is also pulled outward in the radial direction.

  In the fixing means having such a configuration, when the recovery fan portion 9 is fixed to the casing pipe 4, the vertical position of the wedge adjusting screw 9B5, which is a restraining means, resists the elastic force of the release spring 9B4 (illustrated). In the example shown in FIG. As a result, the rust 9B7 that moves up and down moves up and down (downward in the illustrated example). As a result, the horizontally moving rust 9B6 moves radially inward, so that the clamping plate 9B3 presses the outer peripheral surface of the casing pipe 4 via the connecting rod 9B2. The collection fan 9 is fixed to the outer peripheral surface of the casing pipe 4 by pressing the outer peripheral surface of the casing pipe 4 by the clamping plates of the plurality of fixing means arranged at equal angular intervals in the circumferential direction.

  In the release state shown in FIG. 20B, the vertical position of the wedge adjusting screw 9B5 is moved in a direction (upward in the illustrated example) along the elastic force of the release spring 9B4. As a result, the rust 9B7 that moves up and down moves up and down (upward in the illustrated example). As a result, the horizontally moving wedge 9B6 moves radially outward, whereby the clamping plate 9B3 is pulled away from the outer peripheral surface of the casing pipe 4 via the connecting rod 9B2. Thus, the recovery fan unit 9 is released from the fixed state.

  FIG. 21 is an overall perspective view of the recovery fan unit 9 of FIG. 20A. The vane is enclosed and accommodated by a top plate 9D11 and a cylindrical side plate 9D12. An annular wall 9B11 is erected upward from the top surface of the top plate 9D11, and a fixing means is disposed inside the annular wall 9B11. The upper part of the annular wall 9B11 is covered with a fixed portion upper plate 9B10. Hanging wire hooks 9A2 for connecting the lower ends of the suspension wires are provided at the four corners of the fixing unit upper plate 9B10. There is also a through hole through which the casing pipe 4 penetrates in the center of the fixed portion upper plate 9B10. The fixed portion inner wall 9B12 is erected so as to surround the through hole of the casing pipe 4. Each clamping plate 9B3 protrudes through the fixed portion inner wall 9B12, and the pressing surface can be seen.

  FIG. 22 partially shows the recovery fan unit 9 as viewed from the direction of the arrow A in FIG. 20A, that is, a view of the recovery fan unit 9 as viewed obliquely from below. The top plate 9D11 and the cylindrical side plate 9D12 serve as a case for a plurality of blades 9D2. As shown in FIG. 22, each blade 9D2 is configured by a plate having a width that is slightly shorter than the height of the cylindrical side plate 9D12. The number of sheets is appropriate (4 sheets in the illustrated example). The upper edge portion of each blade 9D2 is supported by being connected and fixed to the lower surface of the top plate 9D11. Moreover, the front-end | tip part extended radially from each blade 9D2 is supported by connecting and fixing to cylindrical side board 9D12. Each vane plate 9D2 is preferably formed in a curved shape such that the surface on the traveling direction side in the rotation direction (arrow) of the recovery fan is a concave surface, but in another embodiment, it is a planar shape. There may be (related to claim 6).

  In one example, the recovery fan unit 9 is made of steel, and the top plate 9D11 has a peripheral diameter of 10 m and the cylindrical side plate 9D12 has a height of 15 cm. The blade 9D2 has a height of 14 cm.

  23 and 24 are diagrams showing another embodiment of the wedge fixed type recovery fan section (related to claim 7). In this example, the shape of the top plate 9D11 that supports the upper edge portion of the blade plate 9D2 is different from the example of FIG. 20A. As shown in the cross-sectional view of FIG. 23, the top plate 9D11 has an inclination that gradually decreases toward the radially outer side. This corresponds to, for example, the side shape of a truncated cone. In addition, the upper edge part of the wing plate 9D2 also has a shape along the shape of the top plate 9D11. As described above, when the center portion of the top plate 9D11 is raised, the bottom sediment recovery capability in the fifth step of the bottom sediment collection method described later is higher than that of the flat plate of FIG. 20A. FIG. 24 is an overall perspective view of the recovery fan unit 9 of FIG.

  As described above, the wedge fixing type recovery fan unit 9 can be fixed to a casing pipe having either a shutter type or a slit type recovery port.

(4-2) Air fixed recovery fan (related to claims 4 and 5)
FIG. 25 is a schematic cross-sectional view showing a state in which the air fixed recovery fan unit 9 is fixed to the outer peripheral surface of the casing pipe 4. The recovery fan unit 9 is suspended from the carriage 2 by the suspension wire 9A1 in a state where the casing pipe 4 is penetrated, and can move up and down with respect to the casing pipe 4 when not fixed.

  The structure of the lower half of the recovery fan unit 9 is common to the wedge-fixed recovery fan unit shown in FIG. 20A. That is, a plurality of blades 9D2 extending radially to scrape the sediment mud toward the center are provided. The surfaces of the plurality of blades 9D2 are flat surfaces or curved surfaces, but in any case, the surfaces are perpendicular to the horizontal plane. The top plate 9D11 supports the upper edge portion of the plurality of blade plates 9D2 and is provided with a through hole 9D3 for the casing pipe 4. The peripheral edge of the top plate 9D11 is circular, and a cylindrical side plate 9D12 that extends downward from the peripheral edge and supports the tip portions of the plurality of blade plates 9D2 is provided.

  In the air fixing type fixing means, an annular wall 9B11 is erected on the upper surface of the top plate 9D11 of the blade plate 9D2. The annular wall 9D11 is installed coaxially with the casing pipe 4. A plurality of fixing means are arranged at equiangular intervals in the circumferential direction inside the annular wall 9D11. Each fixing means has the same structure. In the example of FIG. 25, two fixing means are arranged at intervals of 180 degrees. Each fixing means includes a clamping plate 9C3. The sandwiching plate 9C3 has a surface that can press the outer peripheral surface of the casing pipe 4. The holding plate 9C3 of each fixing means presses the outer peripheral surface of the casing pipe 4 toward the axial center of the casing pipe 4, whereby the recovery fan section 9 is fixed. Hereinafter, a specific mechanism of each fixing means will be described.

  An air cylinder 9C4 is fixed to the inner surface of the annular wall 9B11. The base end portion 9C5 of the cylindrical case of the air cylinder 9C4 is pivotally supported so that the cylindrical case can swing in a horizontal plane and is attached to the inner surface of the annular wall 9B11. This is to ensure that the clamping plate 9C3 always presses the outer peripheral surface toward the axial center of the casing pipe 4 even when the recovery fan portion 9 sways. An air pump mechanism is built in the cylindrical case of the air cylinder 9C4, and a connecting rod 9C2 that can expand and contract in the radial direction protrudes from the tip of the cylindrical case. The clamping plate 9C3 is attached to the tip of the connecting rod 9C2. In the illustrated example, the sandwiching plate 9C3 is pivotally supported by the tip of the connecting rod 9C2 so as to be swingable in the vertical plane.

  An air pipe 9C6 for supplying compressed air to the air cylinder 9C4 is further connected to an air pipe (not shown) extending into the casing pipe 4 through an air coupler 9C7.

  When the recovery fan unit 9 is fixed to the outer peripheral surface of the casing pipe 4, compressed air is supplied to the air cylinder 9C4. As a result, the connecting rod 9C2 extends in the radial direction, and the clamping plate 9C3 presses the outer peripheral surface of the casing pipe 4. The collection fan 9 is fixed to the outer peripheral surface of the casing pipe 4 by pressing the outer peripheral surface of the casing pipe 4 by the clamping plates of the plurality of fixing means arranged at equal angular intervals in the circumferential direction.

  When releasing the recovery fan 9, the connecting rod 9C2 is contracted in the radial direction by removing the compressed air from the air cylinder 9C4, and the clamping plate 9C3 is separated from the outer peripheral surface of the casing pipe 4.

  FIG. 26 is an overall perspective view of an air-fixed recovery fan section similar to the recovery fan section of FIG. In the example of FIG. 26, three air cylinders as fixing means are arranged at intervals of 120 degrees. The vane is enclosed and accommodated by a top plate 9D11 and a cylindrical side plate 9D12. An annular wall 9B11 is erected upward from the top surface of the top plate 9D11, and a fixing means is disposed inside the annular wall 9B11. The upper part of the annular wall 9B11 is covered with a fixed portion upper plate 9B10. Hanging wire hooks 9A2 for connecting the lower ends of the suspension wires are provided at the four corners of the fixing unit upper plate 9B10. There is also a through hole through which the casing pipe 4 penetrates in the center of the fixed portion upper plate 9B10. The fixed portion inner wall 9B12 is erected so as to surround the through hole of the casing pipe 4. Each clamping plate 9C3 protrudes through the fixed portion inner wall 9B12, and the pressing surface can be seen.

  Here, with reference to FIG. 27, the outline of the operating method of the air fixed collection | recovery fan part 9 shown in FIG. 25 is demonstrated. The casing pipe 4 illustrated in FIG. 27 includes the slit-type recovery port described above, and is provided with a slit hole 42. The air-fixed recovery fan unit 9 can also be combined with either a shutter-type or slit-type recovery port. However, when combined with the air fixed recovery fan unit 9, it is necessary to make an air piping hole 45 in the recovery port of the casing pipe 4. In FIG. 27, the air pipe 9C8 connected to the coupler 9C7 extends into the pipe through the air pipe hole 45 of the casing pipe 4 and is connected to the rotary joint 9C10. The rotary joint 9C10 is connected to the air hose 9C9. Compressed air is supplied from the trolley through the air hose 9C9.

  The state of FIG. 27 is the operation in the fifth step in the sedimentary mud recovery method described later. In the fifth step, sediment collection work on the ground surface is performed. At the start of the fifth step, the lower side of the slit hole 42 is located on the surface 22 a of the sediment mud 22. In this state, the recovery fan 9 is lowered until the lower end reaches the surface 22 a of the sediment mud 22. And after performing the operation | work (by a diver) which each connects air piping 9C8, coupler 9C7, and rotary joint 9C10, compressed air is supplied. Thereby, the recovery fan part 9 is fixed to the outer peripheral surface of the casing pipe 4.

  Thereafter, the casing pipe 4 is driven and rotated while being lowered. At this time, the recovery fan part 9 fixed to the casing pipe 4 also descends while rotating. This rotation and lowering is performed at a moderate speed that does not wind up the mud. With the operation of the recovery fan 9, the sediment mud 22 in the circular region surrounded by the top plate 9D11 and the cylindrical side plate 9D12 is scraped from the outside to the inside by the blade plate 9D2. When the sediment mud 22 raked up reaches the casing pipe 4, it passes through the slit hole 42 and enters the pipe. Here, referring to FIG. 15, the sediment mud 22 that has entered the casing pipe 4 through the slit hole 42 falls into the excavation hole 21 formed in the casing pipe 4 and accumulates in the excavation hole 21 ( 22b). In this way, the lower side of the slit hole 42 is lowered until it reaches the ground surface.

  FIG. 28 is a cross-sectional view taken along the line B-B of FIG. 27, where the air pipe 9C6 extends from the outside of the casing pipe 4 toward the center, passes through the coupler 9C7, and the air pipe 9C8 passes through the air pipe hole 45. Connected to the rotary joint 9C10. 29 is a cross-sectional view taken along the line CC of FIG. A clamping plate 9C3 attached to the tip of a connecting rod 9C2 extending toward the center from an air cylinder 9C4 installed inside the annular wall 9B11 protrudes from the hole of the fixed portion inner wall 9B12 and presses the outer peripheral surface of the casing pipe 4 is doing.

  30 and 31 are views showing another embodiment of the air fixed recovery fan section (related to claim 7). In this example, the shape of the top plate 9D11 that supports the upper edge of the blade plate 9D2 is different from the example of FIG. As shown in the cross-sectional view of FIG. 30, the top plate 9D11 has an inclination that gradually descends radially outward. This corresponds to, for example, the side shape of a truncated cone. In addition, the upper edge part of the wing plate 9D2 also has a shape along the shape of the top plate 9D11. Thus, if the shape of the central portion of the top plate 9D11 is raised, the bottom sediment recovery capability in the fifth step of the bottom sediment collection method described later is higher than that of the flat plate of FIG. FIG. 31 is an overall perspective view of the recovery fan unit 9 having the same top plate 9D11 shape as FIG.

(5) Outline of sediment sediment recovery method Next, the sediment sediment recovery method according to the second invention will be described with reference to FIGS. 32 to 47. Although the bottom sediment mud recovery apparatus described above is used for the bottom sediment recovery method, depending on whether the casing pipe has a shutter type recovery port portion or a slit type recovery port portion, a preferred embodiment of the recovery method is a partial process. In the following, the case of each recovery port will be described. It should be noted that there is no substantial difference in the process as to whether the recovery fan fixing means is a wedge fixing type or an air fixing type. For easy understanding, FIG. 32 shows the flow of each step of the sediment mud recovery method when each recovery port is used. Since the contents of the first to third steps and the eighth to tenth steps are common, they are shown collectively. There are differences in the fourth to seventh steps. Moreover, the figure number corresponding to each process is attached | subjected.

(6) A method for collecting sediment mud using a casing pipe having a shutter-type collection port (related to claims 10 to 13)
(6-1) 1st process FIG. 33: is a figure which shows typically the 1st process which performs the setting of the trolley 2 and a sediment mud recovery apparatus. The trolley 2 equipped with 2 to 4 spuds (see FIG. 1) at the rear of the trolley, which is widely used in marine operations, is towed to the surface 30 of the sediment removal target area. Sediment mud 22 is deposited on the surface 20a of the ground 20 at the bottom of the target area. The surface 22a to the water surface 30 of the sediment mud 22 is underwater or underwater.

  Next, the two spuds installed at the rear part of the carriage 2 are dropped, and the standing carriage 2 is fixed to the ground 20 at the bottom of the water. If it is not stable due to tidal currents or the like, the anchor device installed in the carrier 2 is used together to fix the carrier 2 so that it does not move in the horizontal direction.

  Thereafter, the casing pipe 4 is lifted by the crane 3, and the casing pipe 4 is initially built in such a manner as to penetrate the casing rotary excavator 6, the work table 5, and the recovery fan unit 9 suspended from the work table 5. Usually, the entire length of the casing pipe 4 is not built at a time, but a plurality of blocks divided into appropriate lengths are sequentially connected and built to finally obtain the required length. Once the required length has been built, the casing pipe 4 is temporarily fixed by the casing rotary excavator 6.

As shown in FIG. 33, at any stage of the to case single pipe 4 initial like an anchor process, attaching the tip cap portion 7 in order to prevent mud from entering from the lower end of the casing pipe 4. For example, after the first block of the casing pipe 4 is installed, the tip cap portion 7 is suspended by the crane 3 and inserted into the pipe from the upper end of the casing pipe 4 to be lowered. As shown in FIG. 18, since the tip cap portion 7 is provided with a roller that rolls in the vertical direction along the inner surface of the casing pipe 4, it can be lowered while maintaining the coaxial state with the casing pipe 4. .

  When the tip cap portion 7 reaches a predetermined position at the lower end of the casing pipe 4, as shown in FIG. 18, the cylinder is operated by hydraulic pressure or the like to press the fixed leg against the inner surface of the casing pipe 4. The cap part 7 is fixed to the casing pipe 4. In addition, it is preferable to attach a stopper projection or the like to the inner surface near the lower end of the casing pipe 4 by welding or the like to prevent the tip cap portion 7 from passing.

  After fixing the front end cap portion 7 to the casing pipe 4, the casing pipe 4 is built up to a required length. Once the casing pipe 4 has been built to the required length, the casing pipe 4 is lowered by the casing rotary excavator 6 until the tip cap portion 7 reaches the surface 22a of the sediment mud 22. There are various means for fixing the casing pipe 4 by the casing rotary excavator 6 using wedges or bands, and any of them may be used.

(6-2) Second Step FIG. 34 is a diagram schematically showing a second step of lowering the lower end of the casing pipe 4 from the bottom mud surface 22a to the ground surface 20a. While the casing pipe 4 is slowly rotated by the casing rotary excavator 6, the casing pipe 4 is gradually lowered until the lower end of the casing pipe 4 reaches the ground surface 20a. At this time, when the tip cap portion 7 rotates, the mud scraping protrusion provided on the cone scrapes the accumulated sediment mud 22 in the outer peripheral direction of the casing pipe 4. As a result, the sediment mud 22 is discharged around the casing pipe 4 without inadvertent stirring.

(6-3) Third Step FIG. 35 is a diagram schematically showing a third step in which the tip cap portion 7 is removed and collected. As shown in FIG. 18, the fixing leg is detached from the casing pipe 4 by contracting the cylinder of the tip cap portion 7, and the tip cap portion 7 is released. Thereafter, the suspension wire is pulled up, and the tip cap portion 7 is taken out from the upper end of the casing pipe 4 and collected on the carriage 2.

(6-4) Fourth Step FIG. 36 is a diagram schematically showing the first half of the fourth step including the penetration step of the casing pipe 4 and the excavation step of the inner soil of the casing pipe 4. While rotating the casing pipe 4 in the direction in which the shutter hole 4B2 is closed by the casing rotary excavator 6, the casing pipe 4 is lowered by a length corresponding to one stroke of the lifting and lowering operation of the casing rotary excavator 6, and the ground Penetration into 20. At this time, the ground 20 can be penetrated while being cut by the cutting blade provided at the lower end of the casing pipe 4 shown in FIG. The inside of the penetrated casing pipe 4 is filled with earth and sand forming the ground 20. Next, the hammer grab 8 lifted by the crane 3 from the upper end of the casing pipe 4 is inserted and lowered into the pipe, the internal earth and sand are excavated, pulled up while holding the excavated earth and sand, and taken out from the casing pipe 4. The hammer grab 8 is selected from, for example, widely known techniques or products that match the inner diameter (for example, 3 m) of the casing pipe 4 and the capacity of the mounted crane 3.

  The penetration of the casing pipe 4 and the excavation and removal work of the internal soil are repeated until the lower side of the shutter hole 4B2 reaches the ground surface 20a. The penetration depth of the casing pipe 4 when the lower side of the shutter hole 4B2 reaches the ground surface 20a is 14 m from the ground surface 20a in the embodiment shown in the above-mentioned bottom sediment recovery device. After this operation, in the pipe from the lower end of the casing pipe 4 to the ground surface 20a, a space for the excavation hole 21 from which earth and sand have been removed is formed. The shutter hole 4B2 is still closed at this time. That is, the rotation direction at the time of penetration of the casing pipe 4 is a direction in which the shutter hole can be kept closed (see FIG. 5A).

  FIG. 37 is a diagram schematically showing the second half of the fourth step including the step of lifting the casing pipe 4 to a predetermined position. After completion of the penetration of the casing pipe 4 and the excavation and removal of the internal sediment, the casing pipe 4 is pulled up (in the direction of the arrow) until the lower side of the shutter hole 4B2 reaches the bottom mud surface 22a. As a result, the lower end of the casing pipe 4 is pulled up from the lower end of the excavation hole 21.

(6-5) Fifth Step FIG. 38 is a diagram schematically showing a fifth step of collecting sediment mud by the collection fan unit 9. First, the recovery fan unit 9 that has been suspended below the work table 5 is suspended along the casing pipe 4. When the recovery fan unit 9 is not in operation, the recovery fan unit 9 is not fixed to the casing pipe 4 and can be raised and lowered. The suspension wire connected to the recovery fan unit 9 is drawn out and lowered, and is stopped when the lower end of the recovery fan unit 9 reaches the vicinity of the bottom mud surface 22a. Subsequently, the recovery fan portion 9 is fixed to the outer peripheral surface of the casing pipe 4. If the wedge is fixed, the horizontally moving wedge is moved and the outer peripheral surface of the casing pipe 4 is pressed by the holding plate. The wedge adjustment screw is operated by the diver. If it is an air fixed type, compressed air is supplied, an air cylinder is extended, and the outer peripheral surface of the casing pipe 4 is pressed by a clamping plate. The diver will perform the air piping connection operation. When the fixing of the recovery fan unit 9 is completed, the hanging wire connected to the recovery fan unit 9 is removed. This work is also performed by the divers.

  Next, the casing pipe 4 is rotated by the casing rotary excavator 6 in the direction opposite to that at the time of penetration. The distance for reversing the upper casing pipe 4B is a length (75 cm in one embodiment) that gives a slight margin to the sum of the width of the shutter hole 4B2 and the width of the protrusion 4A3. As a result, the collection port formed by the shutter holes 4A2 and 4B2 is opened (see FIG. 5B).

  Subsequently, the casing pipe 4 is rotated and lowered in the direction in which the recovery port portion is opened (solid arrow). The fixed recovery fan unit 9 also descends while rotating. The speed of rotation and descent is set so as not to disturb the sediment mud 22. In FIG. 38, the top plate 9D11 of the recovery fan unit 9 has a flat plate shape, but in a more preferable shape, the top plate 9D11 is inclined so that the vicinity of the center of the top plate is high and the peripheral edge is low. In the case of a suitable shape, when the recovery fan part 9 is lowered, the bottom sediment mud 22 below it is raised by an upward force as a reaction force that lowered the recovery fan part 9. When the sediment mud 22 is scraped by the blades and reaches the lower surface of the top plate, it tends to move along the inclination of the top plate. By applying an upward force and a centering force in this way, the sediment mud 22 existing in the circular area directly below the recovery fan portion 9 is scraped toward the casing pipe 4 from the outside to the inside. Even if the top plate 9D11 is not inclined, the effect of scraping to the center can be obtained by the blades, but providing the inclination increases the force toward the center and is efficient.

  Thus, the sediment mud 22 raked up to the casing pipe 4 as indicated by the broken arrow enters the casing pipe 4 through the open shutter hole 4B2 and falls into the excavation hole 21. In this way, the lower side of the shutter hole 4B2 is lowered until it reaches the ground surface 20a, and when it reaches, the lowering and rotation are stopped. At this time, the penetration depth of the casing pipe 4 (related to the volume of the drilling hole 21), the recovery fan so that the surface of the sediment mud 22b dropped into the drilling hole 21 is located below the ground surface 20a. It is preferable to set the diameter of the portion 9 (related to the volume of the bottom sediment 22b to be recovered) and the like. In the above-described embodiment, it is about 1 m below the ground surface 20a. The distance from the surface of the sediment mud 22b dropped into the excavation hole 21 to the ground surface 20a corresponds to the length of the coating layer formed in the seventh step described later.

(6-6) Sixth Step FIG. 39 is a diagram schematically showing a sixth step in which the recovery fan unit 9 is pulled up and recovered. When the collection of the sediment mud 22 at one penetration point is completed, the suspension wire is connected to the collection fan 9 again. This work is done by a diver. Thereafter, the suspension wire is wound up and the recovery fan unit 9 is pulled up to an initial position near the lower side of the work table 5.

(6-7) Seventh Step FIG. 40 is a diagram schematically showing a seventh step of covering (ie, capping) the surface of the sediment mud dropped into the excavation hole in the casing pipe 4 with earth and sand. . First, the recovery port portion formed by the shutter holes 4A2 and 4B2 is closed by rotating the casing rotary excavator 6 in the reverse direction again. In order to efficiently perform the subsequent coating operation, it is preferable to use the tremy tube 10. The tremy pipe 10 is inserted into the casing pipe 4, and the lower end of the treme pipe 10 is taken from the surface of the sediment mud soil (reference numeral 22b in FIGS. 6 and 9) dropped into the drilling hole (reference numeral 21 in FIGS. 6 and 9). For example, it is positioned about 1 m above. Next, using the hammer grab 8 or a separately prepared bucket, earth and sand as the covering material 20b ′ is introduced from the upper part of the tremy tube 10 to a thickness of, for example, about 1 m, and the covering layer (FIGS. 6 and 9). After forming the symbol 20b), the tremy tube is pulled up. The state inside the casing pipe 4 in the seventh step of the shutter-type casing pipe is shown in FIGS. 6 and 9 described above.

  In another embodiment of the seventh step, after closing the shutter hole, the hammer grab 8 is used to grab the earth or sand (not shown) prepared on the carriage 2 and the hammer grab 8 from the upper end of the casing pipe 4. Then, the casing pipe 4 is suspended and the hammer grab 8 is opened near the surface of the sediment mud dropped into the excavation hole to drop the earth or sand onto the sediment mud. Thereafter, the hammer grab 8 is pulled up. This is repeated to form a coating layer having a height of about 1 m, for example.

  The length of the covering layer is set so that the excavation hole is filled with earth and sand or the like and becomes a surface that is substantially uniform with the surrounding ground surface 20a. The earth or sand prepared on the carriage 2 as the covering material 20b 'may be one obtained when the excavation hole is excavated in the fourth step or may be prepared separately. Use of the earth and sand excavated and taken out in the fourth step is most preferable from the environmental viewpoint because no waste earth and sand are generated. When using sand prepared separately for the coating layer, there is a possibility that it may adversely affect the surrounding environment, for example, the earth and sand excavated in the casing pipe is clayey and may cause turbidity in water. is there.

(6-8) Eighth Step FIG. 41 is a diagram schematically showing an eighth step of pulling up and collecting the casing pipe 4. While rotating the casing rotary excavator 6, the casing pipe 4 is pulled upward to be divided into blocks and collected on the carriage 2. On the bottom of the water after the recovery of the casing pipe 4, a circular region where the bottom mud is removed and the ground surface 20a appears and a drilling hole 21 capped by the coating layer 20b at the center thereof are left. The recovered sediment mud 22b is filled in the lower layer of the coating layer 20b.

(6-9) Ninth Step When the eighth step is completed, the spud 11 and anchors shown in FIG. 1 are pulled up, and the carrier 2 is towed and moved horizontally to move to the next bottom sediment. A tow is carried out to the water surface 30 of the mud removal target area | region, and the 9th process which repeats said 1st-8th process in the new object area | region is performed after that. FIG. 42A is a plan view showing the state of the water bottom after repeatedly performing the ninth step. The shape of the sediment removal target area in one work cycle of the present invention is a circular area as shown in the figure from the shape and function of the recovery fan part of the sediment mud recovery apparatus. The diameter of the circular area corresponds to that of the recovery fan. FIG. 42B is a cross-sectional view showing a state similar to FIG. 42A. As in the illustrated example, it is preferable to determine the position of the excavation hole 21 so as to cover the entire plurality of sediment removal target areas without omission. That is, an overlapping portion with an adjacent circular region is set to a minimum area so that the maximum area can be covered with as few repetitions as possible.

(6-10) Tenth Step FIG. 43 shows a tenth step in which the bottom sediment mud in the entire target area is removed by repeatedly performing the ninth step, and then the soil is refilled on the ground surface after the bottom sediment removal. It is a figure shown typically. For example, the earth and sand temporarily mounted with the excavating machine 13 such as a backhoe is mounted on the temporary earth and sand carrier 12 for excavating earth and sand different from the base ship. The trolley 12 has a structure to which a bulwark for storing temporarily loaded earth and sand is attached. The trolley 12 is towed to the water on the ground surface 20a after the bottom mud removal, and the position is fixed with an anchor wire or the like. After that, the temporarily accumulated earth and sand are backfilled in the excavation hole and its surroundings using a backhoe or the like, and the earth and sand 23 is leveled to such an extent that extreme unevenness cannot be formed. This completes the entire work.

(7) Sediment mud recovery method using a casing pipe having a slit type recovery port (related to claims 14 to 17)
(7-1) The 1st-3rd process The 1st-3rd process of the sediment sludge collection method using the casing pipe which comprises a slit type recovery mouth part is that of the casing pipe which comprises the above-mentioned shutter type recovery mouth part. Refer to FIGS. 33 to 35 and their descriptions (6-1) to (6-3) because they are common.

(7-2) Fourth Step FIG. 44 is a diagram schematically showing a fourth step including a step of inserting the casing pipe 4 and a step of excavating the internal soil of the casing pipe 4. While rotating the casing pipe 4 by the casing rotary excavator 6, the casing pipe 4 is lowered by a length corresponding to one stroke of the lifting / lowering operation of the casing rotary excavator 6 and penetrates into the ground 20. At this time, the ground 20 can be penetrated while being cut by the cutting blade provided at the lower end of the casing pipe 4 shown in FIG. The inside of the penetrated casing pipe 4 is filled with earth and sand forming the ground 20. Next, the hammer grab 8 lifted by the crane 3 from the upper end of the casing pipe 4 is inserted and lowered into the pipe, the internal earth and sand are excavated, pulled up while holding the excavated earth and sand, and taken out from the casing pipe 4. The hammer grab 8 is selected from, for example, widely known techniques or products that match the inner diameter (for example, 3 m) of the casing pipe 4 and the capacity of the mounted crane 3.

  The penetration of the casing pipe 4 and the excavation and removal work of the internal soil are repeated until the lower side of the slit hole 42 reaches the bottom mud surface 22a.

(7-3) Fifth Step FIG. 45 is a diagram schematically showing a fifth step of collecting sediment mud by the collection fan unit 9. First, the recovery fan unit 9 that has been suspended below the work table 5 is suspended along the casing pipe 4. When the recovery fan unit 9 is not in operation, the recovery fan unit 9 is not fixed to the casing pipe 4 and can be raised and lowered. The suspension wire connected to the recovery fan unit 9 is drawn out and lowered, and is stopped when the lower end of the recovery fan unit 9 reaches the vicinity of the bottom mud surface 22a. Subsequently, the recovery fan portion 9 is fixed to the outer peripheral surface of the casing pipe 4. If the wedge is fixed, the horizontally moving wedge is moved and the outer peripheral surface of the casing pipe 4 is pressed by the holding plate. The wedge adjustment screw is operated by the diver. If it is an air fixed type, compressed air is supplied, an air cylinder is extended, and the outer peripheral surface of the casing pipe 4 is pressed by a clamping plate. The diver will perform the air piping connection operation. When the fixing of the recovery fan unit 9 is completed, the hanging wire connected to the recovery fan unit 9 is removed. This work is also performed by the divers.

  Subsequently, the casing pipe 4 is lowered while being rotated (solid arrow). The fixed recovery fan unit 9 also descends while rotating. The speed of rotation and descent is set so as not to disturb the sediment mud 22. In FIG. 45, the top plate 9D11 of the recovery fan unit 9 has a flat plate shape, but in a more preferable shape, the top plate 9D11 is inclined so that the vicinity of the center of the top plate is high and the peripheral edge is low. In the case of a suitable shape, when the recovery fan part 9 is lowered, the bottom sediment mud 22 below it is raised by an upward force as a reaction force that lowered the recovery fan part 9. When the sediment mud 22 is scraped by the blades and reaches the lower surface of the top plate, it tends to move along the inclination of the top plate. By applying an upward force and a centering force in this way, the sediment mud 22 existing in the circular area directly below the recovery fan portion 9 is scraped toward the casing pipe 4 from the outside to the inside. Even if the top plate 9D11 is not inclined, the effect of scraping to the center can be obtained by the blades, but providing the inclination increases the force toward the center and is efficient.

  Thus, the sediment mud 22 raked up to the casing pipe 4 as indicated by the broken line arrow enters the casing pipe 4 through the slit hole 42 and falls into the excavation hole 21. In this manner, the lower side of the slit hole 42 is lowered until it reaches the ground surface 20a, and when it reaches, the lowering and rotation are stopped. At this time, the penetration depth of the casing pipe 4 (related to the volume of the drilling hole 21), the recovery fan so that the surface of the sediment mud 22b dropped into the drilling hole 21 is located below the ground surface 20a. It is preferable to set the diameter of the portion 9 (related to the volume of the bottom sediment 22b to be recovered) and the like. In the above-described embodiment, it is about 1 m below the ground surface 20a. The distance from the surface of the sediment mud 22b dropped into the excavation hole 21 to the ground surface 20a corresponds to the length of the coating layer formed in the seventh step described later.

(7-4) Sixth Step FIG. 46 is a diagram schematically showing a sixth step in which the recovery fan unit 9 is pulled up and recovered. When the collection of the sediment mud 22 at one penetration point is completed, the suspension wire is connected to the collection fan 9 again. This work is done by a diver. Thereafter, the suspension wire is wound up and the recovery fan unit 9 is pulled up to an initial position near the lower side of the work table 5.

(7-5) Seventh Step FIG. 47 is a diagram schematically showing a seventh step of covering (ie, capping) the surface of the sediment mud dropped into the excavation hole in the casing pipe 4 with earth and sand. . In order to efficiently perform the covering operation, it is preferable to use the tremy tube 10. The tremy pipe 10 is inserted into the casing pipe 4 and the lower end thereof is taken from the surface of the sediment mud soil (reference numeral 22b in FIGS. 11 and 15) dropped into the excavation hole (reference numeral 21 in FIGS. 11 and 15). For example, it is positioned about 1 m above. Next, using the hammer grab 8 or a separately prepared bucket, earth and sand as the covering material 20b ′ is introduced from the upper part of the tremmy pipe 10 to a thickness of, for example, about 1 m, and the covering layer (FIGS. 11 and 15). After forming the symbol 20b), the tremy tube is pulled up. The state inside the casing pipe 4 in the seventh step of the slit type casing pipe is shown in FIGS. 11 and 15 described above.

  In another example of the seventh step, the grab or sand (not shown) prepared on the carriage 2 is gripped using the hammer grab 8, and the hammer grab 8 is inserted from the upper end of the casing pipe 4. The inside is suspended, and the hammer grab 8 is opened near the surface of the sedimentary mud dropped into the excavation hole, and earth or sand is dropped onto the sedimentary mud. Thereafter, the hammer grab 8 is pulled up. This is repeated to form a coating layer having a height of about 1 m, for example.

  The length of the covering layer is set so that the excavation hole is filled with earth and sand or the like and becomes a surface that is substantially uniform with the surrounding ground surface 20a. The earth or sand prepared on the carriage 2 as the covering material 20b 'may be one obtained when the excavation hole is excavated in the fourth step or may be prepared separately. Use of the earth and sand excavated and taken out in the fourth step is most preferable from the environmental viewpoint because no waste earth and sand are generated. When using sand prepared separately for the coating layer, there is a possibility that it may adversely affect the surrounding environment, for example, the earth and sand excavated in the casing pipe is clayey and may cause turbidity in water. is there.

(7-6) 8th to 10th steps The 8th to 10th steps of the method for collecting sediment mud using the casing pipe having the slit type recovery port portion are the same as those of the casing pipe having the shutter type recovery port portion described above. Refer to FIGS. 41 to 43 and their descriptions (6-8) to (6-10) because they are common.

1 is an overall configuration diagram of a sediment mud collecting apparatus that collects sediment mud accumulated on the ground surface of a water bottom. It is a schematic block diagram of the collection fan part which covers a casing pipe. It is an expanded view of the inner pipe part and outer pipe part of the shutter type | mold collection port part in a casing pipe. It is sectional drawing in the shutter closed state of a shutter type | mold collection port part. It is sectional drawing in the shutter open state of a shutter type | mold collection port part. It is a figure showing a state where a shutter type recovery mouth part is closed. It is a figure which shows the state where a shutter type | mold collection | recovery opening part is open. It is sectional drawing of the front-end | tip part of the state which penetrated the casing pipe which comprises a shutter type | mold collection | recovery port part in the ground. It is an expanded view of the inner pipe part and outer pipe part of a shutter type | mold collection | recovery port part which comprises the air piping hole in the casing pipe combined with an air fixed type | mold recovery fan part. It is sectional drawing of the air piping hole part of FIG. It is sectional drawing of the front-end | tip part state of the state which penetrated the casing pipe which has a shutter type | mold collection port part which comprises an air piping hole in the ground. It is a fragmentary perspective view which shows the slit type | mold collection | recovery port part in a casing pipe. It is sectional drawing of the front-end | tip part of the state which penetrated the casing pipe which has a slit type | mold collection | recovery opening part in the ground. It is a fragmentary perspective view of the slit type | mold collection | recovery port part which comprises the air piping hole in the casing pipe combined with an air fixed type | mold recovery fan part. It is a cross section (A cross section) figure of the air piping hole part of FIG. It is a cross section (B cross section) figure of the slit hole part of FIG. It is sectional drawing of the front-end | tip part of the state which penetrated the casing pipe which has a slit type | mold collection | recovery opening part which comprises an air piping hole in the ground. It is a side view of a tip cap part. It is CC arrow line view of FIG. It is a partially notched side view which shows the state which mounted | worn the front-end | tip cap part with the lower end of the casing pipe. It is a BB arrow line view of FIG. It is sectional drawing which shows the fixed state of the wedge fixed type | mold recovery fan part (horizontal type top plate part) with which the outer periphery of the casing pipe was mounted | worn. It is a fragmentary sectional view which shows the cancellation | release state of the wedge fixed type | mold recovery fan part corresponding to FIG. 20A. It is a perspective view of a wedge fixed type recovery fan part which comprises a horizontal type top plate part. It is A view of FIG. 20A. It is sectional drawing which shows the fixed state of the wedge fixed type | mold recovery fan part (conical top plate part) with which the outer periphery of the casing pipe was mounted | worn. It is a perspective view of a wedge fixed type recovery fan part which comprises a conical top plate part. It is sectional drawing which shows the fixed state of the air fixed type | mold recovery fan part (horizontal type top plate part) with which the outer periphery of the casing pipe was mounted | worn. It is a perspective view of the air fixed recovery fan part which comprises a horizontal type top plate part. It is a partially cutaway sectional view showing a mud recovery state by an air fixed type recovery fan part having a horizontal top plate part. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is sectional drawing which shows the fixed state of the air fixed type | mold recovery fan part (conical top plate part) with which the outer periphery of the casing pipe was mounted | worn. It is a perspective view of the air fixed recovery fan part which comprises a conical top plate part. It is a schematic flow diagram of the sediment mud collection method using the casing pipe which comprises each of a shutter type recovery mouth part and a slit type recovery mouth part. It is a figure which shows typically the 1st process common to the casing pipe which comprises each of a shutter type | mold recovery port part and a slit type | mold recovery port part. It is a figure which shows typically the 2nd process common to the casing pipe which comprises each of a shutter type | mold recovery port part and a slit type | mold recovery port part. It is a figure which shows typically the 3rd process common to the casing pipe which comprises each of a shutter type | mold collection | recovery port part and a slit type | mold collection | recovery port part. It is a figure which shows typically the first half of the 4th process in the case of the casing pipe which comprises a shutter type | mold collection port part. It is a figure which shows typically the second half of the 4th process in the case of the casing pipe which comprises a shutter type | mold collection | recovery port part. It is a figure which shows typically the 5th process in the case of the casing pipe which comprises a shutter type | mold collection port part. It is a figure which shows typically the 6th process in the case of the casing pipe which comprises a shutter type | mold collection port part. It is a figure which shows typically the 7th process in the case of a shutter type | mold collection port part. It is a figure which shows typically the 8th process common to the casing pipe which comprises each of a shutter type | mold recovery port part and a slit type | mold recovery port part. It is a top view which shows typically the condition of the 9th process common to the casing pipe which comprises each of a shutter type | mold collection | recovery opening part and a slit type | mold collection | recovery opening part. It is sectional drawing which shows typically the condition of the 9th process common to the casing pipe which comprises each of a shutter type | mold collection | recovery port part and a slit type | mold collection | recovery port part. It is a figure which shows typically the 10th process common to the casing pipe which comprises each of a shutter type | mold collection | recovery port part and a slit type | mold recovery port part. It is a figure which shows typically the 4th process in the case of the casing pipe which comprises a slit type | mold collection | recovery port part. It is a figure which shows typically the 5th process in the case of the casing pipe which comprises a slit type | mold collection | recovery port part. It is a figure which shows typically the 6th process in the case of the casing pipe which comprises a slit type | mold collection | recovery port part. It is a figure which shows typically the 7th process in the case of the casing pipe which comprises a slit type | mold collection | recovery port part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bottom sediment mud recovery device 2 Cargo 3 Crane 4 Casing pipe 40 Recovery port part 4A Lower casing pipe 4A1 Upper end part 4A2 Shutter hole 4A3 Protrusion 4B Upper casing pipe 4B1 Lower end part 4B2 Shutter hole 4B3 Notch 4B5 Air piping hole 4F Cutter Slit hole 45 Air piping hole 5 Work table 6 Casing rotary excavator 7 Tip cap 7A Tip cap 7A1 Disc 7A2 Cone 7A3 Mud scraping ridge 7B1 Cylinder fixing frame 7B2 Cylinder 7B3 Fixing leg 7B4 Rotary joint 7B5 Supply pipe 7B6 Supply pipe 7B6 Guide roller 7C2 Guide roller frame 7D1 Wire hook 7D2 Suspension wire 7D3 Swivel joint 7D4 Suspension wire 8 Hammer grab 9 Collection fan 9A1 Ri wire 9A2 hanging wire hooks 9B2 connecting rod (connecting means)
9B3 Clamping plate 9B4 Release spring (elastic means)
9B5 Wedge adjusting screw (stopping means)
9B6 Horizontally moving rust 9B7 Vertically moving rust 9B10 Fixed part upper plate 9B11 Fixed part annular wall 9B12 Fixed part inner wall 9C2 Connecting rod (connecting means)
9C3 Clamping Plate 9C4 Air Cylinder 9C5 Cylinder Fixture 9C6 Air Piping 9C7 Coupler 9C8 Air Piping 9C9 Air Hose 9C10 Rotary Joint 9D11 Top Plate 9D12 Cylindrical Side Plate 9D2 Vane Plate 9D3 Through Hole 10 Temporary Tube Excavation Soil 13 Machine 20 Ground 20a Ground surface 20b Cover layer 20b '(for cover layer) Cover material 21 Drilling hole 22 Sediment mud surface 22a Sediment mud surface 22b Sediment mud in the drill hole 23 Backfill material 30 Water surface

Claims (17)

In the sediment mud recovery device that collects sediment mud accumulated on the ground surface of the water bottom,
(a) a trolley that forms a fixed scaffold on the water;
(b) a casing pipe that can be built into the ground from the carriage,
(c) a casing rotary excavator that is installed on the carriage and supports the casing pipe and can be driven to rotate around an axis and move axially;
(d) In the state where the casing pipe is penetrated, the fixing means can be suspended from the carriage and can be attached to and detached from the outer peripheral surface of the casing pipe and fixed to the outer peripheral surface of the casing pipe. A recovery fan part that scrapes sediment mud on the ground surface while rotating and moving in the axial direction together with the casing pipe;
(b1) The casing pipe has a recovery port portion in an axially intermediate portion, and the recovery port portion includes an upper end portion of a lower casing pipe and a lower end portion of the upper casing pipe which are separated from each other in the upper and lower directions. A double-pipe structure portion that is rotatably fitted is formed, and a plurality of shutter holes of the same size are opened at equal intervals in the circumferential direction at corresponding positions of both the upper end portion and the lower end portion, respectively. In addition, the upper end portion and the lower end portion are relatively rotated by the rotational drive by the casing rotary excavator, and the corresponding shutter holes are in a shifted position, and the corresponding shutter holes are in the same position. Can be switched between open and
(d1) The recovery fan part supports a plurality of blades extending radially to scrape the sediment mud on the ground surface, and supports the upper edge of the blades and a through hole for the casing pipe And a cylindrical side plate that extends downward from the periphery of the top plate and supports the tip portions of the plurality of blades. In the sediment mud recovery device that collects sediment mud accumulated on the ground surface of the water bottom,
(a) a trolley that forms a fixed scaffold on the water;
(b) a casing pipe that can be built into the ground from the carriage,
(c) a casing rotary excavator that is installed on the carriage and supports the casing pipe and can be driven to rotate around an axis and move axially;
(d) In the state where the casing pipe is penetrated, the fixing means can be suspended from the carriage and can be attached to and detached from the outer peripheral surface of the casing pipe and fixed to the outer peripheral surface of the casing pipe. A recovery fan part that scrapes sediment mud on the ground surface while rotating and moving in the axial direction together with the casing pipe;
(b'1) the casing pipe has a recovery port portion in an axially intermediate portion, and the recovery port portion is provided with a plurality of slit holes of the same size at equal intervals in the circumferential direction, and
(d1) The recovery fan part supports a plurality of blades extending radially to scrape the sediment mud on the ground surface, and supports the upper edge of the blades and a through hole for the casing pipe And a cylindrical side plate that extends downward from the periphery of the top plate and supports the tip portions of the plurality of blades. (D2) A plurality of the fixing means of the recovery fan portion are arranged at equiangular intervals inside an annular wall erected on the top surface of the top plate coaxially with the casing pipe, and each of the fixing means,
(d2-1) a clamping plate having a surface capable of pressing the outer peripheral surface of the casing pipe;
(d2-2) a vertically moving rust that can move up and down along the inner surface of the annular wall;
(d2-3) restraining means that can be fixed at a predetermined position in the vertical direction to restrain the vertical movement of the rust that moves up and down
(d2-4) a horizontally moving rust that abuts on the inclined surface with the vertically moving rust and is horizontally movable in the radial direction of the annular wall in accordance with the vertical movement of the vertically moving rust;
(d2-5) connecting means for connecting the horizontally moving rust and the clamping plate;
(d2-6) elastic means for urging the horizontally moving rust radially outward of the annular wall;
(d2-7) When the vertical position of the restraining means is moved in a direction against the elastic force by the elastic means, the vertically moving rust moves up and down and simultaneously the horizontally moving rust moves radially inward. The bottom sediment mud collection apparatus according to claim 1, wherein the sandwiching plate presses the outer peripheral surface of the casing pipe via the connecting means. (D2 ′) A plurality of the fixing means of the recovery fan portion are arranged at equiangular intervals inside an annular wall erected on the top surface of the top plate coaxially with the casing pipe, and each of the fixing means
(d2'-1) a clamping plate having a surface capable of pressing the outer peripheral surface of the casing pipe;
(d2'-2) An air cylinder fixed to the inner surface of the annular wall, comprising a connecting rod that can expand and contract in the radial direction of the annular wall, and the tip of the connecting rod is connected to the clamping plate The air cylinder
(d2'-3) a hole for air piping for supplying compressed air to the air cylinder is formed in the casing pipe above the shutter hole of the recovery port; and
(d2'-4) When compressed air is supplied to the air cylinder, the connecting plate presses the outer peripheral surface of the casing pipe when the connecting rod extends in a radial direction. Bottom sediment mud recovery equipment. (D2 ′) A plurality of the fixing means of the recovery fan portion are arranged at equiangular intervals inside an annular wall erected on the top surface of the top plate coaxially with the casing pipe, and each of the fixing means
(d2'-1) a clamping plate having a surface capable of pressing the outer peripheral surface of the casing pipe;
(d2'-2) An air cylinder fixed to the inner surface of the annular wall, comprising a connecting rod that can expand and contract in the radial direction of the annular wall, and the tip of the connecting rod is connected to the clamping plate The air cylinder
(d2'-3) A hole for air piping for supplying compressed air to the air cylinder is formed in the casing pipe above the slit hole of the recovery port, and
(d2 '-4) when supplying compressed air to the air cylinder, according to claim 2, wherein the clamping plate by the connecting rod extends in the radial direction, characterized in that for pressing the casing pipe outer peripheral surface Bottom sediment mud recovery equipment. The bottom sediment mud collection apparatus according to any one of claims 1 to 5, wherein the blade plate has a planar shape or a shape in which the surface of the recovery fan portion on the rotation traveling direction side is curved as a concave surface. The bottom sediment mud recovery apparatus according to any one of claims 1 to 6, wherein the top plate has an inclination that gradually descends radially outward. A tip cap portion that is detachably attached to the lower end of the casing pipe and is used when building the casing pipe from the bottom mud surface to the ground surface,
The tip cap portion is composed of a lower tip cap and an upper support fixing means,
The lower tip cap includes a disk, a cone continuously provided on the lower surface of the disk, and a plurality of spiral mud scraping ridges protruding from the surface of the cone,
The upper support fixing means includes a columnar cylinder fixing frame that extends upward from the center of the upper surface of the disk, a plurality of cylinders that can be moved forward and backward from the outer periphery of the cylinder fixing frame to the outside in the radial direction, and the cylinder The bottom sediment mud collection apparatus according to claim 1, further comprising a fixed leg attached to an arm projecting from each of the tips of each of the first and second casing pipes and capable of contacting the inner surface of the casing pipe. The upper support fixing means further includes an annular guide roller frame supported by a plurality of support pillars extending upward from the peripheral edge of the upper surface of the disk, and a plurality of guide rollers mounted on the guide roller frame at equal angular intervals. Each of the guide rollers includes a wire hook that is pivotally supported so as to be able to roll in the vertical direction along the inner surface of the casing pipe, and that connects a suspension wire that suspends the tip cap portion. The bottom sediment mud recovery apparatus according to claim 8. A casing pipe having a recovery port portion in an intermediate portion in the axial direction, wherein the shutter hole provided in the recovery port portion can be switched between a closed state and an open state by rotation around the axis of the casing pipe And sediment mud on the surface of the ground while being able to be suspended from a trolley with the casing pipe penetrated and rotating and axially moving together with the casing pipe in a fixed state on the outer peripheral surface of the casing pipe In the bottom sediment mud recovery method for recovering bottom sediment mud using a bottom sediment mud recovery device having a recovery fan section
A first step of installing a tip cap portion for preventing sediment intrusion at the lower end of the casing pipe with the shutter hole closed, and building the casing pipe vertically to the bottom mud surface;
A second step of building from the bottom mud surface to the ground surface while rotating the casing pipe;
A third step of removing and collecting the tip cap portion from the lower end of the casing pipe;
The shutter hole is built in the ground while rotating the casing pipe while the shutter hole is closed until the lower side of the shutter hole reaches the ground surface, and the earth inside the casing pipe is excavated and taken out, and then the lower side of the shutter hole A fourth step of pulling up the casing pipe until the bottom reaches the bottom mud surface,
The recovery fan is suspended to the bottom mud surface and fixed to the outer peripheral surface of the casing pipe, and the shutter hole is opened, and then the casing pipe is rotated until the recovery fan reaches the ground surface. A fifth step of scraping the sediment mud and dropping it into the casing pipe from the shutter hole;
A sixth step of releasing the fixed state of the recovery fan and lifting and recovering;
A seventh step of covering the surface of the sediment mud dropped into the casing pipe by introducing the earth and sand from the upper end of the casing pipe after the shutter hole is closed; and
An eighth step of pulling up and collecting the casing pipe;   The first to eighth steps are performed in one bottom sediment removal target area, and then moved in the horizontal direction, and after moving, the ninth step is repeated. 10. A method for recovering bottom mud according to item 10.   The bottom sediment mud recovery method according to claim 11, further comprising a 10th step of filling the ground surface from which sediment sediment has been removed with soil and sand after the ninth step. The sediment mud recovery method according to any one of claims 10 to 12, wherein the earth and sand inside the casing pipe excavated and taken out in the fourth step is used as the earth and sand introduced in the seventh step. A casing pipe provided with a recovery port portion having a slit hole in an intermediate portion in the axial direction, and can be suspended from a trolley with the casing pipe penetrating and fixed to the outer peripheral surface of the casing pipe In the sediment mud recovery method for recovering sediment mud using a sediment mud recovery apparatus having a recovery fan unit that scrapes the sediment mud on the ground surface while rotating and moving in the axial direction together with the casing pipe,
A first step of mounting a tip cap portion for preventing invasion of earth and sand at the lower end of the casing pipe and erected the casing pipe in the vertical direction to the bottom mud surface;
A second step of building from the bottom mud surface to the ground surface while rotating the casing pipe;
A third step of removing and collecting the tip cap portion from the lower end of the casing pipe;
A fourth step of digging and taking out the earth and sand inside the casing pipe while building the casing pipe while rotating the casing pipe until the lower side of the slit hole reaches the bottom mud surface;
After the recovery fan part is suspended to the bottom mud surface and fixed to the outer peripheral surface of the casing pipe, the bottom sediment mud is scraped by lowering the casing pipe while rotating until the recovery fan part reaches the ground surface. A fifth step of dropping from the slit hole into the casing pipe;
A sixth step of releasing the fixed state of the recovery fan and lifting and recovering;
A seventh step of covering the surface of the sediment mud dropped into the casing pipe by introducing the earth and sand from the upper end of the casing pipe with the earth and sand;
An eighth step of pulling up and collecting the casing pipe;   The first to eighth steps are performed in one bottom sediment removal target area, and then moved in the horizontal direction, and after moving, the ninth step is repeated. 14. A method for recovering bottom mud according to item 14.   The bottom sediment mud recovery method according to claim 15, further comprising a tenth step of filling the ground surface from which sediment sediment has been removed with soil and sand after the ninth step. The sediment sediment recovery method according to any one of claims 14 to 16, wherein the sediment contained in the casing pipe excavated and taken out in the fourth step is used as the sediment introduced in the seventh step.

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