JP4469627B2 - 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 aquatic environment has deteriorated remarkably, such as the formation of anoxic water areas or increased COD values due to the absence of red tides due to eutrophication and the absence of oxygen due to abnormal propagation 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 mud recovery apparatus that recovers sediment mud accumulated on the ground surface of the water bottom, and as a main component thereof, a base boat that forms a fixed scaffold on the water; A casing pipe that can be built from the carriage to a predetermined penetration depth in the ground, and a casing rotary excavation that is installed on the carriage and supports the casing pipe and can be driven to rotate and move up and down around the axis. And a mud recovery fan portion mounted on the casing pipe so as to be movable up and down.
Further, the casing pipe includes a shutter portion in an intermediate portion in the axial direction, and the shutter portion has a closed state in which the internal space and the external space of the casing pipe are blocked and communicated with the open state by the casing rotary excavator. It can be switched by rotating around the axis.
Still further, the muddy soil recovery fan is provided at the lower end to rotate the bottom mud in the circular area on the ground surface while scraping to the center, and the recovery fan is positioned in the vicinity of the shutter portion. The fixing means capable of fixing the mud recovery fan part to the casing pipe in a state, the rotation driving means of the recovery fan, and the recovery in a state where the mud recovery fan part is fixed to the casing pipe Elevating means for elevating the fan.
The present invention is configured by applying known techniques and devices, such as the use of a casing pipe rotary excavator widely used in the conventional post-tension pile method or the like.

(2) The invention according to claim 2 is the apparatus according to claim 1, wherein the shutter portion includes an inner tube portion at an upper end of the lower casing pipe and an outer end of the lower end of the upper casing pipe separated from each other. A plurality of slits of the same size at equal intervals in the circumferential direction at corresponding positions of both the inner tube portion and the outer tube portion, formed in a double tube structure portion in which the tube portion is rotatably fitted. Are closed, and the inner tube portion and the outer tube portion are relatively rotated around the axis by the rotational drive around the axis by the casing rotary excavator, so that the corresponding slits are displaced from each other. It is possible to switch between a state and an open state in which each corresponding slit is in the same position.

(3) The invention according to claim 3 is the apparatus according to claim 1, wherein the recovery fan is provided with a top plate portion provided with a through hole through which the casing pipe passes, and downward from the periphery of the top plate portion. And a plurality of blade plates whose upper sides are connected and fixed to the lower surface of the top plate portion;
The inner side of each of the blade plates is located at the periphery of the through hole, and the outer side is connected and fixed to the side wall, and the blade plate has a planar shape or the direction of rotation of the recovery fan. It is characterized in that the side surface has a curved shape as concave as possible.

(4) The invention according to claim 4 is characterized in that, in the apparatus according to claim 3, an inclination is provided that gradually descends from the periphery of the through hole of the top plate portion toward the periphery of the top plate portion. To do.

(5) The invention according to claim 5 is the apparatus according to claim 3 or 4, wherein the mud recovery fan portion is provided above the recovery fan and has a through hole in the casing pipe. With a frame,
The recovery fan rotation drive means comprises:
A ring gear rotatably mounted around the outer periphery of the casing pipe in the through hole of the lower disc-shaped frame;
A vertical cylinder that extends upward from the periphery of a through hole provided in the top plate portion of the recovery fan and is connected to the ring gear;
And a hydraulic rotary motor that is attached to the lower disk-shaped frame and rotationally drives the ring gear.

(6) The invention according to claim 6 is the apparatus according to claim 5, wherein the mud recovery fan part is provided above the lower disk-shaped frame and provided with a through hole of the casing pipe. With a frame,
Lifting means for raising and lowering the recovery fan in a state where the mud recovery fan part is fixed to the casing pipe,
A telescopic stroke jack having both ends connected to the upper surface of the lower disk-shaped frame and the lower surface of the intermediate disk-shaped frame is provided.

(7) The invention according to claim 7 is the apparatus according to claim 6, wherein the mud recovery fan portion is provided above the intermediate plate-shaped frame and provided with a through hole of the casing pipe. With a frame,
Fixing means for the mud recovery fan part,
An upper wedge that hangs down via a link from a position near the through hole of the upper plate-shaped frame, and a lower wedge attached to a position corresponding to the upper wedge at a position near the through-hole of the intermediate plate-shaped frame;
A telescopic clamp cylinder having both ends connected to the upper surface of the intermediate disk-shaped frame and the lower surface of the upper disk-shaped frame;
The lower wedge presses the upper wedge against the casing ring by contraction of the clamp cylinder.

(8) The invention according to claim 8 is the apparatus according to any one of claims 1 to 7, wherein the casing pipe is detachably attached to the lower end of the casing pipe and the casing pipe is built from the bottom mud surface to the ground surface. It has a tip cap that is used when
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 apparatus according to claim 8, wherein the upper support fixing means is further supported by a plurality of support columns extending upward from the peripheral edge of the upper surface of the disk. A frame and a plurality of guide rollers mounted at equal angular intervals on the guide roller frame, each of the guide rollers being pivotally supported so as to be able to roll in the vertical direction along the inner surface of the casing pipe. And the wire hook which connects the suspension wire which suspends the said front-end | tip cap part is comprised, It is characterized by the above-mentioned.

(10) The invention according to claim 10 is a casing pipe having a shutter portion in an axially intermediate portion, wherein the shutter portion communicates with a closed state that shuts off an internal space and an external space of the casing pipe; The casing pipe can be switched by rotating around the axis of the casing pipe, and the bottom mud in the circular region on the ground surface is scraped to the center while being mounted so as to be movable up and down with respect to the casing pipe. In the sediment mud recovery method for recovering sediment mud accumulated on the ground surface of the water bottom, using a sediment mud recovery device having a mud recovery fan unit equipped with a collecting fan.
A first step of installing a tip cap portion for preventing soil intrusion at the lower end of the casing pipe with the shutter portion closed, and erected the casing pipe vertically to the bottom mud surface;
A second step of building the casing pipe from the bottom mud surface to the ground surface;
A third step of removing and collecting the tip cap portion from the lower end of the casing pipe;
A fourth step of building up to a predetermined penetration depth in the ground while rotating the casing pipe and excavating and taking out the earth and sand inside the casing pipe;
A fifth step of scraping the sediment mud by dropping it from the bottom sediment mud surface to the ground surface while rotating the recovery fan after the shutter portion is opened;
A sixth step of raising and collecting the mud soil recovery fan; and
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 portion is closed; and
And an eighth step of pulling up and collecting the casing pipe.
In the main part of the method, the sedimentary mud in the circular region is removed from the water bottom (seabed, river, Sweep to the center without moving from the bottom of the lake). By this method, the sediment mud is dropped into the excavation hole excavated in the casing pipe through the shutter portion of the casing pipe built in the center of the recovery fan without spreading.

(11) The invention according to claim 11 is the method according to claim 10, wherein after performing the first to eighth steps in one bottom sediment removal target region, the ninth step of moving in the horizontal direction is performed. Further, the first to eighth steps are repeated after moving.

(12) The invention according to claim 12 is the method according to claim 10 or 11, 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. The bottom sediment mud collection method according to claim 9 or 10.

  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.

  Moreover, the tip cap part at the time of erection of a casing pipe has a function which extrudes and removes the bottom mud just under the casing pipe around the casing pipe. The collection fan of the mud collection fan part has a function of scraping the sediment mud underneath to the center. In particular, a recovery fan provided with an inclination so that the center portion is high has high recovery efficiency. Sedimented sediment mud is dropped into the inside through the open shutter part of the casing pipe. As for the rotation of the casing pipe and the rotation of the mud recovery fan part when building in the sediment mud, a gentle rotation necessary for quietly moving the sediment mud is sufficient. 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 construction method, it is not necessary to dig up the sediment mud up to the surface of the water or on the land with a drilling device or suck up with a suction device, and the processing can be completed at the sedimentation 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. Does not happen.

Regardless of the degree of consolidation of the bottom of the water, the present invention forms the excavation hole after excavating and taking out the earth and sand in the casing pipe with a hammer grab after the casing pipe penetrates into the ground. It is a method of slowly dropping sediment mud inside. 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, in the present invention, instead of collecting sediment mud on the water, it is dropped into an excavation hole excavated in the local ground, and the excavated soil is used to cover the excavation hole. As a result, it is possible to backfill the surface of the ground, so that no by-products that require treatment or disposal after construction are generated. This is one of the most important effects of the present invention.

  In addition, if the excavated soil is not suitable as backfill soil after capping and capping, such as the soil in the lower ground of the sedimentary mud layer contains a large amount of fine particles, it is of good quality to flatten with the ground line. The earth and sand that have been backfilled and excavated are collected on a trolley, etc., and the remaining soil is treated at the land facility. This avoids polluting the surrounding water area. In addition, excavated sediment does not contain sludge such as sediment mud even if it contains fine particles, so it is managed without chemical treatment or caking treatment, and without the risk of water pollution. It can be used as landfill for construction.

  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 range of the muddy soil recovery fan, and does not input the treatment material, the load on the ecosystem such as useful microorganisms and animals and plants existing in the vicinity is small, and productivity of the fishing ground It is possible to purify only the part where the sediment environment is deteriorating while maintaining the temperature, and the economic effect is great.

  In particular, the bottom sediment mud recovery apparatus of the present invention has a mud recovery fan section that is uniquely rotatable with a hydraulic rotary motor, and collects and deposits bottom sediment within the excavated casing pipe. The effect can be expected.

  The casing pipe is partly made of a double pipe structure, the casing rotary excavator is installed on a carriage, the tip cap part which can be detachably attached and has a spiral protrusion on the cone surface, and hydraulic pressure Other than the mud recovery fan that rotates and moves up and down by driving, no special processing equipment is required, and the casing rotary excavator and casing pipe, trolley, excavator for excavation and backfilling work that are widely used in general are used. By preparing the loaded excavated soil temporary loading carrier, all the steps of the preferred example can be completed. Therefore, it can be implemented at low cost.

  Furthermore, since the same device can be applied to various grounds, it is not necessary to prepare a plurality of devices even in an area where the ground change is large, and the economic effect is high.

  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.

Hereinafter, an embodiment of the present invention will be described based on an example with reference to the drawings.
First, the sediment mud recovery apparatus according to the first invention will be described. 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.
FIGS. 1-13 is a block diagram of the sedimentary mud collection apparatus 1. FIG. The outline of each figure will be described.
FIG. 1 is an overall configuration diagram of a sediment mud recovery apparatus 1. 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.
2-6 is a block diagram which shows the shutter part provided in the axial direction intermediate part of the casing pipe 4. As shown in FIG.
FIG. 7 is a cross-sectional view of the tip portion of the casing pipe 4 in a state where it is built to the depth of penetration in the ground 20. In the example shown in the figure, a tremy tube 10 used for earth and sand backfilling is inserted into the casing pipe 4.
FIGS. 8-11 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.
FIG. 12 is a configuration diagram of a state in which the mud collecting fan unit 9 for collecting sediment mud is attached to the casing pipe 4.
FIG. 13 is a configuration diagram of the recovery fan 9 </ b> D of the mud recovery fan unit 9.

  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 and removes or refills the earth and sand inside the erected casing pipe 4 (see reference numeral 8 in FIG. 17). ) With 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.

  The hammer grab (see reference numeral 8 in FIG. 17) for excavating the inside of the casing pipe 4 is, for example, an inner diameter of 3 m of the casing pipe 4 and the capacity of the mounted crane 3 from widely known techniques or products. Select one that fits.

  The casing pipe 4 will be described with reference to FIGS. As shown in FIG. 2, the casing pipe 4 includes a shutter portion at an axially intermediate portion (not a central portion that bisects the length). The shutter portion 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 shutter portion is in communication with each other by rotational driving around the axis by the casing rotary excavator 6. 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 inner pipe portion 4A1 is welded and fixed to the upper end of the lower casing pipe 4A so as to protrude upward. The inner tube portion 4A1 is fitted to the outer tube portion 4B1 provided at the lower end of the upper casing pipe 4B so as to be rotatable from below. By fitting the inner tube portion 4A1 and the outer tube portion 4B1, a double tube structure portion is formed in the separation region of the casing pipe 4 separated vertically. The shutter portion is formed in this double tube structure portion. A plurality of slits 4A2 are opened at equal intervals in the circumferential direction in the inner pipe portion 4A1 of the lower casing pipe 4A. On the other hand, a plurality of slits 4B2 having the same dimensions are also opened in the outer tube portion 4B1 of the upper casing pipe 4B at positions corresponding to the plurality of slits 4A2.

  Further, a notch 4B3 having an effective movable width corresponding to twice the slit width is formed on the front and rear surfaces of the outer tube portion 4B1 of the upper casing pipe 4B at a position below the slit 4B2. On the other hand, protrusions 4A3 are also provided on the front and rear surfaces of the inner pipe portion 4A1 of the lower casing pipe 4A so as to fit into the notches 4B3.

  3 and 4 are sectional views of the shutter portion of the casing pipe 4. The protrusion 4A3 and the notch 4B3 shown in FIG. 2 are slits 4A2 when the lower casing pipe 4A and the upper casing pipe 4B (ie, the inner tube portion 4A1 and the outer tube portion 4B1) are relatively rotated around the axis. And 4B2 are means for stopping the shutter portion in an open state or a closed state, and are provided at a position suitable for this function. In the closed state of the shutter portion shown in FIG. 3, the slits 4 </ b> A <b> 2 and 4 </ b> B <b> 2 are in a position 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 shutter portion shown in FIG. 4, the slits 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 the slit.

  As an example, the casing pipe 4 having an inner diameter of 3 m is used. 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 inner pipe portion 4A1 having a length of 3 m is welded and fixed to the upper end of the lower casing pipe 4A, and an outer pipe portion 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 inner tube portion 4A1 of the lower casing pipe 4A and the outer tube portion 4B1 of the upper casing pipe 4B are fitted. That is, in the double tube structure portion, the outer peripheral surface of the inner tube portion 4A1 and the inner peripheral surface of the outer tube portion 4B1 can be relatively rotated while sliding with each other.

  Further, a plurality of slits are formed at equal intervals so that the lower sides of the slits 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 slit is preferably about 50 cm as an applicable dimension 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. Moreover, although the height of a slit is about 1 m, for example, it is not limited to this numerical value. The interval between the adjacent slits 4B2 is, for example, about 68 cm. In addition, a position is set so that the lower side of each slit becomes the ground surface position when it penetrates to the penetration depth. Furthermore, a notch 4B3 having a height of 20.5 cm and an effective movable width of 75 cm is formed with respect to the outer tube portion 4B1 at a position slightly below the slit 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 inner pipe portion 4A1 by welding or a bolt nut so as to fit into the notch 4B3. Accordingly, the effective movable width 75 cm of the notch 4B3 is calculated from the slit width 50 cm + the protrusion width 20 cm + the margin 5 cm.

  In the above example, the welding position or attachment position of the protrusion 4A3 is notched in the closed state of the shutter portion shown in FIG. 5 so that the lower casing pipe 4A and the upper casing pipe 4B can be rotated by 55 cm relatively. A position where one side of the protrusion 4A3 comes into contact with one side of 4B3 and stops. The closed state of the shutter portion shown in FIG. 5 is realized by rotating the upper casing pipe 4B, that is, the outer tube portion 4B1, in the direction of the arrow in FIG. In the open state of the shutter shown in FIG. 6, 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. 5 to the open state in FIG. 6 is realized by rotating the upper casing pipe 4B, that is, the outer tube portion 4B1, in the direction of the arrow in FIG.

  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

  8 to 11 are configuration diagrams of the tip cap portion 7. 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. 8 is a side view of the tip cap portion 7. FIG. 9 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. 10 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. 11 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. 10, 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 it is built into the ground while rotating the casing pipe 4A.

  FIG. 12 is a partially cutaway cross-sectional view showing a state in which the mud recovery fan unit 9 is mounted on the outer periphery of the casing pipe 4. The mud recovery fan unit 9 is suspended from the carriage 2 in a state where the casing pipe 4 is penetrated, and is attached to the casing pipe 4 so as to be movable up and down. The mud recovery fan unit 9 is composed of an upper disk-shaped frame 9A, an intermediate disk-shaped frame 9B, a lower disk-shaped frame 9C, and a recovery fan 9D that are connected in order from top to bottom. The recovery fan 9D located at the lower end has a function of scraping to the center while rotating sediment mud in a circular area on the ground surface. The upper disk-shaped frame 9 </ b> A located at the upper end includes a suspension means for the mud recovery fan unit 9.

  The upper disk-shaped frame 9A and the intermediate disk-shaped frame 9B fix the mud soil collecting fan 9 to the casing pipe 4 in a state where the collecting fan 9D is positioned in the vicinity of the shutter portion of the casing pipe 4 described above. It has a fixing means that can. Further, the lower disk-shaped frame 9C is provided with a rotation driving means for the recovery fan 9D. Furthermore, the lower disk-shaped frame 9C and the intermediate disk-shaped frame 9B are also provided with lifting means for moving the collecting fan 9D up and down in a state where the mud collecting fan 9 is fixed to the casing pipe 4.

  A through-hole 9A3 that penetrates the casing pipe 4 in the vertical direction is formed in the center of the upper disk-shaped frame 9A having a predetermined thickness. A plurality of suspension wire hooks 9A2 are provided at predetermined positions on the upper surface 9A4 of the upper disk-shaped frame 9A, and the suspension wires 9A1 are connected to each of them. The upper disk-shaped frame 9A is suspended by these suspension wires 9A1 so that the flat plate surface is horizontal. The upper end of the suspension wire 9A1 is connected to a wire take-up and feeding device such as a winch via a pulley installed on the work table 5 shown in FIG. The wire take-up and delivery device is fixed to the carriage 2. As the suspension wire 9A1 expands and contracts, the upper panel frame 9A moves up and down in the vertical direction. That is, the entire mud recovery fan unit 9 moves up and down with respect to the casing pipe 4.

  Further, a plurality of (four in the illustrated example) links R are provided symmetrically with respect to the center of the casing pipe 4 at positions near the through holes 9A3 on the lower surface 9A5 of the upper disk-shaped frame 9A. The upper wedge 9A6 is suspended via the. Further, the upper end of a plurality of clamp cylinders 9A7 (four in the illustrated example, but only two are shown) that can be expanded and contracted in the vertical direction by hydraulic operation is connected to the vicinity of the peripheral edge of the lower surface 9A5 of the upper disk-shaped frame 9A. Has been. The plurality of clamp cylinders 9A7 are arranged symmetrically about the center of the casing pipe 4 on the lower surface 9A5. Note that illustration of a medium supply pipe for hydraulic operation is omitted.

  The intermediate plate-shaped frame 9B having a predetermined thickness is also provided with a through hole 9B3 through the casing pipe 4 in the vertical direction at the center thereof. Lower wedges 9B6 are attached to positions near the through holes 9B3 on the upper surface 9B4 of the intermediate disc-shaped frame 9B at positions corresponding to the plurality of upper wedges 9A6. As illustrated, the inner surface of the upper wedge 9A6 is along the outer peripheral surface of the casing pipe 4, while the outer surface of the upper wedge 9A6 is in contact with and engaged with the inner surface of the lower wedge 9B6. Furthermore, the lower ends of the plurality of clamp cylinders 9A7 described above are connected to the vicinity of the periphery of the upper surface 9B4 of the intermediate disk-shaped frame 9B.

  As a result, when the clamp cylinder 9A7 is contracted, the distance between the upper plate-like frame 9A and the intermediate plate-like frame 9B is shortened, and the upper wedge 9A6 is strongly pressed against the outer peripheral surface of the casing pipe 4 by the lower wedge 9B6. . Thereby, the upper disk-shaped frame 9A and the intermediate disk-shaped frame 9B are integrated with the casing pipe 4 and fixed. Conversely, when the clamp cylinder 9A7 is extended, the distance between the upper plate-like frame 9A and the intermediate plate-like frame 9B becomes longer, the upper wedge 9A6 is released, and the upper plate-like frame 9A and the intermediate plate-like frame 9B are in the casing. It will detach from the pipe 4.

  Further, a plurality of stroke jacks 9B7 (4 in the illustrated example, but only two are shown) are hung down symmetrically about the center of the casing pipe 4 at a position near the periphery of the lower surface 9B5 of the intermediate disk-shaped frame 9B. . Each stroke jack 9B7 can extend and contract in the vertical direction. Although the stroke jack 9B7 is also hydraulically operated, the medium supply pipe is not shown.

  The lower plate-like frame 9C having a predetermined thickness is also provided with a through hole 9C3 that penetrates the casing pipe 4 in the vertical direction at the center thereof. Further, the lower ends of the plurality of stroke jacks 9B7 are connected to the vicinity of the periphery of the upper surface 9C4 of the lower disc-shaped frame 9C. As the stroke jack 9B7 expands and contracts, the lower disk-shaped frame 9C and the recovery fan 9D move up and down. Furthermore, a ring gear 9C6 is rotatably mounted in the through hole 9C3 of the lower disk-shaped frame 9C so as to surround the outer periphery of the casing pipe 4. The ring gear 9C6 is rotationally driven by a hydraulic rotary motor 9C9 through a pinion 9C8. The medium supply pipe supplied to the hydraulic rotary motor 9C9 is not shown. Since the ring gear 9C6 is supported by the lower disk-shaped frame 9C via the bearing 9C7, even if the ring gear 9C6 rotates, the lower disk-shaped frame 9C does not rotate and only the recovery fan 9D rotates. It becomes.

  The recovery fan 9D includes a recovery fan case 9D1 and a blade 9D2. FIG. 13 shows the recovery fan 9D as viewed from the direction of arrow A in FIG. 12 (that is, the recovery fan 9D is viewed from obliquely below). The recovery fan case 9D1 includes a top plate portion 9D12 and a side wall portion 9D13 extending downward from the periphery of the top plate portion 9D12, and a through-hole 9D3 is provided through the casing pipe 4 at the center of the top plate portion 9D12. ing. As shown in FIG. 12, a vertical cylinder 9D5 extending upward from the peripheral edge of the through hole 9D3 is continuously provided, and the upper end thereof is connected to the ring gear 9C6.

The shape of the top plate portion 9D12 is preferably provided with an inclination that gradually descends from the periphery of the through hole 9D3 toward the periphery of the top plate portion 9D12, and corresponds to, for example, a side shape of a truncated cone. In this way, when the top plate portion 9D12 has a shape in which the central portion is raised, the ability to collect sediment mud in the fifth step of the sediment sediment recovery method described later is high.
However, as another embodiment, a certain recovery capability can be secured even if the top plate portion 9D12 is a horizontal disk.

  As shown in FIG. 13, the blade 9D2 is composed of an appropriate number of blade plates 9D21 (four in the illustrated example) made of a plate having a width that is slightly shorter than the height of the side wall 9D13. The upper side of the plate 9D21 is connected and fixed to the lower surface of the top plate portion 9D12. The inner side of each blade plate 9D21 is located at the periphery of the through-hole 9D3, and the outer side is connected and fixed to the side wall 9D13. Each blade plate 9D21 is preferably formed in a curved shape so that the surface on the traveling direction side in the rotation direction (arrow) of the recovery fan 9D is concave, but in another embodiment, it is a planar shape. It may be.

  In one embodiment, the recovery fan 9D is made of steel and has a top plate portion 9D12 having a diameter of 10 m and a side wall portion 9D13 having a height of 15 cm, and the vertical cylinder 9D5 is integrated with the central through hole. This prevents the mud from scattering upward. The blade plate 9D21 has a height of 14 cm.

  Here, an operation method of the mud recovery fan unit 9 will be described with reference to FIGS. 12 and 13. This operation method is an operation in the fifth step in the sediment mud recovery method described later. In the initial position, the mud recovery fan unit 9 is positioned near the lower side of the work table 5 with the casing pipe 4 being passed through the through holes 9A3, 9B3, 9C3 and 9D3. In this state, the suspension wire 9 </ b> A <b> 1 connected to the winch installed on the work table 5 suspends the mud recovery fan unit 9.

  A shutter in which the lower end of the mud recovery fan unit 9 is provided on the casing pipe 4 by operating the winch when the casing pipe intrusion step and the internal sediment excavation step (fourth step) in the bottom sediment mud recovery method described later are completed. It is lowered until it is located near the upper side of the part (slits 4A2, 4B2). At this time, the lower sides of the slits 4A2 and 4B2 are substantially located on the ground surface, and the slits 4A2 and 4B2 are partially buried in the sediment mud layer. Next, the clamp cylinder 9A7 is contracted by hydraulic operation so that the upper wedge 9A6 is strongly pressed against the outer peripheral surface of the casing pipe 4 by the lower wedge 9B6, and the upper plate-like frame 9A and the intermediate plate-like frame 9B of the mud collection fan unit 9 are pressed. Is fixed to the casing pipe 4.

  A recovery fan 9D for recovering mud can rotate integrally with a ring gear 9C6 connected through a vertical cylinder 9D5. As described above, the ring gear 9C6 is rotationally driven by the hydraulic rotary motor 9C9 through the pinion 9C8.

  The collection fan 9D is moved up and down by four stroke jacks 9B7 provided by connecting the intermediate disk-shaped frame 9B and the lower disk-shaped frame 9C. In one embodiment, the maximum extension length of one stroke jack 9B7 is set to slightly exceed 1 m. This is applied when the height of the slits 4A2 and 4B2 of the casing pipe 4 is 1 m.

  The stroke jack 9B7 is held in the most contracted state until a stage where the casing pipe penetration process and the internal earth and sand excavation process (fourth process described later) are completed. In the bottom sediment mud recovery process of the fifth process, the hydraulic fan 9D is operated to rotate the recovery fan 9D while operating the stroke jack 9B7 to extend and slowly lower the recovery fan 9D. Along with the operation of the recovery fan 9D, the curved blade plate 9D21 of the blade 9D2 of the recovery fan 9D moves the bottom sediment mud in the circular area located directly below the recovery fan 9D from the outside toward the casing pipe 4. Rake. Here, referring to FIG. 7, the sediment mud scraped from the surroundings enters the casing pipe 4 through the slits 4 </ b> A <b> 2 and 4 </ b> B <b> 2 of the open shutter portion, and is excavated in the casing pipe 4. It falls into the hole 21 and accumulates in the excavation hole 21 (reference numeral 22b). In this way, sediment mud is collected while the stroke jack 9B7 is extended by approximately one stroke. After the stroke jack 9B7 is extended by one stroke, the recovery fan 9D is raised by contracting the stroke jack 9B7. When ascending, it is not necessary to rotate the recovery fan 9D.

  Next, the tremy tube 10 will be described with reference to FIG. In the seventh step of the bottom sediment mud recovery method to be described later, the hammer grab used at the time of excavation of the excavation hole is used for capping work to cover the sediment mud 22 deposited on the excavation hole 21 in the casing pipe 4 with the earth and sand 20b. Can be used. Furthermore, it is preferable to use the tremy tube 10 for the purpose of increasing the efficiency of the capping work. In this case, the tremy tube 10 is a pipe having an outer diameter slightly smaller than the inner diameter of the casing pipe 4 and a length substantially the same as that of the upper casing pipe 4A, and has a conical ring whose upper end is opened upward. Use a funnel-shaped attachment. 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. . Tighten the hose to be connected to the outer periphery near the lower end of the tremmy pipe with a smoothed iron wire.

  The earth and sand 20b used for capping is preferably earth and sand excavated in the casing pipe 4; however, when the excavated earth and sand is turbid in the water due to clay or the like, it may affect the surrounding environment. It is preferable to prepare earth and sand separately.

  The earth and sand temporary loading platform ship equipped with a backhoe that temporarily accumulates the earth and sand excavated in the casing pipe 4 and backfills the sediment in the excavation hole after the completion of the sediment mud collection work is provided with a bulwark for storing the earth and sand.

  Next, a sediment mud recovery method according to the second invention will be described with reference to FIGS. The sediment mud collection method suitably performed using the sediment mud recovery apparatus 1 of the first invention is composed of the following steps.

(First step)
FIG. 14 is a diagram schematically showing a first step for setting the carriage 2 and the sediment mud recovery apparatus 1. The trolley 2 equipped with 2 to 4 spuds (see FIG. 1) at the rear of the trolley that is widely used in marine operations and the like is towed to the surface 30 of the target area from which sediment mud is removed. Sediment mud 22 is deposited on the ground 20 at the bottom of the target area. Next, the two spuds installed at the rear part of the carriage 2 are dropped to fix the standing carriage 2 to 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 built in such a manner as to penetrate the casing rotary excavator 6, the work table 5, and the mud collection fan 9 suspended from the work table. 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.

  In an arbitrary stage of the erection process of the casing pipe 4, the tip cap portion 7 is attached 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 inside from the upper end of the casing pipe 4 to be lowered. As shown in FIG. 10, 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, so that it can be lowered while maintaining the coaxial state with the casing pipe 4. it can.

  When the tip cap portion 7 reaches a predetermined position at the lower end of the casing pipe 4, as shown in FIG. 10, 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. When the casing pipe 4 is built up 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.

(Second step)
FIG. 15 is a view schematically showing a second step of lowering the lower end of the casing pipe 4 from the bottom mud surface to the ground surface. 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 sediment mud 22 accumulated on the ground surface 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.

(Third step)
FIG. 16 is a diagram schematically illustrating a third step of removing and collecting the tip cap portion 7. As shown in FIG. 10, 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.

(4th process)
FIG. 17 is a diagram schematically illustrating a fourth step including a penetration step of the casing pipe 4 and an excavation step of internal soil of the casing pipe 4. First, the casing pipe 4 is penetrated into the ground 20 by a length corresponding to one stroke of the lifting operation using the casing rotary excavator 6. At the time of penetration, the casing pipe 4 is lowered while being rotated by the casing rotary excavator 6. At this time, the ground 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, the internal earth and sand are excavated, pulled up while holding the excavated earth and sand, and taken out from the casing pipe 4.

  In this way, until the casing pipe 4 reaches a predetermined penetration depth, the casing pipe 4 is penetrated by one stroke, and the operation of excavating and taking out the internal soil is repeated. The predetermined penetration depth is a depth of 14 m from the ground surface 20a in the case of the embodiment of the bottom sediment recovery device described above. After this operation, an excavation hole 21 from which earth and sand have been removed is formed within a length of 14 m from the lower end of the casing pipe 4. At this time, the lower sides of the slits 4A2 and 4B2 of the shutter portion of the casing pipe 4 are located substantially on the ground surface 20a. The shutter portion formed by the slits 4A2 and 4B2 is closed until this time. That is, the rotation direction when the casing pipe 4 penetrates is set to a direction in which the shutter portion can be maintained in the closed state (see FIG. 5). At this time, it is preferable to set the height of the slit so that the upper sides of the slits 4A2 and 4B2 are higher than the surface 22a of the sediment mud 22.

(5th process)
FIG. 18 is a diagram schematically showing a fifth step of collecting the sediment mud by the mud collecting fan unit 9. First, when the penetration of the casing pipe 4 and the excavation of the internal sediment in the fourth step are finished, the casing pipe 4 is reversed by the casing rotary excavator 6 in the direction opposite to that at the time of penetration. If the upper casing pipe is reversed by the slit width (10 cm in one embodiment) or more, the shutter portion formed by the slits 4A2 and 4B2 of the casing pipe 4 is opened (see FIG. 6).

  The mud recovery fan unit 9 that has been suspended below the work table 5 is suspended along the casing pipe 4. When the mud recovery fan unit 9 is not in operation, the mud recovery fan unit 9 is not fixed to the casing pipe 4 and can move up and down (the clamp cylinder 9A7 in FIG. 12 is extended), and the recovery fan 9D rotates. It stops (the hydraulic rotary motor 9C9 in FIG. 12 is stopped), and the recovery fan 9D is in its uppermost position (the stroke jack 9B7 in FIG. 12 is in the contracted state). The mud collecting fan unit 9 is lowered and stopped once when the lower end of the collecting fan 9D reaches the surface 22a of the sediment mud 22. Subsequently, the mud soil recovery fan unit 9 is fixed to the casing pipe 4 by contracting the clamp cylinder that connects the upper plate frame and the intermediate disk frame of the mud soil recovery fan unit 9 (see FIG. 12).

  Next, the recovery fan 9D of the mud recovery fan unit 9 is gradually lowered while slowly rotating. The speed of rotation and descent is set so as not to disturb the sediment mud 22. As described above, the top plate portion of the recovery fan 9D having a suitable shape is inclined so that the vicinity of the center is high and the peripheral edge is low. When the recovery fan 9D is lowered, an upward force is applied to the sediment mud 22 below it as a reaction force for lowering the recovery fan 9D. Then, when the sediment mud 22 is collected by the blades and reaches the lower surface of the top plate portion, it tends to move along the inclination of the top plate portion. By applying an upward force and a centering force in this way, the sediment mud 22 existing in the circular area inside the peripheral edge of the recovery fan 9D is scraped toward the casing pipe 4 from the outside to the inside. In addition, even when the top plate portion is not inclined, the effect of scraping to the center can be obtained by the blades. However, if the inclination is provided, the force toward the center is increased, which is more efficient.

  Thus, the sediment mud 22 raked up to the casing pipe 4 enters the casing pipe 4 through the open shutter portion and falls into the excavation hole 21. In this way, the recovery fan 9D is lowered until the lower end of the recovery fan 9D reaches the ground surface 20a, and when it reaches, the lowering and rotation are stopped. At this time, the penetration depth and recovery of the casing pipe 4 are such that the surface of the sediment mud soil dropped into the excavation hole 21 (see reference numeral 22b in FIG. 7) is located below a predetermined distance from the ground surface 20a. It is preferable to set the size (diameter and height) of the fan. In the above embodiment, the predetermined distance is about 1 m. The distance from the surface of the sediment mud 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.

(Sixth step)
FIG. 19 is a diagram schematically showing a sixth step of pulling up and collecting the mud collection fan unit 9. When the collection of the sediment mud 22 at one penetration place is completed, the collection fan 9D is first raised and returned to the uppermost position, and then the fixing with the casing pipe 4 is released, and then the suspension wire is wound up to work the work table 5 Pull up to the initial position in the vicinity of the bottom.

(Seventh step)
FIG. 20 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 shutter formed by the slits 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 its lower end is, for example, approximately 1 m above the surface of the sediment mud soil (reference numeral 22b in FIG. 7) dropped into the excavation hole (reference numeral 21 in FIG. 7). Position. 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 (reference numeral 20b in FIG. 7). ) After forming the Tremy tube.

  In another embodiment of the seventh step, after the shutter portion is closed, the earth or sand (not shown) prepared on the carriage 2 is gripped using the hammer grab 8, and the hammer grab 8 from the upper end of the casing pipe 4 is gripped. Is hung down in the casing pipe 4 and the hammer grab 8 is opened near the surface of the sediment mud soil (reference numeral 22b in FIG. 7) dropped into the excavation hole (reference numeral 21 in FIG. 7). Drop the sand on the bottom mud. Thereafter, the hammer grab 8 is pulled up. By repeating this, for example, a coating layer having a height of about 1 m (reference numeral 20b in FIG. 7) is formed.

  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. When the earth and sand excavated and taken out in the fourth step is used, it is the most environmentally preferable 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.

(8th step)
FIG. 21 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.

(9th step)
When the eighth step is completed, the fixing device such as the spud 11 and the anchor shown in FIG. 1 is pulled up, towed the carriage 2 and moved in the horizontal direction on the water surface 30 in the next sedimentary mud removal target area. Ninth step to tow to. FIG. 22 is a plan view showing the state of the water bottom after the above first to ninth steps have been repeatedly performed. The shape of the bottom sediment removal target region in one work cycle of the present invention is a circular region as shown in the figure from the shape and function of the recovery fan of the bottom sediment recovery device. The diameter of the circular area corresponds to that of the recovery fan. FIG. 23 is a cross-sectional view showing a state similar to FIG. 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.

(10th step)
FIG. 24 is a diagram schematically showing a tenth step of refilling the earth and sand on the ground surface after the bottom mud removal after repeatedly performing the first to ninth steps. For example, an excavation and sediment temporary carrier 12 different from the carrier is loaded with excavating machine 13 such as a backhoe and temporarily accumulated sediment (not shown), and the surface of the ground surface 20a after removal of sediment mud Tow and fix the position with anchor wires. Then, the earth and sand temporarily piled up by using a backhoe or the like is backfilled in the excavation hole and its surroundings, and leveled to such an extent that extreme unevenness cannot be formed. This completes the entire work.

1 is an overall configuration diagram of the present invention. It is an expanded view of the overlap part of each slit of the inner pipe part and outer pipe part in a casing pipe. It is sectional drawing of the overlapping part of each slit of the inner pipe part and outer pipe part in a casing pipe in a shutter closed state. It is sectional drawing of the overlapping part of each slit of the inner pipe part and outer pipe part in a casing pipe in a shutter open state. It is a separation region of an upper casing pipe and a lower casing pipe and is a view showing a state in which a shutter provided in a double pipe structure portion is closed. It is a separation region of an upper casing pipe and a lower casing pipe and is a view showing a state in which a shutter provided in a double pipe structure portion is open. It is sectional drawing of the front-end | tip part of the casing pipe penetrated 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 with which the front-end | tip cap part was mounted | worn with the lower end of the casing pipe. It is a BB arrow line view of FIG. It is a partially cutaway sectional view showing a state where a mud collection fan is mounted on the outer periphery of the casing pipe. It is a figure which shows the collection | recovery fan seen from the direction of arrow A of FIG. It is a figure which shows typically the 1st process which sets the collection | recovery apparatus of sediment mud. It is a figure which shows typically the 2nd process of lowering the lower end of a casing pipe to the ground surface. It is a figure which shows typically the 3rd process which collect | recovers the front-end | tip cap parts. It is a figure which shows typically the 4th process including the penetration process of the casing pipe 4, and the excavation process of internal sediment. It is a figure which shows typically the 5th process which is a mud collection process. It is the figure which showed typically the 6th process which is a collection process of a mud collection fan part. It is a figure which shows typically the 7th process of covering, ie capping, the sediment mud dropped in the excavation hole with earth and sand. It is a figure which shows typically the 8th process which collect | recovers a casing pipe. It is a top view which shows the state of the water bottom after performing 1st-9 processes repeatedly. It is sectional drawing which shows the state of the water bottom after repeating 1st-9 processes. It is a figure which shows typically the 10th process which backfills earth and sand on the ground surface after sedimentary mud removal after repeating a 1st-9th process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sediment mud collection device 2 Cargo 3 Crane 4 Casing pipe 4A Lower casing pipe 4A1 Inner pipe part 4A2 Slit 4A3 Protrusion 4B Upper casing pipe 4B1 Outer pipe part 4B2 Slit 4B3 Notch 4F Cutter 5 Worktable 6 Casing rotary excavator 7 Tip Cap 7A Tip Cap 7A1 Disc 7A2 Cone 7A3 Mud Scraping Projection 7B1 Cylinder Fixing Frame 7B2 Cylinder 7B3 Fixing Leg 7B4 Rotary Joint 7B5 Supply Pipe 7B6 Supply Pipe 7C1 Guide Roller 7D2 Guide Wire Frame 7D Joint 7D4 Suspension wire 8 Hammer grab 9 Mud collection fan part 9A Upper board frame 9A1 Suspension wire 9A2 Suspension wire hook 9A3 (Upper Disc-shaped frame) Through hole 9A4 (Upper disc-shaped frame) Upper surface 9A5 (Upper disc-shaped frame) Lower surface R Link 9A6 Upper wedge 9A7 Clamp cylinder 9B Intermediate disc-shaped frame 9B3 (Intermediate disc-shaped frame) Through-hole 9B4 (Intermediate disc-shaped frame) ) Upper surface 9B5 (Intermediate disk frame) Lower surface 9B7 Stroke jack 9C Lower disk frame 9C3 (Lower disk frame) Through hole 9C4 (Lower disk frame) Upper surface 9C5 (Lower disk frame) Lower surface 9C6 Ring gear 9C7 Bearing 9C8 Pinion 9C9 Hydraulic Rotating Motor 9D Recovery Fan 9D1 Recovery Fan Case 9D12 Top Plate 9D13 Side Wall 9D2 Blade 9D21 Blade Plate 9D3 (Recovery Fan) Through Hole 10 Tremy Pipe 11 Spad 12 Excavation Sediment Temporary Carrier 12
DESCRIPTION OF SYMBOLS 13 Excavation machine 20 Ground 20a Ground surface 20b Coating layer 20b '(Coating layer) Coating material 21 Drilling hole 22 Bottom sediment mud 22a Bottom sediment mud surface 22b Bottom sediment mud in excavation hole 23 Backfill material 30 Water surface

Claims (12)

In the sediment mud recovery device that collects sediment mud accumulated on the ground surface of the water bottom,
A trolley that forms a fixed scaffold on the water;
A casing pipe that can be built from the carriage to a predetermined penetration depth in the ground;
A casing rotary excavator that is installed on the carriage and supports the casing pipe and can be driven to rotate around the axis and move up and down;
A mud recovery fan portion mounted to be movable up and down with respect to the casing pipe;
The casing pipe is provided with a shutter portion at an intermediate portion in the axial direction, and the shutter portion has a closed state in which the internal space and the external space of the casing pipe are blocked and an open state in communication with the casing pipe. Can be switched by rotational drive of
In the state where the mud recovery fan part is provided at the lower end to rotate the bottom mud in the circular area on the ground surface and scrape it toward the center, and the recovery fan is positioned in the vicinity of the shutter part. Fixing means capable of fixing the mud recovery fan part to the casing pipe, rotation driving means of the recovery fan, and raising and lowering the recovery fan with the mud recovery fan part fixed to the casing pipe And a bottom sediment mud recovery apparatus. The shutter part is formed in a double pipe structure part in which an inner pipe part at an upper end of a lower casing pipe obtained by vertically separating the casing pipe and an outer pipe part at a lower end of the upper casing pipe are rotatably fitted. A plurality of slits of the same size are opened at equal intervals in the circumferential direction at corresponding positions of both the inner pipe part and the outer pipe part, and the inner part is driven by rotation around the axis by the casing rotary excavator. It is possible to switch between a closed state in which the tube portion and the outer tube portion are relatively rotated around the axis, and the corresponding slits are displaced, and an open state in which the corresponding slits are in the same position. The sediment mud recovery apparatus according to claim 1. The recovery fan has a plurality of top plate portions provided with through holes for penetrating the casing pipe, side wall portions extending downward from the periphery of the top plate portion, and a plurality of upper sides connected and fixed to the lower surface of the top plate portion. A blade plate,
The inner side of each of the blade plates is located at the periphery of the through hole, and the outer side is connected and fixed to the side wall, and the blade plate has a planar shape or the direction of rotation of the recovery fan. The bottom mud recovery apparatus according to claim 1, wherein the side surface has a concave shape as curved as possible. The bottom sediment mud recovery apparatus according to claim 3, wherein an inclination gradually descending from a peripheral edge of the through hole of the top plate portion toward the peripheral edge of the top plate portion is provided. The mud recovery fan part is provided above the recovery fan, and includes a lower disk-shaped frame provided with a through hole of the casing pipe,
The recovery fan rotation drive means comprises:
A ring gear rotatably mounted around the outer periphery of the casing pipe in the through hole of the lower disc-shaped frame;
A vertical cylinder that extends upward from the periphery of a through hole provided in the top plate portion of the recovery fan and is connected to the ring gear;
The bottom sediment mud collection apparatus according to claim 3, further comprising a hydraulic rotary motor attached to the lower disc-shaped frame and configured to rotationally drive the ring gear. The mud recovery fan part is provided above the lower disk-shaped frame and includes an intermediate disk-shaped frame provided with a through hole of the casing pipe;
Lifting means for raising and lowering the recovery fan in a state where the mud recovery fan part is fixed to the casing pipe,
The bottom sediment mud collection apparatus according to claim 5, further comprising an extendable stroke jack having both ends connected to an upper surface of the lower disc-shaped frame and a lower surface of the intermediate disc-shaped frame. The mud recovery fan part includes an upper disk-shaped frame provided above the intermediate disk-shaped frame and provided with a through hole of the casing pipe;
Fixing means for the mud recovery fan part,
An upper wedge that hangs down via a link from a position near the through hole of the upper plate-shaped frame, and a lower wedge attached to a position corresponding to the upper wedge at a position near the through-hole of the intermediate plate-shaped frame;
A telescopic clamp cylinder having both ends connected to the upper surface of the intermediate disk-shaped frame and the lower surface of the upper disk-shaped frame;
The bottom mud recovery apparatus according to claim 6, wherein the lower wedge presses the upper wedge against the casing ring by contraction of the clamp cylinder. 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 shutter portion at an intermediate portion in the axial direction, wherein the shutter portion is in a closed state in which the internal space and the external space of the casing pipe are blocked and communicated with an open state by rotation around the axis of the casing pipe. The casing pipe that is switchable, and a mud recovery fan unit that includes a recovery fan that is attached to the casing pipe so as to be movable up and down and that squeezes to the center while rotating sediment mud in a circular area on the ground surface. In the bottom sediment mud recovery method of recovering bottom sediment mud accumulated on the ground surface of the water bottom using a bottom sediment mud recovery device having
A first step of installing a tip cap portion for preventing soil intrusion at the lower end of the casing pipe with the shutter portion closed, and erected the casing pipe vertically to the bottom mud surface;
A second step of building the casing pipe from the bottom mud surface to the ground surface;
A third step of removing and collecting the tip cap portion from the lower end of the casing pipe;
A fourth step of building up to a predetermined penetration depth in the ground while rotating the casing pipe and excavating and taking out the earth and sand inside the casing pipe;
A fifth step of scraping the sediment mud by dropping it from the bottom sediment mud surface to the ground surface while rotating the recovery fan after the shutter portion is opened;
A sixth step of raising and collecting the mud soil recovery fan; and
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 portion is closed; and
An eighth step of pulling up and collecting the casing pipe;   After performing the first to eighth steps in one bottom sediment removal target region, the method further includes a ninth step of moving in the horizontal direction, and repeating the first to eighth steps after moving. The bottom sediment mud collection method according to claim 10. The sediment sediment recovery method according to claim 10 or 11, 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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