JP2002173929A - Driving method of vertical drain and execution structure therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method and an execution structure enabling a vertical drain to be driven in the improving object ground even if soil bearing power of the whole area of the weak ground is not improved. SOLUTION: A plurality or work roads 4a to 4d are almost parallelly created at a prescribed internal in an improving object area 2, stands 12 supported by crawlers 11 for traveling and moving on a pair of work roads are extended between the work roads, a drain driver 13 is moved on the stands, a drain material 17 is driven at a prescribed interval in the improving object ground between the work roads, and after driving the vertical drain 7, the crawlers are mode to travel on the work roads to move the stands to a drain material undriven place,and the vertical drain is driven in the improving object area between the work roads by repeating a driving process of the drain material from above these stands and a traveling process of the stands on the work roads.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical drain in an area to be improved in order to improve a hard ground by discharging water contained in a very soft ground which cannot be easily accessed by workers and construction machines. And a construction structure for implementing the method.

[0002]

2. Description of the Related Art In the case of placing a vertical drain on an extremely soft ground such as a landfill just after dredging, the surface treatment of the ground by some method so that a draining machine can be used. Need to be done. In general, laid reticulated sheet called a so-called "civil stable sheet" on the entire improvement target ground, laying a sand mat on the net-like sheets, ensuring at least 50 kN / m ² or more bearing capacity I can do it. In addition to this, cement or cement-based solidification material is stirred and mixed to a depth of 1 to 2 m of the surface soil to form a solidified plate on the entire area of the ground to be improved.

[0003]

However, in the above-mentioned conventional surface treatment method, since a net-like sheet, a sand mat or a solidifying board must be laid on the entire area of the ground to be improved, a large construction cost is required. There was a disadvantage that the construction period was long. It is also difficult to procure sand mat materials from the viewpoint of depletion of sand and protection of the natural environment.

The present invention focuses on the above-mentioned problems of the prior art,
The challenge was to cast a vertical drain on the ground to be improved without improving the bearing capacity of the whole area of the soft ground where workers could not easily enter. It is an object of the present invention to provide a construction method and a construction structure which makes possible.

[0005]

In order to solve the above-mentioned problems, the present invention relates to a method of discharging a water contained in a soft ground and installing a vertical drain to improve the ground. In the area, a plurality of passages are arranged side by side at predetermined intervals and constructed, a platform supported by traveling means traveling on the pair of passages is bridged between the passages, and a drain driving machine is moved on the platform to After the drain material is cast at predetermined intervals in the ground to be improved between the passages, the process of driving the drain material from the gantry and the running process of the gantry on the passage are repeated to thereby reduce the distance between the passages. A method for creating a vertical drain in the area to be improved is provided. The method of the present invention also includes a case where a drain material is cast on soft ground for river improvement or the like.In such a case, a plurality of passages are parallel to both sides along the flow of the river. It is provided in a curved shape.

In the present invention, the passage can be constituted by a work road or a pier provided in the area to be improved.

[0007] In the present invention, prior to the step of placing the drain material, at least the object to be improved between the passages to prevent the vertical drain head and the worker from being buried in the soft ground on the ground to be improved between the passages. A step of laying a sheet material or a net material on the ground may be performed.

According to the present invention, there is provided a construction structure for placing a vertical drain for discharging water contained in soft ground, wherein a plurality of passages are constructed at predetermined intervals in an area to be improved, and at least the passages between the passages are provided. In the area to be improved, a mesh material, a sheet material or a mesh sheet material capable of preventing the vertical drain head from being buried in the ground and preventing the worker from being buried in the ground to be improved is laid, and a pair of the passages is provided. A pier is movably mounted on the gantry, and a drain driving machine for driving a drain material at predetermined intervals in the ground to be improved between the pair of passages is provided movably on the gantry. A featured construction structure is provided.

By laying a sheet material or a net-like material on the ground to be improved between the passages, it is possible to prevent the vertical drain head from being buried, prevent the worker from being buried in the soft ground, and provide a loading embankment. Has the advantage of securing the ground strength and promoting drainage.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, the drain material may be any material that can guide moisture contained in the ground. For example, a board-based drain material, a flexible pipe-based drain material, or a sand drain may be used. However, the board-based drain material or the flexible pipe-based drain material is optimal because it is relatively easy to handle and cast and is economical.

Here, the work road may be formed by stirring and mixing cement or cement-based solidifying material into the surface soil in the area for ground improvement, and may be a vertical multi-axis stirring auger or a chain saw type rotor. From the tip of the stirring and mixing device, it can be formed by stirring and mixing while ejecting cement powder, cement milk, cement-based solidifying agent, quick lime, or an agent which solidifies in quicklime or earth and sand into the surface soil of the ground improvement target area. However, among them, cement-based solidified materials are most suitable because of their excellent economic efficiency.

[0012] In the work road creation step, a first work road is first created, and the road creation device is moved on the first work road to a substantially parallel position separated by a predetermined distance. It is also possible to create a second work road, and thereafter successively create work roads at substantially parallel positions separated by a predetermined length while moving the road creation device on the previously created work road in the same manner. is there.

On the other hand, the pier is a temporary structure in which a girder is passed over a leg that is cast on soft ground so that the upper end protrudes above the ground, and a pedestal for placing a drain, a horizontal drainage material, and an airtight sheet. It supports a gantry for laying, and a gantry for transporting materials for legs and girders.

There are two types of legs for the pier: a pile type and a sheet pile type, and a pile type is preferable in terms of economy. In particular, if a steel material such as an H-shaped steel is used as the pile, the pile is grounded. Drilling and pulling out are easy, and the workability of the pile head is also excellent. In the method of constructing a pier by the pile method, a girder is bridged over the head of the pile previously set and a track is provided on this girder. A gantry is placed on the track of a pair of piers located substantially in parallel, a pier erection device having a vibratory hammer, etc. is mounted on the pier, and the pier is sequentially constructed by driving a pile in front and erection of a girder. To construct.

On the other hand, in the sheet pile method, when it is necessary to ensure the vertical supporting force and the horizontal supporting force of the legs, or to minimize deformation such as land subsidence due to ground improvement. It is preferably used in such a case, and is used for relatively small and medium-sized ground improvement. As one of the construction methods of the pier by the sheet pile method, there is a method using a conventional press-fitting sheet pile driving machine that can move along the head of the sheet pile. This press-fitting sheet pile driving machine is installed, and adjacent sheet piles are sequentially press-fitted while moving. Another construction method using the sheet pile method is to bridge a girder over the head of the previously piled sheet pile, provide a track on this girder, place the mount on the track of a pair of piers located almost in parallel, It is performed by a pier erection device having a vibro hammer or the like from above.

The pedestal has about 10 points having a fulcrum on a pier.
A steel beam with a length of about 20 m, with a main girder made of an H-beam or I-beam, a combination of a plurality of H-beams or I-beams, or a truss-like assembly of steel materials Alternatively, a temporary bridge or the like can be used. The gantry has running means such as wheels and endless tracks at a fulcrum, and a construction device such as a drain driving machine is provided on the gantry. In addition, an electric motor, an engine, a winch, or the like can be used as the traveling means of the gantry. Further, when the construction of one lane is completed, the gantry is moved to an adjacent lane using a large crane or a separate track, and performs the construction of the adjacent lane.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. 1 to 6 relate to a construction structure for providing a work road as a passage, a construction method or an apparatus used for the construction method, while FIGS.
FIG. 11 relates to a construction structure for providing a pier as a passage, a construction method or an apparatus used for the construction method.
An embodiment will be described with reference to FIG. FIG. 1A is a plan view schematically showing one step of a vertical draining method.
FIG. 1B is a cross-sectional view taken along the line Ib-Ib in FIG. FIG. 2 is a plan view showing one step of a vertical drain driving method using a solidifying plate forming apparatus 20 different from that in FIG. 1 and 2, a construction structure 1 for driving a vertical drain includes a plurality of work roads 4 a to 4 d formed substantially in parallel at predetermined intervals in a region to be improved, and a traveling movement on a pair of work roads. The gantry 12 that was laid as possible
And a drain driving machine 13 movably provided on the gantry 12 for driving the drain material at predetermined intervals in the ground to be improved between the pair of work roads, as a main part,
Further, a heavy equipment moving road 3 is provided inside or outside the improvement target area so as to connect between the working roads 4a to 4d for moving construction machines and workers, etc., on the previously constructed work road. Are provided with solidifying plate forming devices 20, 30, and 40 as devices for forming the work roads 4a to 4d.

Here, in FIG. 2 to FIG.
2 and the drain driving machine 13 are provided as components of the construction device 10. In addition, the construction device 10 includes a crawler 11 disposed on a pair of work roads as a fulcrum for supporting the gantry 12 from below. , 11, a pair of rails 14, 14 laid on a gantry 12, on which a drain driving machine 13 travels, and a predetermined length of distance from the gantry 12, extending in parallel to the ground surface. A scaffolding member 16 connected to the gantry 12 by a connecting member 15 and a power supply facility 18 provided on the gantry 12.

The drain driving machine 13 will be described in more detail with reference to FIGS. Drain casting machine 1
In 3, a wheel 13h driven on a rail 14 by a motor (not shown) or the like is provided on a lower surface of a base plate 13g, and a boom 13e is provided on the base plate 13g.
Is rotatably erected, and a tower 13b is pivotally attached to the boom 13e and a distal end of a telescopic cylinder 13d arranged in parallel with the boom 13e. The tower 13b is erected substantially vertically, and a casing 13a is provided in the tower 13b. Is extended, and a casing 13a is provided with a driving device 13c provided at a lower end of the tower 13b.
It is configured to move up and down. The drum 1 on which the drain material 17 is wound is placed on the base plate 13g.
A drain material 17 is provided from the drum 13f to the upper end of the casing 13a and supplied to the lower end of the casing 13a.

In the drain driving machine 13, the wheels 13h travel on the rails 14 on the gantry 12 to move laterally between the work roads in the direction of arrow S in FIG. At the same time, a plurality of vertical drains 7 extending substantially vertically are installed at predetermined intervals in the ultra-soft ground by being installed on the ground 2 to be improved between the gantry 12 and the scaffold 16. Therefore, the construction device 10
In this example, the cradle 12 is supported by the crawlers 11 and 11 moving on the work road without being in contact with the ultra-soft ground, and the drain casting machine 13 lays the drain material on the gantry 12 while moving laterally. Therefore, if the surface soil of only the work road portion in the area to be improved is improved, the vertical drain can be cast, and the ground improvement over the entire ultra-soft ground as in the past has become unnecessary.

Next, FIGS. 5A and 5B are a plan view and a front view of a solidifying plate forming apparatus 20 for forming a working road. 5 (a) and 5 (b), the solidified plate forming device 20
Are crawlers 21 and 2 arranged on a pair of work roads.
1 and an axle 21 connecting these crawlers 21 and 21
a, a mount 25 mounted on the axle 21a, and the mount 2
5, a pair of rails 24, 24, a working scaffold 22 having wheels 23 e running on the rails 24 provided on a lower surface, and a work scaffold 22 for contacting and supporting the lower surface of the work scaffold 22. , A plurality of rollers 26 fixed on a gantry 25
a and a plurality of rollers 26b erected on the axle 21a
An anchor member 29 for temporarily fixing the work scaffold 22 on the gantry 25 to prevent the work scaffold 22 from being overturned when the work scaffold 22 is laterally protruded; a ground solidifying device 23 mounted on the work scaffold 22; Power supply equipment 27 mounted on the work scaffold 22 for supplying electric power and solidification material to the solidification device 23, respectively.
And a solidified material bag 28.

Here, the ground solidifying device 23 is provided with the work scaffold 2.
2, a boom 23a pivotally mounted on the top, an arm 23c pivotally mounted on the tip of the boom 23a, a stirring and mixing device 23d pivotally mounted on the tip of the arm 23c, and a telescopic cylinder for rotating the boom 23a and the arm 23c. In the stirring and mixing device 23d, the solidified material such as cement or cement-based solidified material supplied from the solidified material bag 28 is jetted into the surface soil from the front end of the device by air conveyance or the like, and solidified with the surface soil. By solidifying and mixing the materials, a solidifying plate is formed at a predetermined position in the area to be improved.

It should be noted that, in addition to the solidifying plate forming apparatus 20, FIG.
Alternatively, the solidifying plate forming apparatuses 30 and 40 shown in FIG. 6 can be used. The solidifying plate forming device 30 is a crane-type device, and includes a base machine having a crawler running on a work road, a boom raised and lowered by the base machine, and a boom suspended from a tip of the boom by a wire rope or the like. As shown in FIG. 1, a base machine is placed on a previously constructed work road, and a boom is extended from the base machine to a surface layer in an area to be improved using a stirring and mixing device. By forming
The next work road 4d is constructed. In addition, the solidifying plate forming device 40, while solidifying the surface soil in front of the device,
An apparatus of a type for running on the solidified board to form a solidified board, comprising: a base machine 42 pivotally mounted on a crawler 41; 43a, an arm 43c pivotally attached to the tip of the boom 43a, a stirring and mixing device 43d pivotally attached to the tip of the arm 43c, a boom 43a and an arm 4
3c and a telescopic cylinder 43b for rotating the stirring and mixing device 43d. In addition, in the case of the solidifying plate forming apparatus 40, since it is a muddy work vehicle having a floating body,
It is also possible to work directly in the soft unimproved ground and, if necessary, tow it with a wire fixed at one end to the road 3.

Next, a vertical drain driving method according to the present invention will be described with reference to FIGS. In the vertical draining method, first, a road 3 for moving heavy equipment is secured or created inside or outside the improvement target area. The heavy equipment moving road 3 may be provided with a rail 5a as shown.

Next, the first work road 4a is formed on the ground 2 to be improved by the solidification plate forming device 30 or the solidified plate formation device 40 disposed outside the area to be improved. The road 4b is formed substantially parallel to the first work road 4a at a predetermined distance from the first work road 4a. Here, the working roads 4a and 4b are, for example, 100 to 250 kg / m ³ of cement or cement-solidifying material mixed and stirred into the surface soil, a width of 2 to 5 m, a center interval of 10 to 20 m, and a depth of 1 to 1 m.
A solidified board having a strength of about 2 m and about 1 to 10 kg / cm ² is formed, and a sand mat or embankment is provided on the solidified board as necessary. After the first work road 4a is created, the second work road 4b may be created while moving the solidifying plate forming device 30 on the previously created road 4a. Work road 4b
After the formation of the work roads 4c and 4d, the solidification plate forming device 20 shown in FIG. 2 can be run on the first and second work roads 4a and 4b.

After the first and second work roads 4a and 4b are created, the vertical drain head and the worker are prevented from burying in the soft ground on the ground between the work roads 4a and 4b. Sheet material or mesh material (not shown) is laid, and then the crawlers 11, 11 of the construction device 10 are moved to predetermined positions on the work roads 4a, 4b and stopped.
By driving the drain material 17 into the ultra-soft ground while moving the drain driving machine 13 laterally along the rail 14, a plurality of vertical drains 7 buried almost vertically at predetermined intervals are driven. The laying of the sheet material or the net-like material may be performed by hand before draining, but the material may be loaded on the front of the gantry at the time of draining and may be unwound every time the gantry moves.

Subsequently, the work road 4 of the construction device 10
a, a moving / stopping process on the 4b and the drain driving machine 13
When the vertical drain 7 is driven into the area to be improved between the work roads 4a and 4b by repeating the lateral moving process on the gantry 12 and the driving process of the drain material 17, the construction device 10
Is moved to the heavy equipment moving road 3 and is put on the carriage 5b to move to the work roads 4b and 4c.
Similarly, in the ground 2 to be improved between b and 4c, the vertical drain 7
Are sequentially cast. In addition, the construction apparatus 10 is, in addition to the above,
The work roads 4a and 4b may be moved to the work roads 4b and 4c using a crane or the like.

Next, with reference to FIGS. 7 to 11, a construction structure and a construction method in which a pier is provided as a passage will be described. FIG.
(A) and (b) are a plan view and a side view schematically showing one step of a vertical drain driving method using a pier 84. In the improvement target area 2, the work roads 4a to 4d in FIG. The piers 84 are constructed substantially parallel to each other at predetermined intervals, and a gantry 73 is movably bridged over the pair of piers 4, and a track for running the gantry 73 is provided on the pier 4. . Next, FIG. 8 and FIG. 9 are a side view and a front view of the construction device 70, respectively.
3, a drain driving machine 71, a drum 74 a on which a mesh sheet material 74 is wound, and a work scaffold 75. Here, the gantry 73 has wheels 76 on its lower surface for traveling on a track on a pier 84, and rails (not shown) for traveling and laterally moving the drain driving machine 71 on its upper surface. It extends in the direction. In addition, the drain driving machine 71 is driven by a motor (not shown) or the like to move wheels 71 d traveling on rails of the gantry 73.
1c, a tower 71a is erected substantially vertically on the base plate 71c to support a casing 71b so that the casing 71b can move up and down. It is configured to be driven. A drum 72a on which a drain material 72 is wound is provided on the base plate 71c. The drain material 72 is unwound from the drum 72a and supplied from the upper end to the lower end of the casing 71b.

In this construction apparatus 70, the gantry 73 is
While running in the direction of arrow M, the net-like sheet material 74 is unwound from the drum 74a and laid on the ground surface, and the drain driving machine 71 runs on the gantry 73 so that the piers 84, 8
9 in the direction of arrow S in FIG. 9, and sequentially draining the drain material 72 together with the casing 71 b substantially vertically into the ground 2 to be improved, so that the plurality of vertical drains 7 penetrating the net-like sheet material 74 are formed. It is formed in soft ground. Therefore, in the construction apparatus 70, the gantry 73 traveling and moving on the pier 84 is supported upward without touching the ultra-soft ground, and the drain casting machine 71 strikes the drain material 72 while moving laterally on the gantry 73. Therefore, if the pier 84 is constructed in the area 2 to be improved, it is possible to perform the construction of a vertical drain, and it becomes unnecessary to improve the surface layer over the entire ultra-soft ground as in the past, and furthermore, the ground to be improved However, even if the ground is several tens of centimeters deep, the ground improvement can be easily performed.

Next, the jetty 84 and the jetty crane 50 will be described with reference to FIG. The pier 84 includes a pile 84b in which H-shaped steel is cast in a row on the ground 2 to be improved,
A girder 84a formed by bridging a single H-section steel over the pile head is shown in FIG. 7, but in addition, for example, a pile and a girder are arranged in a plurality of rows. It is also possible to use a girder with a floor slab over a girder. Although not shown, a track for guiding the wheels of the gantry is provided on the upper surface of the spar 84a.

An apparatus for erection of the pier 84 is as follows.
As shown in FIG. 10, piers 55, 57 laid over a pair of piers 84, 84 and a pier construction crane 50 installed on the pedestal 55, and the pedestals 55, 57 are provided with piers on the lower surface thereof. It has wheels 55a and 57a for traveling on 84, and a material 84 'such as H-shaped steel as a pile material or a girder material is loaded on the gantry 57, and the pier construction crane 50 is run backward. Here, the pier construction crane 50 is shown in FIG.
As shown in FIG. 0, a crawler 53 for traversing the cradle 55, a base machine 52 rotatably provided on the crawler 53, a boom 51a that is raised and lowered from the base machine 52, and a boom 51a Hammer 5 suspended at the tip of a wire via a wire rope 51b
1c, the H-section steel as the pile 84b is gripped by the vibratory hammer 51c and cast into the ground to be improved, and the H-section steel as the spar 84a is bridged over the pile 84b.

Next, a pier 89 and a pier erection apparatus different from those in FIG. 10 will be described with reference to FIG. In FIG. 11, the pier 89 is composed of a sheet pile 89b cast in a line on the ground 2 to be improved, and a girder 89a formed by bridging one H-shaped steel on the head. Here, similarly to the case of the pier 84, it is also possible to arrange a sheet pile and a girder in a plurality of rows and to put a floor slab on the girder as the pier. Although not shown, the upper surface of the girder 89a is not shown. Is provided with a track for guiding the wheels of the gantry.

As a device for erection of the pier 89 using the sheet pile 89b, a conventional sheet pile crane 6 is used.
0 and a sheet pile press 62. Both devices are configured to be able to travel along the head of a sheet pile continuously provided in the ground and not to fall from the sheet pile head. Here, the sheet pile building crane 60 is a base machine 6 that runs along the head of the sheet pile.
3, a boom 61a attached to the base machine 63 so as to be able to raise and lower, a telescopic cylinder 61b for raising and lowering the boom 61a, and a hook 61d suspended from the tip of the boom 61a by a wire rope 61c. On the other hand, the gantry 57 has wheels 57a on the lower surface, and is bridged between a pair of piers 89, 89 constructed in advance, and is made of a material 8 such as an H-shaped steel sheet pile or a girder.
9 ′ is loaded, and the sheet pile cranes 60 and the sheet pile press-in machine 6
In this case, both devices are driven to follow. When the pier 89 is erected, the sheet pile 89b loaded on the stand 57 is lifted by the sheet pile crane 60 and the sheet pile press-in machine 6
2, the sheet pile 89b is driven into the ground to be improved, and a H as a beam 89a is attached to the head of the continuous sheet pile 89b.
Hang the shaped steel and fix it.

Next, a vertical drain driving method using the piers 84 and 89 will be described. When the piers 84 and 89 are used, the vertical drain driving method is performed by the same process as the method using the working road shown in FIG. That is, as shown in FIG. 7, first, a plurality of piers 84 are constructed in the target area for improvement at a predetermined interval, for example, approximately parallel to about 14 m. Then, the construction device 70 is connected to the adjacent piers 84, 84.
8, the gantry 73 is bridged between the piers 84, 84, and the net-like sheet material 74 unwound from the drum 74 a is moved on the ground while the construction device 70 is traveling in the direction of the arrow M in FIG. 8. And the traveling of the construction device 70 is stopped at a predetermined position. When the running of the construction device 70 is stopped, the vertical drain 7 is driven into the ground 2 to be improved at predetermined intervals while the drain driving machine 71 is moved laterally in the direction of the arrow S in FIG. By repeating such steps, the mesh sheet material 74 and the vertical drain 7 are set on the ground 2 to be improved.

[0035]

According to the present invention, a plurality of passages are formed substantially in parallel at a predetermined interval in the area to be improved, and a gantry supported by a traveling means that travels separately on a pair of passages is bridged between the passages. Drain materials are laid at predetermined intervals in the ground to be improved with a drain laying machine that moves laterally on the gantry, so even if the ground is extremely soft where workers and construction machines can not easily enter. As described above, it is not necessary to provide a civil engineering stabilizing sheet and a sand mat over the entire area of the ground to be improved. Therefore, it is possible to reduce materials and construction costs of the sand mat and the like. In addition, since the installation work of the vertical drain can be performed systematically, the construction period can be shortened. Further, since the supporting force is reliably secured in the passage where the heavy equipment passes, it is easy to prevent deformation of the ground and ensure safety.

In the present invention, when the pier is used as a passage, a movable pedestal is mounted on the pier constructed in the area to be improved, and construction is performed from the pedestal. This is particularly advantageous in the following two points as compared with a case where a work road is provided and a gantry is bridged over the work road. If the improvement depth is about 12 m or less, the construction cost of the pier is lower than that of the work road. Improvement of the ground under several tens of centimeters of water is also easy.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are a plan view and a cross-sectional view showing one step of a vertical drain driving method according to the present invention.

FIG. 2 is a plan view showing one step of a vertical drain driving method according to the present invention.

FIG. 3 is a plan view of a construction apparatus used for a vertical drain driving method.

FIG. 4 is a side view of the construction apparatus of FIG. 3;

FIGS. 5 (a) and 5 (b) are a plan view and a side view, respectively, of a solidifying plate forming apparatus.

FIG. 6 is a side view of a solidifying plate forming apparatus different from FIG.

FIG. 7 is a plan view and a cross-sectional view showing one step of a vertical draining method different from FIG.

8 is a side view of the construction apparatus in FIG.

FIG. 9 is a front view of the construction apparatus of FIG. 8;

FIG. 10 is a side view of the pier erection apparatus in FIG. 7;

FIG. 11 is a side view of the pier erection apparatus different from FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Construction structure for vertical drain driving 2 Area to be improved 4a-4d Working road (passage) 7 Vertical drain 11 Crawler (running means) 12 Mount 13 Drain driving machine 17 Drain material 71 Drain driving machine 72 Drain material 73 gantry 74 net-like sheet material 76 wheels (running means) 84, 89 pier (passage)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Isamu Mitsubata 2-58 Kitaaoyama, Minato-ku, Tokyo Inside the company group (72) Inventor Kaio Kumamoto 2-5-2 Kitaaoyama, Minato-ku, Tokyo No. Aoyama Kiko Co., Ltd. (72) Inventor Kazuo Todoro 2-5-8 Kita-Aoyama, Minato-ku, Tokyo Aoyama Kiko Co., Ltd. F-term (reference) 2D043 CA04 DA09 DC00 DC19

Claims (5)

[Claims] 1. A method of discharging a water contained in a soft ground and placing a vertical drain in order to improve the ground, wherein a plurality of passages are arranged at predetermined intervals in an improvement target area, and a pair of the drains are constructed. A gantry supported by a traveling means that travels on the passage is bridged between the passages, and a drain driving machine is moved on the gantry to drive a drain material into the ground to be improved between the passages at a predetermined interval. After that, a method of placing a vertical drain in the area to be improved between the passages by repeating the step of placing the drain material from the gantry and the step of traveling on the passage of the gantry. 2. The method for placing a vertical drain according to claim 1, wherein a work road or a pier is provided in the area to be improved as the passage. 3. Prior to the step of placing the drain material,
Laminating a mesh material, a sheet material, or a mesh sheet material capable of preventing the vertical drain head from being buried in the ground to be improved and preventing the worker from being buried in the ground to be improved at least in the area to be improved between the passages. The method for placing a vertical drain according to claim 1 or 2, wherein: 4. A construction structure for placing a vertical drain for discharging water contained in soft ground, comprising a plurality of passages arranged at predetermined intervals in a target area for improvement, and running on a pair of said passages. A drain laying machine for movably bridging the gantry and for laying drain materials at predetermined intervals in the ground to be improved between the pair of passages is provided movably on the gantry. Construction structure. 5. The construction structure according to claim 4, wherein the passage is a work road or a pier provided in an improvement target area.