JP2001226993A - Ground improvement method used for basement caisson method and ground improvement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground improvement method used for a basement caisson method and a ground improvement device capable of surely reducing a construction period of time for caisson work, at the same time, surely preventing the inclination of the caisson when it is settled and simply making soil improvement of the bottom ground of the basement. SOLUTION: After the caisson consisting of a sill and a wall skeleton is assembled on a plot of the basement, one or more headrace ducts extended in the direction of the vertical shaft at specific intervals in the horizontal direction are arranged on the outside surface of the wall skeleton, and the ground inside of the caisson is excavated to sink the caisson by self-weight. Water is supplied to the outside ground of the sill through the ducts when excavation is carried out, and after the excavation is completed, a liquid soil improving agent is supplied to the outside ground of the sill.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement method and a ground improvement apparatus used in a basement submersion method, and more particularly to a method of submersion work for excavating the ground and submerging a caisson while reliably reducing the construction period. The present invention relates to a ground improvement method and a ground improvement apparatus used in a basement submersion method, which can surely prevent a caisson from inclining and can easily improve the soil quality of the ground at the basement floor.

[0002]

2. Description of the Related Art Conventionally, a basement is constructed by digging a hole larger than the basement, forming a concrete basement in the hole, and then burying the soil around the basement. And when digging a hole, in order to ensure the safety of work in the hole, for example, a steel sheet pile is erected around the hole, and earth retaining work using erection and shoring is performed as necessary . In order to build the basement in the hole, first, the bottom of the hole is leveled, and then the basement is poured after splitting the stonework and laying concrete. An inner formwork and an outer formwork of the wall are assembled on the base concrete, a reinforcing bar is arranged in the formwork, concrete is poured, and curing is performed. After that, the formwork is removed and the holes around the basement are filled with earth and sand. After that, at the same time as the foundation work of the ground house,
Alternatively, the ceiling construction of the basement is performed simultaneously with the floor construction of the ground house to complete the basement.

In recent years, in order to shorten the construction period of a basement, it has been proposed to construct a basement by a latent box method, for example, as described in Japanese Patent Application Laid-Open No. H10-82061. In this known basement submersion method, after forming a lower frame having a flange on the outer periphery on the basement site,
The lower part of the wall frame is formed on this lower frame to form a part of the caisson. Further, the outer panel and the inner panel, which are part of the caisson, are added to the upper part. By lowering the lower part of the slab, and further adding the outer panel and the inner panel to the upper part, for example, adding the outer panel and the inner panel to the fourth stage, arranging the reinforcing bar at the upper part of the caisson, and joining concrete. Complete the entire caisson. After that, the earth and sand at the bottom of the caisson are excavated to sink the entire caisson.

[0004] The flange of the lower frame used in this method is not very large and has a low rigidity in the thickness direction, so it is easily deformed, and the force acting on the ground from the lower end of the flange, that is, the caisson Excavation of the ground using its own weight can hardly be expected. Therefore, in order to prevent deformation of the lower frame during subsidence, it is necessary to excavate the sand at the bottom of the caisson wider than the outline of the lower frame, and the lower frame receives earth pressure from the surrounding ground and the resistance to subsidence decreases. It did not matter at all.

When excavating earth and sand at the bottom of a caisson, the caisson is held at a constant height by placing the caisson on a jack inserted into the excavation hole or a beam spanning the edge of the excavation hole, and the jack is shortened. This has caused the caisson to sink. Therefore, the proposal of utilizing the weight of the caisson for sinking of the caisson cannot be imagined from the known basement submersion method.

[0006] In short, in the above-mentioned known basement submersion method, excavation of the ground and subsidence of the caisson are performed stepwise, and are not performed simultaneously. Therefore, it is natural that the construction period becomes long. It is.

The inventor of the present invention has proposed a horizontal top plate, an outer plate bent downward from one edge of the horizontal top plate, for the purpose of shortening the construction period of a caisson sinking caisson.
A lower frame using a lower frame member having a reinforcing plate (groove side plate) which is diagonally folded up from the lower edge of the outer surface plate to the lower side of the upper surface plate has been proposed (Japanese Patent Application No. 11-161890). book).

[0008] If this lower frame member is used, the outer plate has, for example, the same height as the plate width of the upper plate, and its lower edge is pushed up from below by a reinforcing plate. The lower frame member has a function as a digging blade to excavate the ground vertically, and uses the weight of the caisson to cut the digging hole at the bottom of the caisson. The perimeter can be excavated. Therefore, the excavation hole at the bottom of the caisson should be excavated to be slightly narrower than the outline of the lower frame. Further, if the excavation hole is made deeper, the caisson sinks while excavating the periphery of the excavation hole by its own weight, so that the caisson sinks at the same time as excavation, thereby shortening the construction period of the submersion work.

[0009]

However, in order to reduce the bending of the lower frame member with respect to the weight of the wall frame, the outer plate of the lower frame member is made, for example, as high as the plate width of the upper plate. There is earth pressure from the ground outside the outer panel, which causes frictional resistance against the settlement of the caisson, and the ground below the caisson is too hard, so that the lower frame member is less likely to scrape off the periphery of the excavation hole, and the caisson May not sink under its own weight.

Further, since the frictional resistance and the resistance of the lower frame member to shaving off the peripheral portion of the excavation hole are large, the settlement speed is slowed down, and the construction period of the submerging work may not be sufficiently reduced.

Furthermore, the caisson that has been caught in the middle of the excavation hole may swiftly sink to the bottom of the excavation hole due to some trigger due to resistance to settlement, and at this time, the caisson may be inclined.

The present invention takes into account such circumstances and adjusts the resistance to the settlement of a caisson and the resistance to excavation of the ground below the caisson to improve the soil quality of the ground at the basement of the basement. It is an object of the present invention to provide a ground improvement method and an apparatus for use in a construction method.

[0013]

The ground improvement method used in the basement submersion method according to the present invention (hereinafter referred to as the method of the present invention) comprises a method of assembling a lower frame on a site of a basement and mounting a wall on the lower frame. After forming part or all of the caisson by completing part or all of the skeleton, the ground improvement method used in the basement submersion method of excavating the ground inside this caisson and sinking the caisson by its own weight Is assumed. In this case, the site for forming the basement may be prepared in advance before the basement is formed.

[0014] In order to achieve the above object, the method of the present invention comprises one or more water conveyance ducts extending in the longitudinal direction at predetermined intervals in the horizontal direction on the outer surface of the wall frame prior to excavation of the ground, In particular, a plurality of water guide ducts are provided, and a soil conditioner is supplied to the ground outside and below the lower frame via the one or more water guide ducts, particularly, the plurality of water guide ducts. Is adopted.

According to the method of the present invention, a liquid soil obtained by dissolving water for softening the soil, a hardening agent, an antibacterial agent, a bactericide, a fungicide, a termiticide, a rodenticide, etc., from the soil improver supply source. By supplying a soil conditioner to the ground outside and below the lower frame through a water guide duct, etc., through a water supply duct, the ground outside and below the lower frame is softened or hardened, and bacterial access is reduced. And prevent the inhabitation or reproduction of bacteria, molds, termites, rats and the like.

Hereinafter, the method of the present invention will be described in more detail. First, the subterranean submersion method premised by the method of the present invention will be described in detail.

In the basement submersion method presupposed by the method of the present invention, first, a lower frame is assembled on the site of the basement. This site does not need to be leveled in advance, but may be leveled in particular. This leveling may be a land where the site is simply leveled, but taking into account the foundation work of the ground building to be performed later, a constant depth over a wider area than the contour of the basement in plan view, for example, the ground level It is preferable that the site has a pit dug down to the foundation depth of the building.

The lower frame is required to have a shape suitable for sinking the caisson by its own weight. For example, a horizontal upper plate, an outer plate bent downward from the outer edge thereof, and It is desirable that a member provided with a reinforcing plate (groove side plate) that is diagonally bent upward from the lower edge of the outer surface plate to below the upper surface plate is connected.

In the basement submersion method, part or all of the wall frame is completed on the lower frame to form part or all of the caisson, and then the ground inside the caisson is excavated. That is, in the basement submersion method to which the method of the present invention is applied, the caisson is formed stepwise, excavating the ground inside the caisson for submerging the partially formed caisson, and forming the caisson. After submerging the part of the caisson, the remaining part of the caisson is formed, and in order to sink the entire caisson, the ground inside the caisson is excavated further deeply, and the entire caisson is settled after the entire caisson And a subterranean submersion method that continuously excavates the ground inside the caisson.

However, in either case,
The basement submersion method presupposed by the method of the present invention is to excavate and sink the caisson by its own weight,
In other words, the method is limited to the basement submersible construction method in which the caisson sinks while excavating the periphery of the excavation hole by its own weight.

Next, prior to the excavation of the ground, the method of the present invention firstly comprises one or a plurality of water guide ducts, particularly a plurality of water guide ducts, extending in the longitudinal direction at predetermined intervals in the horizontal direction on the outer surface of the wall frame. Arranging ducts is an essential feature.

This water guide duct may be disposed on the outer surface of the wall frame prior to excavation of the ground, and may be assembled to the caisson after forming the caisson and before starting excavation of the ground.
Before that, it may be attached to the member constituting the caisson.

For example, as will be described later, before shipment from the factory, an outer panel constituting a part of the wall frame is covered with a longitudinally shaped channel member by, for example, welding so that the open surface thereof is closed by the outer panel. The water guide duct may be supported by the outer panel before the wall frame is assembled on the lower frame by a technique of fixing.

This water guide duct has a function of guiding a liquid such as water, and examples thereof include a pipe having an arbitrary cross-sectional shape, a groove-shaped member and a plate member for closing an open surface thereof. be able to.

Further, the method of the present invention is characterized in that a soil conditioner is supplied to the ground outside and below the lower frame via the one or more water guide ducts, particularly the plurality of water guide ducts.

The timing of supplying the soil conditioner is not particularly limited, but may be any time after excavating the ground inside the caisson, and may be after excavation of the ground.
The soil conditioner is not particularly limited as long as it is a liquid,
For example, an aqueous solution of a curing agent, an antibacterial agent, a bactericide, a termiticide, a rodenticide, or the like can be given as an example, and water alone is also included.

For example, when excavating the ground, when water is supplied to the ground outside and below the lower frame as a soil conditioner, the ground outside and below the lower frame softens, and the ground below the caisson sinks. Friction resistance due to the earth pressure acting from the surroundings and the resistance of the caisson to cutting off the periphery of the drilling hole (drilling resistance) can be reduced, and as the hole is dug deeper, the caisson loses its own weight. As a result, it sinks down while reliably and smoothly excavating the periphery of the excavation hole.

Further, when an antibacterial agent is used as a soil conditioner during or after excavation of the ground, bacteria can be prevented from adhering to and propagating on the lower part of the caisson and the surrounding soil, thereby providing a safe environment. -Sanitation is improved.

Further, when a fungicide is used as a quality improving agent during or after excavation of the ground, bacteria attached to the soil around the caisson can be exterminated, and when a fungicide is used as the soil improving agent. It is possible to prevent fungi from forming or breeding on the lower part of the caisson and its surrounding soil.

Further, during or after excavation of the ground,
Use of a termiticide as a soil conditioner can prevent termites from approaching a building above the caisson or nesting in the building above the ground.

In addition, when a hardening agent is used as a soil conditioner after the excavation is completed, for example, the soil under the caisson that has been softened by using another soil conditioner can be hardened, and the caisson can be deeper than the design value. Can be prevented from sinking.

By the way, in order to supply the soil conditioner to the ground outside and below the lower frame through the water guide duct, it is necessary to lead the soil improver including water to the outside of the lower frame from the lower end of the water guide duct. For this purpose, the lower end of the water guide duct is opened outside the lower frame, or the lower end of the water guide duct is opened at a certain height above the upper surface of the lower frame, Either one may be adopted in which the water guide duct is opened outside the lower frame and at a position separated from the upper surface of the lower frame by a predetermined height.

In these methods, since the extension of the water guide duct outside the lower frame is disadvantageous for preventing damage to the water guide duct and reducing the resistance of the caisson to settlement, It is desirable to open the lower end of the lower frame at a position separated from the upper surface by a certain height on the lower frame.

Next, a ground improvement device (hereinafter, referred to as the device of the present invention) used in the basement submersion method according to the present invention is described.
After forming a caisson by assembling a lower frame on the site of the basement and completing a wall frame on this lower frame, the ground inside the caisson is excavated and used for the basement submersion method of sinking the caisson by its own weight It is assumed that this is a ground improvement device. In this case, the site for forming the basement may be prepared in advance before the basement is formed.

According to the present invention, there is provided a ground improvement apparatus used in such a basement submersible construction method, wherein in order to achieve the above-mentioned object, the vertical axis of the caisson wall frame is vertically spaced at a predetermined interval. The technical means is characterized in that it comprises one or more water guide ducts extending in the direction, in particular a plurality of water guide ducts.

If one or a plurality of water guide ducts, particularly a plurality of water guide ducts, are provided on the outer surface of the wall of the caisson at predetermined intervals in the horizontal direction and extending in the vertical axis direction, particularly, a plurality of water guide ducts are provided. The soil conditioner can be supplied outside and below the lower frame. For example, when excavating the ground, water is supplied as a soil conditioner to the ground outside the lower frame via the one or more water guide ducts, particularly a plurality of water guide ducts, or the water guide duct is provided after the ground excavation is completed. , A liquid soil improver in which a hardener is dissolved can be supplied to the ground outside the lower frame to harden the loose ground by supplying water.

As described above, when excavating the ground, if water is supplied as a soil conditioner to the ground outside and below the lower frame via the one or more water conveyance ducts, particularly the plural water conveyance ducts, the caisson sinks And the resistance of the caisson to excavating the perimeter of the drilling hole by its own weight (drilling resistance) can be reduced. Accordingly, the caisson can be reliably and smoothly settled by its own weight.

Further, when the liquid soil improving agent is supplied to the ground outside the lower frame through the water guide duct after the excavation of the ground is completed, the ground outside and below the lower frame is hardened by the soil improving agent. In addition, the occurrence and reproduction of bacteria, molds, termites, rats and the like can be prevented.

Hereinafter, the device of the present invention will be described in more detail. The basement submersion method premised on the device of the present invention is the same as the basement submersion method premised on the method of the present invention. Detailed description is omitted to avoid duplication of description.

The apparatus of the present invention is actually provided with a soil conditioner supply source for supplying a liquid soil conditioner via these water guide ducts in addition to the water guide duct. Includes a water supply that supplies water.

The water supply source includes a water source such as a river or a lake, a water pump that draws water from the water source and discharges the water, and a pipe that distributes the water discharged by the water pump to a plurality of conduits. For example, a device provided with a pipe for distributing water supplied from a water supply facility to a plurality of water guide ducts is exemplified.

As the soil conditioner supply source, the water supply source, a container for storing the liquid soil conditioner, and the soil conditioner sucked from the container into water flowing through the pipe of the water supply source. A container for storing a liquid soil conditioner, a pump for sucking and discharging the soil conditioner in the container, and one or more liquid soil conditioners discharged by the pump. An example thereof includes a plurality of water guide ducts, in particular, a pipe having a pipe for distribution to the plurality of water guide ducts.

The water guide duct may be any as long as it has a function of guiding a liquid soil conditioner such as water, and examples thereof include a circle, an ellipse, a triangle, an isosceles trapezoid, a square, a rectangle, a rhombus, and the like. Grooves such as pentagons, hexagons, heptagons, octagons, etc. with arbitrary cross-sectional shapes such as pipes, V-shaped grooves, U-shaped grooves, square-shaped grooves, isopod trapezoid-shaped grooves, and T-shaped grooves Examples include a mold member and a plate member closing an open surface thereof.

When the water guide duct is constituted by a pipe,
It is composed of a circular pipe with a screw formed at the lower end, located on the upper surface of the lower frame, outside the wall frame, and screwing the lower end of the water guide duct to separate the water guide duct from the upper surface of the lower frame. If a screw seat is provided to support the vertical axis at a distance of more than the height of the water conveyance duct, the water conveyance duct can be rotated around its axis at any point before the lower frame assembly and before the start of excavation. Can be assembled to the lower frame.

In particular, when assembling the water guide duct to the caisson immediately before starting the excavation, the water guide duct hinders the lower frame construction for assembling the lower frame and the wall frame construction for forming the wall frame on the lower frame. Therefore, the workability of these lower frame work and wall frame work can be improved.

Also, in this case, the lower end of the water guide duct can be located at a certain height from the upper surface of the lower frame on the lower frame, thereby preventing the water guide duct from being damaged during submerging work. This is advantageous because it reduces the resistance of the caisson to sinking during submarine construction.

As described above, the case where the water guide duct is constituted by the outer surface of the wall frame and the groove member on the vertical axis which is in close contact with the outer surface of the wall frame so that the open surface of the groove is closed by this. This includes the case where the channel material is fixed to the outer surface of the wall structure, that is, the outer surface, and the case where the channel material is fixed to the back surface of the outer surface of the wall structure, that is, the inner surface.

In the method and the apparatus of the present invention, the material of the lower frame, the inner and outer panels, the water duct (pipe) and the like are not particularly limited.
Depending on the application, metal, synthetic resin, fume tube, wood, paper or the like can be used.

[0049]

As described above, the method of the present invention comprises, prior to excavation of the ground, one or a plurality of water guide ducts extending in the longitudinal direction at predetermined intervals in the horizontal direction on the outer surface of the wall frame;
In particular, a plurality of water ducts are provided, and when excavating the ground, water is supplied as a soil conditioner to the ground outside the lower frame through these water ducts. And the frictional resistance of the ground outside the lower frame against the sinking of the caisson can be reduced, and the ground below the lower frame can be softened to reduce the resistance of the caisson to the excavation action due to its own weight.

In addition, the method of the present invention comprises, prior to excavation of the ground, one or a plurality of water guide ducts, particularly a plurality of water guide ducts, extending in the longitudinal direction at predetermined horizontal intervals at the outer surface of the wall frame. After the excavation of the ground is completed, the liquid soil improver is supplied to the ground outside the lower frame via the water guide duct, so that the soil improver is applied to the ground outside and below the lower frame after the excavation. The effect of being able to improve soil quality by infiltration is obtained.

Next, the device of the present invention is provided with one or a plurality of water guide ducts, particularly a plurality of water guide ducts, extending on the outer surface of the caisson wall frame at predetermined intervals in the horizontal direction and extending in the vertical axis direction. Therefore, when excavating the ground, water is supplied to the ground outside the lower frame as a soil conditioner through these water guide ducts to soften the ground outside the lower frame, and the ground outside the lower frame against the settlement of the caisson Not only can reduce the frictional resistance of the caisson, but also soften the ground below the lower frame, thereby reducing the resistance of the caisson to the excavating action due to its own weight.

Further, the device of the present invention is provided with a plurality of water guide ducts extending in the longitudinal direction at predetermined intervals in the horizontal direction on the outer surface of the wall frame of the caisson, so that after excavation of the ground is completed, Since the liquid soil improver is supplied to the ground outside the lower frame through the water guide duct, it is possible to improve the soil quality by infiltrating the soil improver into the ground outside and below the lower frame after excavation. A possible function is obtained.

[0053]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention, that is, an embodiment of the method of the present invention and the apparatus of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a perspective view of a caisson used in the present invention, FIG. 2 is a sectional view of a basement site and a caisson used in the present invention assembled thereon, and FIG. FIG. 4 is a plan view schematically showing a lower frame used in the present invention, FIG. 4 is a longitudinal side view of a beam member used in the present invention, and FIG. 5 is a rear view of the beam member used in the present invention;
FIG. 6 is an exploded perspective view of a corner member used in the present invention,
FIG. 7 is a perspective view of a screw seat used in the present invention.

As shown in FIG. 2, the ground improvement method and the ground improvement apparatus used in the basement submersion method according to one embodiment of the present invention are as follows. After the caisson C is formed by completing the wall frame B on the lower frame A, the ground inside the caisson C is excavated, and the ground improvement method used in the basement submersion method of sinking the caisson C by its own weight and This is a ground improvement device.

The site of the basement may be simply flattened, but in this embodiment, in consideration of the relation with the foundation work of the above-ground building, the area of the basement is wider than the outline of the basement, for example, the outline of the basement. The pit P is dug down to the depth of the base lower surface of the ground building over a range extending about 50 cm outward from the ground.

As shown in FIG. 3, the lower frame A is a rectangular frame in a plan view, and is disposed between the corner members 1 arranged at four corners thereof and the corner members 1 paired in the side direction. It comprises a single or a plurality of beam members 2.

As shown in FIG. 4, the beam member 2 includes a main member 21 obtained by bending a single plate material. The main member 21 has a width larger than the thickness of the wall frame B, A horizontal upper surface plate 211 having an inner width or an appropriately divided length, an outer surface plate 212 folded down from one edge of the upper surface plate 21 in the width direction, and an outer surface plate 21
2 has a groove side plate 213 which is bent obliquely upward toward the upper surface plate 211 from the lower end.

The main member 21 is provided on the upper surface plate 211.
The reinforcing rib 214 is folded down from the other edge in the width direction of the upper surface plate 21 and further bent obliquely downward toward the outer surface plate 212, and the other in the width direction of the upper surface plate 21 from the upper edge of the groove side plate 213. And a reinforcing rib 215 that is bent horizontally toward.

As shown in FIG. 5, the beam member 2 is further provided at a plurality of positions (here, three positions) between both ends in the axial direction of the main member 21 and the intermediate portion in order to maintain the cross-sectional shape of the main member 21. Is provided with a reinforcing frame 22 fixed to the support frame.

As shown in FIG. 4, the reinforcing frame 22 is in contact with the groove side plate 213, the outer surface plate 212, the upper surface plate 211, and the reinforcing rib 214 in order, and the inner side surface of the inclined portion of the reinforcing rib 214 is in contact with the groove side plate 213. Of the groove side plate 2
13 has a force plate 221 having a profile vertically descending from above the upper end of the groove side plate 213 to the upper end.

The reinforcing frame 22 includes connecting ribs 222 and 223 which are bent at right angles in one surface direction along the inclined portions of the upper surface plate 211, the outer surface plate 212, the groove side plate 213, and the reinforcing rib 214. 224, 225,
These connecting ribs 222, 223, 224, and 225 correspond to the corresponding upper surface plate 211, outer surface plate 212, and groove side plate 21.
3 and the reinforcing ribs 214 are fixed by, for example, welding. The connecting rib 2 along the inclined portion of the reinforcing rib 214
Numeral 25 extends to above the upper end of the groove side plate 213.

The beam member 2 is further fixed to a seal holding member 23 made of a Z-shaped member fixed on the reinforcing rib 215 of the main member 21, and fixed to an upper end of the seal holding member 23 and the outer surface plate 212. And a groove-shaped reinforcing member 24 to be formed.

The outer surface plate 212 and the groove side plate 21
3, a trapezoidal gutter 32 that is continuous with the entire length of the beam member 2 in the axial direction is formed below the beam member 2 by the seal holding member 23 and the groove-shaped reinforcing member 24.

Both ends of the gutter 32 are opened to the outside through a bottom opening 321 formed between the lower end of the reinforcing frame 22 and the main member 21 and a weight reducing hole 322 formed in a lower portion of the reinforcing frame 22. Further, the portions of the gutters 32 on both sides of the reinforcing frame 22 disposed in the middle of the main member 21 pass through a bottom opening 321 formed by cutting out the lower end of the reinforcing frame 22 and a weight reducing hole 322 formed below the reinforcing frame 22. Communicate with each other. Further, as shown in FIG. 5, openings 323 are provided through the groove side plate 213 at appropriate intervals in the axial direction.

The groove side wall 241 of the groove type reinforcing member 24
On the upper edge, a large number of semicircular reinforcing-bar receiving grooves 242 are formed at regular intervals in the axial direction to receive the lower reinforcing bar of the foundation concrete. A large number of circular rebar receiving holes 216 are formed at regular intervals in the direction and into which the upper rebar of the foundation concrete is inserted.

As shown in FIG. 6, the corner member 1 comprises a top plate 11 which covers the corner of the lower frame A from above, and an end face of the beam member 2 below two outer sides of the top plate 11. And a lower frame corner cover 12 that covers the gutter 3 of the beam member 2 below the lower frame corner cover 12.
1 is formed. After completing the entire wall frame B on the lower frame A connecting the corner member 1 and the beam member 2 to form a caisson C, the ground inside the caisson C is brought close to the plane contour of the caisson C. When excavating, the lower edge of the caisson C sinks down by shaving off the periphery of the excavation hole due to the weight of the caisson C.

At this time, in the caisson C, frictional resistance applied to the outer surface of the lower frame 1 and excavation resistance applied to the lower edge of the lower frame 1 are generated as resistance to settlement and excavation.

The ground improvement apparatus used in the basement submersion method according to an embodiment of the present invention is such a caisson C
In order to reduce frictional resistance and excavation resistance, a plurality of water conveyance ducts extending in the vertical direction at predetermined intervals in the horizontal direction on the outer surface of the wall frame B as shown in FIGS. 5 is provided.

In order to dispose the water guide duct 5, the beam member 2 of the lower frame A is provided at a predetermined interval in the axial direction thereof as shown in FIG.
Is fixed by, for example, welding. The screw seat 6 has an upper end 61 bent at a right angle and a lower end 6
2 is made of a vertically long band steel material bent in a L-shape, and the outer surface plate 212 is formed so that the lower end 62 is along the groove side plate 213.
And the upper surface plate 21 of the main member 21 fixed to the groove side plate 213.
A screw hole 63 is formed in the upper end 61 which is horizontally bent at a predetermined height from 1.

Screws that can be screwed into the screw holes 63 of the screw seats 6 are formed at both ends of each of the water guide ducts 5. By screwing the lower ends of the water guide ducts 5 into the screw holes 63 of the screw seats 6, respectively, it is easy. A plurality of water guide ducts 5 in a short time
Can be arranged on the outer surface of the wall frame B at predetermined intervals in the horizontal direction.

Here, the screw of each water guide duct 5 may be provided only at one end thereof. However, in this embodiment, in order to arrange the water guide duct 5 without considering the upper and lower sides of the water guide duct 5. The screw is provided at both ends of the water guide duct 5.

The upper end 61 of the screw seat 6 may be bent outside the lower frame A. In this embodiment, the upper end 61 of the screw seat 6 is bent inside the lower frame A, and The water guide duct 5 connected to the screw seat 6 does not protrude from the outline of the lower frame A in plan view. By arranging the water guide duct 5 in the outline of the lower frame A in a plan view as described above, the water guide duct 5 can be prevented from being damaged when the caisson C sinks, and the sink of the caisson C caused by the water guide duct 5 can be eliminated. Frictional resistance can be minimized.

The timing of disposing the water guide duct 5 is not particularly limited. However, since the water guide duct 5 hinders the work during the lower frame work and the wall frame work, in this embodiment, the caisson C is installed. After the formation, the water guide duct 5 is provided before starting the excavation.

After the water supply ducts 5 are provided, the water supply ducts 5 are connected to a water supply source (not shown), and when excavating the ground inside the caisson C, the water supply source is connected to the water supply source through the plurality of water supply ducts 5. Water is supplied to the ground outside the lower frame A as a soil conditioner.

In this way, when water is supplied from the water supply source to the ground outside the lower frame A through the plurality of water guide ducts 5 when excavating the ground, the ground outside the lower frame is softened and the caisson In addition to reducing the frictional resistance acting on the outer surface of the lower frame A against the settlement of C, the ground below the lower frame A can be softened to reduce the resistance of the caisson C to the excavation action due to its own weight.

As a result, the caisson C can be reliably and smoothly settled by its own weight with the progress of the excavation, and the excavation in the submerging work and the sinking of the caisson C overlap in time. By doing so, the construction period of the submersible construction work can be shortened reliably.

Further, since the caisson C sinks with its own weight along with the progress of the excavation surely and smoothly, there is no possibility that the caisson C is caught at the middle height of the excavation hole during excavation, and There is no danger that the caisson C, which has been caught at the intermediate height, suddenly falls due to some trigger, and the caisson C tilts at the time of this fall.

In this embodiment, the screw seat 6 is provided so as to extend from the lower part of the groove side plate 213 of the main member 21 along the outer surface plate 21. Therefore, the screw seat 6 serves as a guide for the sinking of the caisson C. The horizontal movement of the caisson C during sinking can be prevented.

Further, if the frictional resistance during excavation and the excavation resistance are not uniform in the circumferential direction of the caisson C, the supply of water to some of the conduits 5 is stopped or the amount of water supplied through the conduit 5 is reduced. May be made different for each water conveyance duct 5 so as to adjust the frictional resistance and the excavation resistance to be equal. When the frictional resistance and the excavation resistance at the time of settlement differ depending on the settlement depth of the caisson C, the supply of water to all the ducts 5 is stopped or the amount of water supplied to all the ducts 5 is increased or decreased on average. It is only necessary to adjust the frictional resistance and the excavation resistance to be equal.

In this embodiment, after the excavation of the ground is completed, the water supply duct 5 is replaced from a water supply source to a soil conditioner supply source (not shown). A soil conditioner, for example, a hardening agent for hardening the ground is supplied to the ground outside the lower frame.

Thus, the ground softened by the supply of water is hardened, and the caisson C can be prevented from sinking deeper than the designed value.

Further, the water guide duct 5 is replaced with another soil conditioner supply source, for example, an antibacterial agent or a bactericide is supplied into the soil to prevent bacteria from adhering around the caisson C and propagating. Or a fungicide is supplied into the soil to prevent mold from adhering to and growing around Caisson C. A termite is supplied into the soil to provide termites around the caisson C. It is possible to prevent them from gathering and breeding, or to supply a rodenticide into the soil to prevent rats from approaching caisson C.

In this embodiment, it is not essential to the present invention that the screw seat 6 is provided along the outer surface plate 21 from the lower part of the groove side plate 213 of the main member 21. For example, as shown in FIG. The inverted L-shaped screw seat 6 may be fixed to the upper surface of the upper plate 211, or the inverted groove-shaped screw seat 6 may be fixed to the upper surface of the upper plate 211 as shown in FIG.

It is not necessary to make the water guide duct 5 detachable from the caisson C. Before the factory shipment or when assembling the caisson C on site, for example, as shown in FIG.
As shown in FIG. 7, a channel member 8 made of, for example, a V-shaped channel member is provided on the surface (or the back surface) of the outer panel member 7 covering the outer surface of the wall frame B.
Is fixed by, for example, welding so that the outer panel member 7 and the channel member 8 form a water guide duct 5 that cannot be disassembled from the caisson C, or a round pipe-shaped water guide duct 5 is used to cover the outer surface of the wall frame B. The member 7 may be fixed to the front surface (or the back surface) by, for example, welding or a pipe holding fitting.

[0086]

As described above, the method of the present invention comprises:
Prior to excavation of the ground, one or a plurality of water guide ducts extending in the longitudinal direction at a predetermined interval in the horizontal direction on the outer surface of the wall frame, in particular, a plurality of water guide ducts are arranged. According to the method of the present invention, water is supplied as a soil conditioner to the ground outside the lower frame through the water guide duct.
When excavating the ground, the ground outside the lower frame is softened, and the friction resistance of the ground outside the lower frame against the sinking of the caisson can be reduced, and the ground below the lower frame is softened to resist the excavation action due to the weight of the caisson. Can be reduced, and as a result, the caisson is more reliably
In addition, the sinking can be smoothly carried out along with the progress of excavation, and the effect of duplicating excavation and caisson subsidence in submarine construction time can be obtained in time, and the effect of reliably shortening the construction period of submarine construction can be obtained. is there.

According to the method of the present invention, the ground outside the lower frame is softened when the ground is excavated, so that the friction resistance of the ground outside the lower frame against the settlement of the caisson can be reduced. The ground below the ground is softened to reduce the resistance of the caisson to the digging action due to its own weight, so the caisson sinks reliably and smoothly as the digging progresses, Therefore, there is no danger that the caisson caught at the middle height of the excavation hole will suddenly fall upon something as a trigger, and there will be no danger of falling during this fall.

Further, according to the method of the present invention, prior to excavation of the ground, one or a plurality of water guide ducts extending in the longitudinal direction at predetermined intervals in the horizontal direction on the outer surface of the wall structure,
A plurality of water guide ducts are provided, and after the excavation of the ground is completed, the liquid soil conditioner is supplied to the ground outside the lower frame via the water guide duct. The effect of improving the soil quality by infiltrating the soil improvement agent into the ground outside and below the lower frame is obtained, and as a result, the effect of easily improving the soil quality near the bottom of the caisson can be obtained.

According to the apparatus of the present invention, one or a plurality of water guide ducts, particularly a plurality of water guide ducts, are provided on the outer surface of the wall of the caisson at predetermined intervals in the horizontal direction and extending in the longitudinal direction. According to the apparatus of the present invention, when the water supply duct is connected to a water supply source, when excavating the ground from the water supply source, the soil outside the lower frame is passed through the water supply duct as a soil conditioner. It can supply water, soften the ground outside the lower frame, reduce the frictional resistance of the ground outside the lower frame against the settlement of the caisson, and soften the ground below the lower frame to prevent the caisson from excavating due to its own weight. As a result, the caisson can be reliably and smoothly settled along with the progress of excavation by its own weight. It is overlapped and subsidence temporally and is the effect that can be reliably shortened construction period of caisson construction is obtained.

According to the apparatus of the present invention, the ground outside the lower frame is softened when the ground is excavated, so that the friction resistance of the ground outside the lower frame against the sinking of the caisson can be reduced, and the lower frame can be reduced. The ground below the ground is softened to reduce the resistance of the caisson to the digging action due to its own weight, so the caisson sinks reliably and smoothly as the digging progresses, Therefore, there is no danger that the caisson caught at the middle height of the excavation hole will suddenly fall upon something as a trigger, and there will be no danger of falling during this fall.

Further, the apparatus of the present invention is provided with one or a plurality of water guide ducts, particularly a plurality of water guide ducts, extending on the outer surface of the caisson wall frame at predetermined intervals in the horizontal direction and extending in the longitudinal direction. Therefore, prior to excavation of the ground, one or a plurality of water conveyance ducts extending in the vertical direction are disposed at predetermined intervals in the horizontal direction on the outer surface of the wall frame, and after the excavation of the ground, the water conveyance is completed. The effect of supplying a liquid soil conditioner through a duct to the ground outside the lower frame and allowing the soil conditioner to penetrate the ground outside and below the lower frame after excavation to improve the soil quality. As a result, the effect of easily improving the soil quality near the basement base can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a caisson used in the present invention.

FIG. 2 is a sectional view of a basement site and a caisson used in the present invention assembled on the basement site.

FIG. 3 is a plan view schematically showing a lower frame used in the present invention.

FIG. 4 is a longitudinal sectional side view of a beam member used in the present invention.

FIG. 5 is a rear view of a beam member used in the present invention.

FIG. 6 is an exploded perspective view of a corner member used in the present invention.

FIG. 7 is a perspective view of a screw seat used in the present invention.

FIG. 8 is a perspective view of a screw seat used in the present invention.

FIG. 9 is a perspective view of a screw seat used in the present invention.

FIG. 10 is a perspective view of a water guide duct used in the present invention.

[Explanation of symbols]

 A lower frame B wall frame C caisson 5 water guide duct 6 screw seat 7 outer panel member 8 grooved material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) E02D 23/14 E02D 29/04 Z 29/00

Claims (8)

[Claims] 1. A lower frame is assembled on a site of a basement, and a part or all of a wall frame is completed on the lower frame to form a part or all of a caisson. Excavating a caisson by its own weight, and submerging the caisson by its own weight, comprising: a ground improvement method used in a basement submersion method, wherein the wall extends horizontally in a longitudinal direction at a predetermined interval on an outer surface of the wall frame prior to excavation of the ground. Alternatively, a ground improvement method used in a basement submersion method, comprising providing a plurality of water guide ducts and supplying a soil conditioner to the ground outside and below the lower frame via one or more water guide ducts. 2. The ground improvement used in a subterranean submersion method according to claim 1, wherein when excavating the ground, water is supplied as a soil conditioner to the ground outside and below the lower frame through one or more water guide ducts. Method. 3. The method of claim 1, wherein after the excavation of the ground is completed, the liquid soil improver is supplied to the ground outside and below the lower frame via one or more water guide ducts. Ground improvement method. 4. The soil improvement method according to claim 1, wherein the water guide duct is assembled to the caisson after the caisson is formed and before the ground excavation is started. 5. The basement submersion method according to claim 1, wherein a water guide duct is formed on an outer panel member constituting an outer surface of the wall frame before assembling the wall frame on the lower frame. Ground improvement method used for 6. A caisson is formed by assembling a lower frame on the site of a leveled basement, completing a wall frame on the lower frame, and then excavating the ground inside the caisson,
A ground improvement device used in a basement submersion method for sinking a caisson by its own weight, comprising one or more water guides extending in the longitudinal direction at predetermined intervals in the horizontal direction on the outer surface of the wall frame of the caisson. Ground improvement device used for basement submersion method characterized by having a duct. 7. The water guide duct is formed of a circular pipe having a thread formed at a lower end thereof. The water guide duct is positioned on the upper surface of the lower frame outside the wall frame, and the lower end of the water guide duct is screwed into the water guide duct to form the water guide duct. 7. The ground improvement apparatus used in a basement submersion method according to claim 6, wherein a screw seat is provided which is separated from the upper surface of the lower frame by a predetermined height or more and is supported in a vertical axis. 8. The water guide duct is constituted by an outer surface or an inner surface of the wall frame, and a groove member on a vertical axis which is in close contact with the outer surface or the inner surface of the wall frame so as to close the open surface of the groove. Item 7. A ground improvement device used in the basement submersion method according to Item 6.