JPH0742711B2 - Building support structure and building construction method in reclaimed land - Google Patents

Description

TECHNICAL FIELD The present invention relates to a building support structure and a building construction method for a reclaimed land plate having a high groundwater level such as a young reclaimed land plate.

(Prior art) For a building constructed on a landfill, when the weight of the building after construction becomes lighter than the buoyancy received from groundwater below the ground surface as the groundwater level rises, Sometimes the whole thing floated up.

In order to deal with such a case, conventionally, earth and sand or mortar is put in the underground pit of the building, or the brim is projected horizontally from the building, and the earth or sand is placed on the brim. Thus, the weight of the building as a whole is increased to impart a weight against the buoyancy.

Moreover, when constructing such a building, conventionally, a water stop wall is built around the planned construction site of the building, waiting for the reclaimed land to solidify, while discharging the groundwater entering the interior. The building was built from the building foundation to the upper part.

(Problems to be solved by the invention) However, in the case of the conventional building support structure, soil,
It requires a lot of materials such as earth and sand and mortar, and there is a drawback that it takes a lot of time and labor to increase the construction cost due to the input of those materials. When a building descends, the load applied from the building to the landfill will increase, and in order to withstand the load, the ground resistance of the landfill must be increased. Has the drawback of taking a long time.

Moreover, in the case of the conventional building construction method on the landfill, the building cannot be constructed on the landfill until the specified bearing capacity is obtained, which requires a long period from the start of landfill to the construction of the building. There was a drawback to

The present invention has been made in view of such circumstances, and the present first invention is a building constructed even in a place with a high groundwater level such as young landfill land. It is an object of the present invention to provide a support structure capable of constructing a building on a landfill site at an early stage by making it possible to stably support irrespective of changes in tide level, and the second invention is the first invention.
It is an object of the present invention to make it possible to further shorten the construction period for obtaining a support structure for a building in the invention.

(Means for Solving Problems) In order to achieve the above-mentioned object, the building support structure in the reclaimed land board of the first aspect of the present invention is provided with a building and a surrounding of the building. A water blocking wall that is constructed in a state of forming a water storage space in which groundwater stays from the lower surface to the lateral outer surface and blocks the groundwater area; a drainage device that discharges groundwater in the water storage space; and water is supplied into the water storage space. The water injection device is used.

In order to achieve the above-mentioned purpose, the construction method for building a landfill board according to the second aspect of the present invention leaves the building construction site of the landfill board unfilled, and places the unfilled area in another place. The building foundation having the water storage chamber divided in the horizontal direction, which was built in, is brought in by sea transportation, the periphery of the building foundation is filled up, and a water blocking wall that blocks the groundwater area of the unfilled portion from the sea side is provided. Build, level the landfill below the building foundation, and fill or almost fill the reservoir with,
The groundwater in the water storage space formed between the building foundation and the water blocking wall is discharged to land the building foundation on the landfill board below it, and the landfill board is drained from the water storage chamber. While constructing an upper building on the building foundation while adjusting the load of the building according to the above, a configuration is provided in which a water injection device that supplies ground water and a drainage device that discharges ground water are installed in the water storage space. Adopted.

(Operation) <Operation of the first aspect of the invention> According to the above configuration, the groundwater that has invaded from the bottom of the water blocking wall after the building is built and is retained in the water storage space is used,
The buoyancy of groundwater supports the building, and due to high tides, typhoons, tsunami, etc., the groundwater level outside the water blocking wall rises, and along with that, water is stopped from below the water blocking wall. When the groundwater level in the water wall rises, the drainage device discharges the groundwater in the water storage space to bring the groundwater level in the water stop wall to a specified level, and continues to discharge a set amount of water to maintain the groundwater level at a constant level. On the other hand, when the groundwater level outside the water cutoff wall decreases due to ebb tide, etc., and when the groundwater level inside the water cutoff wall decreases due to water flowing from below the water cutoff wall. It is possible to supply groundwater into the water storage space by the water injection device to bring the groundwater level in the water cutoff wall to a predetermined level and to continue injecting a set amount of water to maintain the groundwater level constant.

<Operation of the Second Invention> According to the above configuration, in the reclaimed land, while reclaiming the surrounding ground around the planned construction site of the building and reclaiming up to a predetermined level deeper than the building foundation at the planned construction site. , Separately, for example, using the shipbuilding dock, build the building foundation in a suitable place near the planned construction site,
The building foundation that was built is towed by a towboat, etc., carried into the unfilled area of the planned construction site, and the unfilled area such as the carry-in area and the surrounding area of the building is reclaimed, and the water storage chamber formed in the building foundation Of the groundwater in the water storage space and landing the building foundation on the landfill floor below it, and by discharging and supplying groundwater in the water storage chamber, the weight in the horizontal direction By balancing and adjusting the weight of the entire building, the upper building can be built on the building foundation in a stable posture without increasing the load on the landfill board. Further, after the building is constructed, the structure can be supported by the buoyancy of groundwater in the water storage space, and the drainage device and the water injection device installed in the water storage space can be selectively operated to remove the groundwater. By discharging or supplying, it is possible to suppress the fluctuation of the groundwater level inside the water cutoff wall and stably support the building regardless of the fluctuation of the groundwater level outside the water cutoff wall.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a supporting structure for a building in a landfill board according to the first aspect of the present invention, in which a building foundation 1 below the building A is located in groundwater, and the building A is Supported by groundwater buoyancy.

The lower part of the building foundation 1 is horizontally and vertically divided into water storage chambers 2, and the water storage chambers 2 are connected to a water injection device 3 and a drainage device 4, respectively.
… The water can be supplied and drained individually to adjust the weight of the building A and to correct the inclination.

In the water injection device 3, one end of a water injection pipe 6 having a water injection pump 5 is located in groundwater, a strainer 7 is provided at the tip thereof, and a branch water injection pipe 8 is provided at the other end of the water injection pipe 6. Each of them is connected to each other and has a branch water injection pipe 8 ... Each of which has a tip located in each of the water storage chambers 2 ... and configured to inject water into each of the water storage chambers 2 ... Using ground water, and the branch water injection pipes 8 ... An electromagnetic valve 9 for water injection is attached to each of them, and by selecting the electromagnetic valve 9 for water injection to be opened and closed, water can be injected into a predetermined water storage chamber 2.

Further, the drainage device 4 connects the branch drainage pipes 12 to each one end of the drainage pipe 11 having the drainage pump 10 interposed therebetween, and the ends of the branch drainage pipes 12 are located near the bottoms of the water storage chambers 2 ... In addition, a strainer 13 is provided at the tip of the drainage pipe 11, the other end of the drainage pipe 11 is located on the groundwater side, and the water discharged from the water storage chamber 2 is returned to the groundwater.
Then, a drainage electromagnetic valve 14 is attached to each of the branch drainage pipes 12, and the drainage electromagnetic valve 14 is configured to be drained from a predetermined water storage chamber 2 by selecting the drainage electromagnetic valve 14.

Below the building foundation 1, at predetermined intervals in the horizontal direction, an anchor body (not shown) is driven into the support layer below the groundwater, the cable 15 is connected to the anchor body, and the cable 15 The upper end of each of them is inserted into each of the holes 16 formed in the building foundation 1 ... As shown in FIG. 2, a hydraulic jack 17 is attached to the upper part of the water storage chamber 2 of the building foundation 1, Jack 17 ... The connection member 18 placed and supported on each jack and the cable 15 are connected to each other so that the building A floats by groundwater buoyancy.
So that it is blocked by the pulling force of 15 ...
The hydraulic jacks 17 are constructed so that the pulling force can be adjusted by each drive.

Around the building A, a water blocking wall 19 that blocks the groundwater area is built around the entire circumference of the building A. Outside the water blocking wall 19,
Retaining wall block 20 is built to prevent the collapse of the surrounding landfill.

Predetermined locations on the periphery of the building foundation 1 are formed on the inclined surface F,
Slope protection concrete 21 is placed between the land extending from the inclined surface F and a part of the horizontal plane and the landfill board.

The concrete blocks 22 and 22 are cast and solidified at predetermined positions on the upper and lower sides, respectively, over the entire circumference of the inner wall surface of the retaining wall block 20, and on the other hand, at the positions corresponding to the concrete blocks 22 and 22, respectively, the outer periphery of the building A. Concrete blocks 23, 23 are poured and solidified over the entire circumference of the surface, and the movement of the building A in the horizontal direction is regulated by contact between the concrete blocks 22, 23.

Each of the concrete blocks 22 and 23 is a building A
The strength of the concrete blocks 22 and 23 is set to be smaller than that of the concrete blocks 22 and 23 before the building A is collapsed and the building A is prevented from being damaged when a large shock such as an earthquake occurs.

Further, the retaining wall block 20 and the building A are connected to each other via a stretchable joint member 25 having a turnbuckle 24 interposed therebetween, and are configured to prevent the building A from descending. .

With the above configuration, a water storage space S that retains groundwater entering from below the water stop wall 19 is formed between the water stop wall 19 and the building A, and due to the buoyancy of ground water in the water storage space S. Building A is supported.

A branch water injection pipe 8a which is connected to the water injection pipe 6 extends above the water storage space S between the retaining wall block 20 and the building foundation 1, and a water injection solenoid valve for the branch water injection pipe 8a. 9a is attached, and the water injection pump 5 and the water injection pipe 6 are also used as the water injection device 3 for the water storage chamber 2 to form a water injection device 26 for the water storage space S.

The lower end of a branch drain pipe 12a continuously connected to the drain pipe 11 is located in the water storage space S, a strainer 13a is provided at the lower end thereof, and a drain solenoid valve 14a is attached to the branch drain pipe 12a. The drainage pump 10 and the drainage pipe 11 are also used as the drainage device 4 for the water storage chamber 2, and the water storage space S
A drainage device 27 for the

A water level sensor 28 for detecting the groundwater level in the water storage space S is provided at a predetermined position of the retaining wall block 20.
The detection result by is input to a computer 29 composed of a CPU, a ROM and a RAM, so that the detected water level becomes a set water level, the water injection solenoid valve 9a or the drainage solenoid valve 14a is automatically opened and closed to store water. It is configured to keep the water level in the space S constant.

That is, as shown in the third flowchart, the detected water level is input (S1), and at the same time, a timer for setting a predetermined time such as 5 minutes is started (S2).

Then, the detected water level is compared with the preset lower limit water level to determine whether the detected water level is lower than the lower limit preset water level (S3).

When it is determined that the water level is lower than the lower limit set water level, the water injection solenoid valve 9a is opened for a set time (a time shorter than the time set by the timer) to supply the set groundwater to the water storage space S (S4). .

After that, wait until the time set by the timer elapses (S5), and reset the timer after the set time elapses (S6).
To step S1.

In step S3, if the detected water level is not lower than the lower limit side set water level, the process proceeds to step S7, and the detected water level is compared with the preset upper limit side set water level, and the detected water level is higher than the upper limit side set water level. Determine if

If it is determined that the water level is higher than the upper limit set water level, the drainage solenoid valve 14a is opened for a set time (a time shorter than the time set by the timer), and the set groundwater is discharged from the water storage space S (S8 ), And proceeds to step S5.

If it is determined in step S7 that the detected water level is not higher than the upper limit set water level, it is determined that the water level in the water storage space S is within the set range, and the process proceeds to step S5.

By the above processing, the water level in the water storage space S is automatically maintained at the level within the set range regardless of the fluctuation of the groundwater level outside the water blocking wall 19, and the vertical displacement of the building A is suppressed. , The building A is stably supported by a constant buoyancy.

Between the retaining wall block 20 and the outer wall surface of the building A, a displacement sensor 30 for detecting the amount of vertical displacement of the building A with respect to the surrounding ground is provided.

Further, the building foundation 1 is provided with an inclination sensor 31 for detecting the inclination angle of the building A.

Further, between the hydraulic jack 17 and the connecting member 18, there is provided a tension sensor 32, such as a load cell, which detects the pressure between the two and detects the tension of the cable 15.

The detection results of the displacement sensor 30, the inclination sensor 31, and the tension sensor 32 are also input to the computer 29, and water injection or drainage to a predetermined water storage chamber 2 is performed based on the detected displacement amount, the detected inclination angle, and the detected load. As the hydraulic jack 17 is driven and the connecting member 18 is moved up and down to build the upper building 1a on the building foundation 1, the building A is moved at a predetermined position regardless of the weight change of the building A. You can maintain a good horizontal posture.

As the water injection device 26 and the drainage device 27 for the water storage space S, a water injection pipe provided with a dedicated water injection pump,
It may be configured by each drain pipe through which a dedicated drain pump is interposed, and by selectively driving or stopping each of the water injection pump and the drain pump.

The construction method for obtaining the support structure for the building A is not limited to the construction method of the second invention described below, and for example,
It is also possible to construct a water blocking wall 19 at a predetermined location on the Jakusei reclaimed land, and construct a building A from the foundation upward while discharging the groundwater in the water blocking wall 19.

Next, an example of the construction method according to the second aspect of the present invention for obtaining the structure for supporting a building in the landfill according to the first aspect of the present invention will be described.

At a suitable place near the construction site of the building A, such as a shipbuilding dock, the foundation portion 1a of the predetermined size that constitutes the building foundation 1 is constructed, and a predetermined amount of water is stored in the water storage chamber 2. Is supplied to the base portion 1a to give it a predetermined weight and float it on the sea, and as shown in FIGS. 4 (a) and 4 (b), the base portion 1a is towed by a tug 33 and transported by sea. .

On the other hand, on the landfill site B side, as shown in FIG. 5, the site B ₁ that is the construction site of the building A is left unfilled, and the foundation part 1a is carried into the unfilled part B ₁ and the foundations Part 1a
... are integrated with each other to obtain a building foundation 1 of a predetermined size. At this unfilled portion B ₁ , a depth that allows the tugboat 33 ... And the foundation portion 1a to enter is left, and a deeper portion is filled up. Further, an anchor body is constructed at a predetermined position of the unfilled portion B _{1 and} the cables 15 are installed in advance.

After that, as shown in FIG. 6 (a), the periphery of the loaded building foundation 1 is filled up, a guide is attached to the outer periphery of the building foundation 1, and the sheet pile 35 is sequentially driven by the working machine 34. Then, the water blocking wall 19 is constructed to block the groundwater area at the unfilled portion B ₁ from the sea side.

Then, as shown in FIG. 6 (b), the slope protection is performed between the portion extending from the lower slope F of the building foundation 1 to a part of the horizontal surface and the landfill earth facing the slope, using each of them as a formwork. Concrete 21 is placed. At this time,
A resin for preventing the adhesion of concrete is applied to the inclined surface F facing the slope protection concrete 21 and a part of the horizontal surface.

Then, as shown in FIG. 6 (c), the retaining wall block 20 is installed outside the water blocking wall 19, the surrounding ground is filled up, and a ground stabilizer is injected below the building foundation 1. Agitate and level the reclaimed land below the building foundation 1.

Then, as shown in FIG. 6 (d), the water storage chamber 2
... is filled with water or almost filled with water, groundwater in the water storage space S is discharged, and the building foundation 1 is landed on the landfill board below it, and the outer periphery of the building foundation 1 and the retaining wall block 20. The connecting member 25 is attached between the cable 15 and the cable 15, and the cable 15 is connected to the connecting member 18 of the building foundation 1.

Then, as shown in FIG. 6 (e), the crane 36 or the like is used to adjust the load of the building on the landfill board by drainage from the water storage chamber 2 ... The upper building 1a is built on the building foundation 1 to build a predetermined building A.

Finally, the water injection device 26 for supplying the groundwater and the drainage device 27 for discharging the groundwater are installed in the water storage space S to obtain the building support structure of the first invention.

The building foundation 1 includes both with and without an underground structure.

(Effect) <Effect of the First Invention> As described above, according to the first invention, the structure is supported by utilizing the buoyancy of groundwater in the water storage space between the water blocking wall and the structure. It is not necessary to equip the reclaimed land base with sufficient bearing capacity to support the entire load of the object, and materials such as soil, earth and sand, and mortar to increase the weight of the building are not required, so Even so, it is possible to construct buildings early and at low cost, and to plan land use early.

Moreover, draining the groundwater in the water storage space between the water blocking wall and the building with a drainage device or supplying it with a water injection device may cause tides, typhoons, tsunamis, etc. outside the water blocking wall. Regardless of the change in tide level, the groundwater level can be kept constant and the building can be stably supported.

<Effects of the Second Invention> As described above, according to the second invention, the landfill around the planned construction site of the building and the construction of the building foundation can be performed in parallel. Construction of a building can be started without waiting for the ground to solidify, and in addition, the work of excavating a landfill site for the construction of a building foundation can be dispensed with, and water can be injected into the water storage chamber formed in the building foundation. In addition, by constructing the upper building while adjusting the horizontal weight balance of the building and the load applied to the landfill below the building by drainage, after that, the buoyancy of groundwater staying in the water storage space is used. Since it supports the building, the landfill below the building does not require a large amount of earth bearing capacity, and even if it is a young landfill, the building can be well constructed.
In constructing the support structure for the building of the invention, the construction period can be further shortened and the land can be used more efficiently.

[Brief description of drawings]

FIG. 1 is a partially omitted schematic sectional view of an embodiment of a building support structure in a landfill board according to the present invention, FIG. 2 is an enlarged sectional view of an essential part, FIG. 3 is a flowchart, and FIG. a) is
A plan view for explaining the marine transportation state of the building foundation, FIG. 4 (b) is a side view thereof, FIG. 5 is a plan view for explaining the landfill, and FIGS. 6 (a), (b), ( c), (d), and (e) are schematic cross-sectional views illustrating each step of the construction method. 1 ... Building foundation, 1a ... Upper building, 2 ... Water storage room,
19 ... Water stop wall, 26 ... Water injection device, 27 ... Drainage device, A ...
… Building, B …… Reclaimed land, S …… Water storage space.

Claims (2)

[Claims] 1. A building, and a water blocking wall surrounding the building to form a water storage space for accumulating groundwater from a lower surface of the building to a lateral outer surface thereof, and blocking a groundwater area, A structure for supporting a building in a landfill board, comprising a drainage device for discharging groundwater in the water storage space and a water injection device for supplying water to the water storage space. 2. A land for constructing a building on a reclaimed land is left unfilled, and a building foundation having a horizontally divided water storage chamber constructed at another place is carried into the unfilled portion by sea transportation. Then, the surroundings of the building foundation are reclaimed, a water blocking wall that blocks the groundwater area of the unfilled portion from the sea side is constructed, the landfill plate below the building foundation is leveled, and the water storage chamber is filled with water or With almost full water,
The groundwater in the water storage space formed between the building foundation and the water blocking wall is discharged to land the building foundation on the landfill board below it, and the landfill board is drained from the water storage chamber. While constructing the upper building on the building foundation while adjusting the load of the building according to the above, for the water storage space, installing a water injection device for supplying groundwater and a drainage device for discharging groundwater. The construction method of building on the characteristic landfill board.