Construction method

Abstract

To provide a building method to prevent negative friction from acting on piles in a construction area when building embankment on an embankment area adjacent to the construction area through construction of a building having a pile foundation in the construction area at a construction site having a consolidation settlement layer under the ground.SOLUTION: A building method for constructing a building 1 having a pile foundation 11 in a construction area A and building an embankment part 2 on an embankment area B adjacent to the construction area A in a construction site P having a consolidation settlement layer g3 under the ground. The method comprises: a prior stage having a pile installation step for installing piles 11A of the pile foundation 11 in an underground part of the construction area A and an area cutoff wall construction step for constructing an area cutoff wall 3 in the underground part between the construction area A and the embankment area B; and a following stage including an embankment step for constructing the embankment part 2 on the embankment area B after the prior stage.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a construction method, and more particularly to a construction method for constructing a building on a construction site having a consolidated subsidence layer in the ground. [Background technology]

[0002] When constructing a building on a construction site having a consolidated settlement layer as described above, it is possible to adopt a pile foundation (see, for example, Patent Documents 1 and 2) as the foundation supporting the upper part of the building. If the piles of the pile foundation are embedded into a supporting layer deeper than the consolidated settlement layer, it is possible to prevent the building from sinking due to the load of the building being applied to the consolidated settlement layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-257743 A [Patent Document 2] JP 2007-297834 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a construction site having such a consolidated subsidence layer, a case may be considered in which a building having a pile foundation is constructed in the construction area, and an embankment section in which new soil is piled up is constructed in the embankment area adjacent to the construction area.

[0005] However, when an embankment is constructed in an embankment area adjacent to a construction area, the load of the embankment is applied to the consolidated settlement layer of the embankment area, causing the embankment area to sink, and this sinking of the embankment area causes negative friction (a force that pulls the piles downward) to act on the piles of the adjacent construction area.Therefore, when constructing an embankment in an embankment area adjacent to a construction area like this, a construction method that can suppress the negative friction acting on the piles is desired.

[0006] In view of this situation, the main object of the present invention is to provide a construction method that can suppress negative friction acting on piles in a construction area on a construction site having a consolidated subsidence layer in the ground, when constructing a building with a pile foundation in a construction area and constructing an embankment with new soil in an embankment area adjacent to the construction area. [Means for solving the problem]

[0007] The first characteristic configuration of the present invention is a construction method for constructing a building having a pile foundation in a construction area on a construction site having a consolidated subsidence layer in the ground, and constructing a new embankment part in an embankment area adjacent to the construction area, a pile construction step of constructing piles of the pile foundation in an underground portion of the construction area, and an area isolation wall construction step of constructing an area isolation wall in an underground portion between the construction area and the embankment area. conduct The preceding process, After the preceding step is performed, a banking step of constructing the banking portion in the banking area is performed. conduct The point is to execute the subsequent process.

[0008] According to this configuration, the preceding process is executed, and a pile construction step and an area blocking wall construction step are performed to construct piles for the pile foundation in the underground portion of the construction area, and the area blocking wall is constructed in the underground portion between the construction area and the embankment area. Then, the following process is executed, and an embankment step is performed to construct an embankment in the embankment area, so that the effect of subsidence of the embankment area due to the embankment can be blocked by the area blocking wall, and the effect of subsidence of the embankment area can be suppressed from affecting the construction area. Therefore, in a construction site having a consolidated subsidence layer in the ground, when constructing a building with a pile foundation in a construction area and constructing an embankment section with new soil piled up in an embankment area adjacent to the construction area, it is possible to suppress negative friction from acting on the piles in the construction area.

[0009] A second characteristic configuration of the present invention is that, in the area blocking wall construction step, the area blocking wall is embedded into a layer deeper than the consolidated subsidence layer.

[0010] According to this configuration, in the area blocking wall construction step, the area blocking wall, which serves as a resistance element and blocking element for the negative friction caused by the banking in the banking area, is embedded to a layer deeper than the consolidated subsidence layer, so that it is possible to suitably suppress the area blocking wall from subsiding due to the effect of the banking area subsidence caused by the banking. Therefore, it is possible to further improve the effect of suppressing the effect of the area blocking wall from affecting the piles in the construction area due to the subsidence of the banking area, and it is possible to further suppress the effect of negative friction acting on the piles in the construction area.

[0011] A third characteristic configuration of the present invention is that in the area blocking wall construction step, the area blocking wall is constructed as an earth retaining wall for excavating the construction area and constructing an underground portion of the building.

[0012] According to this configuration, an area blocking wall can be constructed that acts as a resistance element and blocking element for negative friction in a form that also serves as a retaining wall required for construction work, thereby suppressing negative friction from acting on the piles in the construction area without increasing costs or construction labor. A fourth characteristic configuration of the present invention is that in the preceding process, a foundation for the pile foundation is constructed on the piles constructed in the pile construction step, and a building construction step is performed in which the remaining part of the building is constructed on the foundation. [Brief description of the drawings]

[0013] [Figure 1] Diagram showing the steps of constructing an area isolation wall [Diagram 2] A diagram showing the pile construction steps and the building construction steps [Diagram 3] Diagram showing embankment steps DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of a construction method of the present invention will be described with reference to the drawings. This construction method is a construction method in which, on a construction site P having a consolidated subsidence layer g3 underground, a building 1 having a pile foundation 11 is constructed in a construction area A, and an embankment section 2 made of newly piled soil is constructed in an embankment area B adjacent to the construction area A, as shown in Figure 3. In this construction method, the preceding steps are an area isolation wall construction step (see FIG. 1), a pile construction step (see FIG. 2), and a building construction step (see FIG. 2), which are executed in that order, and the following step is an embankment step (see FIG. 3). Each step will be described in detail below in order.

[0015] (Area Blockade Wall Construction Steps) As shown in FIG. 1, in the preceding area cut-off wall construction step, an area cut-off wall 3 is constructed in the underground portion between the construction area A and the embankment area B. The area cut-off wall 3 is constructed, for example, by reinforcing an underground diaphragm wall made of soil cement or concrete with a steel core material, reinforcing bars, or the like. The area cut-off wall 3 is embedded with its lower end disposed in a first supporting layer g1, which is a layer deeper than the consolidated settlement layer g3 in the ground G and shallower than a second supporting layer g2 that supports the piles 11A described later. The area cut-off wall 3 is left underground as a permanent structure even after the construction of the building 1 and the embankment 2.

[0016] By constructing the area blocking wall 3 in this manner, the underground portion including the consolidated subsidence layer g3 and layers shallower than the consolidated subsidence layer g3 in the construction area A can be blocked off from the underground portion including the consolidated subsidence layer g3 and layers shallower than the consolidated subsidence layer g3 in the embankment area B by the area blocking wall 3. In this embodiment, the area blocking wall 3 is disposed all around the periphery of the basement of the building 1 in the construction area A, and is configured as a retaining wall when the construction area A is excavated in the subsequent building construction step to construct the basement of the building 1. The area blocking wall 3 can be structured to be connected to the building 1 as a wall pile or the like, or can be structured independently of the building 1 without being connected to it.

[0017] (Pile construction step) As shown in Fig. 2, in the preceding pile construction step, piles 11A of a pile foundation 11 of a building 1 are constructed in the underground portion of the construction area A. Various structures such as precast concrete piles and deep ground improvement piles can be adopted as the piles 11A of the pile foundation 11. The piles 11A, as support piles, are embedded with their lower ends disposed in the consolidated subsidence layer g3 and the second support layer g2, which is a layer deeper than the first support layer g1 that supports the area blocking wall 3.

[0018] (Building construction steps) 2, in the preceding building construction step, a foundation 11B is constructed on top of piles 11A, and the remaining part of the building 1 is constructed on top of the foundation 11B. Note that the method for constructing the building 1 is not limited to the forward construction method in which the building is constructed in order from bottom to top, but a reverse construction method in which the underground part and above ground part are constructed in parallel can also be used.

[0019] (Embankment step) As shown in FIG. 3, in the subsequent embankment step, new soil is piled up in the embankment area B to construct the embankment section 2. Here, after the construction of the embankment section 2, subsidence (see arrow in Figure 3) occurs in the embankment area B as the weight of the embankment section 2 is added to the consolidated subsidence layer g3. However, the effects of the subsidence of the embankment area B can be blocked by the area blocking wall 3 constructed in the preceding area blocking wall construction step, and the effects of the subsidence of the embankment area B can be prevented from extending to the construction area A.

[0020] Furthermore, in the preceding area blocking wall construction step, the area blocking wall 3, which serves as a resistance element and blocking element for the negative friction generated by the embankment in the embankment area B, is embedded into the first supporting layer g1, which is a layer deeper than the consolidated subsidence layer g3, so that the area blocking wall 3 can be effectively prevented from sinking due to the subsidence of the embankment area B caused by the embankment.

[0021] Therefore, in a construction site P having a consolidated subsidence layer g3 in the ground, when a building 1 having a pile foundation 11 is constructed in construction area A and an embankment section 2 with newly piled soil is constructed in embankment area B adjacent to construction area A, negative friction can be suppressed from acting on the piles 11A in construction area A.

[0022] [Another embodiment] Other embodiments of the present invention will be described below. Note that the configurations of the embodiments described below are not limited to being applied alone, but may also be applied in combination with the configurations of other embodiments.

[0023] (1) In the above-described embodiment, an example was shown of a case in which the pile construction step is executed after the area blocking wall construction step in the preceding process, but the pile construction step may be executed before the area blocking wall construction step, or the pile construction step may be executed in parallel with the area blocking wall construction step.

[0024] (2) In the above embodiment, the building construction step is executed in the preceding process, but it may be executed in the following process. In that case, the building construction step can be executed before or after the filling step, or in parallel with the filling step.

[0025] (3) In the above-described embodiment, the area blocking wall 3 is constructed as an earth retaining wall for excavating the construction area A and constructing the underground portion of the building 1, but it may also be constructed as a wall dedicated solely to blocking off the construction area A and the embankment area B at the underground portion.

[0026] (4) In the above embodiment, the area blocking wall 3 is constructed as a permanent structure. However, the area blocking wall 3 may be constructed as a temporary structure.

[0027] (5) In the above embodiment, an example was shown in which the first supporting layer g1 supporting the area blocking wall 3 is shallower than the second supporting layer g2 supporting the piles 11. However, the first supporting layer g1 and the second supporting layer g2 may be deeper than the consolidated subsidence layer g3. The first supporting layer g1 may be deeper than the second supporting layer g2, or the first supporting layer g1 and the second supporting layer g2 may be the same layer at the same depth. [Explanation of symbols]

[0028] 1. Building 2 Embankment 3 Area Blockade 11 Pile foundation 11A pile 11B Basics A Construction Area B Embankment area P Construction site g3 Consolidated subsidence layer

Claims

1. A construction method for constructing a building having a pile foundation in a construction area on a construction site having a consolidated subsidence layer in the ground, and constructing a new embankment part by piling up soil in an embankment area adjacent to the construction area, comprising: A preceding process of constructing piles of the pile foundation in an underground portion of the construction area, and constructing an area isolation wall in an underground portion between the construction area and the embankment area; A construction method comprising: after the preceding step is performed, a subsequent step of performing an embankment step of constructing the embankment portion in the embankment area.

2. The construction method according to claim 1 , wherein in the area blocking wall construction step, the area blocking wall is embedded into a layer deeper than the consolidated settlement layer.

3. 3. The construction method according to claim 1, wherein in the area blocking wall construction step, the area blocking wall is constructed as an earth retaining wall for excavating the construction area and constructing an underground portion of the building.

4. A construction method described in any one of claims 1 to 3, wherein the preceding process involves constructing a foundation for the pile foundation on the piles constructed by carrying out the pile construction step, and then carrying out a building construction step in which the remaining part of the building is constructed on the foundation.

Images