Pile body arrangement method and pile body arrangement system

Abstract

To provide a pile body arrangement method and a pile body arrangement system that can limit the number of pile bodies to the number actually required to support a building load.SOLUTION: A foundation stress calculation is performed for a building to be constructed on the ground in which pile bodies are embedded (S-2), and it is determined whether the foundation stress calculated in the foundation stress calculation meets necessary conditions (S-3). If it is determined that the necessary conditions are met, the number of pile bodies required is calculated taking into account the foundation stress (S-4), and an arrangement of the pile bodies is determined from the number of pile bodies required (S-5). In the foundation stress calculation, a vertical load acting on the foundation is calculated as a value obtained by subtracting a ground reaction force from the building load.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a pile placement method and a pile placement system. [Background technology]

[0002] There is a known structure in which a building is supported by a composite ground in which multiple piles are buried in the ground depending on the strength of the ground. The intervals between buried piles, the arrangement of piles, and the number of piles are sometimes about 2.0 m based on general values ​​described in literature, and sometimes calculated by calculating the foundation stress (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-13494 A Summary of the Invention [Problem to be solved by the invention]

[0004] The building load acts on the foundation from above, and the ground reaction acts from below. Therefore, the vertical load acting on the foundation is the building load minus the ground reaction. However, when calculating the foundation stress, only the building load is used as the vertical load acting on the foundation, and the ground reaction is not taken into account. For this reason, the number of piles is dependent on the results of the foundation stress study, and is in excess of the number actually required to support the building.

[0005] The present disclosure aims to provide a pile arrangement method and pile arrangement system that can limit the number of piles to the number actually required to support the building load. [Means for solving the problem]

[0006] In order to achieve the above-mentioned objective, the pile placement method of the present disclosure performs a stress calculation for the foundation of a building to be constructed on the ground in which piles are buried, determines whether the foundation stress calculated in the foundation stress calculation satisfies the necessary conditions, and if it is determined that the necessary conditions are satisfied, calculates the required number of piles taking into account the foundation stress, determines the placement of the piles from the required number of piles, and in the foundation stress calculation, the vertical load acting on the foundation is calculated as the load of the building minus the ground reaction force.

[0007] In order to achieve the above-mentioned object, the pile placement system of the present disclosure comprises a foundation stress calculation unit that calculates the stress of the foundation of a building to be constructed on the ground in which piles are buried, a foundation stress determination unit that determines whether the stress of the foundation calculated by the foundation stress calculation unit satisfies the necessary conditions, a pile number calculation unit that calculates the required number of piles taking into account the stress of the foundation determined to satisfy the necessary conditions by the foundation stress determination unit, and a pile placement unit that determines the placement of the piles from the required number of piles calculated by the pile number calculation unit, and the foundation stress calculation unit calculates the stress of the foundation as the vertical load acting on the foundation minus the ground reaction force. Effect of the Invention

[0008] According to the present disclosure, the number of pile bodies can be reduced to the number actually required to support a building. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a front view showing an example of a foundation and a pile body. [Diagram 2] FIG. 2 is a block diagram of the pile arrangement system of the present embodiment. [Diagram 3] 1 is a plan view showing the arrangement of piles according to the pile arrangement method of this embodiment. [Figure 4] 4 is a flowchart of a pile arrangement method according to the present embodiment. [Diagram 5] 1 is a plan view showing the arrangement of the number of pile bodies considered in a conventional pile body arrangement method. [Figure 6] 11 is a table comparing the number of pile bodies calculated using the pile body arrangement method of this embodiment with the number of pile bodies calculated using a conventional pile body arrangement method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The pile arrangement method and pile arrangement system are a method and system for determining the arrangement of a plurality of piles 12 buried in the ground 11 supporting a building 13 as shown in FIG. 1. The building 13 in this embodiment is a small-scale building or a medium-scale building. The building 13 is, for example, a house. The piles 12 are support piles such as steel pipe piles and concrete piles, or friction piles in which soil and cement in the ground 11 are mixed. The ground 11 is a composite ground in which a plurality of piles 12 are buried. The foundation 14 of the building 13 is a slab foundation. The foundation 14 of the building 13 is supported by a plurality of piles 12 and the ground 11 between the piles 12, 12. A slab foundation is selected for the foundation 14 of the building 13 based on the results of a ground investigation. The ground reaction force X of the ground 11 between the piles 12, 12 is calculated based on the results of the ground investigation and its analysis.

[0011] As shown in FIG. 2, the pile body arrangement system 1 has a foundation design unit 2, a foundation stress calculation unit 3, a foundation stress determination unit 4, a pile body number calculation unit 5, and a pile body arrangement unit 6. The foundation design unit 2 designs the foundation 14. The foundation stress calculation unit 3 calculates the stress of the foundation 14 of the building 13 designed by the foundation design unit 2. The foundation stress determination unit 4 determines whether the stress of the foundation 14 calculated by the foundation stress calculation unit 3 satisfies the necessary conditions. The pile body number calculation unit 5 calculates the required number of pile bodies 12 in consideration of the stress of the foundation 14 determined to satisfy the necessary conditions by the foundation stress determination unit 4. The pile body arrangement unit 6 determines the arrangement of the pile bodies 12 from the required number of pile bodies 12 calculated by the pile body number calculation unit 5.

[0012] The foundation stress calculation unit 3 calculates, for example, the bending stress, shear stress, and deformation amount (i.e., deflection amount) of the foundation 14. The vertical load used when calculating the bending stress, shear stress, and deformation amount is the value obtained by subtracting the ground reaction force X from the building load P acting on the foundation 14. The building load P acts on the foundation 14 from above. The ground reaction force X acts on the foundation 14 from below.

[0013] For example, the moment M acting on the foundation 14 used in the calculation of bending stress is, if the distance between the pile bodies 12, 12 is L, a building load P acts on the center position between the pile bodies 12, 12 in the foundation 14 from above, and a ground reaction force X acts from below, then conventionally, M=PL / 4 without taking the ground reaction force X into consideration. In the pile body arrangement system 1 of this embodiment, M=(PX)L / 4 taking the ground reaction force X into consideration. The shear force Q acting on the end of the foundation 14 (the part supported by the pile body 12) used in the calculation of shear stress is, conventionally, Q=P / 2. In the pile body arrangement system 1 of this embodiment, Q=(PX) / 2 taking the ground reaction force X into consideration. The deformation amount δ of the foundation 14 is, conventionally, δ=PL 3 / (48×E×I), where E is the Young's modulus and I is the second moment of area. In the pile arrangement system 1 of this embodiment, taking into account the ground reaction X, δ=(PX)L 3 / 48EI.

[0014] If the foundation stress determination unit 4 determines that the bending stress, shear stress, deformation (deflection), etc. of the foundation 14 calculated by the foundation stress calculation unit 3 do not satisfy the necessary conditions, the process returns to the foundation design unit 2, and the foundation 14 is designed again. If the foundation stress determination unit 4 determines that the bending stress, shear stress, deformation (deflection), etc. of the foundation 14 calculated by the foundation stress calculation unit 3 satisfy the necessary conditions, the pile number calculation unit 5 calculates the required number of pile bodies 12 taking into account the stress of the foundation 14. After the pile number calculation unit 5 calculates the required number of pile bodies 12, the pile arrangement unit 6 determines the arrangement of the pile bodies 12 based on the required number of pile bodies 12. In the pile arrangement unit 6, the required number of pile bodies 12 are arranged on the foundation 14 in a plan view seen from the top and bottom, as shown in FIG. 3. In the pile arrangement section 6 , a required number of piles 12 may be arranged under the rising portion 141 of the foundation 14 of the building 13 .

[0015] The pile arrangement method will be described using the flow chart of the pile arrangement method shown in FIG. 4. The foundation 14 of the building 13 is designed in step S-1. The stress calculation of the foundation 14 is performed in step S-2. In the stress calculation of the foundation 14, for example, the bending stress, shear stress, and deformation amount of the foundation 14 are calculated. The vertical load used in the calculation of the bending stress, shear stress, and deformation amount is the value obtained by subtracting the ground reaction force X from the building load P acting on the foundation 14. The moment M, shear force Q, and deformation amount δ acting on the foundation 14 used in the calculation of the bending stress are the same as those described in the explanation of the foundation stress calculation unit 3 above. It is determined whether the stress of the foundation 14 calculated in the stress calculation of the foundation 14 in step S-3 meets the necessary conditions. If it is determined that the stress of the foundation 14 does not meet the necessary conditions, the design of the foundation 14 in step S-1 is returned to and the design of the foundation 14 is performed again. If it is determined that the stress of the foundation 14 satisfies the necessary conditions, the required number of pile bodies 12 is calculated taking into consideration the stress of the foundation 14 in step S-4. The arrangement of the pile bodies 12 is determined from the required number of pile bodies 12 calculated in step S-5. The arrangement of the pile bodies 12 is such that the required number of pile bodies 12 are arranged on the foundation 14 in a plan view. The arrangement of the pile bodies 12 may be such that the required number of pile bodies 12 are arranged under the rising portion 141 of the foundation 14 of the building 13.

[0016] In the pile arrangement method and pile arrangement system 1, the moment M, shear force Q, and deformation δ acting on the foundation 14 are smaller than the values ​​calculated using only the building load P by using the value (PX) obtained by subtracting the subgrade reaction X from the building load P as the vertical load acting on the foundation 14. As a result, even if the interval between the piles 12, 12 is made larger than before, it is possible to obtain values ​​that satisfy the necessary conditions for the bending stress, shear stress, and deformation of the foundation 14. By making the interval between the piles 12, 12 larger, the number of piles 12 can be reduced to the number actually required to support the building load.

[0017] As shown in FIG. 5, in the conventional pile arrangement method, the piles 12 are arranged so that the interval between the piles 12 is 2.0 m or less without considering the ground reaction force X to the building load P. As shown in FIG. 6, in buildings with different installation areas of the foundations 14 of NO. 1 to NO. 13, the number of piles 12 arranged by the pile arrangement method and pile arrangement system 1 of this embodiment was compared with the number of piles 12 arranged by the conventional pile arrangement method. In FIG. 6, the conventional pile arrangement method is written as "2.0 m arrangement". It can be seen that the pile arrangement method and pile arrangement system of this embodiment can reduce the number of piles compared to the conventional pile arrangement method.

[0018] The foundation 14 is a slab foundation. As a result, the ground reaction force X is larger and the vertical load acting on the foundation 14 can be reduced compared to when the foundation 14 is a strip foundation.

[0019] The building 13 is a small or medium-sized building. The number of piles 12 can be calculated taking into account the ground reaction X even in a small or medium-sized building.

[0020] The present disclosure is not limited to the above embodiment and can be modified as appropriate. For example, the foundation 14 may be a strip foundation. The pile arrangement system 1 of the above embodiment has a foundation design unit 2. The pile arrangement system 1 may be configured to calculate the stress of the already designed foundation 14 by the foundation stress calculation unit 3. [Explanation of symbols]

[0021] 1 pile arrangement system, 3 foundation stress calculation section, 4 foundation stress judgment section, 5 pile number calculation section 6 pile arrangement section, 11 ground, 12 pile body, 13 building, 14 foundation, X ground reaction force

Claims

1. We perform stress calculations for the foundation of a building constructed on the ground with buried piles, Determine whether the stress of the foundation calculated in the stress calculation of the foundation satisfies a required condition; If it is determined that the necessary conditions are met, the required number of pile bodies is calculated taking into account the stress of the foundation, The arrangement of the pile bodies is determined based on the required number of the pile bodies; A pile placement method in which the stress calculation for the foundation is performed by taking the vertical load acting on the foundation as the load of the building minus the ground reaction force.

2. The pile arrangement method according to claim 1 , wherein the foundation is a slab foundation.

3. 3. The pile arrangement method according to claim 1 or 2, wherein the building is a small-scale or medium-scale building.

4. a foundation stress calculation unit that calculates stress of the foundation of a building to be constructed on the ground in which the piles are buried; a foundation stress determination unit that determines whether the stress of the foundation calculated by the foundation stress calculation unit satisfies a necessary condition; A pile number calculation unit that calculates the required number of pile bodies in consideration of the stress of the foundation determined to satisfy the necessary condition by the foundation stress determination unit; A pile body arrangement unit that determines the arrangement of the pile bodies from the required number of the pile bodies calculated by the pile body number calculation unit, The foundation stress calculation unit of this pile placement system calculates the stress of the foundation as the vertical load acting on the foundation minus the ground reaction force from the load of the building.

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