JPH09165758A - Pile structure joined with floor slab connected to resin foam and application method of the pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with the curing temporary work for piling and reduce the required number of piles, by using a light replacing material in a piling method for a soft ground. SOLUTION: Paving sand 8 and geogrit or civilwork sheet 7 are laid on the ground excavated in advance and a leveling bed is placed and a light replacing material 5 like polystyrene blocks is laid thereon, and further, reinforcements 2 are arranged thereon and concrete is placed to form a floor slab 1. A piling machine is moved on the floor slab 1 to drive piles 3 from a piling space 4 secured in advance on the floor slab 1 and concrete is charged in the floor slab 1. The decreased value of the subsidence stress resulting from the light replacing material 5 is added in the calculation of the supporting force of the pile 3. Accordingly, the material 5 dispenses with the curing temporary work for the piling machine and the required number of piles is reduced.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile construction method which is one of the countermeasure construction methods in soft ground and is joined to a floor slab connected to a foamed resin material, and a construction method using piles. is there.

[Prior Art] Conventionally, in the pile construction method on soft ground, since the increasing stress of subsidence of a structure exceeds the reaction force of the soft ground, the pile supporting force has been used as a countermeasure against subsidence. In addition, the pile driving method is such that the weight of the pile driving equipment exceeds the ground reaction force of the soft ground, so the work cannot be performed or the pile driving can be performed only after performing various ground improvement methods. In order to calculate the bearing capacity of the pile, the amount of settlement increase stress that is reduced by the foamed resin material is calculated. I didn't.

[Problems to be Solved by the Invention] As described above, the conventional pile construction method is as follows.
Curing temporary work for placing is required, which is troublesome and time consuming, and the number of piles is reduced by reducing the increase in sinking stress with the foamed resin material, which reduces the construction cost accordingly. The present invention has an advantage that the construction period is shortened, and the present invention solves the problems of the above-mentioned conventional pile construction method, and is applicable to various foundations such as buildings, roads, waterways, and underground structures in soft ground. It is possible to provide a pile structure and a pile construction method.

"Means for Solving the Problems" Here, in order to improve such a conventional defect, a predetermined thickness,
In addition, in the pile structure characterized by the fact that the pile is joined to the floor slab connected to the foamed resin material arranged in the necessary area, and in the above-mentioned method of joining the pile structure, the floor slab and the pile are made of concrete. Joining, or a pile structure characterized by joining to the bottom of the floor slab and the head of the pile via a cushioning material, and in the joining method, a board is interposed between the head of the pile and the cushioning material. Pile driving equipment is placed on a board consisting of a pile structure characterized by joining and a floor slab connected to a foamed resin material constructed in a predetermined thickness and required area. Pile is driven from the space for installation, and the floor slab and the pile are joined, and the amount of foam that does not sink due to the weight of pile driving equipment in the method of using the pile and the soft ground. The method of calculating the foam material, which installs the resin material on the ground, is based on the area of the floor slab where the pile work is performed. Calculate the ground reaction force that does not cause subsidence, and then calculate whether the increase stress of subsidence of the pile driving equipment exceeds the ground reaction force.If the ground reaction force exceeds the ground reaction force, excavate the ground with foamed resin material, Calculation of the amount of stress required to reduce the amount of subsidence that does not cause replacement settlement. A method of using piles characterized by placing piles on floor slabs made on the basis of such calculations and bearing capacity of piles. In the calculation, an attempt is made to provide a method of using a pile, which is characterized in that the reduction amount of the increased settlement stress to the ground is added to the pile supporting force by the foamed resin material and the floor slab. The pile structure joined to the floor slab connected to the foamed resin material according to the present invention and the method of using the same will be apparent from the following embodiments.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described with reference to the procedure of the construction method shown in Table 1 based on the perspective view of the whole of FIG. 1 and the sectional view of the FIG. .

At the survey stage, (1) geological survey is conducted,
Obtain the long-term allowable bearing capacity of the ground, then (2) obtain the planned subsidence stress of the structure, and (3) obtain the required long-term acceptable bearing capacity, and examine the countermeasure construction method.

The design will be explained. (4) Calculate the bearing capacity obtained from piles and the amount of stress reduction due to subsidence due to the lightweight replacement material, and the quantity of piles and foamed resin material used from the structural calculation of the structure. 5) is a layout diagram of the board,
From the quantity obtained in (4), find the quantity of piles and the thickness area of the lightweight replacement material, and create a board allocation diagram.

From the investigation and design conditions, which will be described with respect to calculation examples, A) an increase in the settlement of the structure of 3.0 tf / m ²
B) Long-term allowable bearing capacity of ground 1.0 tf / m ² C) Long-term allowable bearing capacity of pile 0.8 tf / m ² D) Increase in settlement due to expanded polystyrene block replacing soil 2.055 tf / m ² E ) Floor slab sinking stress 0.2
5tf / m ² F) Increase in sinking stress of pile driving equipment 0.8t
If f / m ² safety factor Fs = 1.2, A × Fs <(B + C + D−E) 3.6 tf / m ² <3.830 tf / m ² Therefore, there is no subsidence due to the increase in subsidence of the structure. Next, when the pile driving equipment is mounted on the panel and the pile driving work is performed, the calculation for the settlement is F × Fs <B + DE 0.96tf / m ² <2.805tf / m ² Therefore, there is no settlement.

The construction will be explained. (6) is a ground foundation work, in which a leveling layer is applied to the previously excavated ground. The leveling layer is generally laid with sand, and the floor is adjusted. If it is disturbed, lay sand and geogrid or civil engineering sheets and apply a leveling layer.
(7) is a replacement material installation work. The material of the lightweight replacement material is preferably a foam polystyrene block, but if the required strength is satisfied, other foam resins may be mixed with foam resin and concrete foam resin. Material (8) is
The floor slab, which is a floor slab, arranges reinforcing bars for reinforcing the floor slab on (7), secures a pile space, and places concrete. (9) is a pile slab. The piles may be placed before ground excavation or after the floor slab is completed. However, if curing temporary construction for pile placement is necessary, use the floor slab. For example, the cost and construction period for temporary curing work will be saved, and it will be economical. We will explain the case of using a floor slab. The pile head may be placed under the floor slab, in the middle, or on the upper surface, but if the vibration and the vibration due to an earthquake are taken into consideration, the part under the floor slab may be placed. Good (10) is the joint between the pile head and the floor slab. In the pile space of the floor slab, the floor slab is reinforced with reinforcing bars.
▼ Concrete filling joining, Fig. 2 shows when joining under the floor slab, ▲ 10 ▼ Pile heads ▲ 12 ▼ fixed lantern, joining with floor slab via cushioning material, ▲ 12 ▼ surface plate , ▲ 10 ▼
The cushioning material is rubber that is larger than the area of the pile head and is used to protect the cushioning material by distributing the load transmitted from the floor slab to the pile head through the cushioning material (10). However, even a foamed resin material, such as foamed polypropylene, should have a compressive strength that exceeds the bearing capacity of the pile. For example, if the bearing capacity of a pile is 50 tons, (12) If the area is set to 1 m ² , the compressive strength of the cushioning material is 6 Kgf obtained by adding 20% of safety factor to 5 Kg / cm ^2.
This structure, which requires / cm ^2, is also an isolation structure against earthquakes. The present invention provides a pile structure joined to a floor slab connected to such a foamed resin material, and a construction settlement countermeasure and a soil pressure reducing construction method by a construction method using the pile.

[Advantages of the Invention] The pile structure joined to the floor slab connected to the foamed resin material and the method of using the pile according to the present invention are
Since piles and lightweight replacement materials are used, it is very easy to take measures against subsidence of structures and reduce earth pressure, and it is possible to safely construct buoyancy due to water against foamed resin materials. Also, there is no temporary construction work for piles. It also has the effect that the period is short and it can be provided economically and cheaply as compared with the conventional method.

[Brief description of the drawings]

FIG. 1 is an overall perspective view

[Fig.-2] Board cross section

[Explanation of symbols]

(1) Geological survey (2) Planned settlement stress of structure (3) Required long-term bearing capacity (4) Pile bearing capacity and light weight replacement material increase stress reduction amount calculation (5) Board allocation diagram creation ( 6) Ground foundation work (7) Replacement material installation work (8) Floor slab work (9) Pile driving work (10) Pile head and floor slab joint work (11) Construction of floor slab floor slab Pile Pile space Expanded polystyrene leveling layer Geogrid or civil engineering sheet Soil cushioning material ▲ 10 ▼ Pile head ▲ 11 ▼ Filled concrete ▲ 12 ▲ Surface plate

Claims (6)

[Claims] 1. A pile structure in which a pile is joined to a floor slab connected to a foamed resin material arranged in a predetermined thickness and a required area. 2. The method for joining a pile structure according to claim 1, wherein the floor slab and the pile are joined using concrete, or the lower part of the floor slab and the head of the pile are joined via a cushioning material. Characteristic pile structure. 3. The pile structure according to claim 2, wherein the head of the pile and the cushioning material are joined via a board. 4. A pile driving equipment is placed on a board made of a floor slab connected to a foamed resin material having a predetermined thickness and a required area, and a space for pile driving is provided in advance on the floor slab. A method of using piles, which comprises placing the piles and joining the slab to the piles. 5. In soft ground, the amount of foamed resin material that does not sink due to the weight of pile driving equipment is set on the ground. The method of calculating foam material is as follows: Calculate the ground reaction force, and then calculate whether the settlement stress of the pile driving equipment will exceed the ground reaction force.If it exceeds the ground reaction force, excavate the ground and replace the soil with a foamed resin material. A method of using piles, which comprises placing piles on a floor slab made based on such calculation to calculate the amount of increase in stress reduction requirements. 6. A method of using a pile, characterized in that, in the calculation of the pile bearing capacity, a reduction amount of the increased settlement stress to the ground is added to the pile bearing capacity by the foamed resin material and the floor slab.