JP6941553B2 - Pile construction method - Google Patents

Description

The present invention relates to a pile body construction method.

Conventionally, a method for constructing a pile body on the ground has been proposed. In this method, a step of forming a pile hole by excavating the ground, a step of forming a root hardening part by injecting a root hardening liquid into the formed pile hole, and a step of forming a root hardening part, and the injected root hardening liquid are used. It includes a step of adjusting the position or inclination of the pile body before hardening.

JP-A-2017-8490

However, in the method of Patent Document 1, the density of the bottom of the root-consolidating portion is increased by the water spilling from the root-consolidating liquid injected into the root-consolidating portion, and the water content of the root-consolidating liquid is increased at the bottom of the root-consolidating portion. Since components other than the above, sand, etc. are likely to accumulate, for example, in the process of adjusting the position or inclination of the pile body, the movement of the pile body is hindered by what is stored at the bottom of the rooting portion, so that the adjustment is efficient. There was a risk that it would be difficult to do it in a targeted manner. Therefore, there was room for improvement from the viewpoint of workability of the pile body.

The present invention has been made in view of the above, and an object of the present invention is to provide a pile body construction method capable of improving the workability of the pile body.

In order to solve the above-mentioned problems and achieve the object, the pile body construction method according to claim 1 is a pile body construction method for constructing a pile body on the ground, and a pile hole is formed on the ground. The first hardening agent and the pile hole are filled with the pile hole forming step and the storage portion located at the lower end of the pile hole for storing the sediment that settles in the pile hole. A storage portion forming step formed by stirring only the soil of the portion corresponding to the storage portion, and a fixing portion located above the storage portion, for fixing only the lower end portion of the pile body. The fixing portion forming step of forming the fixing portion by stirring only the second hardening agent to be filled and the soil of the portion corresponding to the fixing portion of the pile hole, and the first filling in the storage portion forming step. Before the 1 curing agent and the 2nd curing agent filled in the fixing portion forming step are cured, the insertion step of inserting the pile body into the pile hole and the 1st curing filled in the storage portion forming step It includes an adjustment step of adjusting the position or inclination of the pile body inserted in the insertion step before the agent and the second hardening agent filled in the fixing portion forming step are cured.

The pile construction method according to claim 2 is the pile construction method according to claim 1, wherein the height of the storage portion is set based on the following formula.
H = h1 × α × β-h2
(Here, H is the height of the portion of the storage portion where the sediment can be stored , h1 is the total height of the storage portion and the fixed portion, and α is a predetermined value or more distributed in the ground. The ratio of the presence of soil having a particle size, β is the ratio of the soil remaining in the ground in the storage portion and the fixed portion , and h2 is the height of the fixed portion ).

The pile body construction method according to claim 3 is an upper fixing portion located above the fixing portion in the pile body construction method according to claim 1 or 2, and is a portion other than the lower end portion of the pile body. The first step of forming the upper fixing portion, which comprises forming the upper fixing portion for fixing the upper fixing portion by stirring only the third curing agent to be filled and the soil of the portion corresponding to the upper fixing portion of the pile hole. Each of the 1 curing agent, the 2nd curing agent, and the 3rd curing agent contains a root hardening liquid composed of water and cement, and the mixing ratio of water and cement in the root hardening liquid in the 3rd curing agent is determined. The mixing ratio of water and cement in the root hardening liquid of each of the first curing agent and the second curing agent was lower than that of the water and cement.
The pile construction method according to claim 4 is the pile construction method according to any one of claims 1 to 3, wherein each of the first hardening agent and the second hardening agent is a root hardening liquid. , An admixture for increasing the viscosity and dispersibility of the root hardening liquid.

In the pile construction method according to claim 5 , in the pile construction method according to claim 4 , the mixing ratio of the admixture in the root hardening liquid is 1% or less by weight.

The pile construction method according to claim 6 is the pile construction method according to claim 4 or 5 , wherein the admixture includes a high-performance AE attenuator or a thickener.

The pile construction method according to claim 7 is the pile construction method according to any one of claims 4 to 6 , wherein each of the first curing agent and the second curing agent is the root hardening liquid. Contains a retarder to delay the curing of.

According to the pile body construction method according to claim 1, a storage portion forming step of forming a storage portion located at the lower end of the pile hole by filling with a first hardening agent, and a fixing portion located above the storage portion. The fixed portion forming step of forming the pile by filling the second hardener, the insertion step of inserting the pile body into the pile hole before the first hardener and the second hardener are hardened, and the first hardener and the second hardener. Since it includes an adjustment step of adjusting the position or inclination of the pile body inserted in the insertion step before the hardener is cured, the sediment can be stored in the storage portion, so that the sediment can be stored in the fixed portion. It is possible to avoid storage. Therefore, as compared with the case where the storage portion forming step is not included, it is possible to avoid the sediment from hindering the adjustment of the position or inclination of the pile body in the adjustment step, so that the workability of the pile body can be improved. ..

According to the pile construction method according to claim 2, since the height of the storage portion is set based on the following formula, the height of the storage portion can be set accurately, and the pile body is constructed by the sediment. It becomes possible to store the sediment in the storage portion so that (particularly, the adjustment step) is not hindered.
H = h1 × α × β-h2
(Here, H is the height of the portion of the storage portion where the sediment can be stored , h1 is the total height of the storage portion and the fixed portion, and α is a predetermined value or more distributed in the ground. The ratio of the presence of soil having a particle size, β is the ratio of the remaining soil in the ground in the storage portion and the fixed portion , and h2 is the height of the fixed portion ).

According to the pile construction method according to claim 4 , since each of the first hardening agent and the second hardening agent contains a root hardening liquid and an admixture, the water content of the root hardening liquid is prevented from escaping. In addition to being able to suppress it, it is possible to suppress the aggregation of chemical components (for example, cement components) contained in the root hardening liquid, and it is possible to improve the workability (particularly, the adjusting step) of the pile body.

According to the pile construction method according to claim 5 , since the mixing ratio of the admixture in the root hardening liquid is 1% or less by weight, the desired viscosity and dispersibility in the first curing agent and the second curing agent. The amount of admixture used can be relatively reduced, and the construction cost can be reduced.

According to the pile construction method according to claim 6 , since the admixture contains a high-performance AE attenuator or a thickener, the admixture can be formed from a relatively easily available material, and the admixture can be used. It can be easily produced.

According to the pile construction method according to claim 7 , since each of the first curing agent and the second curing agent contains a retarding agent, the curing of the root hardening liquid can be delayed, and the pile workability. (In particular, the adjustment process) can be further improved.

It is sectional drawing which shows the foundation structure which concerns on embodiment of this invention. It is a graph which shows the relationship between the sedimentation depth and the particle size after the time t = 2 hours after the completion of stirring. It is a graph which shows the particle size distribution of the ground. It is sectional drawing which shows the pile hole forming process of the pile body construction method. It is sectional drawing which shows the storage part formation process of the pile body construction method. It is sectional drawing which shows the lower side fixing part formation process of a pile body construction method. It is sectional drawing which shows the upper side fixing part formation process of a pile body construction method. It is sectional drawing which shows the mounting process of the pile body construction method. It is sectional drawing which shows the insertion process of the pile body construction method. It is sectional drawing which shows the adjustment process of the pile body construction method. It is a figure which shows the characteristic of a test body. It is a figure which shows the test result of the dehydration test. It is a figure which shows the test result of the shear test. It is a figure which shows the test result of the uniaxial compression test.

Hereinafter, embodiments of the pile body construction method according to the present invention will be described in detail with reference to the accompanying drawings. First, the basic concept of the embodiment of [I] will be described, then the specific contents of the embodiment of [II] will be described, and finally, a modified example of the embodiment of [III] will be described. However, the present invention is not limited to the embodiments.

[I] Basic concept of the embodiment First, the basic concept of the embodiment will be described. The embodiment generally relates to a pile body construction method for constructing a pile body on the ground. Here, the "pile body" is a construction member for transmitting the load of the structure to a predetermined stratum in the ground in order to prevent the structure provided on the ground from sinking. Further, the use of the "structure" constructed using this pile body is a concept including, for example, an apartment house such as an apartment or a condominium, an office building, a commercial facility, a public facility, and the like.

[II] Specific contents of the embodiment Next, the specific contents of the embodiment will be described.

(composition)
First, the configuration of the foundation structure constructed by the pile body construction method according to the embodiment will be described. FIG. 1 is a cross-sectional view showing a basic structure according to an embodiment of the present invention. In the following description, the X direction in FIG. 1 is the left-right direction of the foundation structure (-X direction is the left direction of the foundation structure, the + X direction is the right direction of the foundation structure), and the Y direction in FIG. 1 is the foundation structure. The vertical direction (+ Y direction is the upward direction of the basic structure, -Y direction is the downward direction of the basic structure), and the directions orthogonal to the X and Z directions are the front-back direction (the direction leading to the front side of the paper in FIG. 1 is the basis). The front direction of the structure and the direction leading to the back side of the paper surface in FIG. 1 are referred to as the rear direction of the basic structure).

This foundation structure 1 is a structure for supporting the structure, and as shown in FIG. 1, a pile hole 10, a pile body 20, a structural pillar 30, a storage portion 40, a lower fixing portion 50, and an upper side. It includes a fixing portion 60 and a bag-shaped body 70.

(Composition-Pile hole)
First, the configuration of the pile hole 10 will be described. The pile hole 10 is a hole for inserting the pile body 20. The pile hole 10 is formed in the ground G (original ground), and specifically, as shown in FIG. 1, is formed in the vertical downward direction from the ground surface GS of the ground G.

The specific shape and size of the pile hole 10 are arbitrary, but in the embodiment, they are set as follows. That is, first, as shown in FIG. 1, the diameter of the pile hole 10 is set to a size that allows the pile body 20 and the bag-shaped body 70 to be inserted inside the pile hole 10. Specifically, by setting the diameter of the pile hole 10 to be relatively large, the pile body 20 can be installed at a desired position even when the position shift or inclination of the pile hole 10 is large, but the pile hole 10 Since it is necessary to increase the size of the bag-shaped body 70 provided between the pile body 20 and the pile hole 10 according to the diameter, the size is set in consideration of the size of the bag-shaped body 70. Further, the height of the pile hole 10 (length in the vertical direction) is set to a height at which the pile body 20 and the structural pillar 30 can be inserted, as shown in FIG.

(Composition-Pile body)
Next, the configuration of the pile body 20 will be described. The pile body 20 is formed of an elongated body, and is provided inside the pile hole 10 so as to be surrounded by the upper fixing portion 60 and the lower fixing portion 50. Specifically, as shown in FIG. 1, the axis of the pile hole 10 and the axis of the pile body 20 are provided so as to substantially coincide with each other, and the pile head of the pile body 20 (the pile body 20). The upper end portion) is located below the ground surface GS, and the pile bottom portion (lower end portion of the pile body 20) of the pile body 20 is the lower fixing portion 50 (specifically, the lower fixing portion 50) of the pile hole 10. It is provided so as to be located at a portion corresponding to the lower end portion of the stake or a portion near the lower end portion of the stake.

The specific configuration of the pile body 20 is arbitrary, but in the embodiment, a ready-made pile configured by filling the inside of a steel pipe as an outer shell with concrete is used. However, the present invention is not limited to this, and for example, known ready-made piles such as steel pipe piles, PHC piles, and PRC piles may be used.

(Composition-Shinbashira)
Next, the configuration of the structural pillar 30 will be described. The structural pillar 30 is a support pillar provided underground in the ground G to support the structure, and is configured by using, for example, a known structural pillar 30 (for example, a steel pillar) for pile construction. .. Further, as shown in FIG. 1, the structural pillar 30 is provided at a position above the pile body 20 and is joined to the pile body 20 (specifically, the upper end portion of the pile body 20). ing.

(Configuration-Reservoir)
Next, the configuration of the storage unit 40 will be described. The storage unit 40 is for storing sediment. Here, the “precipitate” means a substance that settles in the pile hole 10, and for example, the agent of the first curing agent 41 described later, the second curing agent 51 described later, and the third curing agent 61 described later. It is a concept including components (for example, cement components), sand and gravel of the ground G, and the like. The storage portion 40 is formed of a substantially long columnar body, and is provided at the lower end portion of the pile hole 10 as shown in FIG.

The specific shape and size of the storage unit 40 are arbitrary, but in the embodiment, they are set as follows.

That is, the planar shape of the storage portion 40 is set to a shape corresponding to the planar shape of the pile hole 10, and specifically, it is set to a circular shape. Further, the diameter of the storage portion 40 is set to be substantially the same as the diameter of the pile hole 10.

Further, the height of the portion of the storage unit 40 where the sediment can be stored is set by the method shown below. First, from the sand settling speed v and the time t from the completion of stirring the cement milk and the like in the storage portion 40 and the lower fixing portion 50 to the adjustment of the position of the pile body 2 (hereinafter, referred to as "time after completion of stirring t"). , The amount of sand settling s (= sand settling speed v × time after stirring completed) was calculated, and the calculated amount of sand settling s and the storage section 40 and the lower fixing section 50 From the total height h1, the minimum diameter dm of the sand having the sedimentation amount s> the total height h1 (hereinafter, referred to as “minimum diameter dm”) is determined. Next, the ratio α (hereinafter, referred to as “presence ratio α”) in which soil having a particle size (specifically, the minimum diameter dm) distributed over the ground G and having a particle size equal to or larger than a predetermined value is present is determined. Next, in the storage section 40 and the lower fixing section 5, the excavated water and cement milk are agitated while being injected, so that a part of the soil of the ground G is discharged to the ground surface, but the other part is not discharged. The ratio indicating the amount of this soil, that is, the ratio β in which the soil of the ground G in the storage portion 40 and the lower fixed portion 50 remains (hereinafter referred to as “residual ratio β”) is determined (specifically). The target is determined based on the experimental results, etc.). Then, the height H of the portion of the storage unit 40 where the sediment can be stored is set based on the following equation (1).
H = h1 × α × β-h2 ・ ・ ・ Equation (1)
(here,
H: Height of the portion of the storage portion 40 where the sediment can be stored ,
h1: Total height of the storage section 40 and the lower fixing section 50 α: Presence ratio,
β: Residual ratio,
h2: Height of lower fixing portion 50)

Further, a calculation example relating to the setting of the height H of the portion where the sediment can be stored in the storage unit 40 described above will be described below. FIG. 2 is a graph showing the relationship between the settling depth and the particle size after the time t = 2 hours after the completion of stirring, and the horizontal axis is the particle size and the vertical axis is the settling depth after the time t = 2 hours after the completion of stirring. Is shown. FIG. 3 is a graph showing the particle size distribution of the ground G, where the horizontal axis represents the particle size and the vertical axis represents the passing mass percentage.

（ここで、η：分散媒の粘性、
ｇ：重力加速度、
ｄ：粒子径、
ρ_ｗ：分散媒の密度、
ρ_ｓ：粒子の密度）
ｓ＝７．２ｖ・・・式（３） First, for the minimum diameter dmin, the sand settling velocity v is calculated by the following equation (2) according to the Gibbs approximate equation. Next, assuming that the time t after the completion of stirring t = 2 hours (7200 sec), the amount of sedimentation s of sand at the time t after the completion of stirring is calculated from the above sand settling speed v and the time t after the completion of stirring by the following equation (3). ). Then, using the following formula (3), the minimum diameter dm is specified based on the relationship between the sedimentation depth and the particle size after the lapse of time t = 2 hours after the completion of stirring as shown in FIG. As an example, when the total height of the storage portion 40 and the lower fixing portion 50 is h1 = 3m, considering only the particle sedimentation in the storage portion 40 and the lower fixing portion 50, as shown in FIG. Since it is clear that all particles having a particle size of 0.1 mm or more settle, the minimum diameter of dmin is specified as 0.1 mm.

(Here, η: viscosity of the dispersion medium,
g: Gravitational acceleration,
d: particle size,
ρ _w : Dispersion medium density,
ρ _s : particle density)
s = 7.2v ... Equation (3)

Next, the abundance ratio α is specified based on a graph showing the particle size distribution of the ground as shown in FIG. As an example, when the particle size distribution of the ground G at the depth in the storage portion 40 and the lower fixing portion 50 shows the distribution shown in FIG. 3, when the minimum diameter dm = 0.1 mm, the abundance ratio α = 100%. -Identify the pass percentage = 100% -20% = 80% corresponding to the minimum diameter dm.

The height H of the portion of the storage portion 40 capable of storing the sediment is the total height h1, the minimum diameter dm, and the abundance ratio α of the specified storage portion 40 and the lower fixing portion 50. , Specified based on the above formula (1) from the residual ratio β specified based on the experimental results and the like. As an example, when the total height h1 = 3 m, the minimum diameter dm = 0.1 mm, the abundance ratio α = 80%, and the residual ratio β = 30% of the storage portion 40 and the lower fixing portion 50, the above formula is used. It is specified by the following formula (4) obtained from (1). However, when the height H of the portion where the sediment can be stored in the storage unit 40 is smaller than the height h2 of the lower fixing portion 50, the sediment in the storage unit 40 can be stored. The height H of the portion is specified as zero.
H = h1 × α × β-h2
= 3 × 0.8 × 0.3-h2
= 0.72-h2 ... Equation (4)

By setting the height H of the portion of the storage unit 40 capable of storing the sediment, the height H of the portion of the storage unit 40 capable of storing the sediment is accurately set. It is possible to store the sediment in the storage unit 40 so that the construction of the pile body 20 (particularly, the adjustment step described later) is not hindered by the sediment.

The method of forming the storage portion 40 is arbitrary, but in the embodiment, it is as follows. First, the first curing agent 41 is filled in the portion of the pile hole 10 corresponding to the storage portion 40. Next, the filled first curing agent 41 and the soil in the portion corresponding to the storage portion 40 of the pile hole 10 are agitated. Then, the pile body 20 is not positioned in the storage portion 40, and is formed by curing the agitated product for a predetermined time (for example, half a day or the like).

(Structure-Reservoir-First curing agent)
Here, the first curing agent 41 is used for forming the storage portion 40, and in the embodiment, it is composed of a root hardening liquid, an admixture, and a retarding agent (all of which are shown in the figure). omit).

Of these, the root hardening liquid is a chemical liquid used for fixing the pile body 20, and in the embodiment, it is composed of cement milk and the like. Further, the admixture is an agent for increasing the viscosity and dispersibility of the root hardening liquid, and in the embodiment, it is composed of a high-performance AE attenuator or a thickener. Here, the high-performance AE attenuation agent is an agent for uniformly distributing a large number of air bubbles in the first curing agent 41 to improve the workability of the first curing agent 41, for example, melamine sulfonic acid. This includes system compounds. The thickener is an agent for increasing the viscosity of the first curing agent 41, and for example, a water-soluble polymer compound or the like is applicable. Further, the retarder is an agent for delaying the curing of the root hardening liquid, and in the embodiment, a root hardening delay agent is used.

Further, the method of setting the mixing ratio of water and cement in the root hardening liquid (so-called water-cement ratio) is arbitrary, but in the embodiment, the mixing ratio is set so that the pile body 20 can be fixed. It is set to about 50% to 60%.

The method of setting the mixing ratio of the admixture in the root hardening liquid is arbitrary, but in the embodiment, the weight ratio is set to 1% or less based on the test results described later. It is set in the range of 1% or more and 1% or less. As a result, the amount of the admixture used can be relatively reduced and the construction cost can be reduced while ensuring the desired viscosity and dispersibility of the first curing agent 41.

With such a configuration of the first curing agent 41, it is possible to suppress the water leakage of the root hardening liquid and to prevent the chemical components (for example, cement components) contained in the root hardening liquid from aggregating. This makes it possible to improve the workability of the pile body 20 (particularly, the adjustment step described later). In particular, since the admixture contains a high-performance AE attenuator and a thickener, the admixture can be formed from a relatively easily available material, and the admixture can be easily prepared. Further, since the first curing agent 41 contains a curing agent, the curing of the root hardening liquid can be delayed, and the workability of the pile body 20 (particularly, the adjustment step described later) can be further improved.

(Structure-Lower fixing part)
Returning to FIG. 1, the configuration of the lower fixing portion 50 will be described next. The lower fixing portion 50 is a fixing portion for fixing the lower end portion of the pile body 20. The lower fixing portion 50 is formed of a substantially long columnar body, and is provided at a position above the storage portion 40 as shown in FIG.

The specific shape and size of the lower fixing portion 50 are arbitrary, but in the embodiment, they are set as follows. That is, first, the planar shape of the lower fixing portion 50 is set to a shape (specifically, a circular shape) corresponding to the planar shape of the pile hole 10. Further, as shown in FIG. 1, the diameter of the lower fixing portion 50 is set to be substantially the same as the diameter of the storage portion 40. Further, the height of the lower fixing portion 50 is set to a height required for fixing the pile body 20 based on the diameter of the pile body 20.

The method of forming the lower fixing portion 50 is arbitrary, but in the embodiment, it is as follows. First, the second curing agent 51 is filled in the portion corresponding to the lower fixing portion 50 of the pile hole 10. Next, the filled second curing agent 51 and the soil of the portion corresponding to the lower fixing portion 50 of the pile hole 10 are stirred. Then, the pile body 20 is formed by curing the agitated product for a predetermined time (for example, half a day or the like) while the pile body 20 is positioned in the lower fixing portion 50.

(Structure-Lower fixing part-Second curing agent)
Here, the second curing agent 51 is used for forming the lower fixing portion 50, and in the embodiment, it is composed of a root hardening liquid, an admixture, and a retarding agent. Since the second curing agent 51 is configured to be substantially the same as the component having the same name as the first curing agent 41, detailed description thereof will be omitted.

(Structure-upper fixing part)
Next, the configuration of the upper fixing portion 60 will be described. The upper fixing portion 60 is for fixing a portion other than the lower end portion of the pile body 20 and the structural pillar 30. The upper fixing portion 60 is formed of a substantially long columnar body, and is provided at a position above the lower fixing portion 50 as shown in FIG.

The specific shape and size of the upper fixing portion 60 are arbitrary, but in the embodiment, they are set as follows. That is, first, the planar shape of the upper fixing portion 60 is set to a shape (specifically, a circular shape) corresponding to the planar shape of the pile hole 10. Further, the diameter of the upper fixing portion 60 is set to be smaller than the diameter of the lower fixing portion 50. Further, the height of the upper fixing portion 60 is set based on the shape and size of the pile body 20 and the structural pillar 30.

The method of forming the upper fixing portion 60 is arbitrary, but in the embodiment, it is as follows. First, the third curing agent 61 is filled in the portion corresponding to the upper fixing portion 60 of the pile hole 10. Next, the filled third curing agent 61 and the soil of the portion corresponding to the upper fixing portion 60 of the pile hole 10 are stirred. Then, in a state where the pile body 20 and the structural pillar 30 are positioned in the upper fixing portion 60, the agitated one is cured for a predetermined time (for example, half a day or the like) to form the pile body 20 and the structural pillar 30.

(Structure-Upper fixing part-Third curing agent)
Here, the third curing agent 61 is used to form the upper fixing portion 60, and in the embodiment, it is composed of a root hardening liquid, an admixture, and a retarding agent. Although the third curing agent 61 has almost the same composition as the first curing agent 41, the mixing ratio of water and cement in the root hardening liquid is set as follows. That is, in the embodiment, the compounding ratio is set so that the pile body 20 and the structural pillar 30 can be fixed so that the construction of the pile body 20 (specifically, the adjustment step described later) is not hindered. , The compounding ratio is set lower than that of the first curing agent 41.

(Structure-bag-shaped body)
The bag-shaped body 70 is an adjusting means for adjusting the position or inclination of the pile body 20. Here, "adjusting the position or inclination of the pile body 20" means, for example, setting the inclination of the structural pillar 30 within a predetermined inclination (for example, 1/500 or the like), and setting the lower end of the structural pillar 30. It is a concept including setting the position of the portion or the position of the pile head of the pile body 20 within a predetermined distance (for example, 100 mm) from the axis of the pile hole 10. The bag-shaped body 70 is provided at a position corresponding to the upper fixing portion 60 on the outer peripheral surface of the pile body 20, and specifically, as shown in FIG. 1, the bag-shaped body 70 is the ground surface GS. It is arranged at a position not exposed from the pile body 20 and is attached to a plurality of locations (in the embodiment, a total of four locations in front, rear, right, and left of the pile body 20) with respect to the outer peripheral surface of the pile body 20. There is.

The specific configuration of the bag-shaped body 70 is arbitrary, but in the embodiment, the bag-shaped body 70 is a hollow body formed of a expandable material, and after the adjustment step described later is executed. , It is formed of a hollow body capable of injecting an injection material into the bag-shaped body 70, and is formed of, for example, a resin hollow body. Here, the "injection material" is one that is injected into the bag-shaped body 70, and corresponds to, for example, a gaseous, a liquid, a gel, a solid, or a state in which these states are mixed. However, in the embodiment, it will be described as cement milk.

The method of attaching the bag-shaped body 70 is arbitrary, but in the embodiment, the position or inclination of the pile body 20 can be easily adjusted as the bag-shaped body 70 is positioned downward, but the injection material is stored. The length of the hose (not shown) for sending the injection material to the bag-shaped body 70, which is a hose connected to the plant (not shown), hinders the insertion step or the adjustment step described later. Since there is a risk, it is attached to the upper end portion of the outer peripheral surface of the pile body 20 or a portion near the upper end portion thereof.

(Pile construction method)
Subsequently, the pile body construction method according to the embodiment will be described. FIG. 4 is a cross-sectional view showing a pile hole forming step of the pile body construction method described later. FIG. 5 is a cross-sectional view showing a storage portion forming step of the pile body construction method described later. FIG. 6 is a cross-sectional view showing a lower fixing portion forming step of the pile body construction method described later. FIG. 7 is a cross-sectional view showing an upper fixing portion forming step of the pile body construction method described later. FIG. 8 is a cross-sectional view showing a mounting process of a pile body construction method described later. FIG. 9 is a cross-sectional view showing an insertion step of a pile body construction method described later. FIG. 10 is a cross-sectional view showing an adjustment process of a pile body construction method described later. As shown in FIGS. 4 to 10, the pile body construction method includes a pile hole forming step, a storage portion forming step, a lower fixing portion forming step, an upper fixing portion forming step, a mounting step, an insertion step, and an adjusting step. I'm out.

(Pile body construction method-pile hole formation process)
The pile hole forming step is a step of forming the pile hole 10 in the ground G. In this pile hole forming step, as shown in FIG. 4, the pile hole 10 is formed by excavating the ground G using the excavation device 80.

Here, the excavation device 80 is a device for excavating a pile hole 10 in the ground G. The excavation device 80 is configured by using, for example, a known excavation rod or the like, and includes a shaft portion 81, an excavation portion 82, an injection portion 83, and a stirring portion 84 as shown in FIG. Of these, the shaft portion 81 is a rotating shaft for rotating the excavation portion 82 and the stirring portion 84, and is formed of a rod-shaped body. Further, the excavation portion 82 is an excavation means for excavating the ground G, and is configured by using, for example, a known excavation head, and is attached to the lower end portion of the shaft portion 81. Further, the injection unit 83 is an injection means for injecting various curing agents, and is configured by using, for example, a known nozzle or the like, and is attached to the lower end portion of the shaft portion 81. Further, the stirring unit 84 is a stirring means for stirring what is filled in the pile hole 10, and is configured by using, for example, a known stirring blade, and the length of the shaft portion 81 with respect to the shaft portion 81. A plurality of them are attached at predetermined intervals along the direction.

Regarding the specific contents of the pile hole forming step, first, the excavation region (planar region) of the excavation portion 82 of the excavation device 80 is set to the diameter of the upper fixing portion 60, and then the pile hole 10 is set by the excavation portion 82. The portion corresponding to the upper fixed portion 60 of the above is excavated. Next, the excavation area of the excavation portion 82 is set to the diameter of the lower fixing portion 50, and then the excavation portion 82 corresponds to the lower fixing portion 50 of the pile hole 10. Then, after setting the excavation area of the excavation section 82 to the diameter of the storage section 40 (note that if the diameter of the storage section 40 is the same as the diameter of the lower fixing portion 50, the excavation area of the excavation section 82 is set. (Maintain), the pile hole 10 is formed by excavating the portion corresponding to the storage portion 40 of the pile hole 10 by the excavation part 82. As a result, the diameter of the portion corresponding to each of the storage portion 40 and the lower fixing portion 50 can be made larger than the diameter of the portion corresponding to the upper fixing portion 60.

(Pile construction method-reservoir formation process)
The storage section forming step is a step of forming the storage section 40. In this storage portion forming step, as shown in FIG. 5, the storage portion 40 is formed by filling the portion of the pile hole 10 corresponding to the storage portion 40 with the first curing agent 41 using the drilling device 80. ..

Specifically, first, a predetermined amount of the first curing agent 41 is injected from the injection portion 83 of the drilling apparatus 80 to fill the portion of the pile hole 10 corresponding to the storage portion 40 with the first curing agent 41. Next, by rotating the excavation portion 82 of the excavation device 80, the first curing agent 41 filled in the portion corresponding to the storage portion 40 of the pile hole 10 and the soil in the portion are agitated. Then, the storage portion 40 is formed by curing the agitated product until a predetermined time elapses (for example, half a day or the like) from the agitation.

(Pile construction method-lower fixing part forming process)
The lower fixing portion forming step is a step of forming the lower fixing portion 50 (fixing portion forming step). In this lower fixing portion forming step, as shown in FIG. 6, by filling the portion corresponding to the lower fixing portion 50 of the pile hole 10 with the second curing agent 51 using the drilling device 80, the lower side is formed. The fixing portion 50 is formed.

Specifically, first, by injecting a predetermined amount of the second curing agent 51 from the injection portion 83 of the drilling apparatus 80, the portion corresponding to the lower fixing portion 50 of the pile hole 10 is filled with the second curing agent 51. do. Next, by rotating the excavation portion 82 or the stirring portion 84 of the excavating device 80, the second curing agent 51 filled in the portion corresponding to the lower fixing portion 50 of the pile hole 10 and the soil in the portion are stirred. do. Then, the lower fixing portion 50 is formed by curing the stirred product until a predetermined time elapses (for example, half a day or the like) from the stirring.

(Pile body construction method-upper fixed part forming process)
The upper fixing portion forming step is a step of forming the upper fixing portion 60. In this upper fixing portion forming step, as shown in FIG. 7, the upper fixing portion 60 is filled with the third curing agent 61 in the portion corresponding to the upper fixing portion 60 of the pile hole 10 by using the drilling device 80. To form.

Specifically, first, by injecting a predetermined amount of the third curing agent 61 from the injection portion 83 of the drilling apparatus 80, the portion corresponding to the upper fixing portion 60 of the pile hole 10 is filled with the third curing agent 61. .. Next, by rotating the stirring portion 84 of the excavator 80, the third curing agent 61 filled in the portion corresponding to the upper fixing portion 60 of the pile hole 10 and the soil in the portion are stirred. Then, the upper fixing portion 60 is formed by curing the stirred product until a predetermined time elapses (for example, half a day or the like) from the stirring.

The pile hole forming step, the storage portion forming step, the lower fixing portion forming step, and the upper fixing portion forming step may be executed in a different order as appropriate, or only a part of the steps may be appropriately combined. May be executed. Further, in the pile hole forming step, the storage portion forming step, the lower fixing portion forming step, and the upper fixing portion forming step, the pile hole 10, the storage portion 40, the lower fixing portion 50, and the upper fixing portion 60 were formed. Later, the excavator 80 is removed.

(Pile construction method-mounting process)
The attachment step is a step of attaching the bag-shaped body 70 and the structural pillar 30 to the pile body 20. In this attachment step, as shown in FIG. 8, the bag-shaped body 70 and the structural pillar 30 are attached to the pile body 20 by using a crane (not shown) or an adjustment stand 90.

Here, the crane is for lifting the pile body 20, for example, a known crane or the like is used, and the crane is provided in the vicinity of the pile hole 10 on the ground surface GS. Further, the adjusting stand 90 is a stand for adjusting the position or inclination of the pile body 20, and as shown in FIG. 8, is provided in the vicinity of the pile hole 10 on the ground surface GS, and is provided as a limiting portion and a pressing portion. (Neither is shown). Of these, the limiting portion is a limiting means for restricting movement in the left-right direction, the front-back direction, or the up-down direction with the pile body 20 or the structural pillar 30 penetrating the adjusting stand 90. Further, the pressing portion is a pressing means for pressing the pile body 20 or the structural pillar 30 in the left-right direction or the front-rear direction.

Regarding the specific contents of the mounting process, first, the four bag-shaped bodies 70 are connected to the pile body 20 by using tape, a connecting tool, or the like. Next, each bag-shaped body 70 is connected to the plant via a hose. Next, the pile body 20 is lifted by a crane or the like, and a part of the pile body 20 is inserted into the pile hole 10 by penetrating the pile body 20 through the adjusting stand 90. Then, a part of the pile body 20 is inserted into the pile hole 10 by restricting the movement of the pile body 20 in the left-right direction, the front-back direction, and the up-down direction by the limiting portion of the adjusting base 90 (hereinafter, "first". By connecting the structural pillar 30 to the pile body 20 (specifically, the pile head of the pile body 20) with a connecting tool or the like while maintaining the “restraint state”), the bag-shaped body 70 and The structural pillar 30 is attached to the pile body 20.

(Pile construction method-insertion process)
In the insertion step, the first curing agent 41 filled in the storage portion forming step, the second curing agent 51 filled in the lower fixing portion forming step, and the third curing agent 61 filled in the upper fixing portion forming step This is a step of inserting the pile body 20 into the pile hole 10 before hardening. In this insertion step, as shown in FIG. 9, the pile body 20 is inserted into the pile hole 10 so that the pile bottom portion of the pile body 20 is located in the lower fixing portion 50 by using the adjusting stand 90.

Specifically, first, the pile body 20 is lowered by its own weight by releasing the first restraint state by the adjusting pedestal 90. In this case, if necessary, the adjusting pedestal 90 may lower the pile body 20 while applying rotation about the axis of the pile body 20 to the pile body 20. Then, when the pile bottom portion of the pile body 20 reaches the lower end portion of the lower fixing portion 50, the restricting portion of the adjusting pedestal 90 restricts the movement of the structure pillar 30 in the horizontal direction, the front-rear direction, and the vertical direction. The state in which the pile bottom portion of the pile body 20 is located at the lower end portion of the lower fixing portion 50 is maintained (hereinafter, this state is referred to as a "second restraint state").

(Pile construction method-adjustment process)
In the adjusting step, the first curing agent 41 filled in the storage portion forming step, the second curing agent 51 filled in the lower fixing portion forming step, and the third curing agent 61 filled in the upper fixing portion forming step This is a step of adjusting the position or inclination of the pile body 20 before it is hardened (in the embodiment, about 2 hours have passed since the stirring of the storage unit 40 was completed). In this adjustment step, as shown in FIG. 10, the position or inclination of the pile body 20 is adjusted by using the adjustment stand 90 and the bag-shaped body 70.

Specifically, first, while maintaining the second restraint state, the structure pillar 30 is pressed in the front-rear direction or the left-right direction by the pressing portion of the adjustment stand 90 (in this case, the structure pillar 30 is pressed. The restrictions on movement in the left-right direction and the front-back direction are lifted). The position or inclination of the pile body 20 is adjusted by not pressing the pile body 20 with the bag-shaped body 70 contracted by suction of the injection material from any of the bodies 70, or by combining these actions. In this case, since the sediment is stored in the storage portion 40, it is possible to suppress the accumulation of the sediment in the lower fixing portion 50, so that the position or inclination of the pile body 20 can be smoothly adjusted. Further, in order to accurately adjust the inclination of the pile body 20, for example, with an inclination meter installed on the pile body 20 (the pile head of the pile body 20), the inclination of the pile body 20 is confirmed while checking the inclination angle. May be adjusted. Then, after the position or inclination of the pile body 20 is adjusted, the first curing agent 41, the second curing agent 51, and the third curing agent 61 are cured to form the basic structure 1 of FIG. .. The adjusting stand 90 is removed after the position or inclination of the pile body 20 is adjusted and the first curing agent 41, the second curing agent 51, and the third curing agent 61 are cured. Further, since the bag-shaped body 70 is buried inside the pile hole 10 without removing the bag-shaped body 70 after adjusting the position or inclination of the pile-shaped body 20, it is troublesome to remove the bag-shaped body 70. Since the injection material of the bag-shaped body 70 is cement milk, the strength of the upper fixing portion forming step can be maintained.

Since the sediment can be stored in the storage portion 40 by the pile body construction method as described above, it is possible to prevent the sediment from being stored in the lower fixing portion 50. Therefore, as compared with the case where the storage portion forming step is not included, it is possible to avoid the sediment from hindering the adjustment of the position or inclination of the pile body 20 in the adjustment step, and it is possible to improve the workability of the pile body 20. Become. In particular, it can be said that this pile body construction method is effective for applying to the reverse driving method. This completes the explanation of the pile body construction method.

(Test results)
Next, the results of various tests conducted by the applicant will be described. Here, the test results of a dehydration test, a shear test (vane shear test), and a uniaxial compression test performed to confirm the effect of the first curing agent 41 using a thickener as an admixture will be described.

(Test result-test target)
First, the test objects of the dehydration test, the shear test, and the uniaxial compression test will be described. FIG. 11 is a diagram showing the characteristics of the test piece. This test object is divided into two types, a test body containing no thickener (hereinafter referred to as "first test body") and a test body containing a thickener, and further contains a thickener. Specimens are classified into two types in which the amount of thickener added is different (hereinafter, referred to as "second specimen" and "third specimen").

Here, the first test piece is composed of soil and a root hardening liquid. Specifically, as shown in FIG. 11, the type of soil = fine sand, and the target cement water ratio (hereinafter referred to as “cement water ratio”). Set to "target cement water ratio") = 110%, water cement ratio = 60%, admixture ratio in root hardening liquid (hereinafter referred to as "admixture ratio") = weight ratio 0%. There is. Further, the second test body and the third test body are composed of soil, a root hardening liquid, and an admixture (specifically, a thickener). Specifically, for the second test piece, as shown in FIG. 11, soil type = fine sand, target cement water ratio = 110%, water cement ratio = 60%, admixture mixing ratio = weight ratio 1%. Is set to. As for the third test piece, as shown in FIG. 11, the soil type = fine sand, the target cement water ratio = 110%, the water cement ratio = 60%, and the admixture mixing ratio = weight ratio 2% were set. ing.

(Test result-dehydration test)
Next, the dehydration test will be described. Here, the "dehydration test" is a test for measuring the amount of dehydration of a test piece under a predetermined load. The test method for this dehydration test is arbitrary, but for example, a test piece is set in a known small dehydration tester, and a predetermined compressive load is applied to the test piece by the dehydration tester for a predetermined time (for a predetermined time). Here, it corresponds to measuring the dehydration amount of the test piece until 30 minutes) elapses.

Next, the details of the test results of the dehydration test will be described. FIG. 12 is a diagram showing the test results of the dehydration test. As shown in FIG. 12, the test result of the first test piece could not be measured because the amount of dehydration of the first test piece was too large. On the other hand, with respect to the test results of the second specimen and the test results of the third specimen, the amount of dehydration increased with the passage of time. Moreover, the test result of the third test piece was much lower than the test result of the second test piece. For example, the elapsed time = 30 minutes later, the dehydration amount of the second specimen = 32.8 ml, whereas the elapsed time = 30 minutes later, the dehydration amount of the third specimen = 6.4 ml, and the third test The amount of dehydration of the body was about one-fifth of the amount of dehydration of the second test piece.

From the test results shown in FIG. 12, it was confirmed that the amount of dehydration of the test body can be reduced by adding a thickener to the test body. It was also confirmed that the higher the miscibility compounding ratio, the more the dehydration amount of the test piece can be reduced.

(Test result-shear test)
Next, the shear test will be described. Here, the "shear test" is a test for measuring the shear strength of a test piece. The test method of this shear test is arbitrary, but for example, the test piece is set in a known indoor vane tester, and the resistance of the rotation is increased by rotating the rod of the indoor vane tester inserted in the test piece. It corresponds to measuring the shear strength at predetermined time intervals.

Next, the details of the test results of the shear test will be described. FIG. 13 is a diagram showing the test results of the shear test. As shown in FIG. 13, regarding the test results of the first specimen, the shear strength increased with the passage of time. Specifically, the elapsed time = the shear strength after 4 hours = 1.36 kPa. On the other hand, regarding the test results of the second test body and the test result of the third test body, the shear strength increased with the passage of time as in the first test body, but compared with the test results of the first test body. It was small. Specifically, the elapsed time = the shear strength of the second specimen after 4 hours = 0.58 kPa, the elapsed time = the shear strength of the third specimen after 4 hours = 0.51 kPa, and the elapsed time = 4 hours. It was about half of the shear strength of the first test piece later.

From the test results shown in FIG. 13, it was confirmed that the shear strength can be reduced by adding a thickener to the test piece. It was also confirmed that the effect of reducing the shear strength did not change if the admixture ratio was a certain amount.

(Test result-uniaxial compression test)
Subsequently, the uniaxial compression test will be described. Here, the "uniaxial compressive test" is a test for measuring the uniaxial compressive strength of the test piece. The test method for this uniaxial compression test is arbitrary. For example, a test piece after a lapse of a predetermined period (here, the test piece after a lapse of 4 weeks is applicable) is set in a known uniaxial compression tester. It corresponds to measuring the uniaxial compressive strength of a test piece by applying a compressive load in one direction to the test piece at a predetermined speed by a uniaxial compression tester.

Next, the details of the test results of the uniaxial compression test will be described. FIG. 14 is a diagram showing the test results of the uniaxial compression test. As shown in FIG. 14, the uniaxial compressive strength of the second test piece is 13.8 kPa and the uniaxial compressive strength of the third test piece is 14.5 kPa, which are slightly higher than the uniaxial compressive strength of the first test piece = 13.6 kPa. it was high.

From the test results shown in FIG. 14, it was confirmed that even if the admixture ratio is high, the uniaxial compressive strength is not affected.

Further, from the test results of the dehydration test, the shear test, and the uniaxial compression test, the higher the admixture ratio, the higher the dehydration prevention effect of the test piece and the lower the shear strength. However, it is effective to add a large amount of admixture in the range of 0 to 2% by weight, but from the viewpoint of cost, it can be said that it is appropriate to set the admixture ratio to 1% or less by weight.

(Effect of embodiment)
As described above, according to the embodiment, the storage portion forming step of forming the storage portion 40 by filling the first curing agent 41 and the fixing portion forming step of forming the lower fixing portion 50 by filling the second curing agent 51. The insertion step of inserting the pile body 20 into the pile hole 10 before the first curing agent 41 and the second curing agent 51 are cured, and before the first curing agent 41 and the second curing agent 51 are cured. Since the adjustment step of adjusting the position or inclination of the pile body 20 inserted in the insertion step is included, the sediment can be stored in the storage portion 40, so that the sediment is stored in the lower fixing portion 50. Can be avoided. Therefore, as compared with the case where the storage portion forming step is not included, it is possible to avoid the sediment from hindering the adjustment of the position or inclination of the pile body 20 in the adjustment step, so that the workability of the pile body 20 can be improved. It becomes.

Further, since the height H of the portion of the storage unit 40 capable of storing the sediment is set based on the following equation, the height H of the portion of the storage unit 40 capable of storing the sediment is accurately set. It is possible to store the sediment in the storage unit 40 so that the construction of the pile body 20 (particularly, the adjustment step) is not hindered by the sediment.
H = h1 × α × β-h2
(Here, H: height of the portion of the storage portion 40 where the sediment can be stored , h1: total height of the storage portion 40 and the lower fixing portion 50, α: abundance ratio, β: residual ratio, h2: Height of the lower fixing portion 50).

Further, since each of the first hardening agent 41 and the second hardening agent 51 contains a root hardening liquid and an admixture, it is possible to suppress the water leakage of the root hardening liquid and it is contained in the root hardening liquid. It is possible to suppress the aggregation of chemical components (for example, cement components and the like), and it is possible to improve the workability (particularly, the adjusting step) of the pile body 20.

Further, since the mixing ratio of the admixture in the root hardening liquid was set to 1% or less by weight, the admixture was added while ensuring the desired viscosity and dispersibility of the first curing agent 41 and the second curing agent 51. The amount used can be relatively reduced, and the construction cost can be reduced.

Further, since the admixture contains a high-performance AE attenuator or a thickener, the admixture can be formed from a relatively easily available material, and the admixture can be easily prepared.

Further, since each of the first curing agent 41 and the second curing agent 51 contains a retarding agent, the curing of the root hardening liquid can be delayed, and the workability (particularly, the adjusting step) of the pile body 20 is further improved. Can be made to.

[III] Modifications to Embodiments The embodiments of the present invention have been described above, but the specific configurations and means of the present invention are within the scope of the technical idea of each invention described in the claims. , Can be arbitrarily modified and improved. Hereinafter, such a modification will be described.

(About the problem to be solved and the effect of the invention)
First, the problem to be solved by the invention and the effect of the invention are not limited to the above-mentioned contents, and the present invention solves a problem not described above or an effect not described above. It can also be played, and may solve only some of the tasks described or play only some of the effects described.

(About shape, numerical value, structure, time series)
With respect to the components illustrated in the embodiments and drawings, the shapes, numerical values, or the interrelationships of the structures or time series of the plurality of components shall be arbitrarily modified and improved within the scope of the technical idea of the present invention. Can be done.

(About the foundation structure)
In the above embodiment, it has been described that the foundation structure 1 includes the structural pillar 30, but the present invention is not limited to this, and for example, a pillar or a sword may be provided instead of the structural pillar 30. In this case, the pile head of the pile body 20 is positioned so as to be substantially flush with the ground surface GS (or is located above the ground surface GS), and the pile bottom of the pile body 20 is a pile. It may be provided so as to be located at a portion corresponding to the lower fixing portion 50 of the hole 10, and the pillar or the stake may be provided so as to be located above the ground surface GS.

In the above embodiment, it has been described that the basic structure 1 includes the bag-shaped body 70, but the present invention is not limited to this, and for example, the bag-shaped body 70 may be omitted.

(About various curing agents)
In the above embodiment, it has been described that the first curing agent 41, the second curing agent 51, and the third curing agent 61 are composed of the same constituent elements, but the present invention is not limited to this, and for example, they are different. It may be configured to include components.

Further, in the above embodiment, it has been described that each of the first curing agent 41, the second curing agent 51, and the third curing agent 61 is composed of an admixture and a retarding agent, but the present invention is limited to this. However, for example, at least one of the admixture and the retarder may be omitted.

Further, in the above embodiment, it has been explained that the mixing ratio of the admixture in each of the root hardening liquids of the first curing agent 41, the second curing agent 51, and the third curing agent 61 is 1% or less by weight. However, the weight ratio is not limited to this, and may exceed 1% by weight, for example.

(About bag-shaped body)
In the above embodiment, it has been described that the number of attached bag-shaped bodies 70 is four, but the number is not limited to this, and for example, it may be less than four, or may be four or more. Here, when the number of attached bag-shaped bodies 70 is one, for example, by providing the bag-shaped body 70 whose internal space is divided into a plurality of pieces so as to cover the entire circumference of the pile body 20. The position or inclination of the pile body 20 may be adjusted by appropriately injecting an injection material into each of the divided spaces.

Further, in the above embodiment, it has been explained that the bag-shaped body 70 is buried inside the pile hole 10, but the present invention is not limited to this, and for example, after the position or inclination of the pile body 20 is adjusted in the adjusting step. , The bag-shaped body 70 may be taken out from the pile hole 10 and removed.

Further, in the above embodiment, it has been explained that the bag-shaped body 70 is provided at a position not exposed from the ground surface GS, but the present invention is not limited to this. For example, when the adjusting stand 90 is not used in the mounting step, the inserting step, and the adjusting step, the bag-shaped body 70 may be provided at a position where it is exposed from the ground surface GS.

(About pile construction method)
In the above embodiment, it has been described that in each of the storage portion forming step, the lower fixing portion forming step, and the upper fixing portion forming step, the stirring operation is performed after the various curing agents are filled, but the present invention is not limited to this. For example, this stirring operation may be omitted.

(Additional note)
The pile body construction method of Appendix 1 is a pile body construction method for constructing a pile body on the ground, and is a pile hole forming step of forming a pile hole on the ground and a storage located at the lower end of the pile hole. It is a storage part forming step of forming a storage part for storing the sediment settled in the pile hole by filling with the first hardening agent, and a fixing part located above the storage part. In the fixing portion forming step of forming the fixing portion for fixing the lower end portion of the pile body by filling with the second curing agent, and in the first curing agent and the fixing portion forming step filled in the storage portion forming step. Before the filled second curing agent is cured, it is filled in the insertion step of inserting the pile body into the pile hole and the first curing agent filled in the storage portion forming step and the fixing portion forming step. This includes an adjustment step of adjusting the position or inclination of the pile body inserted in the insertion step before the second hardener is cured.

In the pile body construction method of Appendix 2, the height of the storage portion was set based on the following formula in the pile body construction method described in Appendix 1.
H = h1 × α × β-h2
(Here, H is the height of the storage portion, h1 is the total height of the storage portion and the fixed portion, α: the ratio of soil having a particle size equal to or larger than a predetermined value distributed in the ground, β : Ratio of residual soil in the ground in the storage portion and the fixed portion).

The pile construction method according to Appendix 3 is the pile construction method according to Appendix 1 or 2, wherein each of the first curing agent and the second curing agent has a root hardening liquid and the viscosity and dispersion of the root hardening liquid. Includes admixtures to enhance sex.

In the pile body construction method of Appendix 4, in the pile body construction method described in Appendix 3, the mixing ratio of the admixture in the root hardening liquid was set to 1% or less by weight.

The pile construction method according to Appendix 5 is the pile construction method according to Appendix 3 or 4, wherein the admixture contains a high-performance AE attenuator or a thickener.

The pile construction method of Appendix 6 is the pile construction method according to any one of Supplements 3 to 5, wherein each of the first curing agent and the second curing agent delays the curing of the root hardening liquid. Contains a retarder to cause.

(Effect of appendix)
According to the pile body construction method described in Appendix 1, the storage portion forming step of forming the storage portion located at the lower end of the pile hole by filling with the first hardening agent and the fixing portion located above the storage portion are formed. A fixed portion forming step formed by filling with a second curing agent, an insertion step of inserting a pile body into a pile hole before the first curing agent and the second curing agent are cured, and a first curing agent and a second curing agent. Since it includes an adjustment step of adjusting the position or inclination of the pile body inserted in the insertion step before the agent hardens, the sediment can be stored in the storage portion, so that the sediment is stored in the fixed portion. Can be avoided. Therefore, as compared with the case where the storage portion forming step is not included, it is possible to avoid the sediment from hindering the adjustment of the position or inclination of the pile body in the adjustment step, so that the workability of the pile body can be improved. ..

According to the pile body construction method described in Appendix 2, the height of the storage section is set based on the following formula, so that the height of the storage section can be set accurately, and the pile body is constructed by the sediment ( In particular, it becomes possible to store the sediment in the storage portion so that the adjustment step) is not hindered.
H = h1 × α × β-h2
(Here, H is the height of the storage portion, h1 is the total height of the storage portion and the fixed portion, α: the ratio of soil having a particle size equal to or larger than a predetermined value distributed in the ground, β : The ratio of the remaining soil in the ground in the storage part and the fixed part),

According to the pile construction method described in Appendix 3, each of the first hardening agent and the second hardening agent contains a root hardening liquid and an admixture, so that the water content of the root hardening liquid is suppressed from escaping. At the same time, it is possible to suppress the aggregation of chemical components (for example, cement components) contained in the root hardening liquid, and it is possible to improve the workability (particularly, the adjustment step) of the pile body.

According to the pile construction method described in Appendix 4, the mixing ratio of the admixture in the root hardening liquid was set to 1% or less by weight, so that the desired viscosity and dispersibility of the first curing agent and the second curing agent were obtained. While ensuring, the amount of admixture used can be relatively reduced, and the construction cost can be reduced.

According to the pile construction method described in Appendix 5, since the admixture contains a high-performance AE attenuator or a thickener, the admixture can be formed from a relatively easily available material, and the admixture can be easily used. Can be made into.

According to the pile construction method described in Appendix 6, since each of the first curing agent and the second curing agent contains a retarding agent, the curing of the root hardening liquid can be delayed, and the pile workability (workability of the pile) ( In particular, the adjustment process) can be further improved.

1 Foundation structure 10 Pile hole 20 Pile body 30 Structure Shinbashira 40 Reservoir 41 1st hardener 50 Lower fixing part 51 2nd hardener 60 Upper fixing part 61 3rd hardener 70 Bag-shaped body 80 Excavator 81 shaft Part 82 Excavation part 83 Injection part 84 Stirring part 90 Adjustment stand G Ground GS Ground surface

Claims (7)

It is a pile construction method for constructing piles on the ground.
A pile hole forming step of forming a pile hole in the ground and
It is a storage part located at the lower end of the pile hole, and the storage part for storing the sediment that settles in the pile hole corresponds to the first hardening agent to be filled and the storage part of the pile hole. A storage part formation process that is formed by stirring only the soil in the part,
A fixing portion located above the storage portion, and a fixing portion for fixing only the lower end portion of the pile body is provided as a portion of the second hardening agent to be filled and a portion of the pile hole corresponding to the fixing portion. The fixed part forming process, which is formed by stirring only the soil,
An insertion step of inserting the pile body into the pile hole before the first curing agent filled in the storage portion forming step and the second curing agent filled in the fixing portion forming step are cured.
Before the first curing agent filled in the storage portion forming step and the second curing agent filled in the fixing portion forming step are cured, the position or inclination of the pile body inserted in the insertion step is adjusted. Adjustment process and
Pile body construction method including. The height of the portion of the storage portion where the sediment can be stored was set based on the following formula.
H = h1 × α × β-h2
(Here, H is the height of the portion of the storage portion where the sediment can be stored , h1 is the total height of the storage portion and the fixed portion, and α is a predetermined value or more distributed in the ground. The ratio of soil having a particle size, β is the ratio of soil remaining in the ground in the storage portion and the fixed portion , and h2 is the height of the fixed portion ).
The pile body construction method according to claim 1. An upper fixing portion located above the fixing portion, and the upper fixing portion for fixing a portion other than the lower end portion of the pile body is filled with a third hardening agent to be filled and the upper fixing portion of the pile hole. Including the step of forming the upper fixed portion formed by stirring only the soil of the portion corresponding to
Each of the first curing agent, the second curing agent, and the third curing agent contains a root hardening liquid composed of water and cement.
The mixing ratio of water and cement in the root hardening liquid in the third curing agent was lower than the mixing ratio of water and cement in the root hardening liquid of each of the first curing agent and the second curing agent.
The pile body construction method according to claim 1 or 2. Each of the first curing agent and the second curing agent
Rooting liquid and
Containing an admixture for increasing the viscosity and dispersibility of the root hardening liquid.
The pile body construction method according to any one of claims 1 to 3. The mixing ratio of the admixture in the root hardening liquid was set to 1% or less by weight.
The pile body construction method according to claim 4. The admixture comprises a high performance AE attenuator or thickener.
The pile body construction method according to claim 4 or 5. Each of the first curing agent and the second curing agent contains a delaying agent for delaying the curing of the root hardening liquid.
The pile body construction method according to any one of claims 4 to 6.

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