JP5004064B2 - Improved pile top end forming method - Google Patents

Description

  The present invention relates to a method for forming a top end portion of a columnar improved pile constructed on soft ground.

  When building small-scale buildings such as ordinary houses on soft ground, column-like improved piles are placed on the ground at regular intervals, and foundations are built on them. Cement milk is made by stirring the solidified material and water in the plant to produce cement milk, pumping it out from the tip of the cutting stirring rod while pumping it, and mixing the cement milk and the cutting earth and sand in the column-cut ground. Made by stirring.

  These improved piles are often used as reinforcing piles for soft ground because the piles themselves act as friction piles even if there is no support layer on the ground. This is a case where the end surface and the bottom surface of the foundation constructed thereon are in close contact. If crushed stones such as earth and sand or chestnut stone are interposed between the two, the load applied to the foundation will not be transmitted to the improved pile as it is, and the effect as a pile will be halved.

  Therefore, for example, in Patent Document 1 below, when the improved pile is solidified and the strength as the pile has come out, the top end portion of the pile is cut and leveled flatly, and iron or concrete made thereon After installing the backing plate member, the foundation is built on it.

JP 2000-273879 A

However, the solidification of the improved pile takes 3-4 days in summer and a week in winter. After waiting for it to solidify, it takes time to cut and flatten the top of the pile. There are disadvantages that are too expensive.
Immediately after pulling out the cutting stirrer rod from the cutting hole, the ground surface around the improved pile is disturbed by the cut soil or mud, and the top end of the improved pile is the surrounding ground surface. Therefore, it is inevitable that the earth and sand around the top end cover the top end and the boundary with the surrounding becomes unclear.
In order to solidify the top end portion in such a state, and to cut and flatten it, there is a problem that even if a mechanical device or the like is introduced, it becomes a difficult and troublesome work.

  The present invention has been made to solve these problems, and it is possible to flatten the top end of the improved pile in a short period of time before the improved pile is solidified, and to make the top close to the bottom of the foundation. The purpose is to provide an edge repair method.

The method of forming the improved pile top end according to the invention of claim 1 includes the step of sequentially constructing the improved pile at a plurality of locations on the ground, and the same diameter as that at the top end of the improved pile every time the improved pile is constructed. And a disc-shaped packing having a proof strength and elasticity capable of withstanding the weight of the building constructed thereon, and while pressing the packing against the top end, the packing and the top end a step that to adjust the horizontal level, after each improved pile is solidified, that after removing the sediment or the like overlying the top of the packing of the improved pile and a step of constructing a directly underlying the top of the packing Features.

  The packing is made of a synthetic rubber or natural rubber having a predetermined proof stress and elasticity that can withstand the weight of a small-scale building constructed thereon, and has a thickness of 30 to 50 mm and a diameter of an improved pile. It is formed into a disk shape of 500 to 800 mm in accordance with the size of. In addition, nail holes for fixing the packing to the top end portion of the pile are formed at a plurality of locations on the packing.

  Put such packing on the top end of the improved pile immediately after construction, and adjust the horizontal level of the packing against the horizontal reference of the ground while holding the upper surface by hand. In this case, the horizontal level is preferably matched with the top level of the chestnut laid around the improved pile. When the installation of the packing is thus completed, a nail having a length of about 100 to 150 mm is pushed into the nail hole, and the packing is tightly fixed to the top end of the pile. As a result, since the flat top end surface can be formed by packing on the top end of the pile before the pile is solidified, if the foundation is built directly on top of it, the load applied to the foundation remains as it is. Will be transmitted to.

According to the invention, covered with a packing on the top end portion of the improved pile immediately after construction, to adjust the horizontal level of the with the packing top end while pressing the packing to the top end Runode, and very easy A pile with a flat top end can be formed in a short time. Therefore, even if earth or sand is covered on the packing, it can be easily removed, so that the top end can be flattened extremely easily. Moreover, the disk-shaped packing has the strength and elasticity that can withstand the weight of the building built on it, so if you build the foundation directly on it, the bottom of the foundation and the packing are completely Adhering closely, the effect as a pile can be exhibited to the maximum. In addition, earth and sand, crushed stones, etc. on the packing are not mixed with the improved piles and can be easily removed, so even before the piles solidify, proceed with the laying of crushed stones to the top edge. Even if it is covered with earth or sand, the work can be shortened without worrying about this.

  In addition, if the top surface of each packing is adjusted to the same level, the level of the crushed stone can be easily set to the horizontal level simply by matching the top level of the crushed stone laid around the top surface level of each packing. be able to. Also, even if various external forces or impacts are applied to the packing by laying or rolling the chestnut stone, the top end of the pile will not crack or chip due to the strength and elasticity of the packing. Construction can proceed without waiting for solidification.

  Furthermore, even if the entire foundation is displaced in the horizontal direction due to an earthquake, etc., the foundation does not break the pile by sliding on the packing, so that even after the foundation is displaced, the effect as a pile can be exhibited. it can. In particular, improved piles are not resistant to horizontal forces, so if the pile and the foundation are integrated as before, the top end of the pile will break or the pile will Although it broke from the middle, according to this invention, even if such an external force works, it can escape and it can exhibit the effect | action as a pile.

Illustration of improved pile construction method Appearance perspective view with packing on top of improved pile Longitudinal cross section with packing on top of improved pile Longitudinal sectional view of a solid foundation built on multiple improved piles

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 illustrates a so-called columnar improved pile construction method. First, as shown in FIG. 1A, the cutting stirrer rod 1 is grounded to a calculated depth while rotating the cutting stirrer rod 1. Cut in. Next, as shown in FIG. 1 (b), the cement milk 2 is discharged from the tip of the cutting stirring rod 1 while being reversely raised.

  The cement milk 2 is produced by stirring a cement-based solidified material and water in a plant (not shown). When the pump is pumped into the pipe 3 of the cutting stirring rod 1 by a pump, the cement milk 2 is grounded from the tip of the rod 1. To be discharged.

  Subsequently, as shown in FIG. 1C, the rod 1 is repeatedly forwardly lowered and reversely raised and mixed and stirred until the cement milk 2 and the soil become slurry in the ground. After that, when the cutting stirring rod 1 is pulled out from the cutting hole, an improved pile A as shown in FIG.

  Next, as shown in FIG. 2, the disk-shaped packing B having the same diameter as the pile A is put on the top end C of the pile A, and if the surrounding earth and sand 4 gets in the way, after removing it, Check the upper surface of packing B against the horizontal reference of the ground. If the height of the packing B is less than the design height, the two packings B are stacked, and if there is no necessity, the packing B is left as one. However, when two packings are to be stacked, they are stacked and unified in all piles. And if the upper surface of the packing B is pushed hard by hand, the packing B will sink, and thereby the upper surface level of the packing B is adjusted to the top level of the chestnut. When this is completed, the nail 5 having a predetermined length is pushed into the nail hole provided in the packing B. When the pile A is solidified, the packing B is tightly fixed to the top end portion C, and the top end surface of the packing B becomes a complete plane.

  FIG. 3 is a longitudinal cross-sectional view of a state in which a two-layer packing B is installed at the top end C of the improved pile A thus constructed.

  In this way, when a plurality of improved piles A are driven in place, as shown in FIG. 4, chestnut stones 6 are laid around each pile A, and the top ends of the packing B and chestnut stones 6 are tightened. Adjust the top surface of the to the same level. After that, a foundation formwork is assembled thereon, and a reinforcing bar 8 is laid to directly construct a solid foundation 7 made of reinforced concrete. However, since the construction method is well known, its description is omitted here. .

A Improved pile B Packing C Top end 1 Cutting stirring rod 2 Cement milk 3 Pipe 5 Nail 6 Kuriishi 7 Solid foundation

Claims (1)

The process of sequentially constructing improved piles at multiple locations on the ground, and each time an improved pile is built, the top of the improved pile has the same diameter as that of the pile and the weight of the building constructed on it covered with a disk-shaped packing having a yield strength and elastic to withstand the be the steps that adjust the horizontal level of the with the packing top end while pressing the packing to the top end, each improved pile solidified And a step of constructing a foundation directly on the packing after removing the earth and sand covered on the packing of the improved pile, and a method for forming the top end of the improved pile.

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