JPS6124491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for burying a pile to obtain strong supporting capacity.

Recently, as construction and civil engineering projects have become larger in size, foundation piles are required to have an extremely large supporting capacity.

In general, construction methods similar to milk injection for centrifugal concrete piles and steel pipe piles are often used, but these are mainly used for wall structures, and cast-in-place concrete pile construction methods are mostly used for rigid frame structures. The main methods are the bucket to earth construction method, the reverse circulation construction method, and the all-casing bed construction method.

Both of the former two methods involve inserting a reinforcing bar cage into a drilled hole, then pouring ready-mixed concrete using the tremor pipe method to create cast-in-place foundation piles.

In this case, to prevent the collapse of the hole wall due to earth pressure,
Since the drilled hole is filled with muddy water stabilizing liquid, a muddy water film forms on the surface of the reinforcing bars.

For this reason, the adhesion (bond) of fresh concrete becomes weak.

In addition, the hole wall collapses to a greater or lesser degree, and the hole wall also collapses when reinforcing bar cages are inserted, and collapsed soil mixes into the concrete near the bottom of the hole, weakening the support at the end of the pile and causing a large It had a fatal flaw in that it could not be expected to have sufficient support.

Furthermore, the overflowing muddy water causes various pollution problems, and it also has the disadvantage that it becomes difficult to control the mixing and kneading of the muddy water stabilizer.

Next, the latter method is an all-casing construction method that does not use muddy water, but as the intermediate layer becomes hard and the N value increases after reaching the supporting layer, considerable impact pollution occurs as excavation continues. .

The object of the present invention is to eliminate the above-mentioned drawbacks by digging deeply into supporting solid foundations with a high N value without using mud stabilizing liquid during excavation, and by obtaining extremely good supporting force.

This invention involves constructing a column-row continuous wall by continuously driving soil cement piles in a circular shape, and then installing a steel pipe or pile-shaped column having an auxiliary pile at the tip to increase the bearing capacity so that it is embedded in the continuous wall. Provides a method for burying piles by penetrating them.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, soil cement piles A are continuously driven to construct a circular column continuous wall B.

The construction of the column continuous wall B is carried out by lowering the slider 3 using the leader mast 2 of the excavator 1 as a guide, as shown in FIG.
An auger screw 6 connected to the lower end of the excavator is used to excavate from the ground to the underground.

At this time, a hose (not shown) connected to the upper end of the rod 5 is used to connect the cement milk or water-curing solution mixed with a hardening retardant (for example, bentonite) from the lower end of the auger screw 6 using the axial passage of the rod 5. The soil is injected and mixed with the excavated soil to form a semi-sludgy soil.

When the above-mentioned excavation reaches a predetermined support layer, the cement milk containing the above-mentioned curing retardant or the water-curing solution is replaced with a hardening milk such as a richly-blended cement milk, and the mixture is injected.
Move the rod 5 up and down by about 4 m to form a ready-mixed concrete or cement mortar.

A suitable curing retardant is also added to this.

Also, instead of rich cement milk or hydraulic solution, cement mortar containing a curing retardant may be filled.

As described above, the auger screw 6 is pulled out together with the rod 5, and the soil cement pile A is driven.

The above-mentioned soil cement piles A have overlapping peripheral edges and are driven in a circular manner to construct a column continuous wall B as shown in FIG.

The above-mentioned pillar row continuous wall B can be constructed by driving soil cement piles A one by one, or by arranging multiple rods with auger screws on a semicircular arc line and constructing soil cement piles in a semicircular shape. In some cases, the pile A is driven and then the soil cement pile A is driven in the remaining semicircular shape.

In the uncured column row continuous wall B constructed above,
After hoisting steel pipe or pile-shaped piles C and erecting them so that the axis of each soil cement pile A and the peripheral wall of pile C coincide, and confirming the verticality of pile C,
The pile C is penetrated into the column retaining wall B by applying an external force such as light hammering, hydraulic press-fitting, or steel cable shibori to the head of the pile C.

At the tip of the pile C, an auxiliary pile _C1 for increasing bearing capacity is provided which has a through hole in the vertical direction so as to reduce resistance when buried in the soil cement pile A.

The above-mentioned supporting capacity increasing auxiliary piles _C1 are made by dividing the pipe in the axial direction to form the divided bodies 7, and are divided so that the same number of soil cement piles A are arranged on the inner and outer circumferences of the steel pipe. Both side edges of the body 7 were brought into contact with each other, and the side edges of the divided body 7 were fixed to the steel pipe by welding, but a cylindrical body made by cutting the steel pipe was left with a predetermined gap on the inside and outside of the lower part of the steel pipe ( In some cases, the cylindrical body is fixed to the steel pipe via radial connecting ribs that are inserted (not shown) and welded.

In the case of pile piles, an auxiliary pile (not shown) to increase the bearing capacity is fixed to the ring at the head end by welding, or
Alternatively, supporting capacity increasing auxiliary piles may be molded at the same time as the pile piles are molded.

The method of penetration of the pile C is as follows:
Although the head of the pile C was press-fitted by the forward movement of the jack 10 provided on the leader mast 9 (at this time, the clamp device is applied to fix the jack 10 to the leader mast 9), the head of the pile C was not exposed to external force such as a light hammer. In some cases, it may be penetrated by adding .

In addition, if the ground is such that there is a soft stratum above the supporting layer and consolidation settlement occurs, use bentonite solution or clean water instead of cement milk or hydraulic solution to drill and stir the supporting layer. In the vicinity, the friction of pile C can be gradually reduced and the ideal bearing capacity can be achieved by injecting thickening milk such as cement paste containing rich ingredients and moving it up and down about 4 meters to fill it, or by replacing it with mortar. can demonstrate.

As described above, according to the method for burying piles according to the present invention, a circular column continuous wall is constructed using the soil cement piles to be driven, and the soil cement pile is installed in the unhardened column continuous wall. Steel pipe or concrete pile piles are buried inside the pile, so if the piles are steel pipes, they will be coated with soil cement and will not corrode permanently, and if they are concrete piles, they will not corrode permanently. Since it is in close contact with the cement pile, the friction surface becomes the outer periphery of the soil cement pile, and a remarkable friction effect can be exerted.

In addition, the soil inside the column continuous wall remains the original ground, and the piles can be penetrated and buried without any excavation.

Furthermore, since muddy water stabilizing liquid is not used in the pile burying work, there is no problem of pollution caused by muddy water.

Additionally, when the auger screw reaches the supporting layer during the pouring of soil-cement pillars, instead of the cement milk or hydraulic solution injected during excavation, it switches to hardening milk such as a rich blend of cement paste. Piles can be anchored to supporting solid foundations with a high N value.

In particular, since an auxiliary pile for increasing the bearing capacity is provided at the tip of the pile, the area to which concrete or mortar adheres increases, and it is possible to exhibit an amazing bearing capacity.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention; Fig. 1 is a side view of an excavator, Fig. 2 is a cross-sectional enlarged plan view of a column continuous wall constructed in the same way, and Fig. 3 is a partial cutaway of a pile. FIG. 4 is a front view, FIG. 4 is a side view showing a pile penetration embedding machine, and FIG. 5 is a cross-sectional plan view showing piles buried in a continuous wall of pile rows. A... Soil cement pile, B... Column continuous wall, C...
Pile, C ₁ ...Auxiliary pile to increase bearing capacity, 1...Excavator, 2...
Leader mast, 3...slider, 4...driver,
5... Rod, 6... Auger Screw.

Claims (1)

[Claims] 1. Driving soil cement piles from the ground to a specified depth underground, and when the soil cement piles reach the supporting foundation, hardening milk is injected instead of cement milk cement or hydraulic solution to form a mortar-like structure. After constructing a circular pillar row continuous wall by continuously driving the soil cement piles, a steel pipe or pile-shaped wall with an auxiliary pile to increase the bearing capacity at the tip is installed so that it is buried in the unhardened pillar row continuous wall. A pile burying method characterized by penetrating a pile.