JPH03286024A - Sinking construction by hollow pile such as steel pipe pile and the like - Google Patents

Abstract

PURPOSE:To obtain large tip supporting force by inserting a weight body into a pile, sinking the weight body by its weight while compressing in-pile soil, and closing the hollow pile tip part by the compressed in-pile soil. CONSTITUTION:A steel pipe pile 1 is supported upright on the ground and is forcibly sunk into the ground, by applying blows ant pressure to the top of the pile 1 or by using a rotary pressure insertion device, for construction. In order to apply a pressure load to in-pile soil 2, a weight body 3 is inserted into the pile 1. After the lower end of the pile 1 is sunk up to a hard stratum 5 in prescribed depth, the weight body 3 is lifted up with a rope 4 and recovered to finish the sinking construction. After that, concrete 6 is cast in the pile 1 for a weight. A large tip supporting force is thus obtainable by the compressive action on the in-pile soil 2 by the weight body 3 inserted into the pile 1, even in the sinking construction of the pile 1 with a large diameter.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a construction method for constructing steel pipe piles and the like.

(Prior Art) When sinking a hollow pile such as a steel pipe pile into the ground, a method is adopted in which the steel pipe pile or the like is directly hammered into the ground, press-fitted, or screwed into the ground. In this case, the bearing capacity at the tip of the pile is determined by the soil being compressed and solidified at the tip of the pile during the installation, which blocks the tip (tip-blocking effect), and the bearing capacity of the ground can be transmitted through the blockage at the tip and the entire cross section. It is said that

(Problem to be solved by the invention) However, as the diameter of the pile becomes larger, the soil at the tip of the pile is not compressed strongly during pile sinking, the effect of blocking the tip becomes smaller, and the specified bearing capacity cannot be expected. In addition, even if the diameter of the pile is small, the same problem still exists in soft ground.Therefore, in the past, it was necessary to fill the pit with a large amount of concrete or excavate a large amount of the ground under the pile. However, the construction work was extensive and required an excavator and a large amount of concrete, resulting in a large amount of expense. .

The present invention was made to solve the above-mentioned conventional problems, and even when depositing large diameter steel pipe piles, it is not necessary to use special machines and equipment or to introduce large amounts of materials. The purpose of the present invention is to provide a new method for sinking steel pipe piles, etc., which can obtain a sufficient effect of blocking the tip of the pile with a simple means.

(Means for Solving the Problems) The structure of the present invention for achieving the above object will be described with reference to drawings showing embodiments.
When a hollow pile such as a steel pipe pile 1 is pressed into the ground and sunk, a heavy object 3 is inserted into the pile, and the soil inside the pile 2 is compressed by the weight of the heavy object during the sinking work. This is characterized in that the tip of the pile 1 is closed with compressed pile soil 2.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of an embodiment of the construction method of the present invention. 1 is a steel pipe pile, which is supported upright on the ground, and is deposited by applying impact or pressure to the pile head or by screwing it into the ground using a rotary press-in device. As it is press-fitted into the pile, ±2 will enter the inside of the pile l from its tip. *If the diameter of the pipe pile l to be sunk is small,
Due to the frictional resistance between the inner surface of the pile and the soil 2, the flow of the soil 2 inside the pile is suppressed, and as the pile progresses, it is gradually consolidated, and at the end of the sinking of the pile, the soil 2 inside the pile at the bottom of the pile is becomes highly consolidated. The effect of blocking the tip of the pile can be obtained in this way.

However, the diameter of the steel pipe pile 1 etc. to be sunk is 600111, for example.
If the diameter of the pile exceeds 1, the limit of the frictional resistance between the inner surface of the pile and the pile soil 2 will be exceeded.
Since the consolidated coal of the pile inner soil 2 at the pile tip becomes weaker, the tip blocking effect becomes smaller.

In the present invention, in the process of proceeding with the installation of the steel pipe pile 1, etc.,
A heavy object 3 for applying a compressive load to the soil 2 inside the pile is inserted into the pile 1. As a result, the ±2 that has entered the mine is compressed by the weight of the heavy object 3, resulting in a highly compacted state.

The material of the heavy object 3 is not particularly limited, but it must have enough weight to sufficiently compress the soil. It is also necessary to have a structure that does not impede the rise of groundwater. Generally, it is preferable to use steel weights or gravel. 1st
In the embodiment shown in the figure, a steel weight is used as the heavy object 3. In this case, a water passage gap should be provided between the adjustment weight and the inner surface of the pile. Further, after the steel pipe pile I has been sunk to a predetermined depth, the steel weight 3 should be recovered, and it is preferable to attach a lifting lobe 4 to the steel weight 3.

As shown in Fig. 2, after the lower end of the steel pipe pile l has been sunk to a predetermined depth that reaches the hard stratum 5, the steel weight 3 is pulled up and recovered by the rope 4 to complete the sinking work. At that time, if there is a possibility that the compressed soil inside the pile will return, concrete 6 will be placed inside the pile to prevent it from returning after construction. Since this concrete 6 is used to prevent return, it does not need to be in a large amount.

Figure 3 shows an example of using gravel as the heavy object 3.
In this case, the gravel 3 is left in the pile l as it is. Also in this case, concrete 6 for preventing return can be placed if necessary.

Although the above-mentioned embodiments are shown in the case of steel pipe piles, the construction method of the present invention can be widely applied not only to steel pipe piles but also to hollow piles such as concrete piles and steel pipe-concrete composite piles.

(Effects of the Invention) As explained above, in the construction method of the present invention, when sinking a hollow pile such as a steel pipe pile, a heavy object is inserted into the pile, and the pile is sunk while compressing the soil inside the pile by its own weight. As a result, even when sinking large-diameter piles where conventionally no tip-blocking effect could be achieved, the tip-blocking effect can be expected due to the compression of the soil inside the pile due to the heavy objects inserted into the pile. Therefore, a large tip supporting force can be obtained.

Furthermore, the construction is an extremely simple task of simply inserting a heavy object into the pile, and the effect of closing the tip can be obtained without using any special measures, making it possible to significantly reduce construction costs. , which has many excellent effects.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of the implementation of the present invention, FIG. 2 is a vertical cross-sectional view showing the completed state of pile sinking, and FIG. 3 is a vertical cross-sectional view showing another embodiment. 1...Steel pipe pile 3...Heavy object 5...Hard stratum 2-Pile inner soil 4...Rope 6...Concrete'$1 Figure 3

Claims (1)

[Claims] When hollow piles such as steel pipe piles are press-fitted into the ground, a heavy object is inserted into the pile, and the soil inside the pile is compressed by the weight of the heavy object during the sinking process. A construction method for sinking hollow piles such as steel pipe piles, which is characterized by blocking the pile with compressed soil.