JPS6128627A - Energy-saving construction for deep foundation - Google Patents

Abstract

PURPOSE:To improve the efficiency of work, by a method wherein after a ring frame structure is organized with a shaft core of a supporting rod fixed in ground and the tip of the structure is thrust into ground by a jack via a pressure receiver, ground is excavated by a bit fitted on the structure. CONSTITUTION:After a supporting rod 10 is fixed in the ground, a ring frame structure 12 is organized with a central shaft of the rod 10 portion exposed on the ground. Then, a pressure receiver 16 is held by the rod 10, and the lower face of the pressure receiver 16 is pressed by a jack 14, and the lower end section 13 of the structure 12 is thrust in ground. Then, a rotary shearing device 15 is worked for excavation and a retaining frame 7 is organized, and excavated earth is discharged by using a bucket 4. And after the pressure of the jack 14 is released and the pressure receiver 16 is held downward, eafth is excavated to a specified depth in the same way.

Description

[Detailed Description of the Invention] <Industrial Field of Application> The present invention relates to an improvement of the deep foundation construction method in which a pit was dug manually.

<Prior art> When constructing foundations for bridges and steel towers, water collection wells to prevent landslides, etc. in unexplored mountainous areas where it is extremely difficult to bring in large machinery, there is only one construction method: workers. However, they have no choice but to rely on the old-fashioned deep foundation construction method, which involves digging 20 to 30 meters underground with pickaxes and shovels. For this reason, it can be said that the significance of the existence of the traditional deep foundation method in the civil engineering field is extremely important and significant. This deep foundation construction method allows workers to directly check the soil quality of the supporting ground and apply appropriate measures each time until completion, the bottom of the foundation can be widened at will, and above all, it is large-scale. Its advantages include simplicity and flexibility as it can be done without the use of machinery. However, the actual work is a series of grueling hard labor, and workers are constantly exposed to life-threatening dangers such as falling rocks, water leaks, and lack of oxygen, and they need the experience to judge situations correctly and quickly. By the way, if we briefly explain the conventional deep foundation construction method using Figure 3,
The tools used include a winch 1, a tripod 2, a drainage pump 3, a blower and air pipe (not shown), a packet 4,
Pickaxe 5, shovel 6, earth retaining frame 7, especially if the ground is hard, a big breaker.

Explosives will be provided for air hoses, compressors, and rock drills. The construction process involves first aligning the stakes, then excavating the top, installing the top valve stem, creating a tower landing, and installing a lifting device for transporting earth and sand. Then, the excavation by the workers is started, and as the excavation progresses, the earth retaining framework is installed and the excavation is continued one by one until a predetermined depth is reached.

The skilled workers who carry out such work are gradually aging, and even if it is possible to train replacements to replace them, it is not possible to train them in a very short period of time. It can be said that there are very few people who aspire to such a profession.

This J: Because it depends on the situation, the deep foundation construction method itself gradually becomes impossible to implement due to the actual human resources involved.
It would not be an exaggeration to say that there were even concerns that this would seriously hinder development plans in the near future.

<Problems to be solved by the invention> Drastic countermeasures for the deep foundation construction method under the above-mentioned circumstances were developed after fully taking into account the special circumstances in which this construction method is adopted in cases where it is difficult to bring in large machinery. The urgent task at hand is to somehow make mechanical excavation possible.

The present invention is based on the fact that in the past, even if excavation was carried out using a transportable excavator, mechanical excavation was thought to be impossible due to the lack of effective means to absorb the reaction force during excavation. In view of this, the objective was to devise an effective means to absorb and stop the reaction force during excavation, thereby making mechanical excavation possible.

<Means for Solving the Problems> The deep foundation construction method of the present invention is carried out by the following steps.

B. Support rods fixed deep in the earth are erected up to the ground level.

The annular frame structure is assembled on the ground with the O9 support rod as the axis.

Needless to say, the annular frame structure can be disassembled into components that can be transported deep into mountainous areas, assembled on-site, and dismantled after construction.

C. Push the pressure receiving member locked to the support rod with a jack attached to the annular frame structure to forcibly dig the tip of the annular frame structure into the ground.

2. Excavating with a rotary cutting edge attached to the annular frame structure. The rotary cutting head rotates downward to perform excavation, and then rises and returns to its starting position.

E. Discharge the excavated soil out of the hole.

This work is carried out by workers as usual.

Hey, Ji1! Release the pressure from the lever and lower the pressure receiving member.

Then, repeat the steps from to to above.

<Function> With the above configuration A, the support rod exhibits the function of firmly receiving a reaction force in the direction of lead ml sufficient to cause the tip portion of the annular frame structure to dig into the ground.

In addition, the tip of the annular frame structure that is dug into the ground by the configuration shown in (C) has the ability to firmly receive the rotational reaction force during excavation by the rotary blade opening.

These two effects work together to enable step-by-step mechanical excavation.

<Effects of the Invention> According to the present invention, the tip portion of the annular frame structure is dug into the ground by utilizing the excellent vertical reaction force of the support rod fixed deep in the earth, thereby reducing the impact during mechanical excavation. The reaction force in the direction of rotation can be easily and reliably obtained, and smooth mechanical excavation can be realized. As a result, work efficiency is significantly improved, and construction periods and costs can be significantly shortened and reduced. In this respect, the present invention can be said to be an epoch-making invention. Moreover, this construction method does not impair the original features of the deep foundation construction method, which can be constructed in remote mountainous areas or narrow urban areas where it is impossible to bring in large machinery, and it does not rely entirely on mechanical power. This construction method is a compromise between mechanical power and manual labor, so for example, if a rock is hit during excavation, the worker uses an appropriate method to crush it and remove it, and then mechanically excavates again. It also has the advantage of allowing you to perform work safely and easily.

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

B. Installation of support rods (see Figure 1) Using poling holes dug deep underground for geological measurements,
Support rods 10 are sequentially connected and inserted into the polling hole, and even after the tip reaches the bottom of the polling hole, the support rods 10 are connected until the upper end is sufficiently exposed above the ground. Cement milk is then used to fix the support rod, especially the tip portion indicated by reference numeral 11. As such a support rod 10, commercially available ones can be used, such as a threaded rod made by Vigendesdurb (trade name) with a diameter of 32 mm and a tensile strength of 90 tons.

Assembly of the annular frame structure (see FIG. 1) The annular frame structure 12 is assembled with the support rod 10 portion exposed above the ground as the central axis. The lower end portion 13 of the annular frame structure 12 is suitable for being dug into the ground, and is formed in a form that sufficiently resists rotational forces once it is dug into the ground.

This structure 12 has a pressure cuff of 0 tons with a support rod 10 passed through the middle, and a stroke length of 0.5 m f! j! In addition to the hydraulic hollow jack 14, a rotary blade device 15 is installed which is capable of rotating around the support rod 10 at a low speed while pushing it down and raising it back to the starting position.

c. Excavation work Excavation work shall be carried out in the following order.

■ Lock the pressure-receiving member 16 to the support rod 10, and place the lower surface of the pressure-receiving member 16 in the above-mentioned position 1? By pressing with the levers 14, the lower end portion 13 of the annular frame structure is forcibly dug into the ground (see Figure 1).

■ Next, operate the rotary blade experience @15, apply downward pressure and excavate to the depth shown by the two-dot chain line, then raise it again to the original position, and if necessary, rotate it using a known mechanism. Expand the diameter of the blade and continue digging.

■ To transport the excavated soil, use winch 1 installed on the ground or tripod 2 to transport bucket 1, which can be freely lowered and lowered, using bucket 4.
This is done by a worker who has entered the bottom of the hole. The same goes for assembling the retaining frame 7.

After removing the earth, release the pressure of the G-A7 lever 14 which had been kept pressed until then, and lower the locking position of the pressure receiving member 16 downward. Then repeat the steps ■～■ again. Figure 2 shows an intermediate situation in which digging is progressing in this way. After excavating to a predetermined depth in this manner, the annular frame structure 12 and the like are dismantled at the bottom of the hole, and these disassembled products are transported to the ground using a lift or the like.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams for facilitating understanding of the labor-saving deep foundation construction method of the present invention, and FIG. 3 is an explanatory diagram of the conventional deep foundation construction method. 10... Support rod, 12... Annular frame structure, 13
... lower end portion of the annular frame structure, 14 ... hollow jack, 15 ... rotary blade device, 16 ... locking member.

Claims (1)

[Claims] 1. A labor-saving deep foundation construction method consisting of the following steps A to F. B. Support rods fixed deep in the earth are erected up to the ground level. B. Assemble the annular frame structure on the ground with the support rod as the axis. C. Push the pressure receiving member locked to the support rod with a jack attached to the annular frame structure so that the tip of the annular frame structure digs into the ground. D. Rotate the bit attached to the annular frame structure to excavate. E. Discharge the excavated soil out of the hole. F. Release the pressure from the jack and lower the pressure receiving member. G. Thereafter, repeat the steps C to F above.