JPH035448B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is intended to improve soft ground on which clay, sludge, etc. are deposited.

Conventionally, various methods such as the cement mixing method, sand drain method, etc. have been adopted as methods for improving soft ground, but in the case of the method of mixing the cement, it is necessary to mix the cement evenly into the deep layer. With the sand drain method, it takes a long time to completely drain water and strengthen the ground, and with other methods, it takes a long time to strengthen the ground. The disadvantages were that it took a long time and that it could not be completely improved to the depths, causing uneven subsidence. The purpose of this invention is to solidify clay, sludge, etc. in place and improve the ground uniformly down to the depths within a short period of time.

In this invention, a single-shaft or multi-shaft auger excavation device, a soil compaction agent pumping device, a pneumatic pumping device, and a vibrating bar type soil compaction device are used. First, the auger excavation device and compaction agent pumping device are operated, and the compaction agent is inserted into the ground while being discharged from the tip of the auger. When the auger reaches a predetermined depth, the pneumatic feeding device is operated to eject air from the tip of the auger while raising and lowering the auger to stir the soil.
Mix the consolidation agent and soil thoroughly. Once this stirring is complete, the auger is pulled out, the vibrating rod is inserted to a predetermined depth, and the rod is gradually pulled out while vibrating to compact the ground from the bottom up.

In this case, a suitable solidifying agent to be used is, for example, Sumitomo Cement Co., Ltd.'s cement-based soil conditioner "Tafrock" (registered trademark), which can effectively solidify even organic soil. The amount to be used is determined by a consolidation test of soil samples collected in advance, but for example, 1 ton of water is used for 1 ton of TAFLOCK (registered trademark). Use with. The auger is usually raised and lowered two to three times for stirring.

The soil compaction agent solidifies within a few days and exhibits high strength on the ground after this construction, so there is no need for compaction after construction.

The present invention will be explained below based on illustrated embodiments.

In FIG. 1, reference numeral 1 denotes a working vehicle, which has a tower 2. A driving machine 4 having one hollow rotating shaft 3 at the lower end is supported on the tower 2 so as to be able to move up and down. The book auger 6 is simultaneously driven to rotate.
7 is a solidifying agent pumping device; 8 is an air compressor; these are connected to a drive unit 4 via a switching valve 9 and a hose 10;
The auger 6 is connected to discharge solidifying agent or air from the lower end of the auger 6 through the lumen thereof.

In addition, 11 is a work vehicle similar to 1, and has a tower 12, and the tower 12 has three vibrating rods 14 with an exciter 13 installed at the upper end, and the tower 12 has three vibrating rods 14 at the same center as the auger 6 in the direction perpendicular to the plane of the paper. They are arranged at a distance and supported so that they can be raised and lowered.

During construction, the switching valve 9 should be connected to the solidifying agent pumping device 7.
drive machine 4 and solidifying agent pumping device 7.
When the auger 6 is operated, the auger 6 enters the ground while discharging the solidifying agent from its tip. When the auger 6 reaches a predetermined depth, the air compressor 8 is operated, the switching valve 9 is switched to the air compressor 8 side, and the auger 6 is raised and lowered two to three times while operating the drive unit 4. Although the caking agent is highly viscous, it is well mixed into the soil by the movement of the auger 6 and the air, and excess air is blown out onto the ground surface.

After finishing the excavation with the auger and mixing and stirring the solidifying agent as described above, the work vehicle 1 is moved out,
Another compaction work vehicle 11 is advanced, and the exciter 13
drive the vibrating rod 1 into the excavated area by the auger 6.
4 and gradually pull it out while continuing to operate the vibrator 13 and vibrating the vibrating rod 14, the air remaining in the soil during stirring will be ejected to the surface, and the soil will be gradually removed from the bottom. Firmly compacted.

If the above-mentioned operations are carried out sequentially in the order of A to M as shown in Figure 2, it is possible to uniformly mix the compacting agent into the ground in the area and compact it. . After carrying out such construction,
Since the ground is compacted deep, compaction is not necessary, and the compacting agent completes the compacting reaction within a few days. Therefore, construction of the above-ground structure can be started immediately, and uneven settlement of the ground after construction can be prevented.

FIG. 3 shows a construction device using a single-shaft auger, in which a tower 15 of a working vehicle similar to the working vehicles 1 and 11 shown in FIG. A vibrating rod exciter 18 is supported so as to be able to move up and down separately. When using this device, leave the work vehicle in place,
By rotating the rotary leader 16 90 degrees, the vibrating bar can be brought to the position after the auger has been withdrawn.

The pile-shaped reinforcement parts formed in the ground by the equipment shown in Fig. 1 or 3 may be formed adjacent to each other in order to uniformly strengthen the ground in an area. They can also be formed at strategic points, like the concrete piles shown here.

As described above, according to the present invention, the soil is not only mixed with a compacting agent, but also sufficiently compacted. Therefore, not only is there no need for compaction after construction, but the construction of above-ground structures can be started almost immediately after construction, which greatly shortens the overall construction period, and prevents uneven ground subsidence. Can be done.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of one example of the device used to carry out this invention, Fig. 2 is a plan view illustrating the construction order by the above-mentioned device, and Fig. 3 is another example of the device used to carry out this invention. FIG. 1 and 11...work vehicle, 4...driver, 5...
Multi-shaft device, 6... Auger, 7... Solidifying agent pressure feeding device, 8... Air compressor, 9... Switching valve, 10...
Hose, 13...exciter, 14...vibration rod.

Claims (1)

[Claims] 1. A process of excavating the ground to a predetermined depth while rotating an auger and discharging soil consolidation agent from its tip;
After the auger reaches a predetermined depth, the discharging of the soil compacting agent is stopped, and the auger is raised and lowered while rotating the auger and blowing out air from its tip, and the auger is pulled out from the ground and replaced. A method for improving soft ground that involves inserting a vibrating rod to a predetermined depth and gradually pulling it out while vibrating it.