JPS5915115A - Solidification of soft and underwater ground - Google Patents

Abstract

PURPOSE:To simply and exactly form a temporary foundation ground by a method in which a suction tube is penetrated into soft ground or underwater ground where the passage of water from the surrounding is interrupted, and water is sucked up to solidify the ground. CONSTITUTION:When a pole 2 is erected in a soft ground 1, for example, a water interruption wall 3 to shut out the intrusion of water from the surrounding is settled into the ground 1 under the condition that its side wall 5 is hung down from the peripheral edge of a ceiling plate 4, and the pole 2 and the suction port 8 of a sucker 7 are thrust through the ceiling plate 4. The sucker 7 is actuated to reduce the pressure of a decompression tank 9, and the suction force thus obtained is acted on the suction port 8 to absorb water from soil in the water interruption wall 3. Soft ground can thus be temporarily solidified and therefore, the construction period can be shortened.

Description

[Detailed description of the invention] The present invention relates to a method for fixing soft ground or underwater ground,
The object of the present invention is to provide a construction method that can reliably form a temporary foundation ground in cases where permanent ground formation is not required, such as a scaffolding foundation or a ball-erected foundation, by extremely simple means.

Conventionally used permanent ground consolidation methods include chemical injection method, freezing method, electrochemical consolidation method, and conduit method, but these methods are unsuitable for temporary foundation ground formation and are too expensive. However, the equipment becomes extremely large, the construction costs are high, and the construction period becomes long.

This invention allows for ground assimilation without the use of complicated devices, such as when a temporarily strong foundation is required, such as when vertically supporting a ball for surveying or fixing scaffolding legs. This is a construction method that can be used to restore the soft ground to the pre-assimilation state if it becomes unnecessary. A method for immobilizing soft or underwater ground, which is characterized by inserting a mouth into the ground and sucking in moisture contained in the ground, is assimilated.The outline and detailed explanation of the principle diagram are as follows.

That is, FIG. 1 shows an example of a case where the ball 2 is set up on soft ground 1, and a water flow prevention wall 3 that blocks water flow from the surrounding area has a side wall 5 hanging from the periphery of the top plate 4. After sinking into the ground, the suction 1118 of the top plate 4 & Im ball 2 and the suction device 7 is penetrated. Next, the suction device 7 is operated to reduce the pressure in the decompression tank 9, and its suction is applied to the suction port 8 to absorb moisture from the soil within the water flow prevention wall 3.

The suction device 7 consists of a decompression tank 9 equipped with a drain 10 at the bottom, a high-pressure water supply pump 11, and a jet pump 12. Make it negative pressure. The water source supplied to the jet pump 12 may be a river near the construction site, the sea, a water tank, etc., and may be used for circulation.

In the above principle diagram, a cap-shaped material is shown as the water flow prevention wall 3, but a flexible resin sheet or the like may also be used, or materials with poor water permeability such as bentonite or sludge may be used for construction work such as injection of chemical solution. kinds.

It goes without saying that a water blocking wall should be formed depending on the assimilation range and the like.

The method of the present invention is used not only for forming the foundation ground for poles (1) as described above, but also for forming trenches for embankments, cofferdams, anchors, cable burying, etc. In either case, water content in the ground is sucked after forming the water-flowing low wall, but as long as the suction continues, the soil particles in the ground continue to become dense and fixed together.

If this solidified ground is to be used as a foundation ground or for permanent assimilation, known solidification methods are used. In addition, the temporarily solidified ground is excavated to produce desired items such as cables.

It is also possible to implement methods such as removing suction after installing clay pipes, returning the ground to its original soft state, and then burying the pipes.

As mentioned above, soft ground, etc. can be temporarily solidified in a short period of time by an extremely simple construction method in which the suction port of the suction device is driven completely into the soft ground surrounded by a water flow prevention wall, leaving only a part of the wall. The construction period will be significantly shortened. Furthermore, as shown in the embodiment, the suction device is small and inexpensive and consists of a high-pressure water pump, a jet pump, and a tank, so it is convenient to transport and the construction method of the present invention can be practiced at any construction site. Furthermore, since the high-pressure water used for suction can be recycled, a special water source is not required and it is economical. Incidentally, if the ground where the water flow prevention wall is buried is relatively hard and this cannot be done easily due to the action of negative water suction pressure, it can be done by using a method in combination with excavation means as shown in Fig. 2. That is, the vJz diagram shows the case where the water flow prevention wall 3 is buried after excavation or soft drilling is performed by the jet injection excavation device 13 along the position where the water flow prevention wall 3 is to be buried. Also, unlike the embodiment shown in FIG.
The water contained in the soft ground is sucked out using the negative pressure generated by the jet of high-pressure water supplied from the high-pressure water supply pump 11.

The water blocking wall 3 has a buried portion made of a metal material 5' and a surface made of a resin sheet 4'.

It goes without saying that the excavation means may be not only the jet excavation described above but also mechanical excavation means.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the method of the present invention, and FIG. 2 is an explanatory diagram when a different suction device is used. 1... Soft ground 3... Water flow prevention wall 7...
・Suction device 8... Suction patent applicant Nozomi Tsuki, patent attorney Iwaodo Sugimoto, patent attorney Katsuho Sugimoto Figure 1 Figure 2

Claims (4)

[Claims] (1) Soft or underwater ground, etc., which is characterized by inserting a suction port into soft ground or underwater ground that has been formed in a state where water flow from the surrounding area is cut off to suck in moisture contained in the ground and solidify it. Immobilization method. (2) Immobilization of soft or underwater ground, etc. according to claim 1, using means for forming a water flow blocking wall on the surface of the ground to be solidified or around the surface and underground as the water flow blocking means. Method. (3) The method for fixing soft or underwater ground as set forth in claim 2, wherein the water flow prevention wall is formed by either injecting or burying a water-impermeable substance. (4) The method for immobilizing soft or underwater ground, etc. according to claim 3, wherein the water-impermeable substance is any one of bentonite, metal bisynthetic bile, sludge, and solidified chemical solution.