JPS6350492B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a construction method for an underground continuous water-stop wall.

Groundwater treatment becomes a major issue when excavating permeable ground or constructing civil engineering and architectural structures.

Therefore, in the past, methods for lowering the groundwater level through forced drainage such as the well point construction method and vacuum deep well point construction method, or construction of water shielding walls such as underground continuous water stop walls, water stoppage through chemical injection, and freezing methods, were used to cut off groundwater. A construction method is being used.

However, the former method is not only difficult to use in aquifer formations or gravel formations where the amount of spring water is extremely large, but also tends to require large scale equipment.

On the other hand, the latter not only requires a large amount of construction costs, but also poses a major problem in disposing of the excavated soil that accompanies the construction of water-stop walls.

In view of the above circumstances, this invention was made by further improving the technology related to the latter, and its purpose is to make it possible to economically construct an underground continuous water stop wall using excavated soil, and to It is an object of the present invention to provide a construction method for an underground continuous water-stop wall that can be constructed extremely easily and reliably.

Hereinafter, the present invention will be explained with reference to illustrative embodiments.

In this method, a solidifying slurry 3 is poured into an excavation hole 2 that has been excavated to a predetermined depth using a stable liquid drilling method in which a stable liquid 1 mainly consisting of bentonite mud is used. liquid 1
The underground continuous water-stop wall 5 is constructed by stirring and solidifying the water with a stirring device 4 installed in the excavation hole 2.

The solidifying slurry 3 is a mixture of excavated soil associated with the construction of the underground continuous water stop wall 5 and a solidifying material mainly consisting of a cement bacillus-producing material.

The solidifying agent is a gehlenite dwarf (2CaO・Al ₂ O ₃・SiO ₂・nH ₂ O) created by the reaction between montmorillonite, which is the main clay mineral in bentonite mud, and slaked lime.
Furthermore, in the coexistence of gypsum, cement bacillus (ettringite) (3CaO・Al ₂ O ₃・3CaSO ₄・
32H ₂ O) is expected to have a self-hardening effect. The main additive materials are slaked lime and gypsum. In addition to these main materials, reactive alumina-containing materials (alofan, hydrated haloysalite, blast furnace slag, fly ash, and other industrial waste), iron oxide, various chlorides, alkaline substances (caustic soda, sodium silicate), sodium aluminate, aluminum sulfate By mixing a curing accelerator such as , alum, etc., a curing accelerating effect is expected.

As slaked lime materials, slaked lime for industrial and fertilizer use, carbide sludge, Portland cement, etc. can be used, and as gypsum materials, dihydrate gypsum and anhydrite gypsum can be used. These solidifying materials are mixed with excavated soil in a slurry manufacturing plant 6 to form a solidifying slurry 3.

The stirring device 4 is a laminate in which a plurality of metal panels 7 are arranged in a plurality of layers while maintaining constant intervals. Each of the plurality of metal panels 7 is a mesh plate having a large number of through holes 8 and an aperture ratio of 5 to 30%, and the through holes 8 are arranged in a staggered manner.

A hollow tube 10 having a plurality of discharge ports 9 at predetermined intervals in the material axis direction is fixed to the lower surface of the metal panel 7 in the lowermost layer along the material axis direction of the metal panel 7.

The hollow tube 10 is connected to the slurry manufacturing plant 6 via a hose 11. The pressurized solidifying slurry 3 from the slurry manufacturing plant 6 is fed under pressure to the hollow pipe 10 via the hose 11, and is ejected from the plurality of discharge ports 9.

The stirring device 4 configured in this manner is installed on the crane 12.
It is suspended in the borehole 2 so as to be able to move up and down, and the solidifying slurry 3 spouted into the borehole 2 from the discharge port 9 and the stabilizing liquid 1 in the borehole 2 are stirred. ing. That is, when the stirring device 4 is moved up and down in the excavation hole 2, the mixture of the stabilizing liquid 1 and the solidifying slurry 3 is divided into 1/2, 1/4, and 1/2 by the metal panel 7 having a large number of through holes 8. It is divided into 8 parts and mixed with the mixture flowing into the stirring device 4 from other metal panels 7, and at the same time generates turbulence in the mixture to assist the mixing action.

According to this method, the solidifying slurry, which is a mixture of solidifying material and excavated soil from water stop wall construction, is pumped into the excavated hole excavated by the stable liquid drilling method to the stirring device, and the device is moved up and down to stabilize the slurry. Since the remaining soil is stirred and mixed with the stabilizing liquid, it is possible to build a homogeneous and strong continuous underground water-stop wall by the self-hardening action of the solidifying agent in the solidifying slurry, and it is possible to construct a continuous underground water-stop wall without using conventional reinforcing steel. Construction is extremely simple and reliable as there is no construction or concrete work required.

In addition, since it uses excavated soil and does not require reinforcing bars or concrete, it is extremely economical, and at the same time, there is no problem in disposing of the excavated soil.

[Brief explanation of the drawing]

Figures 1 to 3 a, b, c, and d show embodiments of the present invention. Figure 1 is a perspective view showing the construction state of an underground continuous water-stop wall, and Figure 2 is a stirring Figure 3a is a perspective view of the device; Figure 3b is a plan view of a metal panel in which a large number of rectangular through holes are formed;
3A is a partial vertical sectional view of a laminate made up of the metal panels shown in FIG. 3A, and FIG. d is a partial vertical cross-sectional view of a laminate made of the metal panels of FIG. 3c. DESCRIPTION OF SYMBOLS 1... Stable liquid, 2... Drilling hole, 3... Solidifying slurry, 4... Stirring device, 5... Underground continuous water-stop wall, 6... Slurry manufacturing plant, 7... Metal panel, 8 ...Through hole, 9...Discharge hole, 10...
Hollow tube, 11...hose, 12...crane.

Claims (1)

[Claims] 1. In a slurry manufacturing plant, slaked lime, gypsum, and a hardening accelerator are mixed with excavated soil to create a solidifying slurry, and the solidifying slurry is pumped to a stirring device installed in an excavation hole excavated using the stabilized liquid drilling method to form a solidifying slurry. The agitation device is made to eject from a plurality of outlets of a hollow tube fixed along the material axis to the bottom surface of a metal panel having a large number of through holes and arranged at regular intervals, and the agitation device A construction method for underground continuous water-stop walls, which is characterized by moving the stabilizer up and down to stir and mix with the stabilizing liquid in the excavation hole, causing it to solidify.