Filter-pressing type grouting device for soft formation and grouting method of grouting device

Abstract

The invention discloses a filter-pressing type grouting device for a soft formation and a grouting method. The device comprises a thin grout inlet pipe, a perforated pipe, a variable-diameter contraction pipe, a casing pipe and a thick grout pipe; multiple pipe body holes are formed in the pipe wall of the perforated pipe, the perforated pipe is provided with a filter layer covering all the pipe body holes, the thin grout inlet pipe is connected with the upper end of the perforated pipe, the large-diameter end of the variable-diameter contraction pipe is connected with the lower end of the perforated pipe, the small-diameter end of the variable-diameter contraction pipe is connected with the thick grout pipe, the casing pipe is arranged outside the perforated pipe in a sleeving mode, and the lower end of the casing pipe is connected with the variable-diameter contraction pipe in a sealing mode. The method comprises the steps that 1, a grouting material is prepared; 2, the thick grout pipe is put into a grouting hole, and the lower end of the thick grout pipe is connected with a grouting pipe to reach the hole bottom; 3, cement grout with the pressure value of 0.5-0.8 MPa is delivered to the perforated pipe through the thin grout inlet pipe, the pressure rises as a congestion effect is formed in the variable-diameter contraction pipe, water is filtered out through the filter layer, thin grout is converted into thick grout in the device, and the water which is filtered out is drained through draining pipes; 4, the thin grout is converted into the thick grout in the device, the pressure is increased to 1-2 MPa, and then the thick grout is pressed into the formation.

Description

technical field [0001] The invention relates to a grouting device in the fields of water conservancy engineering, foundation treatment and the like, in particular to a filter press type grouting device and a grouting method for soft strata. Background technique [0002] Soft formations and formations with high water content usually have soft structures, weak cementation, and large grout consumption. During the grout diffusion process, groundwater segregation affects the grouting effect, and grouting is difficult to pressurize, easily causing vertical lifting damage, and grouting is difficult to control. Due to the repeated splitting effect of the fractured surface, the slurry is easy to flow and run along the layer with strong groutability or the surface of the minimum principal stress, extending in a single layer of cake, so that most of the formation fractures cannot be effectively and evenly injected, preventing The seepage effect is difficult to meet the design requireme...

AI Technical Summary

Problems solved by technology

[0002] Soft formations and formations with high water content usually have soft structures, weak cementation, and large grout consumption. During the grout diffusion process, groundwater segregation affects the grouting effect, and grouting is difficult to pressurize, easily causing vertical lifting damage, and grouting is difficult to control. Due to the repeated splitting effect of the fractured surface, the slurry is easy to flow and run along the layer with strong groutability or the surface of the minimum principal stress, extending in a single layer of cake, so that most of the formation fractures cannot be effectively and evenly injected, preventing The seepage effect is difficult to meet the design requirements. Nowadays, the following problems generally exist when grouting soft ground:

[0003] 1. The diffusion range of slurry is difficult to be controlled, and problems such as pulp running and stringing are very serious;

[0004] 2. Most of them require special anti-slurry measures, and the construction is complicated;

[0005] 3. The ground is soft and hard to press, and it is difficult to control the grouting, so a good grouting effect cannot be obtained;

[0006] 4. When the thick grout is directly poured into the soft ground, due to the poor pumpability of the thick grout, the requirements for the construction equipment are higher, the construction difficulty is increased, and the cost is higher

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