Construction method of full-section grouting shield in water-rich rock formation under sensitive buildings

Abstract

Provided is a construction method of a below-sensitive-building water-enriched rock stratum full-section grouting shield. The construction method of the below-sensitive-building water-enriched rock stratum full-section grouting shield includes the construction steps of reinforcing shield sealing, filling the periphery of the shield with bentonite, supplementing grout to gaps behind duct-piece walls, replacing muck with gas, replacing the gas with grout, grouting full sections, detecting grouting effects and conducting shield tunneling. By the adoption of the construction method of the below-sensitive-building water-enriched rock stratum full-section grouting shield, base-rock gap channels can be effectively sealed in all directions, loss of underground water is reduced, tunneling environment is improved, soil transporting of a screw conveyor is facilitated, so that the shield tunnels rapidly, and descending of buildings on the earth surface can be effectively controlled.

Description

technical field [0001] The invention relates to the field of shield tunnel construction, in particular to a full-section grouting shield construction method of a water-rich rock layer under a sensitive building. Background technique [0002] The shield method has the advantages of high degree of automation, high safety factor and fast construction speed, and is widely used in urban subway tunnel construction. The shield machines commonly used in the shield method mainly include mud-water pressure balance shield machines and earth pressure balance shield machines. The mud-water pressurized balance shield machine pressurizes the mud water to balance the external pressure of the excavation surface, and relies on the mud pump to pump the mud to the ground and separates and purifies it. Therefore, it is suitable for water-bearing sand layers, clay layers and weak strata with high groundwater levels. It is not suitable for unbreakable surrounding rock formations. The earth press...

AI Technical Summary

Problems solved by technology

However, if in the water-rich rock formation, the bedrock fissure water and the overburden pore water have a certain degree of connectivity, there are many fissure channels and a large amount of water inflow, and the use of deep hole grouting to stop water or drainage excavation will easily cause the soil to contain water. The water volume is too high and the soil pressure is difficult to control, which leads to the spewing of the screw machine, the failure of the shield tunneling, and the loss of groundwater, which affects the safety of the surface buildings (structures), and it is difficult to meet the expected quality requirements and progress goals

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