Prevention method for foundation pit retaining structure hole-punching and water-gushing caused by blast of stratum with soft upper portion and hard lower portion

Abstract

The invention provides a prevention method for foundation pit retaining structure hole-punching and water-gushing caused by a blast of a stratum with a soft upper portion and a hard lower portion. The method comprises the steps that step 1, geological conditions in a construction site are determined; step 2, rocks above the depth of a blasted and excavated foundation pit are controlled; step 3, two-component polyurethane high polymer materials are injected to block off a vacant cave; step 4, seepage paths of underground water in the stratum are blocked off by combining the injected two-component polyurethane high polymer materials and a high-pressure rotary jet grouting pile; step 5, blasting parameters are optimized; and step 6, the blast of the next unit of blast zone is continued until the blast of all blast zones on the stratum is completed, and the construction of blast zones on the next stratum is conducted after the blasting construction of the stratum is completed. According to the prevention method, defects and deficiencies that under the condition of the foundation pit blasting construction, the blocking effect of the vacant cave is not obvious, and secondary water-gushing is prone to happening are overcome, and the effective prevention of the foundation pit retaining structure hole-punching and water-gushing caused by the blast of the stratum with the soft upper portion and the hard lower portion is achieved.

Description

technical field [0001] The invention relates to a construction technology in the fields of construction, water conservancy, transportation, environment and other underground engineering, in particular to a method for preventing water gushing from penetration of foundation pit enclosure structures caused by blasting of upper soft and lower hard strata. Background technique [0002] Foundation pit engineering is an important part of high-rise building construction and underground space engineering. With the expansion of city scale, the increase of land cost and the progress of construction technology, the foundation pit engineering in my country has gradually shown a trend of deep and large, and the depth of some foundation pits has reached 40m. Foundation pit engineering usually adopts enclosure structures such as underground diaphragm walls as soil and water retaining structures. In South China, there are widely distributed upper soft and lower hard strata, and generally th...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the defects in the prior art, the purpose of the present invention is to provide a method for preventing and preventing water gushing from the hole in the foundation pit enclosure structure caused by the blasting of the upper soft and lower hard strata. The plugging effect is not obvious, and secondary water gushing is easy to occur, so as to realize the effective prevention and control of water gushing caused by the blasting of the upper soft and lower hard strata

Images