Preventive measures for water gushing in foundation pit envelope caused by blasting in upper soft and lower hard strata

Abstract

The present invention provides a method for prevention and control of foundation pit enclosure structure hole penetration and gushing water caused by blasting in upper soft and lower hard strata. The steps of the method are as follows: the first step is to determine the geological conditions of the construction site; the second step is to control the blasting to excavate the rock above the depth of the foundation pit ; The third step is to inject two-component polyurethane high polymer material to seal the cavity; the fourth step is to use the method of combining two-component polyurethane high polymer material injection and high-pressure rotary spraying to form piles to block the groundwater seepage path in the formation; The fifth step is to optimize the blasting parameters; the sixth step is to continue the blasting of the next unit blasting area until the blasting of the blasting area of ​​this layer is completed; after the blasting construction of this layer is completed, the construction of the next layer of blasting area is carried out. The invention overcomes the disadvantages and deficiencies such as inconspicuous cavity sealing effect and easy occurrence of secondary water gushing under the construction conditions of foundation pit blasting, and realizes effective prevention and control of water gushing caused by blasting in upper soft and lower hard strata.

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...

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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

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