Deep Soil Freezing Of Design Research And The Practice Of Guo Tuen Air Shaft Engineering

The security of freezing wall is the key problem of freezing shaft sinking in deep alluvium. It is one of the key technology of " two walls and one bored ". The rationality of its design influences the security of the wall directly, otherwise cause the wall to break , manage brokenly, even flood the well.Firstly, the thesis research the "design of the deep well" , in the course of constructing, the technology that crossing all alleviation layer, weathering zone but enter the craft of intact base rock should be adopted. So, guaranteeing the safty and economy of the whole shaft digging, the calculation of the freezing shaft wall should take according to different depth, the terms of solid, top-down to divided it into different section (namely viscoplasticity, glue plasticity of playing and glue plasticity),then carry on the concrete calculation according to different formulae. The design of freezing wall is the base of arrangement of freezing hole design and other freezing technical parameter design.The arrangement of freezing holes influerences the thickness and intensity of freezing wall directly,guarantees to the key point of freezing wall that reach to the design requirement. On the basis that such deep topsoil as LongGu auxiliary shaft, etc, according to the concrete frozen and constructing problems, this thesis launch the research of the arrangement of multi-circle holes. The main purpose is based on the premise that the freezing wall can reach to designing requirement, and obtained the follow resultsrnot only guarantee the thickness and intensity of freezing wall, but also reduce the top outside freezing wall "invalid thickness" ;not only guarantee the safety of freezing wall in digging shaft, but also help to excavate shaft in advance;not only prevent excavate non-freezing soil in initial stage, but also reduce amount of waste freezing soil of deep department, create the advantage for digging, shorten constructing time;not only guarantee the homogeneity of freezing wall, but also reduce the bloated stress within the frozen soil;not only prevent main-freezing holes from broken by the nearer distance to sidewall, but also try to reduce "freezing soil" in base rock.In a word,a reasonable freezing arrangement is the key point for safty, fast, economy in shaft sinking by freezing.The freezing conceptual design in GuoTun ventilating shaft in this thesis verifies it to be reasonable through engineering practice.