Technical Research Of Soil Nailing In Chengdu Area

With the development of economic, more and more high buildings emerge, so requirements which are on the support of building foundation excavation turn to be sticker. At the same time, there are more and more supporting forms. Soil nail is a type of supporting for building foundation excavation, which has many advantages, such as good stability, less cost and easy construction. For its advantages, soil nail spreads quickly and applies in many areas in our country.Deep foundation pit-retaining is one of key problems in rock and soil engineering. Structure design and finite element method of deep foundation pit-retaining are studied theoretically and numerically in this paper and of importation in design and construction of soil nailing retaining structure of deep foundation pit. Main results are obtained as follows:(1) Based on analysis of current deep foundation pit-retaining and combined with the regional geological conditions in Chengdu, the application of soil nailing support in Chengdu area was clarified.(2) In this thesis, soil nailing definition, classification, applicability and the open questions are presented. The working mechanism and deformation behavior of soil nailing retaining system is also investigated systematically.(3) The principle, method and specific content of the soil nailing design are introduced in detail. The calculation fundamentals of soil nailing is also analyzed and discussed. Moreover, some remarks on design and calculation are made for the current standard method related to soil nailing.(4) Excavation by steps of soil nail retaining structure of deep foundation pit in Chengdu city is simulated by PLAXIS finite element software. Numerical results are in good agreement with tested results, which verifying the correction of calculation, and of signification in design and construction of soil nailing retaining structure of deep foundation pit.