考虑主应力轴旋转的深基坑内支撑布置参数优化

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中图分类号：TU753 文献标志码：A

Abstract：Toreduce plasticdeformationofsurroundingsoilduring excavationofdepfoundationpits，athree-dimensional numerical model of deep foundation pit excavationand supporting was established by using ABAQUS software.Considering changing parametersof horizontal spaceof interal supportsand numberof vertical internal supportlayers，influencesof variatioofinteralsupport layout parameters on stresspaths of surounding soil especiallyonrotationof principalstress axes were explored.Theresults show thatwhen the structure form of internal supportsareselected as non-uniform layout of two ends dense and middle sparse，the principal stress direction angle of point 6* located at z axis in Cartesian coordinate reduces from 88∘ to 40∘ obviously，indicating that non-uniform layout of internal supports can effectively reduce stressconcentrationand significantlyreduce plastic deformationof soilcaused byrotationof principal stressaxes. During excavation of deep foundation pits，principal stress direction angles at points 6* ， 7* and 8* located at z axis are greatly reduced from a peak of 90∘ to less than 10∘ ，indicating that increasing number of vertical internal support layers canalsoefectivelyreduceplasticdeformationof soil causedbyrotationof principal stress axesand significantlyimprove overall stability of deep foundation pits.

Keywords：excavation ofdeep foundationpit；internal support layout；stress path；parameter optimization；rotation of principal stress axis；finite element simulation

深基坑工程大多呈多、大、近、深的特点，导致周围环境对施工引发的地层位移控制提出了更高要求[1-3]。（剩余4599字）