单节护壁掘进深度对护壁工作机理的影响研究

Study on the Effect of Excavation Depth of Single Retaining Wall on Its Force Mechanism

STS管幕结合洞桩法在国内首次被用于沈阳地铁奥体中心站.采用有限差分软件建立三维数值模型,重点研究了人工挖孔桩每节不同掘进深度对桩外围的变形、弯矩和剪力的影响.研究结果表明:随着每节掘进深度的增加,单节土体的最大变形量也随之增大,单节挖孔最大位移值出现在每节的3/4处;在0~5m的开挖深度范围内,掘进距离的改变对剪力变化值影响不大;随着开挖深度的增大,护壁所受剪力逐渐增大,剪力最大值出现在开挖6~8m范围内,剪力值达到17~18kN.

The first practice of STS（Steel Tube Slab）combined with PBA（Pile-Beam-Arch）method in China is the construction of Shenyang Subway Olympic Sports Center Station.In this paper,a three-dimensional numerical model was established by using finite difference software.The effects of the excavation depth of each manual digging pile on the deformation,bending moment and shear force of pile periphery were studied.The results show that with the increase of excavation depth,the maximum deformation of single-section soil mass increases,and the maximum displacement of single-section excavation appears at 3/4 of each section.Within the range of 0-5 mexcavation depth,the change of excavation distance has little effect on the change of shear force.With the increase of excavation depth,the shear force that protection wall bears gradually increases,and the maximum shear force appears within the range of6-8 mexcavation depth and the shear value reaches 17-18 kN.