砂土地层顶管施工土体变形规律三维数值分析

1.长安大学 陕西省公路桥梁与隧道重点实验室,陕西 西安 710064; 2.延安大学 西安创新学院,陕西 西安 710100; 3.陕西省铁路投资集团有限公司,陕西 西安 710054

砂土地层; 顶管; 数值模拟; 土体变形; 地层损失; 顶推力

3D numerical analysis on displacement regularity of pipe jacking sewer in sand soil stratum
LAI Jin-xing1,WANG Kai-yun1,HOU Dan-dan2,LI Feng-ning3

(1.Shaanxi Provincial Major Laboratory for Highway Bridge & Tunnel,Chang'an University,Xi'an 710064,China; 2.Xi'an Creation College,Yan'an University,Xi'an 710100,China; 3.Shaanxi Railway Investment Corporation,Xi'an 710054,China)

sand formation; pipe jacking; numerical simulation; soil deformation; ground loss; propulsion

DOI: 10.13800/j.cnki.xakjdxxb.2015.0409

备注

为得到顶管施工引起的土体变形分布规律、施工扰动范围和土体塑性区特征,以某污水干管顶管工程为依托,采用构建三维弹塑性有限元计算模型的方法,分别考虑正面推进力、地层损失和结构与土体的共同作用等因素对土体变形的影响。结果 表明:仅地层损失作用下,管道周围2D范围内土体受扰动明显,推进面前后方土体均出现沉降,但推进面后方土体下沉趋势较前方土体幅度大; 仅顶推力作用下,施工从横向和竖向对土体的扰动分别集中在管道周围1D和2D范围内,顶进面纵向前方2D范围内土体受扰动明显,推进面后方土体出现沉降,而前方的土体则出现隆起现象,但隆起值较小; 在顶推力和地层损失2种因素共同作用下,地层损失是引起土体沉降的主要因素。通过以上分析认为砂土地层顶管管道周围2D范围内土体易产生位移,在施工中应引起重视,并采取一定措施减少其扰动程度。

Based on the construction of a sewage pipeline engineering in Xi'an,three-dimensional elastic-plastic finite element model is set up to study the regularity of surrounding soil deformation and disturbance range caused by pipe jacking in sand formations.The rule of surrounding soil deformation and range of disturbance and characteristics of plastic zone induced by pipe jacking are obtained from the influence of propulsion and ground loss and joint action.The Research results show that:the soil around the pipe within the range of 2D is disturbed obviously and both sides of the soil surface to promote subsidence occurred,but the rear surface of soil subsidence trend is in a larger magnitudecompared with the front soil.Only in the propulsion,construction from horizontal and vertical on soil disturbance around the pipe were concentrated in the 1D and 2D range,and the soil within the front range of 2D is disturbed obviously from the longitudinal.The soil behind the excavation face appears the settlement,and the soil in front of the excavation face appears the smaller value uplift.Ground loss is the major factor causing soil subsidence under the propulsion and ground loss action.The range of 2D around the soil layer for pipe jacking is easy to displace from above analysis results,and which should be valued and some measures should be taken to reclace the disturbance in construction.