顶管隧道施工环境影响研究

Study of Influence of Pipe-jacking Construction on Environment

采用有限差分法并考虑流固耦合的作用,分析研究了顶管顶进施工对周边地表变形、土体内部位移、孔隙水压力及土体主应力的影响规律。结果表明,顶管顶进过程中沿顶管纵向地表位移在机头前方约1D(D为顶管直径3.8m)处隆起值最大且距离机头越远隆起变形越小;横向地表受顶管施工扰动影响较大的区域为其轴线两侧3D范围内;孔隙水压力先增大后减小,且在顶管机头通过计算断面2D时土体孔隙水压力达到最大;同一水平面上顶管轴线处主应力受到的影响最大,且影响范围约为2D。最后将数值模拟结果与理论值进行对比,得到的结果基本一致。

Surface deformation,soil displacement,pore water pressure and soil stress in consideration of fluid-structure interaction are studied during pipe-jacking construction by finite difference method. The results show that in pipe-jacking construction surface displacement along the axis of pipe-jacking reached the maximum when the pipe is ahead about 1D（D is pipe diameter,3. 8m） and became small when the pipe is away. The surface along the vertical axis of pipe-jacking is greatly influenced on both sides of the3 D of the axis. Soil pore water pressure increased at first and then decreased,and reached the maximum when the pipe is 2D away from the calculated section. Influence of principal stress at pipe-jacking axis is largest in the same horizontal plane and the scope of influence is about 2D. Finally,the numerical results is compared with the theoretical value,the results are basically identical.