顶管施工中地面沉降分析及环境对策

Pipe jacking and environmental measures of land subsidence

市政工程中采用顶管施工可以将作业面移入地下,从而避免了对地面交通的影响。只要施工前选线合理,施工方法恰当,构筑物并不妨碍施工的正常进行。由于大直径顶管施工时在地下开挖引起卸载,虽然后续管节起到支撑作用,但开挖时开挖面四周的土体因应力松弛已向开挖面和隧洞空间膨胀,仍会引起地层损失。对于粘性土,可近似地认为所有的地层损失均表现为地面沉降。顶管施工时,工具管前方土体的移动对邻近已有的构筑物有明显的破坏作用。由于顶管在作业中既有开挖又有沿轴向的顶进,且施工中土体轴向位移量随深度变化,所以工具管附近土体的运动表现为非线性的三维特征。

Municipal works,the top management operations in the construction can be moved into the ground,so as to avoid the impact on the ground of the traffic.As long as the construction before the alignment reasonable,the method appropriate structure does not prevent the construction of the Normal.the diameter the top management in the construction of underground excavation operations,although the section on follow-up to support,but the digging,digging for 4 weeks of the physical Stress Laxation due to the excavation and tunnel space expansion,and will cause losses stratum.The viscosity,similar to that all strata of the losses of ground settlement performance.The top management work,means the front and the movement in the vicinity of the structure of significant harm.The top management in the operation,both the digging and along the axis of the top,Turkey and physical construction axial displacement volume with the deep changes in the near the tool of the Movement of Non-performance linear 3D features.