基于楔形体理论的市政管网超大直径钢顶管施工开挖面极限支护压力研究  

Research on Ultimate Support Pressure on Excavation Face of Super-large Diameter Steel Pipe Jacking Construction in Municipal Pipe Network Based on Wedge-shaped Body Theory

作　　者：梁斌 房鹏帅 李文杰 耿弈 唐刚 LIANG Bin;FANG Pengshuai;LI Wenjie;GENG Yi;TANG Gang(Civil Engineering School,Henan University of Science&Technology,Luoyang 471023,China;CCCC-SHEC Forth Engineering Co.,Ltd.,Luoyang 471013,China)

机构地区：[1]河南科技大学土木工程学院,河南洛阳471023 [2]中交二公局第四工程有限公司,河南洛阳471013

出　　处：《河南科技大学学报（自然科学版）》2023年第4期75-84,I0005,I0006,共12页Journal of Henan University of Science And Technology:Natural Science

基　　金：国家自然科学基金项目(U1604135);中交第二公路工程局有限公司重点科技研发项目(2020-5-19);河南省科技厅产学研合作项目(2015HNCXY011)。

摘　　要：针对极限支护压力不足引起的市政管网超大直径钢顶管施工开挖面失稳破坏问题,分析了开挖面失稳破坏的动态过程,改进既有楔形体-棱柱体模型,利用极限平衡法,提出一种市政管网超大直径钢顶管施工开挖面极限支护压力计算方法。以深圳市某超大直径钢顶管工程为背景,研究了极限支护压力与滑裂面倾角、梯形底角的变化规律,并给出了两者的理论建议值;探讨了影响顶管施工开挖面极限支护压力的控制参数。研究结果表明:当支护压力比分别为0.40和0.15时,开挖面分别处于失稳临界状态和失稳极限状态。开挖面破坏模式符合楔形体-梯形体计算模型。开挖面极限破裂角等于43°,最大梯形底角为79.5°。开挖面极限支护压力随着土体内摩擦角和黏聚力的增大而减小,当摩擦角大于27.5°时,开挖面处于稳定状态;随着顶管埋深直径比增大,开挖面极限支护压力逐渐增加,当埋深直径比大于2.2时,极限支护压力趋于稳定。Aiming at the instability and failure of the excavation face caused by insufficient ultimate support pressure in the construction of the super-diameter steel pipe jacking of the municipal pipe network,the dynamic process of the instability and failure of the excavation face was analyzed.The existing wedge-prism model was improved,and a calculation method for the ultimate support pressure,which applied to oversized diameter steel pipe jacking surface of the municipal pipe network,was proposed by using the limit equilibrium method.In the engineering background of super-large diameter steel jacking pipe in Shenzhen city,the variation law of the ultimate support pressure and the inclination angle of the slip plane,the trapezoidal bottom angle was studied,and theoretical suggested values for both were given.The control parameters affecting the ultimate support pressure of the surface in pipe jacking construction were discussed.The results show that when the support pressure ratio is 0.4 and 0.15,the excavation face is in the critical state of instability and the limit state of instability,and the failure mode of the surface conforms to the wedge-trapezoid calculation model.The ultimate rupture angle of the surface is 43°,and the maximum trapezoidal bottom angle is 79.5°.The ultimate support pressure of the excavation face decreases with the increase of the friction angle and cohesion in the soil.When the friction angle is greater than 27.5°,the excavation face is in a stable state.With the increase of the buried depth to diameter ratio of the pipe jacking,the ultimate support pressure of the excavation face gradually increases.When the buried depth to diameter ratio is greater than 2.2,the ultimate support pressure tends to be stable.

关 键 词：市政管网超大直径钢顶管施工 楔形体理论 滑动面破裂角 极限支护压力 控制参数 

分 类 号：U455[建筑科学—桥梁与隧道工程]