矩形顶管施工多测点位移反分析方法

Back Analysis Method of Displacement of Multiple Measuring Points in Rectangular Pipe Jacking Construction

针对矩形顶管施工穿越土层段地表全范围沉降规律难以准确获取的问题。依托太原地铁2号线长风街站地下通道工程,基于位移反分析理论,综合应用黄金分割法和数值仿真方法,提出了土体弹性模量E与黏聚力c的反演方法。从数值计算结果中可较为准确地获得地表全范围沉降规律。结果表明:相比单测点反演土层参数E、c,选用三测点反演计算方法,更能准确地表达地表沉降规律。三测点反演迭代计算8次,沉降误差函数为0.0181,满足精度要求。选择两个不同位置的测点,对比分析其地表沉降数值计算值与实测值,相对误差分别为0.45%和0.29%;监测断面DBC8的地表沉降计算结果与实测值吻合较好,验证了多测点位移反分析方法的准确性。研究结果可为矩形顶管施工地表沉降规律研究提供一定的指导意义。

When the rectangular pipe jacking construction passes through the soil layer,the surface settlement law is difficult to describe accurately.Comprehensive application of displacement back analysis theory,golden section method and numerical simulation,an inversion method of soil elastic modulus E and cohesive force c was proposed based on the Changfeng Street underpass project of Taiyuan Metro Line 2.The surface settlement law could be obtained accurately through numerical calculation.The results show that compared with E and c from the single-point inversion calculation,the surface settlement can be expressed more accurately by three-point inversion calculation.The settlement error is 0.0181,which satisfies the accuracy requirement after 8 times of inversion calculation.Comparing and analyzing the calculated and measured values of surface settlement at two different points,the relative errors are 0.45%and 0.29%,respectively.In addition,the calculated results of ground settlement of the monitoring section DBC8 are in good agreement with the measured values.The verification results confirm the accuracy of the multi-point displacement method.The results can provide certain guiding significance for the study of surface settlement law of rectangular pipe jacking construction.