考虑土体参数条件随机场的矩形顶管施工地表沉降分析

Ground Settlement Analysis of Rectangular Pipe Jacking Construction Considering Conditions Random Field of Soil Parameter

摘要:

针对运用随机场理论描述土体参数空间变异性时地勘数据使用效能不足的问题,结合Kriging理论和基于贝叶斯压缩感知与KL级数展开法相结合的数据驱动随机场理论,提出了数据驱动的三维条件随机场生成方法,并将该方法应用于苏州市某矩形顶管工程场地的土体参数空间变异性表征,建立了考虑土体参数空间变异性的三维数值模型,分析了顶管施工引起地表沉降规律,并与现场实测结果进行对比验证,最大误差低于10%。研究结果表明:生成的数据驱动条件随机场可以充分利用实际工程场地内的勘察数据,实现土体参数空间变异性条件随机场的优化模拟,完成勘察数据对已知取样点的约束,降低不确定性;相较于确定性计算,不确定计算能够充分表征矩形顶管施工引起地表沉降的趋势和波动范围,为复杂岩土工程设计和施工提供参考依据。

Abstract:

Considering the insufficient utilization efficiency of geotechnical data when using the random field theory to describe the variability of soil parameter space, by combining the Kriging theory and the data-driven random field theory based on Bayesian compressive sensing and Karhunen-Loeve(KL) series expansion method, a data-driven three-dimensional conditional random field generation method was proposed. This method was applied to characterize the variability of soil parameter space in a certain rectangular pipe-jacking project site in Suzhou City. [JP+1]A three-dimensional numerical model considering the variability of soil parameter space was established, and the settlement law caused by pipe-jacking construction was analyzed. The results were compared and verified with the on-site measured data, with the maximum error being less than 10%. The research results show that the generated data-driven conditional random field can fully utilize the survey data in the actual engineering site, achieve the optimization simulation of the conditional random field of soil parameter space variability, complete the constraint of the survey data on the known sampling points, and reduce the uncertainty. Compared with deterministic calculation, uncertain calculation can fully represent the trend and fluctuation range of surface settlement caused by the rectangular pipe-jacking construction, providing a reference basis for the design and construction of complex geotechnical engineering.