HSS模型在盾构模拟中的应用及参数敏感性研究

Application of HSS Model in Shield Simulation and Parameter Sensitivity Research

HSS模型是一种考虑土体硬化并能反应土体小应变特性的本构模型,目前已广泛应用于软土地区基坑工程的工程分析,而在地铁盾构隧道工程分析中应用较少。当前盾构工程分析尚常采用线弹性或M-C等简单本构模型,难以准确描述岩土体实际力学行为。本文通过北京某地铁区间盾构隧道实例验证了HSS模型在盾构掘进模拟中的适用性。同时,基于理想盾构工程模型,利用正交试验开展了HSS模型多参数全范围水平取值的协同敏感性分析,发现地表沉降敏感度最高的参数为Eur,并随Eur增大而减小;衬砌拱顶沉降敏感度最高的参数为Eur,并随Eur增大而减小;衬砌拱底隆起敏感度最高的参数为E50,结果随E50增大而减小。参数敏感性分析结果有助于增强理解各参数对结果影响,辨识关键影响参数。

HSS model is a constitutive model which considers soil hardening and can reflect the small strain characteristics of soil.At present,it has been widely used in the engineering analysis of foundation pit engineering in soft soil area,but it is rarely used in the engineering analysis of subway shield tunnel.At present,simple constitutive models such as linear elasticity or M-C are often used in shield engineering analysis,so it is difficult to accurately describe the actual mechanical behavior of rock and soil.In this paper,the applicability of HSS model in shield tunneling simulation was verified by an example of a subway shield tunnel in Beijing.At the same time,based on the ideal shield engineering model,the cooperative sensitivity analysis of multi-parameter full-range horizontal value of HSS model was carried out by orthogonal test,and it was found that the parameter with the highest sensitivity to surface settlement is Eur,and the surface settlement decreases with the increase of Eur;the parameter with the highest sensitivity to settlement of lining vault is Eur,and the settlement of lining vault decreases with the increase of Eur;the parameter with the highest sensitivity of uplift of lining arch bottom is E50,and the result decreases with the increase of E50.The results of parameter sensitivity analysis are helpful to enhance the understanding of the influence of various parameters on the results and identify the key parameters.