基于等效梁模型的盾构隧道施工期管片上浮影响因素权重分析

摘要

The weights of influencing factors of shield tunnel segments uplifting during construction are studied by equivalent beam model.The lining ring of a Metro shield tunnel in Nanning is simulated by equivalent stiffness Euler beam;the interaction of the soil and tunnel is simulated by equivalent spring;the model is calculated by software Matlab .The calculation results are compared with measured data so as to verify the rationality of the model.The weights of influencing factors are calculated by sensitivity analysis method.The orders of weights of influencing factors are the length of area with unconsolidated grout,grout pressure,deformation modulus of ground,effective rate of longitudinal bending rigidity and vertical force of total thrusting force.The acting mechanisms of influencing factors are analyzed;and then some countermeasures are proposed.%为厘清盾构隧道施工期影响管片上浮各因素的权重大小，在明确管片上浮影响因素的基础上，基于盾构隧道纵向等效梁模型，以等效刚度的欧拉梁模拟盾构隧道衬砌环，以土体与浆液体等价弹簧来模拟土体与隧道之间的相互作用，编制有限元程序对模型进行求解，并以南宁某地铁盾构隧道施工期管片上浮实测数据来验证计算模型的合理性。采用敏感性分析法计算出各主要影响因素的权重排序，由大到小依次为浆液未凝固区长度、浆液压力、地层变形模量、隧道纵向刚度有效率和总推力竖向分力等，分析各因素的作用机制，并提出针对性的控制措施，以指导工程实践。