渗流影响下黏弹塑性岩体隧道支护压力预测的解析模型  

Analytical model for tunnel stability and support pressure prediction of viscoelastic-plastic rock masses under the influence of seepage

作　　者：刘倩 王华宁[1,2] LIU Qian;WANG Huaning(School of Aerospace Engineering and Applied Mechanics,Tongji University,Shanghai 200092,China;State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学航空航天与力学学院,上海200092 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《清华大学学报（自然科学版）》2024年第11期1955-1963,共9页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(12272274)。

摘　　要：对于流变岩体中衬砌支护深埋圆形隧道,该文用黏弹塑性模型模拟岩石流变特性并考虑实际应力路径及非稳态渗流场的影响,推导并获得支护压力及围岩、衬砌应力及位移的精确解析解,可以更快速精准地预测与时间相关的支护结构的受力变化和围岩稳定状态。通过开挖释放荷载下的加载计算获得开挖阶段的流变位移与应力。在支护阶段,通过分离变量法获得全域全时段的非稳态孔压分布;正确考虑支护阶段的加卸载应力路径,得到渗流影响下衬砌支护力以及围岩、衬砌力场和位移场的时效解析解。对比考虑加卸载应力路径和仅按加载路径计算的结果,发现仅按加载路径而未考虑实际应力路径时围岩变形预测值偏小,支护结构按此设计将偏于危险。该文为黏弹塑性岩体中深埋圆形隧道与时间相关的支护压力预测和围岩、衬砌流变力场分析提供了快速预测的方法。[Objective] With the advancement of traffic infrastructure development in China,an increasing number of tunnels and underground projects are being built through soft rock strata characterized by notable rheological properties in high-water-pressure environments.However,the comprehensive consideration of the stress path and unsteady seepage field during the excavation and support process has not been incorporated in predicting tunnel stability and support pressure in rheological rock masses.To solve the aforementioned problem,an analytical method is proposed to rapidly and accurately predict the time-dependent variation of the surrounding rock stability and support pressure.[Methods] The viscoelastic-plastic constitutive model is employed to simulate the rheological behavior of the surrounding rock.Based on the Mohr-Coulomb yield criterion,an exact analytical solution for stress and displacement is derived for the entire construction process of a deep-buried circular tunnel with lining.This solution incorporates the influence of the stress path and unsteady seepage field,utilizing the principles of elasticity-viscoelasticity correspondence and Laplace transformation.The construction process is categorized into two distinct stages.During the excavation stage(0-t_1),the tunnel is rapidly excavated at the onset.This stage is characterized by the absence of any water flow;hence,no additional stress is generated.During this stage,the mechanical field under the release load from the excavation needs to be considered.In the support stage(t_1-t_∞),the lining is applied when t=t_1.After the support is subjected to stress,the stress of the surrounding rock reaches a safe state,leading to the complete unloading of the original plastic zone.Long-term mechanical action may cause cracks or damage in the supporting or waterproof layer,eventually leading to water leakage and gushing.In the support stage,the influence of the seepage field needs to be considered when analyzing the mechanical field.The unsteady pore pressure distr

关 键 词：隧道工程 黏弹塑性解析解 应力路径 非稳态渗流场 支护压力预测 

分 类 号：O319.56[理学—一般力学与力学基础]