渗流损伤耦合作用下深埋圆形隧道的弹塑性解

Elastoplastic solutions of deep-buried circular tunnels under the coupled effect of seepage damage

为了研究深埋圆形隧道在考虑渗流损伤耦合作用下的弹塑性解,选择Drucker-Prager屈服准则,基于Biot有效应力原理推导具有衬砌支护的深埋圆形隧洞在施工阶段和运行阶段下的弹塑性解,得到塑性半径和衬砌围岩应力的公式,分析不同因素对塑性半径和衬砌围岩应力的影响。结果表明:在施工阶段,围岩损伤对塑性区的扩展起到促进作用,同时塑性半径与渗流力呈现正相关趋势,环向应力在衬砌与围岩交界处出现突变并最终趋于地应力;在运行阶段,塑性半径与损伤因子呈线性增加关系,与渗流力呈负相关趋势;随着内压力的进一步增加,对塑性半径的影响分为5个阶段,即低内压力阶段、中低内压力阶段、第一高内压力阶段、第二高内压力阶段、高内压力阶段等。研究结果可为深埋圆形隧道工程建设提供指导和帮助。

In order to study the elastoplastic solution of deeply buried circular tunnels considering seepage damage coupling factors,this paper selects the Drucker-Prager yield criterion and deduces elastoplastic solution of deeply buried circular tunnels with lining support in the stages of construction and operation based on the Biot effective stress principle.Moreover,the formulas of plastic radius and lining surrounding rock stress are deduced,and the effects of different factors on plastic radius and lining surrounding rock stress are ana‐lyzed the formulas for the plastic radius and lining surrounding rock stress are given.The results show that:in the construction stage,the surrounding rock damage promotes the expansion of the plastic zone,at the same time,the plastic radius is positively correlated with the seepage force,and the hoop stress appears abruptly at the junction of the lining and the surrounding rock and finally tends to the crustal stress.In the operation stage,the plastic radius and the damage factor show a linear increase,and show a negative correla‐tion trend with the seepage force.The effect of internal pressure on the plastic radius is divided into five stages.With the further increase of internal pressure,the plastic radius can be divided into five stages:low internal pressure stage,medium-low internal pressure stage,first high internal pressure stage,second high in‐ternal pressure stage,and high internal pressure stage.The above results provide guidance and help for the construction of deep-buried circular tunnel engineering.