基于四阶段模型的深埋硐室围岩分区受力分析  

Zoning Stress Analysis of Surrounding Rock of Deep-buried Chamber Based on Four Stage Model

作　　者：孙卫星 赵永宾 周建 杨新安[2] SUN Wei-xing;ZHAO Yong-bin;ZHOU Jian;YANG Xin-an(CCCC Third Harbor Engineering Co., Ltd., Shanghai 201900, China;Key Laboratory of Road and Traffic Engineering, Ministry of Education, Tongji University, Shanghai 201804, China)

机构地区：[1]中交第三航务工程局有限公司交建分公司,上海201900 [2]同济大学道路与交通工程教育部重点实验室,上海201804

出　　处：《科学技术与工程》2021年第36期15631-15638,共8页Science Technology and Engineering

基　　金：国家自然科学基金(51178336)。

摘　　要：目前,深埋硐室围岩分区的不明确导致弹塑性分析结果不够精确。为研究硐室开挖过程中的弹塑性解,首先,建立圆形硐室四阶段分区受力模型,基于Mohr-Coulomb屈服准则,考虑围岩扩容、软化等岩体特性以及空间效应,推导出开挖过程中硐室围岩弹塑性解;其次,选择锚杆、衬砌支护时机,考虑锚杆与围岩的耦合作用和喷射混凝土的时效特性,得到支护条件下围岩的弹塑性解;最后,结合算例分析了空间效应、支护时机等因素对硐室围岩塑性区应力、位移和范围的影响。基于理论研究的算例分析,揭示了考虑空间效应和支护时机时硐室各分区范围的变化规律。锚杆间排距对围岩位移的控制主要体现在残余区;硬化区扩容系数、开挖过程中的空间效应和支护时机对控制围岩位移的作用不容忽视;当支护距开挖面的距离大于15 m时,可以忽略空间效应;支护越靠近开挖面,支护效果越明显。研究成果为深埋软岩硐室开挖与支护设计提供一定的理论依据。Currently,the lack of clarity in the zone of deep-buried chamber surrounding rock partition leads to less accurate elastoplastic analysis results.In order to study elastoplastic solution of circular chamber excavation and supporting process,the model of four-stage zone model was established firstly.Based on Mohr-Coulomb yield criterion,rock mass characteristics such as rock dilatancy,softening and so on and spatial effect were considered.Therefore,chamber rock elastoplastic solutions in excavation process was deduced.Secondly,based on homogenization method under the condition of bolts,liners support,and the aging characteristics of primary lining concrete,the elastoplastic solution of surrounding rock under supporting condition was obtained by considering the coupling effect between bolts and surrounding rock.Lastly,an example was analyzed to study the effect of different factors such as spatial effect,supporting opportunity and so on to stress of plastic zone,surrounding displacement and plastic zone radius of chamber.The theoretical analysis revealed the variation of the partition range of the chamber considering the spatial effect and the support time.The control of interval distance of rock bolts on the displacement of surrounding rock mainly reflects in the residual zone.The roles of dilatancy factor in the hardening area,the spatial effect in excavation and the support time to control the displacement of surrounding rock can't be ignored.When the distance between the support and the excavation surface is more than 15 m,the space effect can be ignored.The closer the support is to the excavation face,the more obvious the support effect is.The research results provide a certain theoretical foundation to process of deep-buried soft rock chamber excavation and supporting.

关 键 词：支护时机 空间效应 弹塑性解 耦合作用 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]