考虑损伤效应的二向不等压深埋圆形隧道弹塑性统一解  

Elastoplastic unified solution for deep-buried circular tunnels under biaxial non-uniform stresses considering the damage effect

作　　者：杨益 施成华[1,2] 郑可跃 雷明锋 贾朝军[1,2] 娄义黎 YANG Yi;SHI Chenghua;ZHENG Keyue;LEI Mingfeng;JIA Chaojun;LOU Yii(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-speed Railway Construction Technology,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2024年第7期2650-2662,共13页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52178402);中国中铁股份有限公司科技研究开发计划项目(2021-重点-09,2022-重点-10)。

摘　　要：为了研究二向不等压地应力环境下深埋圆形隧道损伤后的力学响应问题,通过考虑深部围岩的损伤效应,基于统一强度理论建立二向不等压深埋圆形隧道弹塑性解,依托华丽高速东马场隧道验证解的准确性和适用性;研究损伤效应和中间主应力对围岩应力分布和变形的影响,并探讨不同侧压力系数、剪胀系数和支护反力下深埋圆形隧道围岩的损伤程度。研究结果表明:二向不等压深埋圆形隧道开挖后,围岩峰后的损伤效应会加剧隧道的挤压变形,考虑损伤效应的变形计算结果与现场实测结果更接近;中间主应力能提高围岩的承载能力,抑制隧道的挤压变形,不考虑中间主应力会高估隧道的变形潜势;侧压力系数决定围岩损伤区的形状和大小,施工时应根据围岩不同位置的损伤程度对关键变形部位进行注浆加固;剪胀系数越大,围岩的损伤程度越大,损伤区的范围越大;支护反力能抑制围岩的损伤效应,在实际工程中需及时施作支护约束围岩变形,以改善围岩的受力情况。To investigate the mechanical response of a deep-buried circular tunnel under biaxial non-uniform stress conditions after damage,an elastic-plastic solution was established based on the unified strength theory,considering the damage effects of the deep surrounding rock.Utilizing the Dongmachang tunnel as a reference case,the influences of damage effects and medium principal stress on the stress and deformation of the surrounding rock were explored.Additionally,the extent of damage within deep soft surrounding rock at varied lateral pressure coefficients,dilation coefficients,and support forces was investigated.The results show that the post-peak damage effects in surrounding rock exacerbate tunnel squeezing deformation after excavating deep-buried circular tunnels under biaxial non-uniform stresses.The deformation calculation results considering damage effects are closer to the on-site measured results.The medium principal stress enhances the load-bearing capacity of the surrounding rock and restrains tunnel squeezing deformation.Disregarding medium principal stress may overestimate the deformation potential of the tunnel.The lateral pressure coefficient governs the shape and size of the damaged rock zone,suggesting that grouting reinforcement at critical deformation sites should be tailored based on the extent of damage at different locations in the surrounding rock.As the dilation coefficient increases,the degree of damage within surrounding rock expands,and the range of complete damage expands.Support forces play a crucial role in restraining post-peak damage in surrounding rock.Consequently,timely implementation of support measures to restrain and stabilize the surrounding rock's response is imperative in practical engineering applications.

关 键 词：二向不等压 损伤效应 深埋圆形隧道 统一强度理论 

分 类 号：U451[建筑科学—桥梁与隧道工程]