考虑结构面蠕变特征的隧道围岩长期变形研究  

Research on long-term deformation of tunnel surrounding rock considering the creep characteristics of structural surfaces

作　　者：郭汝涛 赖登甲 李升连 但路昭 李韦剑 张国华 臧熙玮 GUO Rutao;LAI Dengjia;LI Shenglian;DAN Luzhao;LI Weijian;ZHANG Guohua;ZANG Xiwei(China Railway Development Investment Group Co.,Ltd.,Kunming 650504,China;Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China;Yunnan Infrastructure Investment Co.,Ltd.,Kunming 650032,China;Yunnan Communications Investment&Construction Group Co.,Ltd.,Kunming 650032,China)

机构地区：[1]中铁开发投资集团有限公司,云南昆明650504 [2]中国地质大学(武汉)工程学院,湖北武汉430074 [3]云南建设基础设施投资股份有限公司,云南昆明650032 [4]云南省交通投资建设集团有限公司,云南昆明650032

出　　处：《安全与环境工程》2024年第4期99-108,共10页Safety and Environmental Engineering

基　　金：国家自然科学基金面上项目(42277173)。

摘　　要：在断层破碎带发育地区,岩石结构面蠕变变形影响着隧道运营安全。首先推导了岩石结构面西原蠕变模型有限差分格式;然后基于FLAC3D的Interface单元,采用自定义本构模型的接口,编写西原蠕变模型的动态链接库,实现了隧道围岩结构面蠕变变形数值模拟;接着开展了岩石单节理面蠕变变形验证模拟;最后结合宜昌成品油管道翻坝项目七里村1号隧道工程,利用新开发模型模拟了运营1、5、10、20 a后的隧道围岩长期变形行为。结果表明:(1)新开发模型预测的隧道围岩蠕变变形与解析解是一致的,最大误差小于2%;(2)隧道围岩蠕变变形数值计算结果与现场监测值之间的偏差较小,证明了蠕变模型的可靠性;(3)隧道开挖后,围岩变形较大,随着时间的推移逐渐减小,1 a后位移趋于稳定;(4)隧道运营1~10 a内无明显破坏,运营20 a后出现了集中于拱脚部位的破坏区,且拱脚处应力集中,因此应加强对拱脚的初期支护;(5)低强度和弱膨胀性特征的泥钙质砾岩使得隧道开挖变形较大,在上方断层长期蠕变作用下,隧道拱顶持续向下变形,造成隧道变形较大。In regions where fault fracture zones are developed,the creep deformation of rock structural planes affects tunnel operation safety.First,the finite difference scheme of the Nishihara creep model for rock structural planes was derived.Then,based on the Interface elements in FLAC~(3D)and using a custom constitutive model interface,a dynamic link library for the Nishihara creep model was developed to achieve numerical simulation of creep deformation in the surrounding rock structural planes of tunnels.Subsequently,a validation simulation for the creep of a single rock joint was conducted.Finally,in conjunction with the Qili Village No.1 Tunnel project of the Yichang finished oil transshipment project,the newly developed model was used to simulate the long-term deformation behavior of the tunnel after 1,5,10,and 20 a of operation.The results are as follows:(1)The creep deformation predicted by the new model is consistent with the analytical solution,with a maximum error of less than 2%;(2)The numerical calculation results of tunnel surrounding rock deformation have small deviations from field monitoring,proving the reliability of the creep model;(3)After tunnel excavation,the surrounding rock deformation is significant,gradually decreasing over time,and the displacement tends to stabilize after one year;(4)There is no significant damage within 1 to 10 a of tunnel operation,but after 20 a,damage zones concentrated at the tunnel foot appear,and stress concentration occurs at the tunnel foot,indicating that initial support measures at the tunnel foot should be strengthened;(5)The low-strength and weakly expansive characteristics of the mud-calcareous conglomerate result in significant deformation during tunnel excavation,and under the long-term creep effect of the overlying fault,the tunnel crown continues to deform downward,causing significant tunnel deformation.

关 键 词：石油管道 小断面隧道 岩石结构面 蠕变变形 现场监测 数值模拟 

分 类 号：X951[环境科学与工程—安全科学]