基于全断面施工的超大断面隧道围岩松动圈分布特性研究  

Study on distribution characteristics of surrounding rock loosening circle of super-large section tunnel based on full-section construction

作　　者：燕波 张新锦 彭磊 宁波[1,2,3] Yan Bo;Zhang Xinjin;Peng Lei;Ning Bo(Engineering Research Center of New Materials for Urban Rail Transit,Universities of Shaanxi Province,Weinan 714000,China;College of Surveying and Testing,Shaanxi Railway Engineering College,Weinan 714000,China;Shaanxi Engineering Laboratory of High Performance Concrete,Weinan 714000,China)

机构地区：[1]城市轨道交通新材料陕西省高校工程研究中心,陕西渭南714000 [2]陕西铁路工程职业技术学院测绘与检测学院,陕西渭南714000 [3]陕西省高性能混凝土工程实验室,陕西渭南714000

出　　处：《工程勘察》2023年第12期26-34,共9页Geotechnical Investigation & Surveying

基　　金：陕西省教育厅2023年度青年创新团队科学研究计划项目(23JP027);陕西铁路工程职业技术学院轨道交通绿色建材科技创新团队(KJTD202102);陕西铁路工程职业技术学院中青年科技创新人才(KJRC202102)。

摘　　要：为掌握机械化施工背景下超大断面隧道全断面开挖后围岩松动圈的分布特性,服务于隧道工程动态设计与施工,以某双线高铁隧道为依托,从数值模拟及现场测试两方面进行分析研究。首先基于室内三轴试验获得符合工程实际下的围岩相关参数,之后利用数值模拟的方法,提出以极限剪应变作为围岩松动圈范围的判据,得出超大断面隧道全断面开挖后围岩松动圈的分布范围,最后通过现场波速测试测得松动圈厚度,分析围岩波速随孔深的变化情况,并与模拟结果对比分析。结果表明:以极限剪应变判据模拟得出围岩松动圈范围边墙两侧呈“月牙形”分布,拱顶及仰拱处呈“半圆环形”分布,边墙处松动圈厚度达到最大值1.10m;现场测试结果表明,边墙处围岩松动圈厚度为1.00~1.10m,拱腰处围岩松动圈厚度为0.50~0.60m,拱肩处围岩松动圈厚度为0.40~0.50m。室内试验为数值模拟提供了合理的围岩参数,模拟结果与实测结果较为吻合,验证了以极限剪应变判据在模拟确定围岩松动圈范围中的合理性及可靠性。本文研究成果可为今后类似工程提供一定思路及参考。In order to master the distribution characteristics of surrounding rock loose circle after full-face excavation of super-large cross-section tunnel under the background of mechanized construction and serve the dynamic design and construction of tunnel engineering,based on a double-track high-speed railway tunnel,the numerical simulation and field tests are analyzed and studied.Firstly,based on the indoor triaxial tests,the relevant parameters of surrounding rock in line with engineering practice are obtained.Then,by using the method of numerical simulation,the limit shear strain is put forward as the criterion of the range of surrounding rock loose circle,and the distribution range of surrounding rock loose circle after full section excavation of super large section tunnel is obtained.Finally,the thickness of loose circle is measured by field wave velocity tests,and the change of surrounding rock wave velocity with hole depth is analyzed,and the simulation results are compared and analyzed.The results show that:according to the limit shear strain criterion,the distribution of the surrounding rock loose circle on both sides of the sidewall is‘crescent',and the distribution at the vault and inverted arch is‘semi-circular';the thickness of the loose circle at the sidewall reaches the maximum value of 1.10m;field test results show that the thickness of surrounding rock loose circle at side wall is 1.00~1.10m,the thickness of surrounding rock loose circle at arch waist is 0.50~0.60m,and the thickness of surrounding rock loose circle at arch shoulder is 0.40~0.50m.Laboratory tests provide reasonable surrounding rock parameters for numerical simulation.The simulation results are in good agreement with the measured results,which verifies the rationality and reliability of the limit shear strain criterion in determining the range of surrounding rock loose circle by simulation.It can be seen that the study results can provide some ideas and reference for similar projects in the future.

关 键 词：隧道工程 围岩松动圈 极限剪应变 数值模拟 声波测试 

分 类 号：TU459[建筑科学—岩土工程]