基于松动圈理论深埋黄土隧道围岩压力计算方法  

A Method for Calculating Surrounding Rock Pressure of Deep Loess Tunnel Based on Loose Broken Rock Zone Theory

作　　者：徐强 刘勇[1,2] 宋玉香 雷升祥[1,2,3] 朱永全 马凯蒙 XU Qiang;LIU Yong;SONG Yu-xiang;LEI Sheng-xiang;ZHU Yong-quan;MA Kai-meng(Key Laboratory of Roads and Railway Engineering Safety Control of Ministry of Education, Shijiazhuang Tiedao University, Shijiazhuang 050043, China;School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China;China Railway Construction Corporation Limited, Beijing 100855, China;School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China)

机构地区：[1]石家庄铁道大学,道路与铁道工程安全保障省部共建教育部重点实验室,石家庄050043 [2]石家庄铁道大学土木工程学院,石家庄050043 [3]中国铁建股份有限公司,北京100855 [4]西南交通大学土木工程学院,成都610031

出　　处：《科学技术与工程》2021年第23期10054-10060,共7页Science Technology and Engineering

基　　金：国家重点研发计划(2018YFC0808704);中铁十二局集团第四工程有限公司科研项目(201794-5)。

摘　　要：为研究深埋黄土隧道的围岩压力计算方法,通过对深埋黄土隧道开挖后的围岩应力状态进行分析,明确了松动圈的定义,推导了松动圈的表达式,提出了基于松动圈理论的深埋黄土隧道围岩压力计算方法,并基于现场试验监测数据,与既有计算方法的计算结果进行了对比分析,验证了该方法的适用性,分析了含水率变化对老黄土的物理力学参数和围岩压力的影响。结果表明:松动圈为塑性区的内圈,是塑性区内切向应力小于初始地应力的部分;黄土隧道的松动圈较普通巷道和岩石隧道的松动范围大得多,更易受隧道开挖影响;基于松动圈理论的围岩压力计算方法与其他计算方法相比较,计算结果与实测值接近且存在一定的安全储备,使用该方法对深埋黄土隧道围岩压力进行计算是可行的;含水率变化对黏聚力影响较大,由17%增大到21%时,黏聚力减小了25%,围岩压力增大了30%。可见,基于松动圈理论的围岩压力计算方法可为深埋黄土隧道以及其他软弱土质围岩隧道的围岩压力计算提供思路。In order to study the method of calculating the surrounding rock pressure in deeply buried loess tunnels,by analyzing the stress state of the surrounding rock after excavation in deep loess tunnels,the definition of loose broken rock zone was defined,and the calculation formula of the loose broken zone of the surrounding rock was deduced.A method for calculating the surrounding rock pressure of deep-buried loess tunnels based on the loose broken rock zone theory was put forward.Based on the field test data,the applicability of the method was verified by a comparative analysis with the existing calculation method,the effect of water content variation on physical and mechanical parameters and surrounding rock pressure of old loess was analyzed.The results show that the loose broken rock zone is the inner part of the plastic zone,which is the part where the tangential stress in the plastic zone is less than the initial ground stress.The broken rock zone of loess tunnels is much larger than that of ordinary roadways and rock tunnels,indicating that the loess tunnel is more susceptible to tunnel excavation.The calculation results of the proposed method are closer to the measured value of loess tunnels than that of other calculation methods and it is able to provide better safe allowance to some degree.Thus,the calculation of the surrounding rock pressure of deep-buried loess tunnels with the broken rock zone theory is feasible.The change in water content has a large effect on the cohesion,which decreases by 25%when increasing from 17%to 21%,and the surrounding rock pressure increases by 30%.It can be seen that the calculation method of surrounding rock pressure based on the loose zone theory can provide ideas for the calculation of surrounding rock pressure of deep buried loess tunnels and other soft soil surrounding rock tunnels.

关 键 词：围岩压力 深埋黄土隧道 围岩应力状态 松动圈 现场试验 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]