摘要
盾构开挖面支护压力计算属于隧道工程稳定性分析的核心内容之一。现阶段理论研究主要集中于水平隧道开挖面的失稳机理,未能充分考虑盾构机纵向倾角的影响。选取仰坡、水平和俯坡3种掘进工况,基于前期模型试验结果与极限平衡理论,构建了密砂地层盾构隧道纵坡开挖面三维理论模型,结合Terzaghi松动土压力理论推导出开挖面主动极限支护压力计算公式。采用有限差分软件Flac3D^(5.0)构建三维数值模型,分析了密砂地层不同纵坡条件下的开挖面失稳模式及支护压力的变化特点,结合模型试验结果,综合确定理论模型核心参数(对数螺旋线高度系数和滑裂面倾角)的选取方法。通过开展与其他理论方法的对比分析,验证了该理论模型的可行性。研究结果表明:隧道由俯角倾斜渐变至仰角倾斜的过程中,开挖面失稳区域逐渐扩大,且相应极限支护压力呈近似两阶段线性增加,支护压力的增加幅度在隧道由水平渐变至仰角倾斜期间显著提升;开挖面支护压力随隧道直径的增加同步增大,且在仰坡条件下,隧道直径对支护压力的影响更为显著。该研究成果对于盾构纵坡掘进施工具有一定的指导意义。
The prediction of shield tunnel face support pressure is one of the core issues for the stability analysis of tunnel engineering.Current studies mainly focused on the failure mechanism of horizontal shield tunnel face.The impact of longitudinal inclination angles on the tunnel face was rarely considered.In this study,a series of three-dimensional analytical models were conceived based on the observations of previous laboratory tests and the limit equilibrium theory,which can calculate the active limit face support pressure of shield tunnel in dense sand stratum within three tunneling conditions,i.e.,upward tunneling,horizontal tunneling and downward tunneling.The expression of limit face support pressure was deduced combining with the earth pressure theory of Terzaghi.The characteristics of failure mode and face support pressure with different longitudinal inclination angles were investigated by finite difference method Flac3D^(5.0).The core parameters(the height coefficient of log-spiral and the inclination angle of the slip surface)of the proposed model are determined by numerical simulations and previous laboratory tests.The efficacy of the proposed model was evaluated by comparing with the solutions of other analytical methods.The results indicate that the area of failure zone is gradually enlarged from the downward slope to upward slope,and the corresponding limit face support pressure linearly increases within two stages.The increment of face support pressure is obviously enhanced from horizontal to upward slope.In addition,the face support pressure increases simultaneously with the increasing of tunnel diameter,and the impact of tunnel diameter on face support pressure is more significant for the upward tunneling condition.This study can provide some reference for the tunneling of shield machines.
作者
程诚
赵文
王迎超
路博
韩健勇
陈阳
程思高
CHENG Cheng;ZHAO Wen;WANG Ying-chao;LU Bo;HAN Jian-yong;CHEN Yang;CHENG Si-gao(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China;School of Rail Transportation,Soochow University,Suzhou 215131,Jiangsu,China;School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,Liaoning,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China;School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,Shandong,China;School of Civil Engineering and Architecture,Xi'an University of Technology,Xi'an 710048,Shaanxi,China;Sinohydro Bureau 6Co.Ltd.,Shenyang 110000,Liaoning,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2023年第4期157-168,共12页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51878127,42272313,52008338)
国家留学基金委公派项目(201906080128)
徐州市重点研发项目(社会发展)(KC21298)
西安市科协青年人才托举计划项目(095920221358)
中央高校基本科研业务费专项资金项目(2022QN1028)
关键词
隧道工程
主动极限支护压力
极限平衡理论
密砂地层
纵向倾角
tunnel engineering
active limit face support pressure
limit equilibrium theory
dense sand stratum
longitudinal inclination angl
