摘要
针对目前砂土地层圆形隧道施工中易于塌方的工程难题,结合物理模型试验结果,采用PFC2D对砂土地层变形规律进行数值模拟,并分析隧道埋深、地层损失率、颗粒粒径以及级配对砂土地层变形的影响。结果表明,砂土圆形隧道施工产生的扰动力传递是一个渐变过程;隧道埋深越大,沉降槽宽度越大,地表最大沉降越小,越易形成完整的拱形稳定区和"Λ"型失稳区;地层损失率越高,沉降槽宽度和地表最大沉降越大,且地层损失率与地表最大沉降之间存在明显的线性关系;土体颗粒直径越大,沉降槽宽度越大,地表最大沉降越小,扰动力传递越快,拱形稳定区越不易形成;而颗粒级配对沉降槽宽度与地表最大沉降影响不显著。上述研究成果对砂土地层圆形隧道施工具有重要的借鉴意义。
Aiming at the engineering problems of collapse caused by circular tunnel construction in sand,the influences of cover depths,ground loss ratio,particle size and gradation on the stratum deformation in sand were numerically simulated by PFC2D based on the physical model test results.The results showed that the transmission of disturbance force,which was caused by the circular tunnel construction in sand,was a gradual process,the deeper the buried depth was,the larger the width of settlement trough was,the smaller the maximum settlement value of the ground surface was,and the easier to form the completed arch-shaped stable zone and the"A"instability zone;the settlement trough width and the maximum settlement value of the ground surface became large with the increase of the ground loss ratio and there was a linear relationship between the ground loss ratio and the maximum settlement value of the ground surface;the larger the particle size was,the larger the width of settlement trough was,the smaller the maximum settlement value of the ground surface,the faster the disturbance force transmit and the less likely to form the arched stable zone;the influence of particle gradation on the settlement trough width and the maximum settlement value of the ground surface was not significant.The results are of great reference significance for the circular tunnel construction in sand.
作者
房倩
杜建明
王赶
王中举
王官清
FANG Qian;DU Jianming;WANG Gan;WANG Zhongju;WANG Guanqing(Tunnel and Underground Engineering Research Center of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;China Railway Siyuan Survey and Design Group Co.,LTD.,Wuhan 430063,Hubei,China)
出处
《隧道与地下工程灾害防治》
2020年第3期67-76,共10页
Hazard Control in Tunnelling and Underground Engineering
基金
国家自然科学基金高铁联合基金重点支持资助项目(U1934210)
北京市自然科学基金资助项目(8202037)
关键词
圆形隧道
地表变形
砂土
数值模拟
circular tunnel
stratum deformation
sand
numerical simulation
