摘要
西安轨道交通工程修建于我国黄土地区,地铁停车线区间具有埋深浅、净距小、断面型式分布不对称等特点,开挖时为了避免左右线之间扰动过大,需要确定一个合理的掌子面错开距离。以西安地铁8号线工程的存车线区间为研究背景,通过FLAC^(3D)有限差分软件对不同方案下的开挖进行动态模拟,对模拟结果进行整理分析,并结合现场实际监测数据来验证模拟的正确性。研究发现:不同方案对围岩变形及应力的最终值几乎无影响,但需要控制变形速率与过程中的极值影响;隧道掌子面对已开挖土体的纵向影响范围约为3倍跨度,当掌子面错距为2~3倍的跨度时可以有效地控制围岩的变形速率,而当隧道错距较大时,开挖过程中围岩的最大剪应力显著增加,同时中间土柱部位产生了较大的相对位移差,不利于围岩稳定。基于研究结果,可以将掌子面的错距缩减至约30 m,以保证施工安全,提高施工效率。
Xi’an rail transit project is built in the loess area of China.The subway parking line interval is featured with shallow buried depth,small clear distance and asymmetric distribution of sections.To avoid excessive disturbance between the left and right lines during excavation,we need to determine a reasonable stagger distance of the working face.We took the parking line interval of Xi’an Metro Line 8 project as the research background,and dynamically simulated the excavation under different schemes by using FLAC^(3D) finite difference software.By comparing the simulation results with the actual monitoring data,we verified the correctness of the simulation.We found that the final deformation and stress of surrounding rock was hardly affected by different schemes,but the deformation rate and the extreme value in the process need to be controlled.The longitudinal influence range of tunnel face on excavated soil reached about 3 times the span.When the offset of tunnel face is 2-3 times the span,the deformation rate of surrounding rock can be effectively controlled.When the offset of tunnel is large,the maximum shear stress of surrounding rock increased significantly during excavation,and meanwhile leading to large relative displacement difference between the middle soil column,unfavorable to the stability of surrounding rock.In conclusion,we suggest to reduce the offset of the working face to 30 m to ensure construction safety and improve construction efficiency.
作者
邵珠山
王孟辉
SHAO Zhu-shan;WANG Meng-hui(School of Civil Engineering,Xi’an University of Architecture&Technology,Xi’an 710055,China;Shaanxi Key Lab of Geotechnical and Underground Space Engineering,Xi’an University of Architecture&Technology,Xi’an 710055,China)
出处
《长江科学院院报》
CSCD
北大核心
2022年第10期80-87,共8页
Journal of Changjiang River Scientific Research Institute
基金
国家自然科学基金面上项目(11872287)
陕西省重点研发计划项目(2019ZDLGY01-10)。
关键词
隧道工程
合理错距
数值模拟
围岩稳定
小净距
非对称断面
tunnel engineering
reasonable offset
numerical simulation
stability of surrounding rock
small clear distance
asymmetrical cross-section
作者简介
邵珠山(1968-),男,山东枣庄人,教授,博士,博士生导师,主要从事岩石细观力学与隧道工艺研究。E-mail:shaozhushan@xauat.edu.cn。
