摘要
为研究盾构隧道穿越上软下硬地层时,开挖面内不同土岩厚度比对地表沉降的影响,以贵阳轨道交通3号线某区间隧道为工程背景,保持隧道埋深和双线隧道间距不变,建立7种工况下的三维有限元模型,通过与实测数据对比分析得到沉降规律,并利用双线隧道的44组地表沉降数据,拟合出适用于当地复合地层的Peck分段公式。研究结果表明:从整体看,数值模拟的沉降曲线均为W形,地表最大沉降位于先行隧道上方;穿越红黏土层时地表更易受到扰动而产生不均匀沉降,随着土岩厚度比的减小,模拟曲线对称性增强,左右隧道的沉降差缩小,整体沉降值基本表现为减小趋势;总结土岩厚度比与修正系数的关系,图表显示Peck分段公式能较好地预测贵阳上软下硬地层的沉降规律。
To study the effect of different soil-to-rock thickness ratios on surface settlement in the excavation surface when shield tunnel crosses the upper soft and lower hard strata,a three-dimensional finite element model is established under seven working conditions based on an interval tunnel of Guiyang rail transit line 3 and with constant tunnel burial depth and the spacing between the two-lane tunnels,and the settlement law is obtained by comparing and analyzing the measured data.Using 44 sets of surface settlement data from the two-lane tunnel,a Peck segmentation formula applicable to the local composite strata is fitted.The research results show that the settlement curves of the numerical simulation are all W-shaped from the overall point of view,and the maximum settlement of the ground surface is located above the preceding tunnel;the ground surface is more likely to be disturbed resulting in uneven settlement when crossing the red clay layer,and the symmetry of the simulated curve increases as the soil-to-rock thickness ratio decreases,the settlement difference between the left and right tunnels decreases,and the overall settlement value basically shows a decreasing trend.The relationship between the soil-to-rock thickness ratio and the correction factor is summarized,and the graph shows that the Peck segmentation formula can better predict the settlement pattern of the upper soft and lower hard strata in Guiyang.
作者
袁侨蔚
刘远明
欧洵
黄城
李应肖
YUAN Qiaowei;LIU Yuanming;OU Xun;HUANG Cheng;LI Yingxiao(School of Civil Engineering,Guizhou University,Guiyang 550025,China;Key Laboratory of Geotechnical and Engineering Safety of Guizhou Province,Guiyang 550025,China)
出处
《铁道标准设计》
北大核心
2024年第2期167-175,共9页
Railway Standard Design
基金
贵州省自然科学基金项目(黔科合基础-ZK[2022]一般082)
贵阳城市轨道交通科研项目(GD3-FW-YJ-05-2020-13-ZB)。
关键词
上软下硬地层
盾构隧道
地表沉降
数值模拟
修正公式
upper soft and lower hard strata
shield tunnel
ground settlement
numerical simulation
revised formula
