洛阳粉质黏土与砂卵石复合地层地铁变形控制指标研究  

Subway deformation control index of silty clay and sand-pebble composite strata in Luoyang

作　　者：郜新军[1] 苏庆辉 张浩[1] 周同和[1] 李珊珊 GAO Xinjun;SU Qinghui;ZHANG Hao;ZHOU Tonghe;LI Shanshan(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学土木工程学院,河南郑州450001

出　　处：《铁道科学与工程学报》2024年第11期4624-4636,共13页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(41602297,52078469)。

摘　　要：为解决如何控制并及时预测隧道掘进引发的地表沉降,科学制定合理的地表沉降监控指标的问题,依托洛阳洛河Ⅰ级、Ⅱ级阶地2种典型地貌中粉质黏土与砂卵石复合地层下盾构隧道工程,以土体参数的空间变异性为切入点,针对当前隧道变形控制指标未能结合自身轨道交通工程特点、工程地质条件等问题,在考虑土体参数空间变异性的基础上,研究随机场中的变异系数和相关距离对地表变形的影响,并进一步结合现场监测数据统计分析和基于随机场理论的可靠度分析。结果表明:考虑空间变异性土体的等效弹性模量小于相应均质土的弹性模量;确定性分析的双线隧道地表沉降曲线呈双峰“W”形,随机分析的地表沉降曲线为一簇离散性曲线,且都为双峰型。变异系数对地表沉降的影响较为明显,而竖向相关距离在2D内、水平相关距离在10D内对地表沉降的影响较大。根据可靠度分析,洛河Ⅰ级、Ⅱ级阶地2种典型地貌条件下隧道最大地表沉降服从标准正态或对数正态分布形式,综合考虑安全性和经济性,建议洛河Ⅰ级阶地地貌的双线盾构隧道地表沉降监控指标为40 mm,洛河Ⅱ级阶地地貌的双线盾构隧道地表沉降监控指标为30 mm。研究结果可为进一步探索地表沉降预测方法和控制措施,科学制定合理的地表沉降监控指标提供参考。To address the issue of controlling and timely predicting surface settlement induced by tunnel excavation,it is essential to scientifically establish reasonable monitoring indicators for surface settlement.Leveraging the shield tunneling projects in the composite strata of silty clay and sandy gravel under two typical geomorphological features—Loess Plateau Level Ⅰ and Level Ⅱ—in Luoyang,this study focused on the spatial variability of soil parameters.Considering the limitations of current tunnel deformation control indicators,which failed to integrate the characteristics of rail transit engineering and geological conditions,this article investigated the impact of variation coefficients and correlation distances within a stochastic field on surface deformation.Additionally,this article incorporated statistical analysis of field monitoring data and reliability analysis based on stochastic field theory.The results are drawn as follows.The equivalent elastic modulus of spatially variable soil is lower than that of corresponding homogeneous soil.Deterministic analysis reveals a double-peaked“W”-shaped surface settlement curve for twin-tube tunnels,while stochastic analysis yields a cluster of discrete curves,all exhibiting double peaks.The influence of variation coefficients on surface settlement is significant,with vertical correlation distances within 2D and horizontal correlation distances within 10D having substantial effects.Reliability analysis demonstrates that the maximum surface settlement of tunnels under the geomorphological conditions of Loess Plateau Level Ⅰ and Level Ⅱ follows either a standard normal or lognormal distribution.Considering safety and economy,this article recommends surface settlement monitoring indicators of 40 mm for twin-tube shield tunnels in Level Ⅰ terrain and 30 mm for those in Level Ⅱ terrain.These research findings can provide valuable insights for further exploring surface settlement prediction methods,control measures,and the rational formulation of monitori

关 键 词：空间变异性 弹性模量 可靠度 变异系数 相关距离 监控指标 

分 类 号：U456.3[建筑科学—桥梁与隧道工程]