摘要
砂卵石地层具有渗透性强、孔隙率大、自稳性差和受扰反应大等特点,若盾构施工参数控制不当则会发生掌子面失稳、坍塌和涌水等安全事故。确定富水砂卵石层盾构掘进引起地表沉降和管片隧道变形的影响因素,对于安全施工具有重要的指导意义。本文以洛阳地铁区间盾构穿越洛河富水砂卵石地层为工程背景,基于流固耦合理论,运用ABAQUS软件构建盾构掘进的三维有限元模型,数值模拟和现场实测的地表沉降数据基本吻合,验证了模型的准确性。采用单因素分析法研究了盾构掘进压力、同步注浆压力和等代层厚度等3个参数对地表沉降与管片变形的影响规律,研究结果表明:增大盾构掘进压力和同步注浆压力,减小等代层厚度,均能减小地表和隧道的拱顶沉降;而增大盾构掘进压力,减小同步注浆压力和等代层厚度,可减小隧道拱腰的水平变形。采用正交试验方法确定了3个影响因素对地表沉降和管片拱顶沉降两个指标的敏感性,从大到小排序均为:同步注浆压力、盾构掘进压力和等代层厚度。
The sandy cobble stratum layers have characteristics such as strong permeability,high porosity,poor selfstability,and large response after disturbance.If the parameters of shield tunneling are not properly controlled,some safety accidents would occur,such as instability of the tunnel face,collapse,and water gushing.Therefore,identifying the influencing factors of ground settlement and segment tunnel deformation during shield tunneling in the water-rich sandy cobble stratum has important guiding significance for safe construction.The shield tunneling through sandy cobble stratum under Luohe in the Luoyang metro section is taken as the engineering background in this paper.A three-dimensional finite element model of shield tunneling construction is established using ABAQUS software based on the fluid-solid coupling theory.The numerically simulated and on-site measured ground settlement data are basically consistent,and the accuracy of the finite element model is verified.The single-factor analysis method is used to study the influential parameters of ground settlement and segment deformation,which include shield tunneling pressure,synchronous grouting pressure,and equivalent layer thickness.The results indicate that increasing shield tunneling pressure and synchronous grouting pressure,while reducing equivalent layer thickness,can reduce surface settlement and segment tunnel arch crown settlement.Conversely,increasing shield tunneling pressure while reducing synchronous grouting pressure and equivalent layer thickness can reduce the horizontal displacement of the arch waist of the segment tunnel.The sensitivity of influencing factors to the two indicators of ground settlement and segment arch settlement is determined using the orthogonal experimental method.The descending orders for both are:synchronous grouting pressure,shield tunneling pressure,and equivalent layer thickness.
作者
徐平
黄振磊
XU Ping;HUANG Zhenlei(School of Water Conservancy and Transportation,Zhengzhou University,Zhengzhou 450001,China;China Construction Infrastructure Co.,Ltd.,Beijing 100037,China)
出处
《工程地质学报》
CSCD
北大核心
2024年第5期1787-1797,共11页
Journal of Engineering Geology
基金
国家自然科学基金项目(资助号:51278467)
中国铁道科学研究院基金项目(资助号:2022YJ280)。
关键词
富水砂卵石层
盾构隧道
地表沉降
管片变形
影响因素
敏感性分析
Water-rich sandy cobble stratum
Shield tunnel
Ground settlement
Segment tunnel deformation
Influential factor
Sensitivity analysis
