首页|静-动荷载作用下欠固结软土盾构隧道长期沉降与最优埋深计算方法

静-动荷载作用下欠固结软土盾构隧道长期沉降与最优埋深计算方法

Calculation Method of Long-Term Settlement and Optimal Tunnel Depth of Shield Tunnel in Under-Consolidated Soft Soil Under Static and Dynamic Load

扫码查看
原文链接
  • NETL
  • NSTL
  • 万方数据
为研究地表堆载、列车荷载和欠固结软土固结沉降联合作用下的盾构隧道长期沉降数值及其变化规律问题,依托广州市南沙至珠海(中山)城际项目,利用PLAXIS建立有限元模型计算外部作用下的盾构隧道长期沉降值,通过单因素敏感性分析和非线性拟合方法分析各影响因子对长期沉降的影响并确定 5 种关键影响因子,提出长期沉降与最优埋深计算方法.研究结果表明:1)超固结比与隧道埋深对长期沉降影响最大,上部堆载荷载值、荷载作用宽度和列车荷载影响次之,而荷载距离、列车速度和渗透系数对长期沉降的影响可以忽略不计;2)为求解盾构隧道长期沉降值,提出静-动荷载作用下欠固结软土盾构隧道的长期沉降计算方法,计算值与模拟值吻合良好;3)将国家规范中盾构隧道变形控制值(20 mm)作为隧道沉降控制值,代入长期沉降计算公式,反推得到隧道最优埋深计算公式,其中软土欠固结特性对最优埋深影响最大.为有效控制长期沉降发展,建议将隧道整体置于较好的土层中,如需设置在淤泥及淤泥质土层中,则应进行地基处理、排水固结,以改善土体欠固结程度.
In order to study the long-term settlement and its variation law for shield tunnel under combined action of surface load,train load,and consolidation settlement of under-consolidated soft soil,a finite element model is established by PLAXIS to calculate the long-term settlement of shield tunnel under external action based on the Nansha-Zhuhai(Zhongshan)intercity line in Guangzhou.The effect of each influencing factor on long-term settlement is analyzed by single factor sensitivity analysis and nonlinear fitting method,and five key influencing factors are identified.The calculation method of long-term settlement and optimal tunnel depth is proposed.The results show that:(1)The over-consolidation ratio and tunnel depth have the greatest influence on long-term settlement,followed by the load magnitude,load width,and train load,while the effects of load distance,train speed,and permeability coefficient on long-term settlement can be neglected.(2)In order to solve the long-term settlement of shield tunnel,a calculation method is proposed for shield tunnel in under-consolidated soft soil under static and dynamic load,and the calculation result is in good agreement with the simulation result.(3)By taking the control value of 20 mm for shield tunnel deformation specified in the national standard as the tunnel settlement control value,and substituting it into the equation for long-term settlement,the equation for optimal tunnel depth is obtained.The under-consolidation characteristics of soft soil have the greatest influence on the optimal tunnel depth.In order to effectively control the long-term settlement,it is suggested that the entire tunnel should be constructed in soil with better quality.If a tunnel has to be constructed in mud and mucky soil strata,foundation treatment should be carried out,and drainage consolidation should be performed to improve the consolidation degree of soil.

under-consolidated soft soilshield tunnellong-term settlementnonlinear fittingsurface loadtrain load

仉文岗、唐学成、刘汉龙、杨文钰、刘智成、王鲁琦、李红蕊

展开 >

重庆大学土木工程学院,重庆 400045

山地城镇建设与新技术教育部重点实验室,重庆 400045

库区环境地质灾害国家地方联合研究中心,重庆 400045

广州地铁集团有限公司,广东 广州 510220

展开 >

欠固结软土 盾构隧道 长期沉降 非线性拟合 上部堆载 列车荷载

中国工程院院地合作重大项目国家资助博士后研究人员计划广州地铁集团公司科研委托项目重庆城投基础设施建设有限公司联合技术攻关科研项目

2022-DFZD-10GZC20242129JT204-100111-23001CQCT-JS-SC-GC-2022-0081

2024

10.3973/j.issn.2096-4498.2024.09.012

隧道建设(中英文)
中铁隧道集团有限公司洛阳科学技术研究所

隧道建设(中英文)

CSTPCD北大核心
影响因子：0.785
ISSN：2096-4498
年,卷(期)：2024.44(9)