大直径浅埋隧道下穿运营高铁防护措施研究  

Research on Protection Measures of Large Diameter Shallow Tunnel Passing through Operating High-speed Railway

作　　者：赵大亮 谌启发 王冰 ZHAO Daliang;CHEN Qifa;WANG Bing(China Railway Fifth Survey and Design Institute Group Co.Ltd,Beijing 102600,China)

机构地区：[1]中铁第五勘察设计院集团有限公司,北京102600

出　　处：《铁道工程学报》2023年第11期64-69,93,共7页Journal of Railway Engineering Society

基　　金：中国铁建股份有限公司科研计划课题(2021-056);中铁第五勘察设计集团有限公司科研计划课题(T5Y2021-A03)。

摘　　要：研究目的:由于技术规程对受下穿工程影响引起高铁桥墩的位移要求高,为保证盾构施工期间运营高铁的安全,必须要对大直径浅埋隧道盾构下穿高铁段采取可靠的防护措施。本文依托国内首个下穿运营高速铁路的大直径盾构项目——苏州市城市主干道下穿沪宁城际铁路工程,针对其软土地区及高铁桥墩变形高等特点,研究盾构施工中地层损失率、隔离桩桩径及桩长、钢护筒内灌注材料等参数对高铁桥墩的影响,提出安全可靠的加固方案。研究结论:(1)隧道盾构下穿饱和粉、细砂土层,建议对隔离桩内的土体进行加固,提高土体稳定性;(2)隔离桩刚度随着直径的增加而增加,盾构施工对高铁桥墩的影响随之减小;(3)根据不同桩长的隔离桩水平变形和对高铁桥墩的影响,结合嵌入土层类型和深度,确定了合理的隔离桩桩长;(4)钢护筒内灌注不同材料的隔离桩,组合刚度主要由钢护筒的直径和壁厚决定,钢护筒内土体注浆对高铁桥墩影响比灌注混凝土的小;(5)提出软土地区下穿运营高铁工程的加固方案和安全评估思路,可以确保工程实施中和实施后沪宁城际铁路的运营安全,可为以后类似工程提供参考。Research purposes:In order to ensure the safety of operation of high-speed railway during large-diameter shallow-buried tunnel shield construction,reliable reinforcement measures must be taken for the undercrossing section of high-speed railway due to the high displacement requirements of the technical regulations caused by the impact of underpass engineering.In this paper,based on the first large-diameter shield project of high-speed railway in China,Suzhou city main road undercrossing Shanghai-Nanjing intercity railway engineering,for soft soil area and the high deformation characteristics of high-speed rail piers,the influence of the loss rate of formation,the isolation pile diameter and pile length,and the pouring material in steel casing on high-speed railway bridge pier is studied,and a safe and reliable reinforcement scheme is put forward.Research conclusions:(1)When the tunnel shield passes through the saturated silt and fine sand soil layer,it is suggested that the soil in the isolation pile should be strengthened to improve the stability of soil.(2)As the diameter of the isolation pile increases,its stiffness also increases,and its influence on the high-speed railway bridge pier decreases.(3)According to the horizontal deformation of the isolation pile of different pile lengths and its influence on the high-speed railway bridge pier,and combined with the type and depth of embedded soil layer,the reasonable length of the isolation pile is determined.(4)The combined stiffness of the isolation pile filled with different materials in the steel casing is mainly determined by the diameter and wall thickness of the steel casing,and the influence of soil grouting in the steel casing on the high-speed railway is less than that of concrete.(5)The reinforcement schemes and safety assessment ideas for underpass operation of high-speed railway in soft soil areas are put forward to ensure the operation safety of high-speed railway during and after the implementation of the project,which can provide reference for simi

关 键 词：高铁桥梁 浅埋大直径隧道 盾构施工 地层损失 基础变形 

分 类 号：U455.91[建筑科学—桥梁与隧道工程] U238[交通运输工程—道路与铁道工程]