浅埋卵石土层隧道超前支护措施研究  

Study on Advanced Support Measures for Shallow-buried Tunnel in Pebble Soil Layer

作　　者：邓祥辉[1,2] 刘锦涛 王睿 DENG Xiang-hui;LIU Jin-tao;WANG Rui(School of Civil&Architecture Engineering,Xi'an Technological University,Xi'an Shaanxi 710021,China;Xi'an Key Laboratory of Civil Engineering Testing Technology and Destruction Analysis for Military and Civil Usage,Xi'an Shaanxi 710021,China)

机构地区：[1]西安工业大学建筑工程学院,陕西西安710021 [2]西安市军民两用土木工程测试技术与毁损分析重点实验室,陕西西安710021

出　　处：《公路交通科技》2023年第1期136-143,共8页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51408054);陕西省自然科学基础研究计划项目(2023-JC-YB-327);陕西省教育厅服务地方专项计划项目(22JC040)。

摘　　要：卵石土层是隧道开挖过程中常遇的特殊围岩之一,该围岩强度低、自稳定性差,在隧道开挖中若采取的超前支护措施不当,容易出现掌子面失稳、拱部掉块,甚至局部坍塌等工程事故。因此,研究浅埋卵石土层隧道超前支护措施是非常必要的。以青海省石羊岭隧道工程为依托,采用数值模拟的方法对无支护措施、超前小导管、地表注浆以及超前小导管+地表注浆联合支护分别建立了模型,并对模型模拟的结果进行了对比分析。在此基础上,通过对比数值模拟和实测的位移值,确定了浅埋卵石土层隧道的超前支护方式。结果表明:对比无支护措施、超前小导管、地表注浆以及联合支护4种超前支护形式在竖向位移与水平位移可知,联合支护在控制隧道变形方面优于其他3种支护措施。从4个典型断面的变形监测结果来看,采用联合支护时数值模拟与现场实测的隧道变形趋势基本吻合,同时,变形值的平均误差较小,仅为13%,说明建立的数值模型是可靠的;从模拟结果来看,在相同条件下采用地表注浆的隧道围岩变形比采用超前小导管的变形量小23%,这说明在浅埋卵石土层隧道开挖中采用地表注浆控制隧道围岩变形的作用要大于超前小导管。可见,采用超前小导管+地表注浆联合支护可有效控制浅埋卵石土层隧道变形量。Pebble soil layer is one of the special surrounding rocks often encountered in the process of tunnel excavation. The surrounding rock has low strength and poor self-stability. If improper advanced support measures are taken in tunnel excavation, it is prone to have engineering accidents such as instability of tunnel face, arch falling, and even local collapse. Therefore, it is necessary to study the advanced support measures for shallow-buried tunnel in pebble soil layer. Relying on the Shiyangling Tunnel project in Qinghai Province, the models of no support measure, advanced small pipe, surface grouting and combined support of advanced small pipe + surface grouting are established respectively by using the numerical simulation method, and the results of the model simulation are compared and analyzed. On this basis, by comparing the numerical simulated and measured displacement values, the advanced support mode of shallow buried tunnel in pebble soil layer is determined. The result shows that(1) the comparison of vertical displacements and horizontal displacements of 4 kinds of advanced support forms(no support measure, advanced small pipe, surface grouting and combined support) shows that the combined support is superior to the other 3 support measures in controlling tunnel deformation;(2) from the deformation monitoring results of 4 typical sections, the numerical simulated value is basically consistent with the measured tunnel deformation trend when using the combined support, and the average error of the deformation value is small, only 13 %, indicating that the established numerical model is reliable;(3) from the simulation result, the deformation of tunnel surrounding rock with surface grouting is 23 % less than that with advanced small pipe under the same condition, indicating that the effect of surface grouting on controlling the deformation of tunnel surrounding rock is greater than that of advanced small pipe in the excavation of shallow-buried tunnel in pebble soil layer. It can be seen that the use of

关 键 词：隧道工程 超前支护措施 数值模拟 卵石土层 现场实测 对比分析 

分 类 号：U455.1[建筑科学—桥梁与隧道工程]