花岗岩山岭隧道洞口浅埋段超前支护形式研究  

Selection of Advance Support Type at Shallow Buried Tunnel Portal in Granite Mountain

作　　者：黄聪聪 刘振平[2] HUANG Congcong;LIU Zhenping(HBCI Expressway Development Co.Ltd.,Wuhan 430050;Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071)

机构地区：[1]湖北交投高速公路发展有限公司,武汉430050 [2]中国科学院武汉岩土力学研究所,武汉430071

出　　处：《土工基础》2021年第6期670-673,共4页Soil Engineering and Foundation

基　　金：湖北省自然科学基金(E0312502)。

摘　　要：山岭隧道洞口浅埋段超前支护形式的合理选取既要兼顾经济性,更要考虑施工的安全风险。现以三峡翻坝江北高速公路寨子包隧道为背景,针对出口左幅洞口全~强风化花岗岩浅埋段,采用ABAQUS软件对无超前支护、双层小导管以及大管棚三种超前支护方案分别进行模拟计算,并与现场实测数据进行对比分析。结果表明:在三台阶开挖过程中,大管棚对沉降变形与塑性区扩展有明显的抑制作用,沉降变形特征和累计值与实测数据比较接近,而双层小导管在阻止变形与围岩整体破坏方面作用较小。因此,对寨子包隧道出口左幅洞口位置变更后,仍选择大管棚超前支护方案的合理性进行了验证,为今后浅埋隧道超前支护方案的设计与施工提供参考。The selection of an appropriate advance support type in the shallow buried tunnel portal in the mountain should both consider the construction cost and the safety as well as the risk during the construction.In the construction of the Zhaizibao Tunnel in Fanba Jiangbei Highway Project near Three Gorges,the finite element analysis by using ABAQUS software was used to simulate three different types of advanced support of left side of the tunnel portal excavations in the strongly to completely weathered granite rock mass,namely,no advance support,double-layer small diameter perforated pilot grouting pipe and large diameter perforating pilot grouting pipe shield.The results show that,in the process of Three Benches excavation,the large diameter perforated pilot grouting pipe shield method had obvious effect in controlling the excessive settlement deformation and development of plastic zone expansion,the predicted settlement deformation characteristics and cumulative value are close to the measured value,while the double-layer small diameter perforated pilot grouting pipe method had little effect on controlling the deformation and overall failure of the surrounding rock mass.Therefore,the selecting of the advanced support type of large diameter perforated pilot grouting pipe shield method for the left tunnel portal of Zhaizibao Tunnel exit was validated.This project provides a method the design and construction of the advance support for the similar tunnel in the future.

关 键 词：山岭隧道 浅埋 超前支护 沉降变形 

分 类 号：U456[建筑科学—桥梁与隧道工程]