基于强度折减法的大跨隧道对临近桥基影响的研究  

Research on Influence of Long-span Tunnels on Adjacent Bridge Foundations Based on Strength Reduction Method

作　　者：张安睿[1] 曹琨 ZHANG Anrui;CAO Kun(Guizhou Transportation Planning Survey & Design Academe Co., Ltd., Guiyang 550000, China)

机构地区：[1]贵州省交通规划勘察设计研究院股份有限公司,贵阳550000

出　　处：《交通科技》2020年第4期98-101,共4页Transportation Science & Technology

基　　金：贵州省重大科技专项计划项目([2018]3011)资助。

摘　　要：为探究大跨隧道施工对临近桥基的影响,依托松坎隧道施工工程,基于强度折减法,对隧道临近桥基施工时岩土体的临界破坏特征、整体安全系数进行数值模拟研究,分析隧道与桥基间距对施工安全系数的影响。研究表明,塑性区贯通位置在两隧道中间,由拱腰不断延伸至地面;隧道施工整体稳定性分析应综合考虑塑性区贯通及对临近桥基的影响,单纯以拱顶沉降作为判据存在不足;当折减系数小于2.4时,桥梁处于稳定状态,隧道施工对桥梁的影响很小,当隧道与桥基间距大于25 m时,隧道施工的安全系数较高,再增加安全距离意义不大。To explore the impact of the construction of the long-span tunnel on the adjacent bridge foundation,the Songkan Tunnel construction taken as the engineering background.Based on the strength reduction method,the critical failure characteristics and overall characteristics of the rock and soil during the construction of the tunnel near the bridge foundation,and the safety factor was numerically simulated and analyzed.The influence of the distance between the tunnel and the bridge foundation on the safety factor of construction was also analyzed.The research results show that the penetration position of the plastic zone is in the middle of the two tunnels,and it continuously extends from the arch waist to the ground.The overall stability analysis of the tunnel construction should comprehensively consider the penetration of the plastic zone and its influence on the adjacent bridge foundation.It is insufficient to take arch crown settlement as the only criterion.When the reduction factor is less than 2.4,the bridge is in a stable state,and the tunnel construction has little impact on the bridge;when the distance between the tunnel and the bridge foundation is greater than 25 m,the safety of the tunnel construction is relatively high,and it does not make much sense to increase the safety distance.

关 键 词：强度折减法 隧道 桥基 安全系数 

分 类 号：U459[建筑科学—桥梁与隧道工程]