隧底岩溶洞对结构稳定影响的理论解  

Analysis of Bottom Cave Effection for Karst Tunnel by Elastic Foundation Beam Method

作　　者：罗立峰 傅鹤林[2] 李凯[1,2] 何翊武[2] 毛阿立[2] 

机构地区：[1]广东南粤交投韶赣高速公路管理中心,广东韶关510800 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《公路工程》2015年第3期109-115,共7页Highway Engineering

基　　金：交通部重点科研项目(SG-YS-B48);湖南省交通科技计划项目(2012027)

摘　　要：以温克尔弹性地基梁理论为基础,对岩溶地区隧道底部溶洞影响衬砌受力进行了研究,简化推导出了隧道拱脚部分等代梁的位移和内力计算公式,对比分析了不同溶洞规模、不同介质压缩模量之比情况下梁的受力状态。计算分析结果表明:溶洞填充物压缩模量的变化对衬砌受力有明显影响,溶洞填充物与围岩压缩模量越接近,则溶洞对衬砌受力的影响越微弱,反之,影响效果越显著;溶洞规模越大,其填充物压缩模量的变化对衬砌受力的影响幅度也随之增大;梁的反弯点在溶洞与围岩交界处,且交界处剪力达到最大值,往溶洞方向位移急剧增大,梁段处于不利受力状态,容易产生裂缝。Based on Winkler elastic foundation beam theory,studied the tunnel lining force in karst area with bottom karst cave,derived the displacement and internal force calculation formula of equivalent beam which include tunnel arch foot section,and comparatively analyzed the beam＇s stress state under different cave scale and different cave media＇s compression modulus ratio. The results show that：the changes of cave filler＇s compression modulus have obvious effect on lining stress. Cave fillers and surrounding rock have closer compression modulus,influence of karst cave on the lining stress is more weak,on the contrary,effect is more significant. With the increase of cave＇s scale,the influence amplitude of filler＇s compression modulus on lining stress also increase. The beam＇s inflection point is at the junction of cave and surrounding rock,at which shear force reached the maximum value,and toward to the cave direction displacement increases sharply. This section of beam is in adverse stress state,easy to produce the cracks.

关 键 词：岩溶隧道 弹性地基梁 溶洞 压缩模量 裂缝 

分 类 号：TU248.9[建筑科学—建筑设计及理论]