多级让压支护体系在软岩大变形公路隧道中的应用研究  

Study on Application of Multi-level Yielding Support System in a Highway Tunnel in Soft Rock with Large Deformation

作　　者：张子洋 汪波[1] 刘金炜 宁其冉 王杰 喻炜 ZHANG Ziyang;WANG Bo;LIU Jinwei;NING Qiran;WANG Jie;YU Wei(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031;Zhejiang Highway and Water Transport Engineering Consulting Group Co.,Ltd.,Hangzhou 310000)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031 [2]浙江公路水运工程咨询集团有限公司,杭州310000

出　　处：《现代隧道技术》2024年第3期108-118,227,共12页Modern Tunnelling Technology

基　　金：国家自然科学基金(U2034205)。

摘　　要：基于让压支护技术理念,依托杜家山隧道工程,探讨多级让压不同让压点和让压量组合下围岩及支护结构响应变化规律,并对比多级让压支护与一级让压支护在各自最优让压点和让压量下的支护效果。结果表明,采用二级让压时,当让压点和总让压量一致,随着一级让压量减小,二级让压量增大,围岩的水平位移、拱顶沉降、最小主应力和塑性区均呈现先减小后增大趋势;当让压量保持一致,一级让压点增大,二级让压点逐渐减小,拱顶沉降、边墙水平收敛位移和围岩塑性区均先增加后减小,但变化幅度较小,围岩最小主应力值呈先减小后增大态势,因此围岩释放的形变能先增大后减小。当挤压型大变形隧道采用二级让压模式,让压量分阶段进行释放时,围岩释放形变能减少,支护结构能较好控制围岩变形,围岩进行充分应力重分布,二级让压围岩—结构受力变形相比一级让压更为均衡。By using the technical concept of yielding support and using the Dujiashan Tunnel Project as an example,this paper is intended to investigate the response variation pattern of surrounding rock and support structure under different combinations of yielding point and yielding quantity of multi-level yielding support.Also the supporting effects of multi-level yielding support and one-level yielding support under their optimum yielding point and yielding quantity are compared.As the results indicate:If two-level yielding support is used and the yielding point and total yielding quantity remain unchanged,then as the first-level yielding quantity decreases,the secondary-level yielding quantity increases,and the horizontal displacement of surrounding rock,crown settlement,minimum principal stress and plastic zone all decrease before increasing.If the yielding quantity remains unchanged and the first-level yielding point increases,then the secondary yielding point gradually decreases,and the crown settlement,side wall horizontal convergent displacement and surrounding rock plastic zone all increase before decreasing,but with minor margin of variation.The minimum principal stress of surrounding rock decreases before increasing,so the deformation energy released by the surrounding rock increases before decreasing.If a tunnel with large squeezing deformation is built with the two-level yielding support and the yielding quantity is released stage by stage,then the deformation energy released by the surrounding rock decreases.The support structure can effectively control the surrounding rock deformation.Stress redistribution of surrounding rock is adequately achieved.The stress and deformation of surrounding rock-structure under two-level yielding support system is more balanced than under one-level yielding support system.

关 键 词：软弱围岩 多级让压支护 让压点 让压量 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]