公路隧道单侧扩建围岩与衬砌力学响应与安全特性试验研究  

Experimental Research on Mechanical Response and Safety Characteristics of Surrounding Rock and Lining of Unilateral Extension of Highway Tunnel

作　　者：徐龙旺 韦勇克 林志[3] 伍汉 杨红运 XU Longwang;WEI Yongke;LIN Zhi;WU Han;YANG Hongyun(Guangxi Communications Design Group Co.,Ltd.,Nanning,Guangxi 530029,China;Guangxi Xinfazhan Communication Group Co.,Ltd.,Nanning,Guangxi 530029,China;State Key Laboratory of Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]广西交通设计集团有限公司,广西南宁530029 [2]广西新发展交通集团有限公司,广西南宁530029 [3]重庆交通大学省部共建桥梁及隧道工程国家重点实验室,重庆400074

出　　处：《公路工程》2024年第4期6-14,21,共10页Highway Engineering

基　　金：国家自然科学基金项目(52078089,51904043)。

摘　　要：公路隧道单侧式扩建施工是常见的扩挖方式,但其施工力学行为与安全性鲜有报道。通过模型试验模拟了公路隧道单侧式扩建施工的全过程,对公路隧道单侧式扩建施工时的围岩应力、衬砌应力、轴力、弯矩与安全性进行研究。得到以下主要结论:①扩建隧道时,受到二次扰动的围岩强度急剧降低,破坏程度明显增大,在扩挖侧拱腰与拱顶区域最为显著。②隧道扩建过程中,前榀旧衬砌,应力重分布效应将增加后榀旧衬砌压应力;新衬砌在安装后逐渐承担围岩荷载,其应力显著增加,尤其在拱顶和拱腰位置。③大部分衬砌模型的安全系数小于2.0,尤其是拱脚部位最容易失稳,拱脚区域需要额外的加固措施,以防止潜在的结构失稳和破坏。④以试验数据为指导,提出了超前支护上下台阶法,以及将洞渣回填作为隧道上台阶开挖施工平台,实现了安全高效施工。In order to study the construction mechanical behavior and safety of highway tunnel in unilateral expansion construction,the surrounding rock stress,lining stress,axial force,bending moment and safety of highway tunnel in unilateral expansion construction are studied by model test.The results are as follows:①When the tunnel is expanded,the strength of surrounding rock affected by secondary disturbance decreases sharply,and the damage degree increases obviously,especially in the area of the extension side arch and vault.②In the process of tunnel expansion,the stress transfer will increase the compressive stress of the old lining;The new lining gradually bears the load of surrounding rock after installation,and its stress increases significantly,especially at the position of vault and arch.③The safety factor of most lining models is less than 2.0,especially the arch foot is the most vulnerable to instability,and the arch foot area requires additional reinforcement measures to prevent potential structural instability and damage.④According to the guidance of the test data,the method of advance support and upper and lower steps is proposed,and the dregs backfill is used as the construction platform of tunnel upper step excavation to realize safe and efficient construction.

关 键 词：公路隧道 单侧式扩建 施工力学行为 安全性分析 

分 类 号：U451[建筑科学—桥梁与隧道工程]