单洞三车道公路隧道扩挖成四车道的开挖方案的探讨及思考

Discussion and Consideration on the Excavation Scheme of Expanding Three Lanes into Four Lanes of Single Highway Tunnel

目前对单洞2车道的公路隧道扩建成4车道的工程实例和相关研究已有不少,但对单洞3车道隧道扩建成4车道隧道的相关案例及研究鲜有报道。以某公路隧道扩建项目为例,基于对既有3车道隧道受力状态的不同认识和技术措施所起的不同作用,提出3种扩挖方案,并对扩挖方案中遇到的问题提出思考,供类似工程参考。

At present,there are many engineering examples and related studies on the expansion of a single-tunnel with two lanes into the four lanes of highway tunnel,but few cases and studies on expanding a single tunnel with three lanes into the four lanes of highway tunnel have been reported.Taking a highway tunnel expanding project as the example,three expanding schemes are put forward based on the different understanding of the mechanical behavior of the existing three-lane tunnel and different effects of technical measures,and the problems encountered in the expanding schemes are considered to provide reference for the project.