下穿既有高速公路顶推箱涵变形和应力分析方法

Methods of Deformation and Stress Analysis of the Box Culvert Incremental Launching Construction Down the Existing Highway

采用超前加固和顶推施工在既有高速公路下方修建箱涵方法具有开挖量小、混凝土方量少、不需中断高速交通等优势,但也面临计算复杂等问题。以某高速公路下穿顶推箱涵工程为例,采用MIDAS分析软件,横向杆件梁单元构建箱涵梁格模型,考虑汽车荷载和周围覆土换算荷载,通过变形等效用弹簧劲度模型确立土体与箱涵间约束关系,建立了顶推箱涵变形和应力分析方法。该方法通过对施工过程中箱涵的沉降、线形和应变等实测数据进行了验证,具有较高的计算精度。可为后续工程施工安全质量控制提供参考。

The method of building culvert under the existing highway with advance reinforcement and top push construction was adopted,the method had the advantages of less excavation,less concrete,and no need to interrupt high-speed traffic,but there were some problems such as the complicated calculation.In this paper,the box culvert incremental launching construction down the existing highway was taken as an example.A method for analysis of deformation and stress of top-push culvert was established.The method was implemented by MIDAS analysis software,the box culvert lattice model was constructed by the transverse beam element,the vehicle load and the surrounding soil were considered,the constraint relationship between soil and box culvert was established by deformation and other utility spring stiffness model.The method was verified by the measured data of settlement,line shape and strain of culvert in the construction process, and has high calculation accuracy.It can provide reference for safety quality control of follow-up engineering construction.