新建高速铁路下穿既有公路桥梁防护方案研究

Research of Protection Schemes of Newly-built High Speed Railway Underpassing Existing Highway Bridge

近年来,公路与铁路市场建设规模不断扩增,二者立交跨越情况越发常见,与之配套的安全防护措施的研究也逐渐为人们所重视。依托于某山区高速铁路项目,由其与既有公路交叉的典型工点出发,简要介绍目前国内该类型立体交叉的基本原则和形式。然后详细阐述高铁下穿既有公路桥梁的防护方案,并综合讨论不同防护方案的优缺点,得到一般的适用性结论:当公路建设单位条件和预算宽松的情况下,优先考虑"换梁"方案,其次选择"既有公路桥改造"方案;当公路建设单位关于对既有公路桥梁的影响容许度较低时,可选择"新建刚架桥"方案;当下穿高铁墩高较低或路基段时,也可以考虑"高铁上方搭设倒U形防护棚"方案。最后结合该工点的工程条件,给出了推荐方案并论证。

In recent years,the market of highway and railway construction is expanding continuously,the interchange crossing each other is becoming more and more common,and researches on corresponding safety protection measures are attracting more and more attention.Based on a mountain high speed railway project,this paper briefly introduces the basic principles of this type of three-dimensional crossing in China,and the general situation and engineering background of the project.Then,the paper elaborates the protection schemes of existing highway bridges under high-speed railway,comprehensively discusses the advantages and disadvantages of different protection schemes,and obtains the following general applicability conclusions.When the conditions and budget of the highway construction unit are in favor,the"beam replacement"scheme will be given priority,followed by the"reconstruction of the existing highway bridge"scheme.When the highway construction unit has low tolerance to the influence on the existing highway bridge,the"new rigid bridge"scheme can be adopted.When the height of pier of high-speed railway is low or in the subgrade section,the scheme of"setting up inverted U-shaped protective shed above high-speed railway"could also be considered.Finally,according to the engineering conditions of the work point,the recommended scheme is given and demonstrated.