桥梁防治危岩落石的设计标准探讨  

Study on Design Standard of Bridge for Preventing Dangerous Rockfall

作　　者：杨少军[1] 刘琛[1] 高明昌[1] YANG Shaojun;LIU Chen;GAO Mingchang(China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《铁道标准设计》2020年第S01期74-79,共6页Railway Standard Design

基　　金：国家铁路局铁路工程建设标准计划项目(2019JS019);中国铁路总公司科技研究计划项目(2018G-031);中国铁建股份有限公司科技研究计划课题(2018-B11)。

摘　　要：完善与提升交通基础设施安全防护技术标准是实现交通强国建设目标的重要内容之一。而国内铁路桥梁设计标准中关于落石防护领域尚属空白。结合艰险山区铁路桥梁建设中面临的危岩落石风险,从落石运动规律、桥梁棚洞结构形式、落石冲击力计算方法和轻型缓冲层材料的耗能性能4个方面出发,开展科研试验与理论分析研究,探讨桥梁工程防治危岩落石设计标准制定的关键技术问题。研究结果表明:(1)落石运动规律应结合坡面整治措施确定,建议将落石冲击最大速度规定为25m/s并按200kJ与500kJ两级设防;(2)提出用于落石防护的UHPC装配式桥棚一体化结构形式;(3)经三种砂土缓冲层冲击力计算公式理论分析,提出推荐计算方法;(4)通过EPS缓冲层耗能性能试验研究提出冲击力计算公式。Improving the safety protection technical standards of transportation infrastructure is one of the important measures to realize the goal of building a powerful transportation country.However,the domestic railway bridge design standards are still absent in the field of rockfall protection.Combined with the risk of rockfall in the construction of railway bridge and tunnel connection project in difficult mountainous area,research experiment and theoretical analysis are carried out from four aspects:the law of rockfall movement,the structural form of bridge shed and tunnel,the calculation method of rockfall impact force and the energy dissipation performance of lightweight buffer layer material.The results show that:(1)The law of rockfall movement should be combined with slope regulation measures.It is suggested that the maximum impact velocity of rockfall should be set at 25 m/s and protected at 200 kj and 500 kj levels;(2)UHPC prefabricated bridge shed integrated structure for rockfall protection is proposed;(3)The recommended calculation method is proposed based on the theoretical analysis of the impact force calculation formula of three kinds of sand buffer layer;(4)Based on the experimental study of energy dissipation performance of EPS buffer layer,the calculation formula of impact force is proposed.

关 键 词：铁路桥梁 落石 防护结构 冲击力 冲击能量 缓冲层 耗能 设计标准 

分 类 号：U21[交通运输工程—道路与铁道工程] U445[建筑科学—桥梁与隧道工程]