铁路防治危岩落石桥梁-棚洞一体化结构设计研究

Research on Design of Railway Bridge-shed Integrated Structure for Preventing Falling Rocks

危岩落石灾害是世界范围内高山峡谷地区一种常见的地质灾害类型,具有分布范围广、破坏力强、发生突然等特点,对其危害范围内的构筑物和人类活动构成了严重威胁。当受种种条件限制,考虑空间、地形和投资等因素,桥梁-棚洞一体化结构在提高山区铁路危岩落石防治技术综合水平、保障铁路运营安全方面优势明显。基于RocFall等软件,探讨了危岩落石的冲击计算参数、冲击能量、影响范围、桥梁-棚洞一体化结构的防护能级与防护范围等,提出适用于高速铁路常用跨度32 m简支箱梁的钢筋混凝土刚架式桥梁-棚洞一体化结构设计方案。结果表明:钢筋混凝土刚架式桥梁-棚洞一体化结构在500 kJ的防护能级及以下是可行的;主力(单线活载)+落石冲击荷载为最不利荷载组合,也是结构设计的荷载控制组合,此时结构响应和各项指标满足规范要求。

Rockfall disaster is a common type of geological disasters in high mountains and valleys around the world.It has wide range,strong destructive power and sudden occurrence,and poses a serious threat to the structures and human activities within its hazard range.Considering various constraints,space,topography,investment and other factors,the bridge-shed integrated structure has obvious advantages in improving the comprehensive level of rockfall prevention technology in mountainous areas and ensuring the safety of railway operations.Based on RocFall and some other softwares,this paper discusses the impact parameters,impact energy and impact range of dangerous rock and rockfall,and the protection energy level and protection range of the integrated bridge-shed structure.This paper proposes a reinforced concrete rigid frame bridge-shed integrated structure design scheme which is suitable for high-speed railway 32 m simple-supported box girder.The results show that this bridge-shed integrated structure is feasible at the protection energy level of 500 kJ and below.The main force(single-track live load)combined with the rockfall impact load is the most unfavorable load combination,and it is also the load control combination for structural design.At this time,the structural response and all indicators comply with the mandatory standards.