一、引言穿越铁道路线下的结构物,有公路、河道、上下水道、电信管道等,甚至包括铁道线路的穿越,种类极为繁多。特别是近几年来城市的发展,各种公用服务设施水平的提高,随之也要求保安和防 I. INTRODUCTION Structures that cross the railway line include roads, rivers, sewers, telecom pipelines, and even the crossing of railway lines. The types are extremely varied. In particular, the development of cities in recent years, the improvement of various public service facilities and the consequent need for security and prevention