相邻两座小净距大跨度多孔框架涵下穿铁路顶进施工技术

Jacking Construction Technology of Two Adjacent Small Clear Distance Frame Culverts with Large Span and Multi-hole Underpassing the Railway

下穿已有建(构)筑物施工是目前城市河道及道路改造工程中面临的重要难题之一,施工工艺不当极易造成已有建(构)筑物的开裂、失稳,甚至坍塌等事故的发生。针对这一难题,结合怀柔小泉河分洪渠工程改造项目中两座相邻6.3 m净距的多孔框架涵下穿既有铁路的顶进施工实例,通过采取三桩施工、路基注浆、线路加固、路基加固等有效措施,使顶进过程中铁路路基的沉降控制在规定范围内,确保了施工的安全。该小净距大跨度框架涵下穿铁路的顶进施工,其成功经验可为类似工程提供参考。

Construction underpassing the existing building （structure） is one of the important problems in the current reno- vation project of urban fiver channel and road. Improper construction process is very easy to cause cracking, instability or even collapse and other accidents for the existing building （structure）. Aiming at the problem, this paper combines with the jacking construction example of two adjacent frame culverts with 6.3 m spacing and multi-hole underpassing the railway in the flood diversion channel renovation project of Huairou Xiaoquan River, through three piles＇ construction, subgrade grouting, lines consolidation, subgrade reinforcement and other effective measures, it effectively ensures that the settlement of the railway subgrade during jacking is within the specified scope, and thus the construction safety is guaranteed. The jacking construction of a small clear distance and large span frame culvert underpassing the railway can provide references for similar projects.