某高速铁路路基帮宽段沉降控制方案研究

摘要

沉降控制一直是高速铁路路基设计施工考虑的重要部分,然而国内外对高速铁路路基帮宽段的沉降影响研究较少.依托实际工程,研究高速铁路无砟轨道帮宽后既有路基的沉降控制方案,运用有限元软件Midas GTS-NX模拟路基填筑普通填料和轻质混凝土情况下旋喷桩、钢管微型桩的加固效果.结合施工技术的合理性,最后确定该工程条件下"钢管微型桩+轻质混凝土"更为合适.同时,考虑到施工影响,建议在既有线旁施工过程中放慢压桩速度,对此段高铁实行限速处理及实时监测的措施以保证安全.%Settlement control has been an important part of high-speed railway design and construction, but less study is conducted at home and abroad on the settlement influence of the widened subgrade.Based on engineering practices, this paper studies the settlement control scheme for existing high-speed railway subgrade after widening, simulates the existing subgrade reinforcing effect contributed by rotary jet grouting pile and steel micro-pile with normal filling material or lightweight concrete by means of the finite element software Midas GTS-NX.In view of the rationality of construction technology, it is finalized to use steel micro-pile+lightweight concrete in this engineering project.At the same time, considering the construction influence, it is recommended to slow down the piling speed during the construction near the existing line, limit the traffic speed and conduct real-time monitoring on this high-speed railway.