繁忙干线间列车振动作用下连续刚构钻孔桩施工技术

Construction Technique for Bored Piles under the Action of Train Vibration of a Flat-Slab Continuous Rigid Frame Bridge across Busy Railway Lines

武康上行客车线跨京广线无梁板刚构跨线桥跨越5条电气化既有铁路繁忙干线,桥位处地质条件复杂,邻线列车振动对桩基施工有影响。通过方案比选后选用冲击钻成孔方式进行桩基施工,施工中采用10m加长钢护筒和适当增加泥浆相对密度等措施,同时采取必要的安全防护措施,在确保桩基施工质量的同时也保证了既有铁路运营安全。

A flat-slab rigid frame bridge on Wukang up-bound passenger line overpasses 5 busy existing electrified railway lines, the geological condition at the bridge site is complex and the vibration of trains running on the adjacent lines poses impact on the pile foundation construc- tion. The application of electric impact drill in the pile foundation construction was determined by the scheme comparison and selection. During the construction, the 10 m lengthened steel tube was used and the relative density of the slurry was improved, in addition, necessary safety pre- cautions were taken to guarantee the quality of pile foundation construction and the safe operation of the existing lines as well.