高速铁路采空区桩板结构路基沉降数值模拟

Numerical Simulation Analysis on Sheet-Pile Subgrade Settlement of High-speed Railway in Goaf Region

桩板结构在国内多条高速铁路软土黄土路基中已得到广泛应用,但该结构用于处理路基采空区的研究成果不多。以合肥至福州高速铁路采空巷道上方车站桩板路基为研究对象,数值模拟分析路基的变形规律,为桩板结构处理高速铁路采空区地基设计施工提供有价值的参考。研究表明:路基沉降主要集中于地基浅层;桩身长的桩的沉降量要小于桩身短的沉降量;穿过采空巷道的桩和没有穿过采空巷道的桩两者沉降量相差不大;结构能够有效限制采空巷道顶板变形;采用桩+承台板结构作为采空巷道地基的工程处理方法是有效的。

Sheet-pile structure has widely been used for treating soft or loess subgrades of domestic high-speed railways, but has rarely been seen for treating subgrade in goaf region. This paper took the sheet-pile subgrade at a station of the Hefei-Fuzhou high-speed railway above a goaf roadway as the research object, and analyzed the deformation pattern of the subgrade by the use of numerical simulation, so as to provide valuable reference for subgrade design and construction of high-speed railway using sheet-pile structure in goaf region. The research results show that the subgrade settlement mainly concentrates in the shallower layers; the settlement quantity of longer piles are less than that of shorter piles; there is little difference on settlement quantity between the pile passing through the goaf roadway and the pile not passing through the goaf roadway ; this structure can effectively restrict the deformation of the goaf roadway top slab; it is effective to use piles plus bearing platform structure as the treatment measures for subgrade above goaf roadway.