【作者】 张世亮；

【导师】 程谦恭；

【作者基本信息】 西南交通大学 ， 地质工程， 2013， 硕士

【摘要】 目前国内对于通过采空区的高速铁路,绝大部分采取绕避,但同时考虑线路的平顺,只针对无法绕避的小型采空区进行工程治理。国内对于桩板结构应用于软土地基尚有研究,但将桩板结构应用于采空区的处理上却很少。本文以高速铁路合福线五府山车站采空区路基桩板结构处理工程为依托,采用物理模型的方法,研究桩板结构的作用机理和沉降规律等。主要研究内容和成果如下：(1)对国内外采空区的研究现状以及采空区的处理进行了分析总结,对物理模型试验理论进行了阐述。(2)对模型试验原型段五府山车站采空巷道路基的工程地质条件进行了调查分析。(3)根据模型试验相似原理,设计了模型试验方案,并按照设计方案完成模型试验,根据试验数据,绘制相关曲线,得到如下结论：①桩身轴力随着桩身深度增加逐渐减小,桩顶处轴力最大,采空巷道段轴力恒定；随着桩长的增加,端承力逐渐减小。②桩侧摩阻力随着桩身深度的增加不断减小,在桩的上段,侧摩阻力较大,到达采空巷道部分,侧摩阻力为零；随着桩长的增加,侧摩阻力分担的荷载增加。③桩土应力比与桩体荷载分担比变化规律相似,都是随着荷载的增加增大,在最终荷载情况下,桩土应力比为127,桩所分担的荷载为55.8%。④随着荷载的增加,承台顶面、承台下方桩间土沉降量都逐渐增大；虽然各处沉降量略有差异,.但差别都很小；可见,承台为刚性承台,在荷载作用下整体受力,整体沉降：随着路堤荷载增加,沉降曲线都是由陡变缓,最终趋于稳定增长。⑤桩板结构对采空巷道的处理效果较好,承台板总体沉降较小,采空巷道附近桩体轴力较小,采空巷道顶板基本没有沉降。更多还原

【Abstract】 The mined-out area is commonly avoided in most of the high-speed railway in China at present, and some small mined-out area is controlled considering the straight and smooth of the railway track.There is alreadly some researches about pile-plank structure in soft soil foundation, but the corresponding research of this structure used in mind-out area is rare. In this dissertation, based on the regulation project for mined-out area below the WuFuShan station roadbed of Hefei-Fuzhou high-speed railway, the working mechanism and the settlement of the pile-plank structure were studied by model test. The main achievements of the research are showed as follows:①The axial force gradually decreases with the increment of the pile depth, the maximum axial force appears at the top of the pile, the axial force is constant in the mined-out area; the end bearing capacity gradually decreases with the increment of the pile length.②The skin friction of piles decreases with the increment of the pile depth, it is bigger on the upper section of the pile and is zero in the mined-out area; the load shared by the skin friction increases with the growth of the pile length.③The change regulation of the pile-soil stress ratio is similar to the sharing stress ratio of piles, they both increase with the increment of loads, The pile-soil stress ratio is127and the sharing stress ratio of piles is55.8%at the ultimate load.④The settlement gradually increas with the increment of the load; the settlement in different locations are diverse, but the difference is very small; it turns out to be that the plank is rigid under loads, it is affected by forces and appears to sink as a whole; as the load increases, the settlement curves are steep initially and become gentle later, and remain a stabilized increasing trend finally.⑤The treatment effect of pile-plank structure used for mined-out area is essentially obvious. The overall settlement of the plank is relatively small, and the axial force of the pile is small around the mined-out area and the settlement on the roof of the mined-out area is barely zero value.更多还原