采空巷道上方高速铁路桩板路基模型试验研究  

Model test on pile-plank roadbed of high-speed railway overlying goafs

作　　者：李传宝[1] 程谦恭[2] 梁鑫[2,3] 张世亮[2] 

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063 [2]西南交通大学地质工程系,成都610031 [3]广西科技大学土木工程学院,广西柳州545006

出　　处：《岩土力学》2014年第11期3101-3110,3128,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.41172260;No.41372292;No.51108393);国家重点基础研究发展计划(973计划)(No.2008CB425801);高等学校博士学科点专项科研基金(No.20110184110018);铁四院科技研究开发计划课题(No.2010K31;No.2013K20)

摘　　要：桩板结构作为高速铁路采空区路基的复合地基,目前尚处于工程应用的探索阶段,缺乏相应的机制分析。以合福高速铁路(合肥-福州)上饶五府山车站采空巷道上方桩板结构路基为原型,通过物理模型试验获取桩的内力、土的应力、桩和承台板、土及采空巷道顶板的沉降三大类数据,得出了模型中桩和桩间土的内力分布、路基和采空区沉降规律。研究表明,荷载作用下桩顶处轴力最大,桩身轴力沿桩身逐渐减小,采空巷道段轴力恒定;桩侧摩阻力沿桩身不断减小,桩侧无负摩阻力,采空巷道部分桩侧摩阻力为0;桩土应力比与桩土荷载分担比变化规律相似,桩所分担的荷载随着荷载的增加逐渐增大直至一稳定值;承台板和桩间土的沉降均匀,沉降量很小;采空巷道和非采空巷道上方的路基沉降基本相同,采空巷道顶板最底端基本没有变形;模型中桩板结构对采空区路基加固效果良好。The pile-plank structure, as a composite foundation for roadbed treatment in goaf, is still being held up by lack of recommendation and regulations. In order to study the behavior of this structure, the example of the Wufushan station in Hefei-Fuzhou high-speed railway was researched by model test; and then a series of data of pile axial force, soil pressure, and settlements of pile, bearing platform, soil, and goal roof was obtained. Based upon the results of these data, an analysis of the variations of pile axial load, soil pressure, and settlement characteristics of this structure was conducted. Some conclusions are drawn as follows. （1） Under the effect of overlying load, the value of pile axial load presents a decrease as the increase of depth with its maximum appeared at the top of pile. The pile axial load along the sections distributed in goafs maintains constant as the increase of depth. （2） As the increase of depth, the skin resistance of pile also reduces along pile without negative value presented. The value along the sections in goals is zero. （3） The variation of pile-soil stress ratio is similar to that of pile-soil load share ratio. The load shared by the pile firstly presents an increasing trend as the increase overlying load and tends to stable finally. （4） The settlements of bearing platform and soil among piles are even and small. There is almost no difference in the settlements in goafs and non-goaf regions, and almost no deformation occurred at the bottom of goaf roof. （5） Pile-plank has a good effect on reinforcement for goaf roadbed.

关 键 词：高速铁路 采空巷道 桩板路基 模型试验 应力 沉降 

分 类 号：TU473[建筑科学—结构工程]