低矮路堤下膨胀土地基现场浸水试验研究

发布时间：2018-05-18 12:40

本文选题：路基工程 + 低矮路堤　；参考：《岩石力学与工程学报》2014年08期

【摘要】：为研究低矮路堤下中强膨胀土地基浸水饱和后的变形特性,依托云桂高速铁路建设,通过人工浸水方式开展不同高度等尺寸路基现场浸水试验。试验采用砂孔、砂槽及砂垫层等方式多面浸水,并同步观测路基填土期、稳载期及人工浸水期地基表面与路基表面的变形。研究结果表明:从路基填筑开始到人工浸水结束,膨胀土地基的变形曲线呈"S"型分布。沿路基横断面方向,地基表面的膨胀变量呈"锅底"型分布,路基表面的膨胀变量呈"V"型分布,地基表面的相对膨胀量随路基填高的增加而呈线性递减。通过对比不同路基填高的相对膨胀量表明,地基表面的相对膨胀量均大于路基表面的相对膨胀量,地基表面的膨胀变形沿路基本体呈衰减变化。在试验成果的基础上,初步提出以路基表面膨胀变形为0作为控制标准确定路基临界填高的设计思路。现场试验的设计原则与实施方法也可为今后研究铁路路基下膨胀土地基胀缩特性提供参考。
[Abstract]:In order to study the deformation characteristics of saturated medium and strong expansive soil foundation under low embankment, based on Yun-Gui high-speed railway construction, the in-situ soaking test of subgrade with different height and equal size was carried out by artificial soaking method. Sand holes, sand grooves and sand cushion were used in the experiment. The deformation of subgrade surface and subgrade surface was observed simultaneously during filling period, steady loading period and artificial flooding period. The results show that from the beginning of subgrade filling to the end of artificial flooding, the deformation curve of expansive soil foundation is "S" type distribution. Along the cross-section of the road foundation, the expansion variables on the surface of the foundation are "pot bottom" and those on the surface of the subgrade are "V". The relative expansion of the surface of the foundation decreases linearly with the increase of the filling height of the subgrade. By comparing the relative expansion of different subgrade filling heights, it is shown that the relative expansion of the subgrade surface is larger than that of the subgrade surface, and the swelling deformation of the foundation surface is attenuated along the road basic body. Based on the experimental results, the design idea of determining the critical filling height of the subgrade with the expansion deformation of the embankment surface as the control standard is put forward preliminarily. The design principle and implementation method of field test can also provide a reference for the study of expansion and shrinkage characteristics of expansive soil foundation under railway subgrade in the future.
【作者单位】：西南交通大学土木工程学院;西南交通大学道路工程四川省重点实验室;中铁二院工程集团有限责任公司;
【基金】：铁道部科技研究开发计划项目(2010G003 F)
【分类号】：U416.167

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