混凝土板下部土拱形成规律研究

发布时间：2018-01-23 21:33

本文关键词： 土拱效应刚性约束土体沉陷覆土压力　出处：《河北工业大学学报》2014年06期 　论文类型：期刊论文

【摘要】：土拱效应是岩土工程中的常见现象,地下穿越施工过程中开挖断面上部土体相互挤密,引起地层不均匀沉陷,在洞顶局部区域形成土拱.当表层存在刚性混凝土面板时,可对地表变形产生约束,改变原有应力传递路径和土拱影响范围.对此,采用ABAQUS有限元软件建立仿真分析模型,针对不同板厚、埋深和管径条件下的土拱形成规律进行研究,探讨地基沉陷与管顶覆土压力分布特征.研究结果表明,土拱效应导致地基内部主应力方向发生偏转,管顶两侧竖向应力有明显增加,刚性道面板板底未发生隆起变形,开挖断面覆跨比指标不是评价土拱效应的唯一指标,需结合具体参数条件进行讨论.
[Abstract]:Soil arch effect is a common phenomenon in geotechnical engineering. In the process of underground crossing construction, the upper soil mass of excavation section is compacted with each other, resulting in uneven subsidence of stratum. The soil arch is formed in the local area of the roof of the tunnel. When there is a rigid concrete slab on the surface, the deformation of the earth surface can be restrained, and the original stress transfer path and the influence range of the soil arch can be changed. ABAQUS finite element software is used to establish the simulation analysis model, and the formation law of soil arch under different plate thickness, buried depth and pipe diameter is studied. The results show that the soil arch effect results in the deflection of the direction of the principal stress in the foundation and the obvious increase of the vertical stress on both sides of the pipe top. There is no uplift and deformation at the bottom of rigid track slab, and the ratio of overpass to span of excavation section is not the only index to evaluate the soil arch effect, which needs to be discussed in combination with the specific parameter conditions.
【作者单位】：中国民航大学机场学院;上海建工四建集团有限公司;
【基金】：国家自然科学基金(51408598) 中央高校基金项目(3122014B004) 中国民航大学科研启动基金(2011QD13X)
【分类号】：TU990.3
【正文快照】： 土拱效应是岩土工程中的常见力学现象[1].一般认为土拱的形成需要具备3个基本条件,即土体间的不均匀变形、拱脚以及足够的土体抗剪强度[2].当进行地下穿越施工时,土体挖掘会引起开挖断面上部土层向下沉陷,土颗粒变位后相互挤密进而在洞顶局部范围内形成土拱(Soil Arch),并将拱

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