地下水对黄土群桩基础影响的试验研究

发布时间：2018-04-17 05:41

本文选题：道路工程 + 桩基础　；参考：《中国公路学报》2015年09期

【摘要】：为了研究地下水上升对桩基础承载能力及变形的影响,通过室内承台-桩-土自身体系的模型试验,对在竖向荷载作用下地下水位较低以及地下水缓慢上升时桩基础沉降、地基附加应力及桩与承台的荷载分担情况进行了测试,根据模型相似规律对测试数据进行了分析和比较。试验结果表明:在地下水上升时桩基础的Q-S曲线表现出非线性,呈现出明显的陡降形;与水位不变的情况相比,在有地下水上升的情况下,基础沉降中不可恢复的塑性变形所占的比例增大;在荷载不变的情况下,水位的上升会造成桩端阻力和侧阻力快速、明显下降,基础沉降迅速增大数倍,对建(构)筑物的安全使用影响很大;地下水上升时土体附加应力均随着时间的增长而增长;加水后由于土含水量的增加,土体变软,力学性质变差,沉降发展加快,土体承担的荷载比例缓慢增加,直到桩基呈现出刺入型破坏特征时,增长速度才加快。
[Abstract]:In order to study the influence of underground water rise on the bearing capacity and deformation of pile foundation, the settlement of pile foundation under vertical load is studied by the model test of pile-soil system under vertical load.The additional stress of the foundation and the load sharing between pile and cap are tested, and the test data are analyzed and compared according to the similarity law of the model.The test results show that the Q-S curve of pile foundation is nonlinear when the groundwater is rising, showing a steep descent, and when the groundwater level is constant, when the groundwater is rising, the results show that the Q-S curve of the pile foundation is nonlinear, and that the Q-S curve of the pile foundation shows a sharp descent.The proportion of the unrecoverable plastic deformation in the settlement of the foundation increases. Under the condition of constant load, the increase of water level will cause the resistance at the pile tip and the side resistance to decrease rapidly, and the settlement of the foundation will increase several times rapidly.It has a great influence on the safe use of the building; the additional stress of the soil increases with the increase of time when the groundwater rises; after adding water, the soil becomes soft, the mechanical property becomes worse, and the settlement development is accelerated, because of the increase of the soil water content,The load ratio of soil increases slowly until the pile foundation presents the characteristics of piercing failure.
【作者单位】：长安大学公路学院;中国民航机场建设集团公司西北分公司;长安大学电子与控制工程学院;
【基金】：陕西省交通运输厅科技项目(15-21K)
【分类号】：TU473.1;TU46

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