平面应变加、卸荷条件下黄土的非线性变形特性的研究

发布时间：2018-07-09 23:19

本文选题：黄土 + 平面应变试验　；参考：《岩土工程学报》2015年S1期

【摘要】：针对黄土深基坑开挖坑壁土体侧向变形和填土路堤地基加载侧向挤出变形等平面应变问题,利用西安理工大学真三轴仪改变加载机构,模拟平面应变条件下路堤黄土地基竖向加载和黄土基坑侧向卸载,进行了竖向加载和侧向卸载的黄土平面应变试验,研究了平面应变条件下不同含水率原状Q3黄土的加、卸载应力应变关系。揭示了平面应变竖向加载应力路径下原状Q3黄土的大、小主应力差与轴向应变及轴向应变与侧向应变服从双曲线关系;平面应变侧向卸载应力路径下原状Q3黄土的大、小主应力差与侧向应变及侧向应变与轴向应变也服从双曲线关系。依据平面应变条件下三向的切线线弹性关系,建立了切线弹性模量和泊松比随应力应变状态变化的关系,以及非线性本构模型。经平面应变加、卸载应力路径下原状黄土应力应变关系的模型计算与试验结果比较,验证了两种平面应变路径下非线性模型的正确性。
[Abstract]:In view of the lateral deformation of the excavation wall of the deep foundation pit and the lateral extrusion deformation of the embankment foundation, the loading mechanism is changed by the true three axis instrument of the Xi'an University of technology. The vertical loading of the loess foundation and the lateral unloading of the loess foundation are simulated under the plane strain condition, and the vertical loading and lateral unloading are carried out. In the plane strain test, the stress and strain relationship of unloaded Q3 loess with different water content under plane strain conditions is studied. The size of the original Q3 loess under the vertical loading stress path of the plane strain is revealed. The relationship between the small main stress difference and axial strain and the axial strain and the lateral strain uniform and the lateral unloading stress of the plane strain are studied. The relationship between the stress difference and lateral strain and lateral strain and axial strain also obeys the hyperbolic relationship between the original Q3 loess and the lateral strain and the axial strain. The relationship between the tangent elastic modulus and the Poisson's ratio with the stress and strain state and the nonlinear constitutive model are established by the plane strain plus. The comparison between the model and the experimental results of the stress-strain relationship of intact loess under the stress path verified the correctness of the two nonlinear models under plane strain paths.
【作者单位】：西安理工大学岩土工程研究所;西安工业大学北方信息工程学院;
【基金】：国家自然科学基金项目(41272320) 陕西省教育厅省级重点实验室项目(13JS074)
【分类号】：TU444

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