黄土梁峁区高填方地基变形规律研究

随着城镇化步伐加快,陕北黄土高原梁峁区三四线城市出现越来越多的高填方工程,陕北大孔隙黄土与特殊地形地貌共同作用下引起建筑物地基发生严重不均匀沉降,导致上部结构开裂甚至失稳垮塌,危及人身与财产安全。为了全面分析梁峁区高填方地基变形规律,课题组在陕北黄土高原某梁峁区填方场地选取了西北地区最大的试验场(直径超过90m),通过原位监测对高填方地基地应力、含水率以及地基沉降进行了研究,分析了黄土填方地基含水率随季节变化规律及其影响深度,并发现黄土高填方地基中存在土拱现象,总结出沉降与填方高度的关系。利用三维数值模拟反演分析推测出高填方地基的最终沉降量,对上部结构作用下地基变形规律进行了预测,为类似黄土地区高填方工程设计及其变形计算提供参考。

IN-SITU TESTS ON DEFORMATION LAWS OF HIGH FOUNDATION IN LOESS PLATEAU AREA

With the accelerating pace of urbanization, more and more building foundations appear in hilly areas of loess plateau. Building foundations can have serious uneven subsidences because of large pore loess and special landform, which can lead to crack, or even collapse of buildings. The crustal stress, water content and foundation sedimentation of loess hilly-gully high-stacked foundation are studied via in-situ monitoring. The changing law of filled foundation's water content with season and the affected depth are analyzed. It is found that there exists a soil arch in high-stacked foundation. The relation between sedimentation and filling depth is concluded. The final sedimentation volume is analyzed and conjectured by the use of three-dimension numerical simulation inversion. The foundation deformation law under the effect of upper construction is predicted which provides reference for similar loess high-stacked engineering design and its deformation calculation.