中文摘要：

在晋中地区大厚度自重湿陷性黄土场地进行了打设注水孔的浸水试验,提出了一种浸水试坑外部土层水平位移的监测方法,对地表及地下湿陷变形、水分扩散规律、浸水湿陷范围、试坑周围裂缝发展及试坑外围地下水平位移进行了监测和研究,对地区修正系数的计算方法进行了探讨。结果表明：该场地黄土湿陷经历初始浸水、湿陷起始、剧烈湿陷、稳定湿陷、剧烈固结、稳定固结6个阶段；探讨了浸水过程中水分扩散规律及其对湿陷变形的影响,提出了“湿陷沉降迟滞-突变”效应并用“层壳”作用对其进行了解释；对比其它试验资料发现地面湿陷影响范围与自重湿陷性土层厚度的比值具有一定规律,均在1.6左右；建立了一个以面积为权重的反算方法并算得该地区为0.7；试坑周围的裂缝发展经历侧向拉开、纵向发展、新裂缝产生、受压变窄4个阶段；该场地实测自重湿陷下限深度为18 m；试坑外围浅部土层向试坑中心方向位移,深部土层则向外部位移,拐点的深度随与试坑距离的增大而减小。研究成果已经应用于该场区后期地基设计,并可指导该地区未来工程建设。

英文摘要：

The immersion tests on a self-weight collapse loess site are conducted by setting water injection holes in Jinzhong City of Shanxi Province, China. A method for measuring the horizontal displacement of underground loess outside the test pit is proposed. The collapsible deformation of ground surface and underground, the influence region of loess collapse, the development process of fissures around the test pit and the underground lateral deformation are monitored and studied. The computing method of area correction factor is discussed. The results indicate that the curve of the collapsible process includes 6 stages. The influence region of the loess collapse relates to the thickness of the self-weight collapsible loess, and their ratio is about 1.6, which is obtained from the results of 4 immersion tests in 4 provinces. A new computing method based on the weighted average of the area that stands for different collapse volumes is established, and then the area correction factor is calculated as 0.7, which is greater than the value given by the Chinese Code. The development process of the fissures around the test pit experiences 4 steps, and the thickness of the self-weight collapsible loess determined by the immersion tests is 18 m, which is less than the value got from the indoor soil tests. The shallow loess outside the test pit moves inside while the deep loess moves outside, and the depth of inflection point decreases when the distance between the monitoring line and the test pit increases. All the results have been applied to the design of foundation treatment in later construction projects in this site, and they can also guide other projects in nearby regions.