Shang Y.,Shanxi Investigation Research and Design Institute |
Hu M.,Shanxi Investigation Research and Design Institute |
Yan J.,Shanxi Investigation Research and Design Institute |
Huangfu H.,Water Resources Management Committee Office of Xinzhou City |
And 4 more authors.
Journal of Hohai University
Submerging tests with setting water injection holes and sensors, like moisture meters, were set up on a large-thickness self-weight collapsible loess field in Yuci District, in Jinzhong City, Shanxi Province. The results show that the diffusion pattern of the wetting front is rather complicated due to the feature of moisture spreading in test pits from the bottom up, from the top down, and from the center to the two sides because of setting water injection holes. After 52 days of immersion, the whole section of exploratory wells basically reached saturated water content in the test pits. The layout of water injection holes saved a great deal of time and cost of the experiment. The curve of volumetric water content changing with time can be divided into four stages: the early stable stage of volumetric water content, the growth and change stage of volumetric water content, the steady and extended stage of saturated water content, the late and slightly decreasing stage of volumetric water content. ©, 2015, Editorial Office of Journal of Hohai University (Nature Sciences). All right reserved. Source
Ma Y.,Northwest University, China |
Wang J.-D.,Northwest University, China |
Peng S.-J.,Northwest University, China |
Li Y.-W.,Shanxi Investigation Research and Design Institute |
And 2 more authors.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering
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 β0 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 β0 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. Source