Seepage-stress coupled modeling for rainfall induced loess landslide

Although rainfall is rare on the Loess Plateau of western China, landslides occur frequently there in rainy season. Surveys report that landslide hazards always follow heavy rains. In this study, a seepage-stress coupling model for rainfall induced landslide is used to examine an actual disastrous event in Yulin by the end of July, 2017. The effects of rainfall duration, rainfall intensity and soil weakening on slope stability are studied in detail. The results illustrate that the safety factor drops sharply at first and then is gradually declining to below 1.05 during additional two days of heavy rain. With soil strength softening considered, the slope would be more unstable, in which the weakening in soil cohesion is found to be a more sensitive factor.

Centrifuge model test and field measurement analysis for foundation pit with confined water

The similarity law of centrifuge test was developed for the seepage field and stress field of a foundation pit with confined water by analyzing control equations,and a similarity index and a similarity coefficient of centrifuge test were obtained.Based on the deep foundation pit of the Huangxing Road Station of the Shanghai metro line M8,the deformation stability of the pit was tested.Finally,a comparative study was conducted on the test results of the pit deformation and the field measurement results.Comparison results show that the pit deformation regularity of the test is basically identical with that of the field measurement,and the difference in pit deformation between the test and the field measurement is within 50%.The centrifuge model test can effectively simulate the displacement response of the ground and retaining structure during dewatering and excavation for the pit with confined water,which provides a reliable basis for the design and construction of the pit with confined water.