The E24 profile slope analyzed belongs to a series of excavated slopes of the Haizhou Opencast Coal Mine. It seems to be divided into Downslope Part and Upslope Part. Its profile comprises two noticeable coal seams, c...The E24 profile slope analyzed belongs to a series of excavated slopes of the Haizhou Opencast Coal Mine. It seems to be divided into Downslope Part and Upslope Part. Its profile comprises two noticeable coal seams, called the 8# and 9# weak layers, considered as the potential failure surfaces. In consideration of the actual configuration as in the perspective of any modification, assessing the stability of this slope with various profile forms under given conditions, and assessing the risk of instability and quantifying the influence of earthworks or other modifications to the stability of this slope, have constituted the primordial objectives carried out. From assumed potential failure surfaces, any specific profiles and specified slip surfaces are defined. A factor of safety (FoS) is computed for each specified slip surface; the smallest FoS found corresponds to the least favorable slip surface. The safety factor values obtained are compared to the suggested safety factor. Limit equilibrium methods of vertical slices implemented in Slope/W, computer program for slope stability analyses, have been adopted to perform the E24 slope stability analysis. The safety factor values computed with 9# weak layer are lower than for 8#; the factors of safety obtained with Sarma's method are the smallest; more, without groundwater (long term) overall values are greater than those determined under groundwater condition (short term). The lowest safety factor value is found for a profile depending on an adopted earthwork sequence. The E24 profile slope stability analysis shows the instability risk for the deepest weak layer, and also shows the short and long term stability of this slope for the envisaged earth movements. However it demonstrates the existence of instability risk for any earthwork firstly affecting the downslope part.展开更多
This study aims at exploring the void space gas effect of earthquake-triggered slope instability and providing a new method for studying the formation mechanism of earthquake-triggered landslides. We analysed the basi...This study aims at exploring the void space gas effect of earthquake-triggered slope instability and providing a new method for studying the formation mechanism of earthquake-triggered landslides. We analysed the basic characteristics, kinematic characteristics, initiation mechanisms and physical mechanical parameters of the Daguangbao landslide, generalized a landslide prototype, and established a geological model and performed simulation tests. Based on the seismic wave propagation theory of rock-soil mass, rock fracture mechanics and the effective stress principle, we found that the void space gas effect is due to the occurrence of excess void space gas pressure when the dynamic response of seismic loads impacts the void space gas in weak intercalated layers of the slope. The excess void space gas pressure generated by the vibration(earthquake) damages the rock mass around the void space with a certain regularity. The model test results show that the effective shear strength of the rock mass can be reduced by 4.4% to 21.6% due to the void space gas effect.展开更多
基金Project of NSFC (No. 40472136)Scientific Research Foundation for the Returned Overseas Chinese Scholar, State Education Ministry(No. 120413133)985 Project of Jilin University (No. 105213200500007)
文摘The E24 profile slope analyzed belongs to a series of excavated slopes of the Haizhou Opencast Coal Mine. It seems to be divided into Downslope Part and Upslope Part. Its profile comprises two noticeable coal seams, called the 8# and 9# weak layers, considered as the potential failure surfaces. In consideration of the actual configuration as in the perspective of any modification, assessing the stability of this slope with various profile forms under given conditions, and assessing the risk of instability and quantifying the influence of earthworks or other modifications to the stability of this slope, have constituted the primordial objectives carried out. From assumed potential failure surfaces, any specific profiles and specified slip surfaces are defined. A factor of safety (FoS) is computed for each specified slip surface; the smallest FoS found corresponds to the least favorable slip surface. The safety factor values obtained are compared to the suggested safety factor. Limit equilibrium methods of vertical slices implemented in Slope/W, computer program for slope stability analyses, have been adopted to perform the E24 slope stability analysis. The safety factor values computed with 9# weak layer are lower than for 8#; the factors of safety obtained with Sarma's method are the smallest; more, without groundwater (long term) overall values are greater than those determined under groundwater condition (short term). The lowest safety factor value is found for a profile depending on an adopted earthwork sequence. The E24 profile slope stability analysis shows the instability risk for the deepest weak layer, and also shows the short and long term stability of this slope for the envisaged earth movements. However it demonstrates the existence of instability risk for any earthwork firstly affecting the downslope part.
基金funded by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (No.SKLGP2016Z015)the Natural Science Foundation of China (No. 41572308)
文摘This study aims at exploring the void space gas effect of earthquake-triggered slope instability and providing a new method for studying the formation mechanism of earthquake-triggered landslides. We analysed the basic characteristics, kinematic characteristics, initiation mechanisms and physical mechanical parameters of the Daguangbao landslide, generalized a landslide prototype, and established a geological model and performed simulation tests. Based on the seismic wave propagation theory of rock-soil mass, rock fracture mechanics and the effective stress principle, we found that the void space gas effect is due to the occurrence of excess void space gas pressure when the dynamic response of seismic loads impacts the void space gas in weak intercalated layers of the slope. The excess void space gas pressure generated by the vibration(earthquake) damages the rock mass around the void space with a certain regularity. The model test results show that the effective shear strength of the rock mass can be reduced by 4.4% to 21.6% due to the void space gas effect.
