In order to explain the formation process of slope hazards, and to identify the key factors leading to instability of a slope, Emeishan basalt saprolite in vadose zones of the Touzhai landslide in Zhaotong, Yunnan, wa...In order to explain the formation process of slope hazards, and to identify the key factors leading to instability of a slope, Emeishan basalt saprolite in vadose zones of the Touzhai landslide in Zhaotong, Yunnan, was studied. The formation and evolution of Emeishan basalt saprolite was examined using, amongst other techniques, field investigations,thin section analysis, scanning electron microscopy(SEM) observations, chemical analysis, physical and water-physical property tests of rock masses. Field observations revealed that the majority of the weathered rock blocks were presented as a concentric layer structure in which an internal corestone was enveloped with several layers of external saprolized crust. Chemical and mineralogical analysis identified that iron was the most sensitive element and that the weathering progress usually started with the oxidation of Fe2+ to Fe3+ in rock blocks. Alkaline elements such as Si, Ca, Mg, Na and K were also dissolved and Fe and Al were concentrated in saprolized crusts. Results indicated that loss on ignition(LOI) also increased significantly. SEM results showed that the weathering intensity of thebasalt blocks decreased gradually from the outside to the inside, and the mineral morphology significantly differed on both sides of the weathering front. The saprolized crusts presented cellular microstructure features due to the generation of micropore and clay minerals. Thin section analysis showed that plagioclase was relatively more stable than pyroxene and chlorite during weathering. With a centripetal propagation of the weathering front, saprolized crusts became thicker and corestones became smaller; fresh Emeishan basalt blocks gradually turned into saprolized blocks. Due to the loose structure and low strength of saprolite, the quality of the Emeishan basalt mass significantly deteriorated, this being a potentially important factor which caused the Touzhai landslide to occur.展开更多
This paper sets up a complete CO2 contact angle test system by a visualization autoclave, uses the hanging drop-method respectively getting the advancing angle and receding angle of CO2, on the shale surface under the...This paper sets up a complete CO2 contact angle test system by a visualization autoclave, uses the hanging drop-method respectively getting the advancing angle and receding angle of CO2, on the shale surface under the different temperature, and uses the Snake method measuring contact angle of droplet images, to make the wettability experimental study for CO2 on the shale surface. According to contact angle data, wettability of CO2 on the shale surface is preferable; the temperature is the higher, the wettability is better. At the same time, by analyzing correspondingly with scanning electron microscope images of shale sample, it is obtained that shale with different surface structures has affected wettability of CO2.展开更多
基金funded by the Joint Funds of the Natural Science Foundation of China with the Natural Science Foundation of Yunnan (Grant No. U1502232,U1033601)the Research Fund for the Doctoral Program of Higher Education of China(Grant No. 20135314110005)
文摘In order to explain the formation process of slope hazards, and to identify the key factors leading to instability of a slope, Emeishan basalt saprolite in vadose zones of the Touzhai landslide in Zhaotong, Yunnan, was studied. The formation and evolution of Emeishan basalt saprolite was examined using, amongst other techniques, field investigations,thin section analysis, scanning electron microscopy(SEM) observations, chemical analysis, physical and water-physical property tests of rock masses. Field observations revealed that the majority of the weathered rock blocks were presented as a concentric layer structure in which an internal corestone was enveloped with several layers of external saprolized crust. Chemical and mineralogical analysis identified that iron was the most sensitive element and that the weathering progress usually started with the oxidation of Fe2+ to Fe3+ in rock blocks. Alkaline elements such as Si, Ca, Mg, Na and K were also dissolved and Fe and Al were concentrated in saprolized crusts. Results indicated that loss on ignition(LOI) also increased significantly. SEM results showed that the weathering intensity of thebasalt blocks decreased gradually from the outside to the inside, and the mineral morphology significantly differed on both sides of the weathering front. The saprolized crusts presented cellular microstructure features due to the generation of micropore and clay minerals. Thin section analysis showed that plagioclase was relatively more stable than pyroxene and chlorite during weathering. With a centripetal propagation of the weathering front, saprolized crusts became thicker and corestones became smaller; fresh Emeishan basalt blocks gradually turned into saprolized blocks. Due to the loose structure and low strength of saprolite, the quality of the Emeishan basalt mass significantly deteriorated, this being a potentially important factor which caused the Touzhai landslide to occur.
基金Fund project： This Paper is funded by the National Natural Science Foundation of China （NO. 51076170）.
文摘This paper sets up a complete CO2 contact angle test system by a visualization autoclave, uses the hanging drop-method respectively getting the advancing angle and receding angle of CO2, on the shale surface under the different temperature, and uses the Snake method measuring contact angle of droplet images, to make the wettability experimental study for CO2 on the shale surface. According to contact angle data, wettability of CO2 on the shale surface is preferable; the temperature is the higher, the wettability is better. At the same time, by analyzing correspondingly with scanning electron microscope images of shale sample, it is obtained that shale with different surface structures has affected wettability of CO2.
