The paper focuses on the formation of Nanzhangzhuang ground fissure through emphatically analysing factors including the intersection fault dislocation,the deep ground-water over-exploitation together with the landfor...The paper focuses on the formation of Nanzhangzhuang ground fissure through emphatically analysing factors including the intersection fault dislocation,the deep ground-water over-exploitation together with the landform and lithology features.Features of the ground fissure are explained in detail after describing the geological setting in the study area.The paper also provides dynamic mode of the ground fissure formation via force analysis of the soil body unit at ground fissures.Conclusions can be drawn that the stress state of soil bodies changed with the activities of two intersection faults,namely Hengshui fault and Hubei fault.In addition,the stress fields control the development of ground fissure.The deep groundwater in Hengshui area dropped considerably in recent years,to be precise,the water elevation of deep groundwater dropped from -26 m to -94 m by 2010 at the centre of groundwater funnel.The over-exploitation of deep groundwater in Hengshui area enlarged the ground fissures.The data concerning shallow borehole show that the vertical lithology mainly consists of silt,silty clay and silty sandy soil,which all belong to the middle-compressed soil.The lateral extension of the soil bodies occur with pumping and tectonic creep,and the clay layers on both sides of the cracks can stay upright.Thus the ground fissure came visible.展开更多
Based on the systematical collection and processing of data on the influence of mining-induced earthquakes on water table regime in deep well Lu-15 in Taozhuang Coal Mine since 1980, we study the characteristics of co...Based on the systematical collection and processing of data on the influence of mining-induced earthquakes on water table regime in deep well Lu-15 in Taozhuang Coal Mine since 1980, we study the characteristics of coseismic effect of water table in deep well in this paper. We have found precursory phenomena of water table in deep well before mining-induced earthquake. Here we discuss the physical mechanism of coseismic effect of mining--induced earthquake on water table in deep well.展开更多
The four diversion tunnels at Jinping Ⅱ hydropower station represent the deepest underground project yet conducted in China, with an overburden depth of 1500-2000 m and a maximum depth of 2525 m.The tunnel structure ...The four diversion tunnels at Jinping Ⅱ hydropower station represent the deepest underground project yet conducted in China, with an overburden depth of 1500-2000 m and a maximum depth of 2525 m.The tunnel structure was subjected to a maximum external water pressure of 10.22 MPa and the maximum single-point groundwater inflow of 7.3 m^3/s. The success of the project construction was related to numerous challenging issues such as the stability of the rock mass surrounding the deep tunnels, strong rockburst prevention and control, and the treatment of high-pressure, large-volume groundwater infiltration. During the construction period, a series of new technologies was developed for the purpose of risk control in the deep tunnel project. Nondestructive sampling and in-situ measurement technologies were employed to fully characterize the formation and development of excavation damaged zones（EDZs）, and to evaluate the mechanical behaviors of deep rocks. The time effect of marble fracture propagation, the brittleeductileeplastic transition of marble, and the temporal development of rock mass fracture and damage induced by high geostress were characterized. The safe construction of deep tunnels was achieved under a high risk of strong rockburst using active measures, a support system comprised of lining, grouting, and external water pressure reduction techniques that addressed the coupled effect of high geostress, high external water pressure, and a comprehensive early-warning system. A complete set of technologies for the treatment of high-pressure and large-volume groundwater infiltration was developed. Monitoring results indicated that the Jinping II hydropower station has been generally stable since it was put into operation in 2014.展开更多
基金Hebei Province Natural Science Foundation of China(D2017403020)the Joint foundation of Key Laboratory of Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences(KF201602)
文摘The paper focuses on the formation of Nanzhangzhuang ground fissure through emphatically analysing factors including the intersection fault dislocation,the deep ground-water over-exploitation together with the landform and lithology features.Features of the ground fissure are explained in detail after describing the geological setting in the study area.The paper also provides dynamic mode of the ground fissure formation via force analysis of the soil body unit at ground fissures.Conclusions can be drawn that the stress state of soil bodies changed with the activities of two intersection faults,namely Hengshui fault and Hubei fault.In addition,the stress fields control the development of ground fissure.The deep groundwater in Hengshui area dropped considerably in recent years,to be precise,the water elevation of deep groundwater dropped from -26 m to -94 m by 2010 at the centre of groundwater funnel.The over-exploitation of deep groundwater in Hengshui area enlarged the ground fissures.The data concerning shallow borehole show that the vertical lithology mainly consists of silt,silty clay and silty sandy soil,which all belong to the middle-compressed soil.The lateral extension of the soil bodies occur with pumping and tectonic creep,and the clay layers on both sides of the cracks can stay upright.Thus the ground fissure came visible.
文摘Based on the systematical collection and processing of data on the influence of mining-induced earthquakes on water table regime in deep well Lu-15 in Taozhuang Coal Mine since 1980, we study the characteristics of coseismic effect of water table in deep well in this paper. We have found precursory phenomena of water table in deep well before mining-induced earthquake. Here we discuss the physical mechanism of coseismic effect of mining--induced earthquake on water table in deep well.
文摘The four diversion tunnels at Jinping Ⅱ hydropower station represent the deepest underground project yet conducted in China, with an overburden depth of 1500-2000 m and a maximum depth of 2525 m.The tunnel structure was subjected to a maximum external water pressure of 10.22 MPa and the maximum single-point groundwater inflow of 7.3 m^3/s. The success of the project construction was related to numerous challenging issues such as the stability of the rock mass surrounding the deep tunnels, strong rockburst prevention and control, and the treatment of high-pressure, large-volume groundwater infiltration. During the construction period, a series of new technologies was developed for the purpose of risk control in the deep tunnel project. Nondestructive sampling and in-situ measurement technologies were employed to fully characterize the formation and development of excavation damaged zones（EDZs）, and to evaluate the mechanical behaviors of deep rocks. The time effect of marble fracture propagation, the brittleeductileeplastic transition of marble, and the temporal development of rock mass fracture and damage induced by high geostress were characterized. The safe construction of deep tunnels was achieved under a high risk of strong rockburst using active measures, a support system comprised of lining, grouting, and external water pressure reduction techniques that addressed the coupled effect of high geostress, high external water pressure, and a comprehensive early-warning system. A complete set of technologies for the treatment of high-pressure and large-volume groundwater infiltration was developed. Monitoring results indicated that the Jinping II hydropower station has been generally stable since it was put into operation in 2014.
