By utilizing the two numerical codes RFPA3 D and FLAC3 D, the effect of heterogeneity on failure mode and failure mechanism of rock around deep underground excavations under tri-axial stress is analyzed. It is found t...By utilizing the two numerical codes RFPA3 D and FLAC3 D, the effect of heterogeneity on failure mode and failure mechanism of rock around deep underground excavations under tri-axial stress is analyzed. It is found that zonal disintegration is a large scale shear-slip failure developed in deep surrounding rock mass under tri-axial stress, which is accompanied by a large amount of tensile failure. The distance between fractures and the number of fractures have a close correlation with the rock mass heterogeneity. With an increase of the homogeneity index of the rock mass, the distances between fractures decrease and the number of fractures increases. For an intact hard rock mass with relative high homogeneity, only failure mode characterized as v-shaped notches can be formed due to the intersection of intensively developed shear bands. None of the zonal disintegration can be formed due to the fact that with increasing homogeneity, the failure mechanism of rock mass is gradually dominated by shear failure rather than tensile failure.展开更多
The karst process acts as carbon sequestration for atmospheric CO_2.The amount of karst carbon sequestration (KCS) depends on the discharge of karst catchment and inorganic carbon concentration of the water body.Based...The karst process acts as carbon sequestration for atmospheric CO_2.The amount of karst carbon sequestration (KCS) depends on the discharge of karst catchment and inorganic carbon concentration of the water body.Based on the data from the monitoring station on Banzhai subterranean stream located in Maolan National Nature Reserve of Guizhou province,the process and influence factors of KCS have been analyzed.It shows that the amount of KCS is about 353 t C per year in the catchment of Banzhai subterranean stream,and there is good linear relationship between the strength of KCS and discharge of the stream at various time scales.Therefore,how to monitor the discharge accurately is the key to the estimation of KCS.And stations with real-time monitoring function are very important for KCS calculation because of strong seasonal variability of the karst water cycle.展开更多
Albania has a lot of water re,;ources including： seas, rivers, lakes, lagoons as well as underground waters. Albania has about 485 mm precipitation annual year, with the forms of rain and snow. Most precipitations de...Albania has a lot of water re,;ources including： seas, rivers, lakes, lagoons as well as underground waters. Albania has about 485 mm precipitation annual year, with the forms of rain and snow. Most precipitations descend from the rivers and flow into the Adriatic Sea. About 23% of underground waters are distributed in all country and used by people for different activities. There are also a lot of kinds of natural habitats and ecosystems, such as： Mediterranean shrubs, broadleaves forests, conifer forests, mixed forests, alpine and sub-alpine pasture ecosystems, meadows, rock area, marine ecosystems, coastal, lagoons and other wetland areas, lakes, rivers, but of course and agricultural area. All of them have good correlations between the vegetation and water resources. This correlation is more evident near the rivers, lakes, lagoons etc..展开更多
基金supported by the National Natural Science Foundation of China (Nos. 51304036, 51222401 and 51174045)the Fundamental Research Funds for the Central Universities of China(Nos. N120101001 and N120601002)+1 种基金the National Basic Research Program of China (No. 2013CB227900)the China-South Africa Joint Research Program (No. 2012DFG71060)
文摘By utilizing the two numerical codes RFPA3 D and FLAC3 D, the effect of heterogeneity on failure mode and failure mechanism of rock around deep underground excavations under tri-axial stress is analyzed. It is found that zonal disintegration is a large scale shear-slip failure developed in deep surrounding rock mass under tri-axial stress, which is accompanied by a large amount of tensile failure. The distance between fractures and the number of fractures have a close correlation with the rock mass heterogeneity. With an increase of the homogeneity index of the rock mass, the distances between fractures decrease and the number of fractures increases. For an intact hard rock mass with relative high homogeneity, only failure mode characterized as v-shaped notches can be formed due to the intersection of intensively developed shear bands. None of the zonal disintegration can be formed due to the fact that with increasing homogeneity, the failure mechanism of rock mass is gradually dominated by shear failure rather than tensile failure.
基金funded by the project (No.41072192)from National Natural Science Foundation of Chinathe project(No.1212011087122)from China Geological Survey
文摘The karst process acts as carbon sequestration for atmospheric CO_2.The amount of karst carbon sequestration (KCS) depends on the discharge of karst catchment and inorganic carbon concentration of the water body.Based on the data from the monitoring station on Banzhai subterranean stream located in Maolan National Nature Reserve of Guizhou province,the process and influence factors of KCS have been analyzed.It shows that the amount of KCS is about 353 t C per year in the catchment of Banzhai subterranean stream,and there is good linear relationship between the strength of KCS and discharge of the stream at various time scales.Therefore,how to monitor the discharge accurately is the key to the estimation of KCS.And stations with real-time monitoring function are very important for KCS calculation because of strong seasonal variability of the karst water cycle.
文摘Albania has a lot of water re,;ources including： seas, rivers, lakes, lagoons as well as underground waters. Albania has about 485 mm precipitation annual year, with the forms of rain and snow. Most precipitations descend from the rivers and flow into the Adriatic Sea. About 23% of underground waters are distributed in all country and used by people for different activities. There are also a lot of kinds of natural habitats and ecosystems, such as： Mediterranean shrubs, broadleaves forests, conifer forests, mixed forests, alpine and sub-alpine pasture ecosystems, meadows, rock area, marine ecosystems, coastal, lagoons and other wetland areas, lakes, rivers, but of course and agricultural area. All of them have good correlations between the vegetation and water resources. This correlation is more evident near the rivers, lakes, lagoons etc..
