The seismic computed tomography （CT） method is derived from the basic principles of X-ray section scanning first applied in medical science. The method records P-wave arrivals between shots and receivers in separate...The seismic computed tomography （CT） method is derived from the basic principles of X-ray section scanning first applied in medical science. The method records P-wave arrivals between shots and receivers in separate boreholes. Using the velocity information from 2D seismic P-wave arrival inversion, we can determine the distribution of velocity in rock and soil bodies. This paper introduces a practical case of using the seismic CT method for detecting the structure of the rocks for tunnel engineering and to utilize SIRT algorithms for doing first arrival time iterative inversion. Compared with other exploration methods, it is more efficient and accurate.展开更多
Studies on susceptibility to debris flows at regional scale （ioo-looo km2） are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography,...Studies on susceptibility to debris flows at regional scale （ioo-looo km2） are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography, can be used to predict susceptible areas rapidly while necessitating few input data. In this research, Flow-R model is implemented to create the susceptibility map for the debris flow of the Vizze Valley （BZ, North-Eastern Italy; 134 km^2）. The analysis considers the model application at local scale for three sub-catchments and then it explores the model upsealing at the regional scale by verifying two methods to generate the source areas of debris-flow initiation. Using data of an extreme event occurred in the Vizze Valley （4 August 2012） and historical information, the modeling verification highlights that the propagation parameters are relatively simple to set in order to obtain correct runout distances. A double DTM filtering - using a threshold for the upslope contributing area （0.1 km^2） and a threshold for the terrain-slope angle （15°） provides a satisfactory prediction of source areas and susceptibility map within the geological conditions of the Vizze Valley.展开更多
At 5 am 24 th June 2017, a catastrophic landslide hit Xinmo Village, Maoxian County, Sichuan Province, China. The slide mass rushed down from an altitude of 3400 m and traveled 2700 m in a high velocity. The 13 millio...At 5 am 24 th June 2017, a catastrophic landslide hit Xinmo Village, Maoxian County, Sichuan Province, China. The slide mass rushed down from an altitude of 3400 m and traveled 2700 m in a high velocity. The 13 million m^3 deposition buried the whole village and caused about 100 deaths. The source area of the landslide is located in a high steep slope, average slope angle is 40o and maximal angle is 65o. The strata are interbedded Triassic Zagunao Formation metamorphic sandstone and slate with the dip slope angle of 45°. Based on high-resolution satellite remote sensing image, UAV image, DEM data, and field investigation, failure mechanism, travel features, and deposit characteristics were analyzed. The results showed that this landslide was influenced by Songpinggou Fault zone. According to the topography before the failure, the landslide is located in the back scarp of an antecedent landslide induced by Diexi Earthquake in 1933. The bedding slope provided potential rupture surface. Historical seismic activities and long-term gravitational deformation caused rock mass accumulated damages. Weathering and precipitation weakened the rock mass and finally induced shearing and tension failure. A huge block detached from the top rock slope, pushed the past landslide deposits in the middle part, rushed out of the slope bottom in a high velocity and buried the Xinmo Village. The rapid movement entrained and brought the soil into the Songping Gully which recoiled with and bounced back from the opposite mountain.展开更多
文摘The seismic computed tomography （CT） method is derived from the basic principles of X-ray section scanning first applied in medical science. The method records P-wave arrivals between shots and receivers in separate boreholes. Using the velocity information from 2D seismic P-wave arrival inversion, we can determine the distribution of velocity in rock and soil bodies. This paper introduces a practical case of using the seismic CT method for detecting the structure of the rocks for tunnel engineering and to utilize SIRT algorithms for doing first arrival time iterative inversion. Compared with other exploration methods, it is more efficient and accurate.
基金granted by the Junior Research Grant Universitàdegli Studi di Padova,year 2013,prot.CPDR138494(“Criticitàidrauliche nel reticolo montano nei riguardi del movimento di detrito legnoso e di colate detritiche”Prof.Vincenzo D’Agostino)
文摘Studies on susceptibility to debris flows at regional scale （ioo-looo km2） are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography, can be used to predict susceptible areas rapidly while necessitating few input data. In this research, Flow-R model is implemented to create the susceptibility map for the debris flow of the Vizze Valley （BZ, North-Eastern Italy; 134 km^2）. The analysis considers the model application at local scale for three sub-catchments and then it explores the model upsealing at the regional scale by verifying two methods to generate the source areas of debris-flow initiation. Using data of an extreme event occurred in the Vizze Valley （4 August 2012） and historical information, the modeling verification highlights that the propagation parameters are relatively simple to set in order to obtain correct runout distances. A double DTM filtering - using a threshold for the upslope contributing area （0.1 km^2） and a threshold for the terrain-slope angle （15°） provides a satisfactory prediction of source areas and susceptibility map within the geological conditions of the Vizze Valley.
基金partially supported by the National Science Foundation of China(Grant No.41572302)the Funds for Creative Research Groups of China(Grant No.41521002)
文摘At 5 am 24 th June 2017, a catastrophic landslide hit Xinmo Village, Maoxian County, Sichuan Province, China. The slide mass rushed down from an altitude of 3400 m and traveled 2700 m in a high velocity. The 13 million m^3 deposition buried the whole village and caused about 100 deaths. The source area of the landslide is located in a high steep slope, average slope angle is 40o and maximal angle is 65o. The strata are interbedded Triassic Zagunao Formation metamorphic sandstone and slate with the dip slope angle of 45°. Based on high-resolution satellite remote sensing image, UAV image, DEM data, and field investigation, failure mechanism, travel features, and deposit characteristics were analyzed. The results showed that this landslide was influenced by Songpinggou Fault zone. According to the topography before the failure, the landslide is located in the back scarp of an antecedent landslide induced by Diexi Earthquake in 1933. The bedding slope provided potential rupture surface. Historical seismic activities and long-term gravitational deformation caused rock mass accumulated damages. Weathering and precipitation weakened the rock mass and finally induced shearing and tension failure. A huge block detached from the top rock slope, pushed the past landslide deposits in the middle part, rushed out of the slope bottom in a high velocity and buried the Xinmo Village. The rapid movement entrained and brought the soil into the Songping Gully which recoiled with and bounced back from the opposite mountain.
