The geological hazards of landslides in Hanwang Town, Ziyang County, Ankang City, Shaanxi Province, have emerged. Yet, the current understanding of the spatial distribution characteristics and influencing factors of l...The geological hazards of landslides in Hanwang Town, Ziyang County, Ankang City, Shaanxi Province, have emerged. Yet, the current understanding of the spatial distribution characteristics and influencing factors of landslides in this area remains unclear. Combining the results of remote sensing interpretation and field investigation, seven influencing factors, namely, elevation, slope direction, slope gradient, distance from rivers, distance from faults, engineering geologic lithology, and distance from roads, are selected for the study. The distribution characteristics of landslides in each influencing factor and the influence of the resolution of the Digital Elevation Model(DEM) on the results are statistically and analytically analyzed. Furthermore, two highrisk landslides within the study area were subjected to comprehensive analysis, integrating the findings from drilling and other field investigations in order to examine their deformation mechanisms. Based on this analysis,the following conclusions were derived:(1) 34 landslides in the study area, mainly small earth landslides, with a distribution density of 0.42/km~2, threatening 414 people and property of about 55.87 million Yuan.(2)The landslides in the study area easily occur in the <400 m elevation range;the landslides are developed in all slope directions, the gradient is mainly concentrated in the range of 10°–40°, the distribution density of the landslides is higher in the closer distance from the river and the faults(0–200 m), the landslide-prone strata are mainly the softer and weaker metamorphic rocks, and the landslides are mainly around roads.(3) The resolution of the DEM should be selected based on the specific conditions of the study area, the requirements of the investigation, and the scale of the landslide. Opting for an appropriate DEM resolution is advantageous for understanding the patterns of landslides and conducting risk assessments in the region.(4) The Zhengjiabian landslide is a traction Landslide. The landslide body is a binary structure of gravel soil and slate weathering layer, and the damage process can be divided into three stages:(1)damage to the leading edge and stress release,(2)continuous creep and cracking,(3)rainfall infiltration and damage. The predominant slope material in the Brickyard landslide comprises clay, and the landslide is triggered by a combination of the traction effect resulting from the excavation at the slope's base and the nudging effect caused by the stacking load of the brick factory. Additionally, the Brickyard landslide exhibits persistent creep deformation. The study results provide a scientific basis for disaster prevention and mitigation in the Hanwang Township area.展开更多
Due to the joint development characteristic and macropore structure of loess,it is easy to cause structure collapse under earthquake or artificial vibration.The study on the loess disaster effect and its mechanism und...Due to the joint development characteristic and macropore structure of loess,it is easy to cause structure collapse under earthquake or artificial vibration.The study on the loess disaster effect and its mechanism under earthquake action is insufficient due to its complexity.Hence,to study the deformation and mechanical properties more accurately,the dynamic characteristics of saturated remolded loess under cyclic dynamic load were tested using a GDS dynamic triaxial instrument in this paper.The test results show that strain and pore water pressure increase gradually at different rates with the development of vibration,and there is an obvious inflection point in the time-history curve of both.When the number of vibrations(N)exceeds this point,the strain increases rapidly,and pore water pressure tends to be stable.Under the action of large amplitude and low-frequency dynamic load,the strain and pore water pressure increase rapidly with fewer vibrations and the deviator stress(q)decreases rapidly,while the sample achieves damage faster with the increase of amplitude.During the application of a dynamic load,the effective stress(p)gradually decreases and its rate of change slows down.Finally,when the saturated remolded loess is subjected to a constant-amplitude dynamic load,the combination of large amplitude and low frequency leads to the failure of the sample in the shortest time.展开更多
In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in thi...In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in this paper.Three identification approaches of remote sensing images are integrated in this method:object-oriented,texture feature,and digital elevation based on DSM and DEM.So RGB threshold classification method is used to classify the identification results.The accuracy of building structure classification based on each feature and the multi-feature fusion are compared and analyzed.The results show that the building structure classification method is feasible and can accurately identify the structures in large-area remote sensing images.展开更多
基金financially supported by the National Key Research and Development Program of China(2022YFC3003400)National Natural Science Foundation of China(No. 41402254)Department of Science and Technology of Shaanxi Province(No. 2019ZDLSF07-0701, 2022SF-445)。
文摘The geological hazards of landslides in Hanwang Town, Ziyang County, Ankang City, Shaanxi Province, have emerged. Yet, the current understanding of the spatial distribution characteristics and influencing factors of landslides in this area remains unclear. Combining the results of remote sensing interpretation and field investigation, seven influencing factors, namely, elevation, slope direction, slope gradient, distance from rivers, distance from faults, engineering geologic lithology, and distance from roads, are selected for the study. The distribution characteristics of landslides in each influencing factor and the influence of the resolution of the Digital Elevation Model(DEM) on the results are statistically and analytically analyzed. Furthermore, two highrisk landslides within the study area were subjected to comprehensive analysis, integrating the findings from drilling and other field investigations in order to examine their deformation mechanisms. Based on this analysis,the following conclusions were derived:(1) 34 landslides in the study area, mainly small earth landslides, with a distribution density of 0.42/km~2, threatening 414 people and property of about 55.87 million Yuan.(2)The landslides in the study area easily occur in the <400 m elevation range;the landslides are developed in all slope directions, the gradient is mainly concentrated in the range of 10°–40°, the distribution density of the landslides is higher in the closer distance from the river and the faults(0–200 m), the landslide-prone strata are mainly the softer and weaker metamorphic rocks, and the landslides are mainly around roads.(3) The resolution of the DEM should be selected based on the specific conditions of the study area, the requirements of the investigation, and the scale of the landslide. Opting for an appropriate DEM resolution is advantageous for understanding the patterns of landslides and conducting risk assessments in the region.(4) The Zhengjiabian landslide is a traction Landslide. The landslide body is a binary structure of gravel soil and slate weathering layer, and the damage process can be divided into three stages:(1)damage to the leading edge and stress release,(2)continuous creep and cracking,(3)rainfall infiltration and damage. The predominant slope material in the Brickyard landslide comprises clay, and the landslide is triggered by a combination of the traction effect resulting from the excavation at the slope's base and the nudging effect caused by the stacking load of the brick factory. Additionally, the Brickyard landslide exhibits persistent creep deformation. The study results provide a scientific basis for disaster prevention and mitigation in the Hanwang Township area.
基金financially supported by the National Natural Science Foundation of China(No.42090053,No.41922054).
文摘Due to the joint development characteristic and macropore structure of loess,it is easy to cause structure collapse under earthquake or artificial vibration.The study on the loess disaster effect and its mechanism under earthquake action is insufficient due to its complexity.Hence,to study the deformation and mechanical properties more accurately,the dynamic characteristics of saturated remolded loess under cyclic dynamic load were tested using a GDS dynamic triaxial instrument in this paper.The test results show that strain and pore water pressure increase gradually at different rates with the development of vibration,and there is an obvious inflection point in the time-history curve of both.When the number of vibrations(N)exceeds this point,the strain increases rapidly,and pore water pressure tends to be stable.Under the action of large amplitude and low-frequency dynamic load,the strain and pore water pressure increase rapidly with fewer vibrations and the deviator stress(q)decreases rapidly,while the sample achieves damage faster with the increase of amplitude.During the application of a dynamic load,the effective stress(p)gradually decreases and its rate of change slows down.Finally,when the saturated remolded loess is subjected to a constant-amplitude dynamic load,the combination of large amplitude and low frequency leads to the failure of the sample in the shortest time.
基金sponsored by National Key R&D Program of China(2018YFC1504504)Youth Foundation of Yunnan Earthquake Agency(2021K01)Project of Yunnan Earthquake Agency“Chuan bang dai”(CQ3-2021001).
文摘In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in this paper.Three identification approaches of remote sensing images are integrated in this method:object-oriented,texture feature,and digital elevation based on DSM and DEM.So RGB threshold classification method is used to classify the identification results.The accuracy of building structure classification based on each feature and the multi-feature fusion are compared and analyzed.The results show that the building structure classification method is feasible and can accurately identify the structures in large-area remote sensing images.
