A field damage survey of 1,005 buildings damaged by the Wenchuan Earthquake in Dujiangyan City was carried out and the resulting data was analyzed using the statistical method. It is shown that buildings that were sei...A field damage survey of 1,005 buildings damaged by the Wenchuan Earthquake in Dujiangyan City was carried out and the resulting data was analyzed using the statistical method. It is shown that buildings that were seismically designed achieved the desired seismic fortification target; they sustained less damage than the non-seismically designed buildings. Among the seismically designed buildings investigated, RC frame buildings performed the best in terms of seismic resistance. Masonry buildings with a ground story of RC frame structure were the second best, and masonry buildings performed the worst. Considering building height, multistory buildings sustained more severe damage than high-rise buildings and 2- and 3-story buildings. Compared to residential buildings, public buildings, such as schools and hospitals, suffered more severe damage.展开更多
Conducting a hazard assessment for secondary mountain hazards is the technical basis for reconstructing destroyed highways and for disaster prevention.It is necessary to consider the role and influence of structural e...Conducting a hazard assessment for secondary mountain hazards is the technical basis for reconstructing destroyed highways and for disaster prevention.It is necessary to consider the role and influence of structural engineering measures as an important assessment factor.In this study,based on six substantial field investigations conducted between July 2008 and July 2012,a 2 km wide zone along both sides of the Dujiangyan Wenchuan(Du Wen) Highway was selected as the study area.Microgeomorphic units and small watersheds in the study area were extracted with GIS software and used as basic assessment units.Through field investigations,remote sensing surveys and experimental analysis,a structural engineering effectiveness assessment was conducted using the technique of principal component analysis.The results showed the following:1) A total of 491 collapses,12 landslides,32 slope debris flows and 17 gully debris flows were scatted across the study area.The total overall areal density of all mountain hazards was 25.7%.The distribution of secondary hazards was influenced mainly by seismic intensity,active fault zones,lithology,slope and altitude.More than 70% of secondary hazards occurred in zones with a seismic intensity of XI,a distance to the fault zone of between 0 and 25 km,a slope between 25° and 50°,and an altitude of between 1,000 m and 1,800 m.2) Different structural engineering measures play different roles and effects in controlling different types and scales of secondary mountain hazards.3) With a secondary mountain hazard area of 128.1 km2and an areal density of 34.9%,medium,high and very high hazard zones accounted for 74% of the study area and were located on the high,steep slopes along both sides of the highway.The low hazard zone was located mainly in the valley floor,on gentle slope platforms and at locations 1.5 km away from the highway the hazard area was 45 km2and the areal density was 3.3%.4) The methodology for hazard assessment of secondary mountain hazards,which is based on five factors,solves such key technical problems as the selection of assessment units,multi-source data fusion,and the weight calculation for each assessment index.This study provides a new and more effective method for assessing secondary mountain hazards along highways,and the proposed models fit well with validation data and field observations.The findings were applied to reconstruction and disaster mitigation in the case of the Du Wen Highway and proved to be feasible.展开更多
The focal mechanism solution on the seismic fault plane can reflect the geometric and kinematic characteristics of faults, and it is an important way to further study the fine structure of fault plane. From the focal ...The focal mechanism solution on the seismic fault plane can reflect the geometric and kinematic characteristics of faults, and it is an important way to further study the fine structure of fault plane. From the focal mechanism solution of the earthquakes around the Dujiangyan fault in Longmenshan fault zone, we derived the average dip angle of Dujiangyan fault is 45.1° based on the seismic moment tensor theory. In order to refine the fault geometry structure, this paper decomposed it into multiple sub-fault planes along the length and width of the fault plane and forms a number of models A13, B13, A23 a, A23 b, A23 c, B23 a,B23 b and B23 c, then calculated the sub-fault’s dip of each model. In order to clarify exactly which one of the fault models is closest to the real fault model, the fault slip was carried out for each model in turn, then compared the surface displacement of each model with GPS observations. The results show that B23 c model with high dip in shallow and small dip in deep is the best model, the lengths of each subfault of Dujiangyan fault from south to north are 33 km, 21 km and 46 km, respectively. When the depth of the fault bottom is about 11 km, the dip angles are 70.56°, 67.41° and 45.55°.When the depth of the fault bottom is about 30 km, The fault dip angles are 44.55°, 29.18° and 44.25°.展开更多
In view of disaster-prevention and evacuation functions of urban green spaces, data collection, field investigation and questionnaire survey were integrated to analyze current situation and functions of green spaces i...In view of disaster-prevention and evacuation functions of urban green spaces, data collection, field investigation and questionnaire survey were integrated to analyze current situation and functions of green spaces in Dujiangyan City. Suggestions for enhancing disaster-prevention and evacuation functions of urban green spaces were proposed on the basis of analyzing and summarizing investigation results.展开更多
Based on the overview of researches on circulation channel of agricultural products,this article presents the status quo of circulation channel of Dujiangyan kiwi fruit,including the production and circulation pattern...Based on the overview of researches on circulation channel of agricultural products,this article presents the status quo of circulation channel of Dujiangyan kiwi fruit,including the production and circulation pattern of Dujiangyan kiwi fruit. Then it analyzes the problems in the current circulation channel of Dujiangyan kiwi fruit as follows: first,the long circulation channel leads to inefficient circulation and high costs; second,the deep processing capacity is poor,and the added value of fruits is low; third,the application of cold chain logistics technology is insufficient; fourth, blocked information circulation makes the cooperative relations between the subjects in channel fragile. Finally corresponding countermeasures and recommendations are put forward as follows: shortening circulation channel and improving circulation efficiency; improving deep processing capacity,and increasing added value of fruits; strengthening the use of cold chain logistics technology and equipments; establishing rational interest distribution mechanism,and consolidating cooperation between the circulation subjects.展开更多
The Dujiangyan Project,located at the junction of the upstream of the Minjiang River and Chengdu Plain,Sichuan Province,China,is an irrigation system project as important as the Great Wall in the history of China.With...The Dujiangyan Project,located at the junction of the upstream of the Minjiang River and Chengdu Plain,Sichuan Province,China,is an irrigation system project as important as the Great Wall in the history of China.Without dam structures,this project has been continuously playing its crucial role in diverting water for irrigation,separating sediments,and controlling flood for 2275 years.In this study,the predicaments of the Dujiangyan Project under the background of rapid urbanization and social economic development were summarized by conducting the field research and using the Indicators of Hydrological alteration(IHA)method:excessive diversion of water,disruption of hydrological pulses,erosion and deposition imbalance and conflicts between power generation and water supply.These contradictions have led to the weakening of the function of automatic water diversion and sand removal in the Dujiangyan Project.Considering the influence of climate change and strong human activities,we pointed out the challenges faced by the millennium ancient weir in balancing human and environmental water usage and project operation and management based on the simulation results of the hydrological model.The corresponding suggestions about strengthening agricultural water saving,generating artificial flood peak were provided to protect and continue to maintain the function of the Dujiangyan Project.展开更多
文摘A field damage survey of 1,005 buildings damaged by the Wenchuan Earthquake in Dujiangyan City was carried out and the resulting data was analyzed using the statistical method. It is shown that buildings that were seismically designed achieved the desired seismic fortification target; they sustained less damage than the non-seismically designed buildings. Among the seismically designed buildings investigated, RC frame buildings performed the best in terms of seismic resistance. Masonry buildings with a ground story of RC frame structure were the second best, and masonry buildings performed the worst. Considering building height, multistory buildings sustained more severe damage than high-rise buildings and 2- and 3-story buildings. Compared to residential buildings, public buildings, such as schools and hospitals, suffered more severe damage.
基金supported by the National Natural Science Foundation of China(Grant No.40901273)the Open Fund of Key Laboratory of Special Environment Road Engineering of Hunan Province(Changsha University of Science and Technology,Grant No.kfj120404)+1 种基金the Western China Communication Science and Technology Projection(Grant No.2008-318-221-56)the Graduate Innovation Foundation of Hunan University of Science and Technology(Grant No.S120033 and S120034)
文摘Conducting a hazard assessment for secondary mountain hazards is the technical basis for reconstructing destroyed highways and for disaster prevention.It is necessary to consider the role and influence of structural engineering measures as an important assessment factor.In this study,based on six substantial field investigations conducted between July 2008 and July 2012,a 2 km wide zone along both sides of the Dujiangyan Wenchuan(Du Wen) Highway was selected as the study area.Microgeomorphic units and small watersheds in the study area were extracted with GIS software and used as basic assessment units.Through field investigations,remote sensing surveys and experimental analysis,a structural engineering effectiveness assessment was conducted using the technique of principal component analysis.The results showed the following:1) A total of 491 collapses,12 landslides,32 slope debris flows and 17 gully debris flows were scatted across the study area.The total overall areal density of all mountain hazards was 25.7%.The distribution of secondary hazards was influenced mainly by seismic intensity,active fault zones,lithology,slope and altitude.More than 70% of secondary hazards occurred in zones with a seismic intensity of XI,a distance to the fault zone of between 0 and 25 km,a slope between 25° and 50°,and an altitude of between 1,000 m and 1,800 m.2) Different structural engineering measures play different roles and effects in controlling different types and scales of secondary mountain hazards.3) With a secondary mountain hazard area of 128.1 km2and an areal density of 34.9%,medium,high and very high hazard zones accounted for 74% of the study area and were located on the high,steep slopes along both sides of the highway.The low hazard zone was located mainly in the valley floor,on gentle slope platforms and at locations 1.5 km away from the highway the hazard area was 45 km2and the areal density was 3.3%.4) The methodology for hazard assessment of secondary mountain hazards,which is based on five factors,solves such key technical problems as the selection of assessment units,multi-source data fusion,and the weight calculation for each assessment index.This study provides a new and more effective method for assessing secondary mountain hazards along highways,and the proposed models fit well with validation data and field observations.The findings were applied to reconstruction and disaster mitigation in the case of the Du Wen Highway and proved to be feasible.
基金financially supported by the National Natural Science Foundation of China under Grant No.41304013Science and Technology Project Plan of Weinan of 2016 No.2016KYJ-1-1State Key Laboratory of Geo-information Engineering No.SKLGIE2017-M-3-3
文摘The focal mechanism solution on the seismic fault plane can reflect the geometric and kinematic characteristics of faults, and it is an important way to further study the fine structure of fault plane. From the focal mechanism solution of the earthquakes around the Dujiangyan fault in Longmenshan fault zone, we derived the average dip angle of Dujiangyan fault is 45.1° based on the seismic moment tensor theory. In order to refine the fault geometry structure, this paper decomposed it into multiple sub-fault planes along the length and width of the fault plane and forms a number of models A13, B13, A23 a, A23 b, A23 c, B23 a,B23 b and B23 c, then calculated the sub-fault’s dip of each model. In order to clarify exactly which one of the fault models is closest to the real fault model, the fault slip was carried out for each model in turn, then compared the surface displacement of each model with GPS observations. The results show that B23 c model with high dip in shallow and small dip in deep is the best model, the lengths of each subfault of Dujiangyan fault from south to north are 33 km, 21 km and 46 km, respectively. When the depth of the fault bottom is about 11 km, the dip angles are 70.56°, 67.41° and 45.55°.When the depth of the fault bottom is about 30 km, The fault dip angles are 44.55°, 29.18° and 44.25°.
文摘In view of disaster-prevention and evacuation functions of urban green spaces, data collection, field investigation and questionnaire survey were integrated to analyze current situation and functions of green spaces in Dujiangyan City. Suggestions for enhancing disaster-prevention and evacuation functions of urban green spaces were proposed on the basis of analyzing and summarizing investigation results.
基金Supported by Social Science Foundation of Sichuan Center for Rural Development Research ( CR1021)
文摘Based on the overview of researches on circulation channel of agricultural products,this article presents the status quo of circulation channel of Dujiangyan kiwi fruit,including the production and circulation pattern of Dujiangyan kiwi fruit. Then it analyzes the problems in the current circulation channel of Dujiangyan kiwi fruit as follows: first,the long circulation channel leads to inefficient circulation and high costs; second,the deep processing capacity is poor,and the added value of fruits is low; third,the application of cold chain logistics technology is insufficient; fourth, blocked information circulation makes the cooperative relations between the subjects in channel fragile. Finally corresponding countermeasures and recommendations are put forward as follows: shortening circulation channel and improving circulation efficiency; improving deep processing capacity,and increasing added value of fruits; strengthening the use of cold chain logistics technology and equipments; establishing rational interest distribution mechanism,and consolidating cooperation between the circulation subjects.
基金This research was jointly supported by the National Natural Science Foundation of China(Grant No.51579161,51779160)the China Meteorological Data Sharing Service System.
文摘The Dujiangyan Project,located at the junction of the upstream of the Minjiang River and Chengdu Plain,Sichuan Province,China,is an irrigation system project as important as the Great Wall in the history of China.Without dam structures,this project has been continuously playing its crucial role in diverting water for irrigation,separating sediments,and controlling flood for 2275 years.In this study,the predicaments of the Dujiangyan Project under the background of rapid urbanization and social economic development were summarized by conducting the field research and using the Indicators of Hydrological alteration(IHA)method:excessive diversion of water,disruption of hydrological pulses,erosion and deposition imbalance and conflicts between power generation and water supply.These contradictions have led to the weakening of the function of automatic water diversion and sand removal in the Dujiangyan Project.Considering the influence of climate change and strong human activities,we pointed out the challenges faced by the millennium ancient weir in balancing human and environmental water usage and project operation and management based on the simulation results of the hydrological model.The corresponding suggestions about strengthening agricultural water saving,generating artificial flood peak were provided to protect and continue to maintain the function of the Dujiangyan Project.