The report summarizes the observed damage to a variety of buildings near the epicenter of the M6.8 Luding earthquake in Sichuan Province,China.They include base-isolated buildings,multi-story reinforced concrete(RC)fr...The report summarizes the observed damage to a variety of buildings near the epicenter of the M6.8 Luding earthquake in Sichuan Province,China.They include base-isolated buildings,multi-story reinforced concrete(RC)frame buildings,and masonry buildings.The near-field region is known to be tectonically highly active,and the local intensity level is the highest,that is,0.4g peak ground acceleration(PGA)for the design basis earthquake,in the Chinese zonation of seismic ground motion parameters.The extent of damage ranged from the weak-story collapse that claimed lives to the extensive nonstructural damage that suspended occupancy.The report highlights the first observation of the destruction of rubber bearings and viscous dampers in the isolation layer of Chinese seismically isolated buildings.It also features the rare observation of the brittle shear failure of RC columns in moment-resisting frames in a region of such a high seismic design requirement.Possible reasons that may have attributed to the reported damage are suggested by providing facts observed in the field.However,careful forensic analyses are needed before any conclusive judgment can be made.展开更多
Gaoshiti-Moxi structure belt of An-Yue Sinian gas reservoir, which was China’s largest monomer Marine carbonate gas reservoir up to now, located in vying-dragon female temple structure group that belong to the ancien...Gaoshiti-Moxi structure belt of An-Yue Sinian gas reservoir, which was China’s largest monomer Marine carbonate gas reservoir up to now, located in vying-dragon female temple structure group that belong to the ancient uplift slope of the middle of Sichuan. With the exploration and development of high temperature and high pressure carbonate reservoir, a large number of challenges and problems, such as long isolation section, active oil-gas show, large temperature difference, prone to super retarding cement slurry and gas channeling at flare position, have been encountered in the cementing of 177.8 mm hang-liner. In order to solve these problems, numerous measures and methods have been put into use for reducing the safety risk of cementing and improving cementing quality. The large temperature difference channeling cement slurry system, effective anti-pollution spacer and high-pressure packer type liner hanger were developed and applied for field tests in the early stage of development. In addition, equilibrium pressure cementing technology, optimizing of centralizer placement and plasma column structure, improvement of pump displacement and hold pressure while waiting on cement were used to ensure nice displacement efficiency and cementing quality. As Moxi X well for example, the cementing quality factor of merit was 40.29% and the qualification rate was up to 78.87% after adopting the cementing measures and methods above. The cementing quality was much higher than previous level and provided technical support for Gaoshiti-Moxi area.展开更多
Based on the principle of “pre-disaster prevention outweighs rescue during disasters”, this study targets areas threatened by natural disasters, and develops an automatic algorithm based on the Prim algorithm to ser...Based on the principle of “pre-disaster prevention outweighs rescue during disasters”, this study targets areas threatened by natural disasters, and develops an automatic algorithm based on the Prim algorithm to serve as an automatic identification system. In the face of natural disasters that disable key facilities in the region and prevent settlements from contacting the outside world or outsiders from sending rescuers to the settlements, the proposed system helps to identify whether these regions will become isolated areas and conduct disaster mitigation and relief resource allocation before any natural disaster in order to reduce potential disaster losses. An automatic identification system, based on the threshold of channel blocking due to broken roads and bridges, determines through the decision tree model and relevant patterns whether such regions will become isolated areas by identifying areas based on the results of model analysis. The proposed system’s identification results are verified by actual case histories and comparisons;the results can be used to correctly identify isolated areas. Finally, Microsoft Visual Studio C # and Google Map are employed to apply the results and to produce an information mode for the determination and decision support of isolated areas affected by natural disasters.展开更多
基金the Natural Science Foundation of China(52122811).
文摘The report summarizes the observed damage to a variety of buildings near the epicenter of the M6.8 Luding earthquake in Sichuan Province,China.They include base-isolated buildings,multi-story reinforced concrete(RC)frame buildings,and masonry buildings.The near-field region is known to be tectonically highly active,and the local intensity level is the highest,that is,0.4g peak ground acceleration(PGA)for the design basis earthquake,in the Chinese zonation of seismic ground motion parameters.The extent of damage ranged from the weak-story collapse that claimed lives to the extensive nonstructural damage that suspended occupancy.The report highlights the first observation of the destruction of rubber bearings and viscous dampers in the isolation layer of Chinese seismically isolated buildings.It also features the rare observation of the brittle shear failure of RC columns in moment-resisting frames in a region of such a high seismic design requirement.Possible reasons that may have attributed to the reported damage are suggested by providing facts observed in the field.However,careful forensic analyses are needed before any conclusive judgment can be made.
文摘Gaoshiti-Moxi structure belt of An-Yue Sinian gas reservoir, which was China’s largest monomer Marine carbonate gas reservoir up to now, located in vying-dragon female temple structure group that belong to the ancient uplift slope of the middle of Sichuan. With the exploration and development of high temperature and high pressure carbonate reservoir, a large number of challenges and problems, such as long isolation section, active oil-gas show, large temperature difference, prone to super retarding cement slurry and gas channeling at flare position, have been encountered in the cementing of 177.8 mm hang-liner. In order to solve these problems, numerous measures and methods have been put into use for reducing the safety risk of cementing and improving cementing quality. The large temperature difference channeling cement slurry system, effective anti-pollution spacer and high-pressure packer type liner hanger were developed and applied for field tests in the early stage of development. In addition, equilibrium pressure cementing technology, optimizing of centralizer placement and plasma column structure, improvement of pump displacement and hold pressure while waiting on cement were used to ensure nice displacement efficiency and cementing quality. As Moxi X well for example, the cementing quality factor of merit was 40.29% and the qualification rate was up to 78.87% after adopting the cementing measures and methods above. The cementing quality was much higher than previous level and provided technical support for Gaoshiti-Moxi area.
文摘Based on the principle of “pre-disaster prevention outweighs rescue during disasters”, this study targets areas threatened by natural disasters, and develops an automatic algorithm based on the Prim algorithm to serve as an automatic identification system. In the face of natural disasters that disable key facilities in the region and prevent settlements from contacting the outside world or outsiders from sending rescuers to the settlements, the proposed system helps to identify whether these regions will become isolated areas and conduct disaster mitigation and relief resource allocation before any natural disaster in order to reduce potential disaster losses. An automatic identification system, based on the threshold of channel blocking due to broken roads and bridges, determines through the decision tree model and relevant patterns whether such regions will become isolated areas by identifying areas based on the results of model analysis. The proposed system’s identification results are verified by actual case histories and comparisons;the results can be used to correctly identify isolated areas. Finally, Microsoft Visual Studio C # and Google Map are employed to apply the results and to produce an information mode for the determination and decision support of isolated areas affected by natural disasters.
