The basic element in any sustainable dam project is safety, which includes the following safety elements： O structural safety, dam safety monitoring, operational safety and maintenance, and emergency planning. Lon...The basic element in any sustainable dam project is safety, which includes the following safety elements： O structural safety, dam safety monitoring, operational safety and maintenance, and emergency planning. Long-term safety primarily includes the analysis of all hazards affecting the project; that is, hazards from the natural environment, hazards from the man-made environment, and project-specific and site-specific hazards. The special features of the seismic safety of dams are discussed. Large dams were the first structures to be systematically designed against earthquakes, starting in the 1930s. How- ever, the seismic safety of older dams is unknown, as most were designed using seismic design criteria and methods of dynamic analysis that are considered obsolete today. Therefore, we need to reevaluate the seismic safety of existing dams based on current state-of-the-art practices and rehabilitate deficient dams. For large dams, a site-specific seismic hazard analysis is usually recommended. Today, large dams and the safety-relevant elements used for controlling the reservoir after a strong earthquake must be able to withstand the ground motions of a safety evaluation earthquake. The ground motion parameters can be determined either by a probabilistic or a deterministic seismic hazard analysis. During strong earthquakes, inelastic deformations may occur in a dam; therefore, the seismic analysis has to be car- ried out in the time domain. Furthermore, earthquakes create multiple seismic hazards for dams such as ground shaking, fault movements, mass movements, and others. The ground motions needed by the dam engineer are not real earthquake ground motions but models of the ground motion, which allow the safe design of dams. It must also be kept in mind that darn safety evaluations must be carried out several times during the long life of large storage dams. These features are discussed in this paper.展开更多
大多数用于灌溉和供水的坝为高度小于 15 m 的土坝,并称之为乡村坝。国际大坝委员会所辖大坝的坝高都在15 m 以上,这些小型水坝并不在委员会管辖范围之内。通常,乡村坝由地方社区或水坝工程建设经验不足的组织资助修建起来的,印度尤其...大多数用于灌溉和供水的坝为高度小于 15 m 的土坝,并称之为乡村坝。国际大坝委员会所辖大坝的坝高都在15 m 以上,这些小型水坝并不在委员会管辖范围之内。通常,乡村坝由地方社区或水坝工程建设经验不足的组织资助修建起来的,印度尤其如此。例如 1 月 26 日发生在印度古茶拉底省的 Bhuj 地震,波及到 240 座水坝。显然这些坝的质量远比不上水电站大坝的质量,然而小型水坝的事故将会影响到整个大坝行业的前景,所以这些乡村水坝也应该满足基本的设计与安全准则,以免对整个大坝行业造成负面影响。展开更多
Earthquakes can affect large dam projects in many different ways.Usually,design engineers are focussing on ground shaking and neglect the other aspects.The May 12,2008 Wenchuan earthquake has damaged 1803 dams and res...Earthquakes can affect large dam projects in many different ways.Usually,design engineers are focussing on ground shaking and neglect the other aspects.The May 12,2008 Wenchuan earthquake has damaged 1803 dams and reservoirs,and 403 hydropower plants with an installed capacity of 3.3GW.Among these dams were the 132-m-high Shapai RCC arch dam and the 156-m-high Zipingpu concrete face rockfill dam.These recently completed dams are dam types which,up to now,have not experienced strong ground shaking.The widespread mass movements have caused substantial damage to dams and surface powerhouses in Sichuan.The different features of earthquake hazard are presented,i.e.,ground shaking,faulting and mass movements.It is proposed to prepare project-specific safety plans for all dams,which consist of a matrix where the possible hazards and the corresponding countermeasures are listed.The earthquake behaviors of the Sefid Rud,Zipingpu and Shapai dams,which,in the past,have experienced strong ground shaking from nearby earthquakes,are discussed.Finally,the need for strong motion instrumentation of large dams is discussed.It is proposed that major dams with large damage potential,dams located in areas of high seismicity,and dams showing signs of abnormal behavior be equipped with strong motion instruments.展开更多
文摘The basic element in any sustainable dam project is safety, which includes the following safety elements： O structural safety, dam safety monitoring, operational safety and maintenance, and emergency planning. Long-term safety primarily includes the analysis of all hazards affecting the project; that is, hazards from the natural environment, hazards from the man-made environment, and project-specific and site-specific hazards. The special features of the seismic safety of dams are discussed. Large dams were the first structures to be systematically designed against earthquakes, starting in the 1930s. How- ever, the seismic safety of older dams is unknown, as most were designed using seismic design criteria and methods of dynamic analysis that are considered obsolete today. Therefore, we need to reevaluate the seismic safety of existing dams based on current state-of-the-art practices and rehabilitate deficient dams. For large dams, a site-specific seismic hazard analysis is usually recommended. Today, large dams and the safety-relevant elements used for controlling the reservoir after a strong earthquake must be able to withstand the ground motions of a safety evaluation earthquake. The ground motion parameters can be determined either by a probabilistic or a deterministic seismic hazard analysis. During strong earthquakes, inelastic deformations may occur in a dam; therefore, the seismic analysis has to be car- ried out in the time domain. Furthermore, earthquakes create multiple seismic hazards for dams such as ground shaking, fault movements, mass movements, and others. The ground motions needed by the dam engineer are not real earthquake ground motions but models of the ground motion, which allow the safe design of dams. It must also be kept in mind that darn safety evaluations must be carried out several times during the long life of large storage dams. These features are discussed in this paper.
文摘Earthquakes can affect large dam projects in many different ways.Usually,design engineers are focussing on ground shaking and neglect the other aspects.The May 12,2008 Wenchuan earthquake has damaged 1803 dams and reservoirs,and 403 hydropower plants with an installed capacity of 3.3GW.Among these dams were the 132-m-high Shapai RCC arch dam and the 156-m-high Zipingpu concrete face rockfill dam.These recently completed dams are dam types which,up to now,have not experienced strong ground shaking.The widespread mass movements have caused substantial damage to dams and surface powerhouses in Sichuan.The different features of earthquake hazard are presented,i.e.,ground shaking,faulting and mass movements.It is proposed to prepare project-specific safety plans for all dams,which consist of a matrix where the possible hazards and the corresponding countermeasures are listed.The earthquake behaviors of the Sefid Rud,Zipingpu and Shapai dams,which,in the past,have experienced strong ground shaking from nearby earthquakes,are discussed.Finally,the need for strong motion instrumentation of large dams is discussed.It is proposed that major dams with large damage potential,dams located in areas of high seismicity,and dams showing signs of abnormal behavior be equipped with strong motion instruments.
