混凝土大坝抗震安全评价的发展趋向

一大批世界级超高拱坝已经和即将在我国西南和西北强地震活动区进行建设。大坝在国民经济发展中占有重要地位,大坝的抗震安全评价将成为我国地震工程研究的一个重要方向。本文对大坝抗震安全评价的研究现状进行了扼要总结,特别对大坝抗震安全有关的若干重要技术问题进行了深入讨论。其中包括抗震设防标准与地震动输入模式;混凝土材料的率敏感特性及其对大坝地震响应的影响;坝-水库-地基动力相互作用效应;强震时拱坝横缝的非线性张合效应;混凝土大坝的非线性地震响应与损伤发展的模拟等。对现有分析模型和方法的有效性及其局限性进行了评述。最后,对该课题今后进一步研究的方向提出了建议。

Developing Tendency of the Seismic Safety Evaluation of Large Concrete Dams

A great many large dams have been built and will be built in high seismic areas of China. As large dams have great significance for the national economic development, so the seismic safety evaluation of large dams is an important part of earthquake engineering. In this paper, recent research activities on the seismic safety evaluation of large concrete dams are briefly reviewed. Some key problems, which are very important for the assessment of seismic performance of concrete arch and concrete gravity dams are discussed in details. This includes seismic design criteria and earthquake input mechanism, strain-rate sen- sitive behavior of concrete material and its influence on the seismic response of concrete dams, dynamic dam-reservoir-foundation interaction effect, influence of joint opening on the seismic response of arch dams during strong earthquakes, nonlinear seismic response and damage development simulation of large concrete dams subjected to severe seismic actions. Comments on the ability and limitations of present available analysis procedures have been made. Finally, suggestions for further advanced study on this subject are proposed.