地震涌浪的产生与传播机理及其对土石坝安全影响的研究

Most of the large built or building reservoirs with a storage capacity of or over 0.1 million cubic meters, are grouped mainly in Southwest China, where is a multi-earthquake-happening area, and it is should be noted that it is necessary to research the effect of the earthquake on the safety of reservoirs. Previous researches mainly focus on the effect of the earthquake on the dam structure and the stability of reservoir banks, and rarely refer to the possible harm of earthquake-induced surge waves to the dam, especially to the earth rock dam. However, the earth rock dam, which is typically created by the emplacement and compaction of loose particles, might be unsafe when there are strong surge waves overtop the dam or when the hydraulic erosion or dam leakage happen. Therefore, the generation mechanism and propagation characteristics of earthquake-induced surge waves, as well as its potential hazard to earth rock dam will be emphatically analyzed in the research. Firstly, a database for statistical and theoretical analysis will be established based on the fieldwork of earthquake-induced surge waves in China, then by combining the developed three-dimensional numerical flume model, a three-dimensional numerical simulation platform for researching the generation mechanism and propagation characteristics of earthquake-induced surge waves will be set up, and finally the effect of earthquake-induced surge waves on the safety of earth rock dam structure will be researched by combing flume tests with numerical simulations. This research will offer technical support for more reasonably designing the dam structure, and provide the theoretical base for more accurately assessing the hazard of earthquake-induced surge waves.

我国已建与在建10万立方米及以上库容的大型水库大多集中在西南地区，而西南地区是我国地震多发地带，研究地震对水库安全的影响尤为重要。以往的研究主要考虑的是地震直接对坝体结构和库岸稳定的影响，而对地震通过激发水库涌浪进而对大坝尤其是土石坝产生的潜在危害尚认识不足。由于土石坝为松散颗粒填筑碾压而成，强烈的库区涌浪极易造成大量水体短时间越过坝顶形成坝面冲刷、坝体渗漏加剧等一系列不利影响。在本研究中我们将着重分析地震激发水库涌浪的产生机理与传播特性及其对土石坝的安全影响。首先我们将对受地震影响的国内水库进行实地涌浪调查并建立数据库进行统计与理论分析，然后在此基础上开发三维数值模型研究地震激发水库涌浪的产生机理与传播特性，最后结合水槽试验与数值模拟研究地震涌浪对土石坝坝体结构安全的影响。本项目的研究工作将为更加合理的坝体结构设计提供技术支持，并为更加准确地评估地震涌浪作用下的土石坝风险提供理论依据。

我国大型水库大多集中在西南地区，而西南地区是我国地震多发地带，研究地震对水库安全的影响尤为重要。以往的研究主要考虑的是地震直接对坝体结构和库岸稳定的影响，而对地震通过激发水库涌浪进而对大坝尤其是土石坝产生的潜在危害尚认识不足。由于土石坝为松散颗粒填筑碾压而成，强烈的库区涌浪极易造成大量水体短时间越过坝顶形成坝面冲刷、坝体渗漏加剧等一系列不利影响。本研究针对真实地震作用下的涌浪特性主要进行了数值模拟研究，结合大尺度水槽试验分析了涌浪对均质土石坝的安全影响。通过对多种不同特性的地震信号进行分析研究，得到了大涌浪的激发机制以及库岸/边坡涌浪冲高特性；针对多风险（涌浪与超标洪水）作用下的坝体破坏机理进行了试验研究，分析了溃坝峰值流量的过程线。上述研究成果可以为更加合理的坝体结构设计提供技术支持，并为更加准确地评估地震涌浪作用下的土石坝风险提供理论依据。