Background

In modern times, 82% of the strong earthquakes in mainland China happened in western areas where about 80% of China's river sources and the majority of China's 13 large hydropower bases are located. Therefore, it is of strategic importance to prevent seismic catastrophe and ensure the seismic safety of high dams in the west region, considering the seismic issue and the "unimaginable" consequences of secondary disasters in case of destructive earthquakes. The study conducts breakthrough exploration and research on the traditional seismic safety concepts and methods that lag behind the realities, which highlights the strategic focus of "preventing catastrophic dam failure of uncontrollable water release and consequent serious secondary disasters during extreme earthquakes" in a large number of high concrete dams in highly seismic areas of western China.

Contents

    · Researching ground motion at the dam site, including the determination of extreme earthquakes at the dam site, the characteristics of near-fault motions and the resynthesis of ground motions near the epicenter of Wenchuan earthquake;

    · Investigating the damage and failure mechanism of high dams and the aseismic capacity to prevent catastrophes under extreme earthquakes;

    · Examining the dynamic properties of dam concrete, including the dynamic strength and the stress-strain relations of full-graded aggregate dam concrete; 

    · Probing into strategies of preventing seismic catastrophes in high dams, covering seismic safety evaluation criteria, emergency plans and seismic measures.

Achievements

    · The stochastic finite fault method has been innovatively used to reasonably determine the ground motions of near-fault earthquake in high dam projects;

    · The whole-process stress-strain curve and the basic damage evolution law of dam concrete under cyclic load have been studied through full-graded dam concrete test;

    · A new method has been proposed for nonlinear dynamic analysis of the seismic damage and failure mechanism of dam concrete and ground rock system, an efficient parallel computing program independently developed, and large-scale seismic calculations of high dams successfully performed on the Tianhe-1 supercomputer;

    · The Code for Seismic Design for Hydraulic Structures of Hydropower Projects, the first national standard in China, has been compiled, putting forward the contingency plan for destructive earthquakes in high dams.

Application

The achievements have been used for seismic evaluation of Shapai arch dam after Wenchuan earthquake by reasonably explaining and verifying the actual seismic conditions. They have provided important technical support for the Feasibility Study Report of Wudongde Hydropower Station and been adopted in the seismic design of Wudongde hydropower project.

Application of the stochastic finite fault method to forecast the maximum credible earthquake

Test of Shapai dam concrete cores under dynamic loads

Finite element mesh for seismic analysis of Shapai arch dam (number of nodes: over 1.2 million)

The parallel program for the computation of seismic response of dam developed by IWHR is running on the Tianhe-1 supercomputer