Main Participants: TU Jin, LI Deyu, GUO Shengshan, LIANG Hui, ZHONG Hong, LI Chunlei, ZHANG Cuiran, WANG Haibo, ZHAO Lijun, WANG Shaoqing, YAN Chunli, LIU Biao, LI Zhiyuan, ZHANG Boyan, WANG Jing

Hydropower plays an irreplaceable role in China's energy development and energy restructuring. The southwest and northwest parts of China, although rich in hydropower resources, are prone to strong earthquakes. Therefore, ensuring the seismic safety of dams is a significant challenge that must be addressed. After nearly thirty years of exploration and research, remarkable progress has been made in the theory and technology of seismic analysis of high dams, yet further work is still needed to fully meet the needs of constructing super-high arch dams in areas with high seismic intensity. Specifically, material performance, numerical models, high-performance computing and safety evaluation criteria needs to be further explored. This study aims to build a system for simulating the entire dynamic damage process of the super-high arch dam-foundation systems, which conforms better to the actual seismic behavior as well as to propose quantitative safety evaluation criteria to prevent major seismic catastrophes.

·   Studying the seismic damage evolution and damage mechanism of the dam-foundation system of super-high arch dams;

·   Developing super-large-scale high performance computing software for super-high arch dams based on refined mesh and cloud computing;

·   Studying quantitative safety evaluation criteria for super-high arch dams against major seismic catastrophes.

·   Having developed testing apparatus and technology for fully-graded concrete under tension-compression loading-unloading cycles, proposed a bilinear model for the stress-strain relationship during tension-compression conversion after the occurrence of tensile damage, and established a numerical model for the constitutive relationship that better reflects the actual condition during tension-compression conversion;

·   Having developed high performance cloud computing software with independent intellectual property for seismic analysis of high arch dam-foundation multi-coupling systems. By utilizing the "Tianhe-1" super computing platform, the time-history analysis of dynamic damage of super-high arch dam-foundation multi-coupling systems with 10 million+ degrees of freedom were completed for the first time;

·   Having developed a simulation system for the whole process of dynamic damage of high arch dam-foundation systems that conforms better to the actual seismic behavior, defined a unified criterion based on the inflection point on the curves of characteristic variables due to seismic overloading, and established the quantitative safety evaluation criteria for high arch dams against major seismic catastrophes.

The research has been applied to seismic safety analysis and research of several high arch dams constructed in seismically-active areas, including the seismic safety analysis of the Longpan Dam, seismic safety review of the Wudongde Dam, static and dynamic analysis and safety evaluation of the Batang Toru Dam, and seismic safety analysis of the Zhongyu Dam,  providing important technical support for the design and construction of super-high arch dams in areas prone to strong earthquakes.

Fig.1 A typical whole process stress-strain curve for fully-graded concrete samples in an axial tension-compression cyclic test

Fig.2 Numerical model for high arch dam-foundation multi-coupling systems

Fig.3 Parallel computing efficiency tested by an example with 10 million+ degrees of freedom

Fig.4 Refined mesh for high arch dam-foundation multi-coupling systems

Fig.5 Unified criterion for the maximum seismic capacity of a damage-stability coupling system