Cracking Analysis of High Concrete Gravity Dams Under Floodwater and Seismic Effects

As economic develops, energy demand is also increasing. The development of hydroelectric energy has become one of the important measures to deal with energy crisis. In order to develop hydropower, many high concrete dams are being built or about to build in China. These dams are often operating at high water level and in high seismic intensity region. Accident due to the high concrete dam failure may cause serious harm to the economic development and the safety of the people, so it has an important significance to study the security and stability of high concrete dam under high water level and seismic. In the paper, Longtan high concrete dam was studied as an example, the strain softening characteristic of dam concrete is considered using linear softening curve, and a smear crack model is selected for the dam concrete crack. The seismic fracture response of concrete gravity dams is researched by considering the effects of dam-reservoir interaction for different case. Two dimensional seismic numeric analysis was performed by using Koyna earthquake acceleration-time records in 1976 Dam concrete cracking range and cracking law under different water level and seismic time was discussed, the over load method was also used in the paper. From research the positions which easy to generate cracks are pointed out. The research result can provide useful reference for dam structure design and safety operation.