Influence of construction interfaces on dynamic characteristics of roller compacted concrete dams

GU Chong-shi(顾冲时)^{1, 2, 3}, WANG Shao-wei(王少伟)^{1, 2, 3}, BAO Teng-fei(包腾飞)^{1, 2, 3}

(1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,
Hohai University, Nanjing 210098, China;
2. National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety,
Hohai University, Nanjing 210098, China;
3. College of Water-conservancy and Hydropower, Hohai University, Nanjing 210098, China)

Abstract:To study the influence of construction interfaces on dynamic characteristics of roller compacted concrete dams (RCCDs), mechanical properties of construction interfaces are firstly analyzed. Then, the viscous-spring artificial boundary (VSAB) is adopted to simulate the radiation damping of their infinite foundations, and based on the Marc software, a simplified seismic motion input method is presented by the equivalent nodal loads. Finally, based on the practical engineering of a RCC gravity dam, effects of radiation damping and construction interfaces on the dynamic characteristics of dams are investigated in detail. Analysis results show that dynamic response of the RCC gravity dam significantly reduces about 25% when the radiation damping of infinite foundation is considered. Hot interfaces and the normal cold interfaces have little influence on the dynamic response of the RCC gravity dam. However, nonlinear fracture along the cold interfaces at the dam heel will occur under the designed earthquake if the cold interfaces are combined poorly. Therefore, to avoid the fractures along the construction interfaces under the potential super earthquakes, combination quality of the RCC layers should be significantly ensured.

Key words:roller compacted concrete dam; construction interface; nonlinear fracture; radiation damping; viscous-spring artificial boundary; dynamic response