拱坝有缝坝体-坝基系统的非线性抗震分析

本文将坝体和坝肩裂隙岩体作为允许局部开裂和大变形的非线性连续体，用动态接触单元模型进行概化模拟，对小湾高拱坝坝体-坝基系统在高水位运行期遇设计地震荷载作用时的动力反应进行了非线性数值计算，研究了横缝对坝体应力、变形的影响，并对坝肩裂隙岩体的抗震稳定进行了分析评价，数值分析表明：横缝对拱坝坝体的应力和变形影响显著，坝肩潜在滑面的开裂和滑移导致坝体应力增大，坝体的抗震安全性降低，但在运行期高水位遇设计地震荷载时坝体和坝肩裂隙岩体整体稳定。

Nonlinear seismic analysis of high arch dam-foundation system with contraction joints

A 3-D dynamic contact unit model is developed to analyze the nonlinear seismic response of the dam-foundation system in high arch dam. In the model the effects of contraction joints in dam and fissures in abutment rock mass are taken into account and the system is assumed as a non-linear continuous body admitting the local fracture and large deformation. The model is applied to calculate the influence of transverse joints on stress and deformation of the arch dam in Xiaowan Project. The aseismic stability of the abutment is also analyzed. The result shows that the transverse joints may significantly affect the stress and deformation of the dam, and the potential cracking and sliding of the abutment will reduce the safety of the dam. However, the dam and abutment in Xiaowan Project is stable in the impounding period even the water level of reservoir reaches very high levation.