高山峡谷场地P-SV波散射放大效应及地震动场模拟方法

我国西部山区规划建设的桥梁、隧道和大坝等重大工程面临高风险强震灾害威胁，保障其抗震安全是我国经济社会平稳发展的重大需求。山区是地震高烈度区工程震害最严重的区域之一，高山峡谷地形地震放大效应是其重要原因。亟需解决传统工程抗震分析与设计非一致地震动输入难以考虑高山峡谷地形效应的问题。本项目针对制约地震P-SV波传播理论发展的半无限水平地表应力自由条件难以满足的瓶颈难题，建立高山峡谷场地P-SV波传播粘弹性解析模型，实现考虑场地/地基材料非线性的地震波传播等效线性化方法。开展大型振动台试验、并结合现有地震密集台阵监测数据检验理论方法。探明场地地震动地形放大效应机理，提出适用于高山峡谷场地地震动场的计算方法，实现复杂地形条件下工程非一致地震动场的合理、高效模拟。将进一步发展地震波传播理论、丰富地震动场模拟方法，为西部山区重大工程抗震设计提供必要的科学依据。

Major projects such as bridges, tunnels and dams planned and constructed in western mountainous areas of China are facing the threat of high-risk strong earthquake disasters. To ensure their seismic safety is an important requirement for the steady development of China's economy and society. Mountain area is one of the areas with the most serious engineering earthquake damage in high seismic intensity area, and the seismic amplification effect of mountain-canyon topography is an important reason. It is urgent to solve the problem that it is difficult to consider the topographic effect of high mountains and canyons in the traditional engineering seismic analysis and design. Aiming at the bottleneck problem that restricts the development of P-SV wave propagation theory, this project is prepared to establish viscoelastic analytical models for mountain-canyon sites and realize equivalent linearization method of seismic wave propagation considering the nonlinearity of site/subgrade material. The applicant will carry out large-scale shaking table tests and take advantage of the existing monitoring data from seismic dense array to verify the theoretical method. The mechanism of the amplification effect of the ground motion by the mountain/canyon will be explored. The calculation method of the amplified ground motion field in the mountain-canyon site will be proposed to achieve a reasonable and efficient simulation of engineering non-uniform seismic field under such kind of complex topographic conditions. This project will further develop the theory of seismic wave propagation, enrich the method of seismic field simulation, and provide the necessary scientific basis for seismic design of major projects in mountain canyon areas.