高坝泄洪诱发场地振动响应分析及传播规律

为研究高坝泄洪诱发场地振动的问题,提出一种基于黏弹性人工边界的有限元数值模拟和水力学模型试验相结合的方法计算场地振动响应。以国内某工程为例,计算不同工况下场地振动响应,分析泄洪量和泄洪调度方式对场地振动的影响,揭示不同岩体条件下振动波的传播规律。结果表明:该工程各种泄洪方式都不会对周边居民的生活造成影响;泄洪量越大,下游场地振动响应越大,当3个溢洪洞泄洪条件一致时,采用2号洞泄洪最不利;同等泄洪条件下,采用4洞均分泄洪的振动响应小于按设计开度泄洪的振动响应;模型范围内放大振动波的主因是断层左右岩体性质的差异,断层的存在进一步加大了放大效应。

Response analysis and propagation law of site vibration induced by high dam flood discharge

In order to study the problem of site vibration induced by flood discharge of high dams, a method combining finite element numerical simulation and hydraulic model test is proposed to calculate the site vibration response. Taking a domestic project as an example, the vibration response of the concerned area under different working conditions was calculated. The influence of flood discharge and flood discharge scheduling mode on the site vibration was analyzed, and the propagation law of vibration wave under different rock conditions was revealed. The results show that the life of the surrounding residents cannot be affected by any kinds of flood discharge methods of the project. The larger the discharge, the greater the vibryation response of the downstream site can be. When the flood discharge conditions of the three spillway tunnels are the same, the No. 2 tunnel discharge is the most unfavorable. Under the same flood discharge conditions, the vibration response of the four tunnels is less than that of the designed opening. The main reason for amplifying the vibration wave in the model range is the difference nature of the rock mass around the fault, the existence of faults further increases the amplification effect.