注浆压力动载荷作用下盖重非线性响应简化分析

Simplified Analysis of Concrete Covering Dynamic Response under Grouting Pressure Fluctuating Load

为解决大坝混凝土盖重在注浆压力动载作用下产生抬动效应导致盖重破坏,从而影响大坝防渗等工程实际问题,建立了一种混凝土盖重在固结注浆压力动载荷作用下的非线性动力学响应简化分析模型.考虑到盖重下方基层在注浆压力动载荷作用下具有非线性、滞后性、变形累计、强度和刚度退化等特性,采用了Bouc-Wen退化迟滞模型,并对盖重下方土层与岩层分别采用了不同的刚度系数与阻尼系数,分析了混凝土盖重在注浆压力动载影响下非线性动态力学响应的滞后效应,得到了不同外载荷频率作用下,盖重抬动位移与变形速度的非线性响应曲线.实例分析结果表明,该模型可以较好地模拟各种工况下盖重注浆的非线性动力学响应问题,为动载作用下的盖重注浆抬动位移控制提供了一种参考方法.

In order to address the dam concrete covering uplift effect caused by the dynamic load of grouting pressure,in which the dam concrete covering will damage the anti-seepage properties of the dam, a simplified model was developed for the hysteretic nonlinear dynamic response analysis of concrete cover-ing under consolidation grouting pressure fluctuating load.The nonlinearity,hysteresis,accumulated de-formation and stiffness degeneration characteristics of concrete covering under grouting pressure fluctua-ting load were considered.Then,the Bouc-Wen degradation hysteresis model was adopted to analyze the hysteretic effect of nonlinear dynamic response of concrete covering by considering the soil and rock stra-tum under the concrete covering with different stiffness and damping coefficients.According to the actual grouting parameters,the result shows that the predictions of the model are in very good agreement with values measured from experiments.