坝体混凝土碳化影响下的拱坝工作性态研究

Research on the operational behavior of arch dams body under the influence of concrete carbonation

为研究坝体混凝土碳化作用下的拱坝工作性态,以某抽水蓄能电站下水库拱坝为例建立了三维有限元分析模型,并结合弹塑性理论、等效应力与强度折减法分析了碳化前后温升与温降工况下的拱坝应力与安全稳定性变化情况。结果表明,混凝土碳化对温降工况下坝体拉应力和压应力的影响程度均要大于温升工况,拉应力对碳化影响较为敏感,温降工况下拉应力增大约4.23%;碳化作用对温升工况下的拱坝-坝肩整体稳定性大于温降工况,温升工况下碳化后的安全系数约降低了2.41%。研究结果可为同类工程的安全运行提供参考。

To study the operational behavior of arch dams under the concrete carbonization action,a three-dimensional finite element analysis model was established based on a lower reservoir arch dam of a pumped storage power station.Combined with elastoplastic theory,equivalent stress and strength reduction method,the arch dam stress and safety stability under temperature rise and temperature drop conditions were analyzed before and after carbonization.The results showed that the influence of concrete carbonization on tensile and compressive stress of dam body under temperature drop condition was greater than that under temperature rise condition.The tensile stress was more sensitive to concrete carbonization,and it increased by about 4.23%under the temperature drop condition.Meanwhile,the influence of concrete carbonization on the overall stability of the arch dam-rock shoulder under temperature rise condition was greater than that under temperature drop condition,and the safety factor under the condition of temperature rise decreased by about 2.41%after carbonation.The research results can provide reference for the safe operation of similar projects.