某电厂贮灰坝失稳过程及破坏机制研究

Study of instability process and failure mechanism of ash storage dam in a power plant

运用非饱和土土力学理论分析了某电厂贮灰坝失稳过程,揭示了该贮灰坝的失稳和破坏机制。分析表明,随着子坝挡水历时的增加,积水不断下渗,浸润线逐渐抬高,非饱和区域相应减少,坝体中受此影响的部位的孔隙水压力也随之不断增高,抗剪强度不断降低。此过程发展到一定程度,则导致贮灰坝产生破坏和滑动。上述分析清楚地诠释了干滩长期消失会使贮灰坝的稳定性遭受巨大威胁的原因。其研究结果可为贮灰坝、尾矿坝在类似工况下的稳定性评价和预测预报提供借鉴。

Based on unsaturated soil mechanics theory, the instability process of ash storage dam in a power plant is analyzed and failure mechanism of that is revealed. With the increase of lasting time of retaining water by the 1^st sub dam, some phenomena will occur, such as water infiltrates into the dam body gradually, the phreatic surface rises constantly, the unsaturated region reduces corresponsively, the pore water pressure increases and the shear strength decreases continuously in the site which is influenced by water infiltration. When the process develops to a certain degree, the damage and slide of this ash storage will happen. The analysis in this paper explains clearly the reason why the stability of this ash storage dam suffers great threat if the dry beach disappears for a long period. This study may provide a reference for stability evaluation and forecast of those ash storage dams and tailings dams with the similar working condition.