向家坝水电站左岸近坝边坡抬升变形数值模拟

为深入认识向家坝水电站左岸近坝边坡的抬升变形现象,利用流固耦合数值试验研究了岩体的扩容变形机理,在此基础上采用流固耦合数值分析方法对向家坝水电站左岸近坝边坡的抬升变形过程进行了数值模拟,得到了近坝边坡抬升变形的空间分布,并对泄压孔泄压对抬升变形的控制效果进行了评价。结果表明:岩体扩容体积应变随岩体渗透系数增大而增大,随变形模量增大而减小,岩体初始应力对抬升变形的影响微弱;渗流场改变是引起近坝边坡抬升变形的直接诱因,边坡抬升变形是岩土体内渗流场和应力场相互作用的结果,采用流固耦合理论揭示近坝边坡的抬升变形机制是合理的;深层泄压孔可以有效控制近坝边坡的抬升变形量。

Numerical simulation of uplift deformation of left bank slope near dam of Xiangjiaba Hydropower Station

To further understand the uplift deformation phenomenon that occurs at the left bank slope near the dam of Xiangjiaba Hydropower Station, hydro-mechanical coupling numerical tests were used to study the mechanism of rock mass expansion and deformation. Based on the hydro-mechanical coupling analysis, the uplift deformation process was simulated. The spatial distribution of the deformation was obtained and the control effect of the pressure relief holes on the uplift deformation was evaluated. The results indicate that the volume expansion strain of the rock mass increases with the permeability coefficient and decreases with the increase of deformation modulus. The initial stress has little effect on uplift deformation. Variation of the seepage field is the direct cause of uplift deformation and the uplift deformation is also the result of the interaction between seepage field and stress field. It is reasonable to use hydro-mechanical coupling theory to reveal the uplift deformation mechanism. Deep drainage holes for pressure relieving are effective for the controlling of the uplift deformation.