阿尔塔什水利枢纽水垫塘边坡稳定性试验研究及数值模拟

Experimental study and numerical simulation on slope stability of cushion pool for Altash Water Control Project

通过阿尔塔什水利枢纽水工模型试验,分析了其水垫塘护坡在6种工况下的脉动压力、上举力的分布规律。结果发现,护坡受水垫塘横向涡旋影响,使脉动压力作用范围较广,1#表孔、2#表孔、中孔全开泄洪时,随着上游水位的升高,脉压峰值向下游偏移,且峰值逐渐增大,校核水位时脉动压力达到最大;随上游水位的升高,最大上举力总体呈增大趋势,单位面积最大上举力峰值为5.36×9.8 kPa,位于右岸X/L(各测点相对于护坡长度的位置)为0.63位置,且各工况下脉动上举力最大值均出现在X/L为0.63位置。水垫塘边坡衬砌在动水压力作用下存在上浮和倾覆两种主要的破坏形式,通过模型试验与数值模拟结合的方式对两种破坏形式进行分析研究,结果显示,边坡衬砌满足安全要求,不会发生上浮和倾覆破坏。通过模型试验计算分析水垫塘检修工况下的边坡稳定性,结果表明衬砌满足安全要求,不会发生失稳破坏。

Through the hydraulic model experiment made on Altash Water Control Project,the distribution laws of the fluctuatingpressure and uplift force on the slope protection of its cushion pool under six operation conditions are analyzed. The result findsout that the slope protection is impacted by the transverse vortex in the cushion pool,which makes impacting range of the fluctuat-ing pressure more wide. When No.1 surface outlet,No. 2 surface outlet and the mid-level outlet are fully opened for flood dis-charge,the peak value of the fluctuating pressure deviates to the downstream along with the rise of the upstream water level;moreover,the peak value is continuously increased and the fluctuating pressure reaches the maximum at the check water level.Following with the rise of the upstream water level,the maximum uplift force presents an increasing trend generally and the maxi-mum uplift force per unit area is 5.36×9.8 kPa,which occurs at the position of X/L(the relative positions of all the measuringpoints to the length of the slope protection) = 0.63. All the fluctuating uplift forces under all the operation conditions occur at theposition of X/L = 0.63. Under the hydrodynamic effect,two main failure modes,i.e. uplifting and overturning,are there for thelining of the slope protection of the cushion pool. Both the failure modes are analyzed and studied through model experiment combined with numerical simulation,from which the result shows that the slope lining can meet the relevant safety requirement,andthen no uplifting and overturning failures are to happen therein. Furthermore,through model experiment the slope stability underthe maintenance condition of the cushion pool is analyzed and calculated,and then the result indicates that the lining can meetthe relevant safety requirement,thus no instability failure is to occur as well.