中厚覆盖层上中低面板堆石坝应力变形分析

在中厚覆盖层上修建中低面板堆石坝目前较为普遍,其应力变形特性与深厚覆盖层上修建的高面板坝有较大差异,因此有必要进行研究。利用目前应用较为广泛的邓肯-张E-B模型,采用二维有限元分析法针对位于宽河谷中的双溪口面板堆石坝竣工期及蓄水期的堆石体及面板的应力变形特性进行研究。结果表明:相比竣工期,蓄水期坝体沉降、向下游的水平位移、大坝大小主应力、应力水平及面板挠度均有所增加,其中以面板挠度及大坝水平位移增加最为明显,挠度增加了16.61 cm,水平位移增加约1倍,沉降增加幅度约为8%,大、小主应力增加10%~20%,应力水平增加约50%。大坝在竣工期及蓄水期的应力及变形均在允许范围内,大坝运行正常。

Finite element analysis of stress and deformation characteristics of low-faced rockfill dam on mid-thick overburden

It is necessary to make studies of the stress and deformation properties of the low-faced rockfill dam on mid-thick overburden with difference from high dam on deep overburden. Based on Duncan-Chang E-B model， the 2D finite element method is applied to analyze the stress and deformation characteristics of Shuangxikou concrete face rockfill dam during construction period and impoundment period. The analysis results show that compared with completion period， the settlement of dam body， horizontal displacement， principal stress， stress level and slab deflection during the impoundment period increased. The slab deflection and horizontal displacement of the dam increased most significantly， of which the deflection increased by 16.61 cm， the largest increment in the horizontal displacement up to about 1 times， the vertical displacement increased by about 8%， the major and minor principal stress increased by 10% to 20%， and the stress level increased by approximately 50%. The stress and deformation of the dam are all within the allowable range， and operation of the dam is in a normal condition.