考虑时变效应的面板堆石坝三维湿化变形研究

THREE-DIMENSIONAL WETTING DEFORMATION FOR CONCRETE FACED ROCKFILL DAM CONSIDERING TIME-EFFECT

针对堆石料浸水后的湿化变形并不是瞬时产生,而是一个渐进发展过程这一现象,建议将湿化变形进行时变计算.首先采用Prandtl--Reuss流动法则推导了湿化剪切应变分量,然后叠加湿化体积应变分量,获得三维湿化应变分量;通过分析三维湿化应变分量和单轴应力状态下的湿化应变的关系,指出有关文献推导的三维湿化应变分量计算公式不严谨;然后类比于堆石料流变变形计算公式,推导了湿化变形时变计算公式.实例分析表明,湿化引起坝顶沉降随时间逐渐增大,变形稳定的时间与湿化变形速率呈反比关系.

Since the wetting deformation of the rockfill material after soaking is not generated instantaneously but rather in a gradual development process, the time-effect analysis for the wetting deformation is proposed in this paper. The formula for the wetting shear strain component of the rockfill material is derived based on the Prandtl-Reuss flow rule. Then the three-dimensional wetting strain component is obtained by superposition of the wetting volumetric strain component. The relationship between the three-dimensional wetting strain component and the wetting strain component in the uniaxial state is analyzed. It is pointed out that the computational formula of the three-dimensional wetting strain component in literature is not rigorous. In analogy with the formula of the three-dimensional rheological deformation of the rockfill material, the time-effect computational formula of the wetting deformation is derived. Example analysis shows that the settlement of the dam crest produced by the wetting deformation increases with time, and the time for the steady deformation is inversely proportional with the rate of the wetting deformation.