碾压混凝土坝层内力学参数渐变分析模型

由于碾压混凝土的施工过程和压实机理，激振力和振动加速度等参数沿层深呈指数衰减分布。在此影响下，碾压混凝土的抗压强度、密度等参数同样沿层深逐渐衰减。针对碾压层内力学参数的渐变特性，将碾压层分解成多层结构，用分解刚度法及串、并联模型建立了综合等效参数与层内渐变力学参数之间的转换关系，导出了积分型和离散型两种计算公式。这种渐变模型下的层面特性由碾压层内参数渐变特性及上、下表面参数的差异来描述。对弹性模量、瞬时弹性模量、延迟弹性模量、黏性系数以及渗透系数等力学参数给出了具体的等效变换公式及求解方法，并计算了在不同碾压厚度和不同的各向异性情况下指数分布的具体形态和参数变化规律。

Analytic model for gradual variation of concrete intra layer mechanical parameters in RCCD

Based on the assumption that the reduction of compressive strength and density of concrete along the depth of the rolling layers in RCCD is following the exponential law, the layers are decomposed into multiple layers and the transform relationship between the comprehensive equivalent parameters and gradually varying mechanical parameters is established by using stiffness partition method and serieswound and shunt-wound model. The corresponding integral formula and discrete formula are deduced. The characteristics of rolling layers can be described by the variation of parameters within the layer and the difference of parameters between the upper surface and bottom surface. On this basis, formula for calculating the elastic modulus, instantaneous elastic modulus, delayed elastic modulus, viscosity coefficient and permeability coefficient are deduced. The distribution patterns and variation law of the parameters for various roiling layer thicknesses under the condition of anisotropic are also investigated.