黏土颗粒间液桥从形成至断裂时毛细力的演化规律

通过土颗粒间形如液桥的水分毛细力认识和解释非饱和土的持水特性日趋为土力学界所关注。为研究黏土颗粒间液桥毛细力的演化规律，将黏土颗粒其简化为一对平行的片状颗粒，不考虑黏土颗粒表面的粗糙度。以Young-Laplace方程为基础，推得表征黏土颗粒间液桥毛细力关于固-液接触角和液桥体积的无量纲表达式；再令该无量纲表达式为0，绘制出固-液接触角与无量纲液桥体积的关系曲线，将1/3＜vLB＜1范围划分为液桥的断裂区、形成区和消失区，这种分区方法对描述黏土样在毛细阶段和吸附阶段的持水特性至关重要。最后，分析了液桥形成时毛细力与液桥体积和固-液接触角的关系，结果表明：当固-液接触角一定时，液桥的毛细力随其体积增大呈递增趋势，而当液桥体积一定时，其毛细力随固-液接触角增大呈先增后减的趋势。

Evolution of capillary force of liquid bridge between clay particles in process from its formation to rupture

Investigation on the capillary force of water in the form of liquid bridge between soil particles is increasingly concerned by soil mechanics researchers. To investigate the evolution of capillary force of liquid bridge between clay particles, these particles are simplified as a pair of parallel platy particles, without considering the actual surface roughness of these particles. Based on Young-Laplace equation, the dimensionless expression is derived to describe the evolution of capillary force with liquid bridge volume and solid-liquid contact angle. By making the dimensionless expression zero, a curve is then plotted based on combination of the solid-liquid contact angle and the dimensionless liquid bridge volume, which displays three different regions in the range of 1/3＜vLB＜1 (where vLB is the dimensionless liquid bridge volume), including the regions of rupture, formation, and nonexistence for liquid bridge. This approach plays a significant role in describing the water retention behaviors of clay specimen in the capillary and adsorption stages. The evolution of capillary force with liquid bridge volume and solid-liquid contact angle is finally analyzed in the region of liquid bridge formation. It can be observed that the capillary force is an increasing function of the liquid bridge volume with a fixed solid-liquid contact angle, while it increases first and then decreases as the solid-liquid contact angle increases with a fixed liquid bridge volume.