孔隙分布对垫层料冻融强度影响的试验研究

为了研究寒冷环境下垫层料冻融强度机制与规律,利用直接剪切仪对不同孔隙尺寸和不同孔隙数量垫层料冻胀融沉后的试样进行了直接剪切试验,试验结果表明:垫层料强度指标随孔隙尺寸和孔隙数量变化而变化。冻融循环后的摩擦角与等效孔隙数量成线性关系,且线性回归斜率随等效孔隙尺寸的增大而增大;冻融循环后的粘聚力与等效孔隙数量也成线性关系,且线性回归斜率随等效孔隙尺寸的增大而减小。发现存在一个级配范围,可在该范围内调整不同粒径含量,使垫层料冻融后强度基本不变同时渗透性可控。

The influence of pore size distribution on cushion material strength after freezing-thawing cycle

To study the mechanisms of strength of cushion material after freeze-thaw cycles in cold environment, a series of cushion material samples with different gradation after one freeze-thaw cycle have been tested on direct shear apparatus, test results show that: the cushion material strength indicators number vary with the pore size and the pore quantity. The relationship of friction angle and equivalent pore quantity is linear, and the slope of the regression linear increases with increasing of equivalent pore size; the relationship of cohesion and equivalent pore quantity is also linear and the slope of the regression linear decreases with increasing of equivalent pore size. It has been found that the strength of cushion material after thawing is not altered and the permeability can be adjusted by changing particle content under a gradation range.