冻融循环对风化砂改良膨胀土回弹模量影响研究

Research on the influence of freeze-thaw cycles on resilient modulus of weathered sand improved expansive soil

文章研究了风化砂改良膨胀土的回弹模量值与风化砂掺量、冻融循环次数之间的定性和定量关系。在膨胀土中分别掺入0、10%、20%、30%、40%、50%的风化砂,在经过0、1、3、6、9、12次冻融循环后,在杠杆压力仪上进行回弹模量值测试。试验结果表明:在同一掺砂比例下,风化砂改良膨胀土的回弹模量均随冻融循环次数的增大而减小,且其回弹模量随冻融循环次数增加呈对数形式衰减,到12次冻融循环后,趋向于稳定;在同一冻融循环次数下,风化砂改良膨胀土的回弹模量随掺砂比例的增大先增大后减小,总体呈现下降趋势,当掺砂比例为10%时,其回弹模量最大。

The qualitative and quantitative relationships between the resilient modulus of weathered sand improved expansive soil and the weathered sand content and cycle times of freeze-thaw were researched. 0, 10%, 20%, 30%, 40%, 50% of the weathered sand was added into the expansive soil respectively. The resilient modulus test was done by using the lever pressure instrument after 0, 1, 3, 6, 9, 12 cycles of freezing and thawing. The test results showed that with the increase of cycles of freeze-thaw, the resilient modulus of weathered sand improved expansive soil decreased at the same mixed sand ratio. The resilient modulus logarithmically decayed with the increase of freeze-thaw cycles. When the cycles of freeze-thaw reached 12 times, the resilient modulus tended to be stable. With the increase of the mixed sand ratio, the resilient modulus of weathered sand improved expansive soil first increased and then decreased at the same times of freeze-thaw, showing a downward trend. When the mixed sand ratio reached 10%, the resilient modulus was maximum.