风化砂改良膨胀土动弹性模量试验研究

Experimental Study on Dynamic Elastic Modulus of Expansive Soil Improved by Weathered Sand

通过一系列动三轴试验,在不同掺砂量v、不同围压下σ3,研究风化砂改良膨胀土动弹性模量及阻尼比的变化规律。试验结果表明:同一围压下,掺砂量v≤15%时,改良土动弹性模量Ed及Ed max随掺砂量增加而减小,当掺砂量v>15%时,Ed及Ed max随掺砂量增加而增大,临界掺砂量为15%,当掺砂量v>25%后,继续增大掺砂量对Ed及Ed max的影响减弱。结果证实,风化砂掺入使改良土的承载能力及抗振性能有所提高,建议风化砂改良膨胀土的最佳掺砂量为25%。

Through a series of dynamictriaxial tests,under different sand content v and different confining pressures σ3,the changes of dynamic elastic modulus and damping ratio of weathered sand improved expansive soil were studied.The test results show that:under the same confining pressure,when the sand content v≤15%,the dynamic elastic modulus Ed and Ed max of the improved soil decrease with the increase of sand content;when the sand content v>15%,Ed and Ed max increase with the increase of sand content,the critical sand content is 15%,when the sand content v>25%,the effect of increasing sand content on Ed and Ed max decreases.The results show that the bearing capacity and anti vibration performance of the improved soil are improved by the addition of weathered sand.It is suggested that the optimal amount of sand to be added is 25%.