土工袋单元体循环剪切特性试验

Experimental study on cyclic shear characteristics of single soilbag

采用室内大型剪切系统通过变剪切应变幅值条件下土工袋单元体系列循环剪切试验,研究了土工袋单元体的袋内材料填充率、竖向应力、剪切应变幅值等因素对其动力特性的影响。结果表明:在竖向应力为80 kPa时,袋内材料填充率越大土工袋减振效果越好,综合考虑施工效率等因素,建议采用90%作为土工袋单元体的最优填充率;竖向应力越大土工袋单元体的动剪切模量越大,水平剪切变形越大土工袋单元体的阻尼比越大;扰动较小时土工袋具有保持自身稳定的能力,扰动足够大时土工袋利用自身柔性提升阻尼,大量耗散振动能量。

The effects of material filling rate,vertical stress,amplitude of shear strain and other factors on the dynamic characteristics of single soilbag were studied by the cyclic shear test of single soilbag under the condition of variable shear strain amplitude using a large indoor shear system.The results showed that when the vertical stress is 80 kPa,the greater the material filling rate,the better the damping effect of the single soilbag.Considering the construction efficiency and other factors,it is suggested that 90%should be used as the optimal filling ratio of the single soilbag.When the vertical stress is greater,the dynamic shear modulus of the single soilbag is large and the greater the horizontal shear displacement amplitudes,the greater the damping ratio of the single soilbag.In other word,when the disturbance is small,the single soilbag has the ability to maintain its own stability,while the disturbance is large enough,the single soilbag uses its own flexibility to lift the damping and dissipates a large amount of vibration energy.