不同加载条件下泡沫轻质土力学特性试验研究

Experimental Study on Mechanical Properties of Foamed Lightweight Soil under Different Loading

通过对湿重度分别为5.5 kN/m^(3)和6.0 kN/m^(3)的泡沫轻质土进行不同约束边界的无侧限抗压强度试验及三轴剪切试验,研究了泡沫轻质土在不同加载方式、加载边界条件下的强度力学特性。试验结果表明:在不同摩擦边界条件下,泡沫轻质土无侧限抗压强度试验其应力-应变曲线均出现软化特性,在无摩擦条件下,由于接触面与试样间的套箍约束作用较弱,其无侧限抗压强度极限值降低,峰值强度对应的应变减小;湿重度为6.0 k N/m^(3)的泡沫轻质土比湿重度为5.5 kN/m^(3)的泡沫轻质土配合比中增加约9.4%的水泥掺量,而强度增加约42%,水泥掺量和气泡群量的改变会对泡沫轻质土强度有显著影响。

Under different loading constraints,the various unconfined compressive strength test and triaxial shear test are carried out on the foamed lightweight soil with the wet weight of 5.5 kN/m^(3) and 6.0 k N/m^(3) respectively.The strength and mechanical properties are investigated under different loading methods and loading boundary conditions.The test results show that both the stress-strain curves of lightweight foam soil under different friction boundary conditions show softening characteristics.Under the frictionless condition,the unconfined compressive strength decreased and the strain corresponding to the peak strength decreased as well due to the weak constraint between the loading plate and the soil sample;For the lightweight foam soil with bulk density of 6.0 kN/m^(3),the cement content increased by 9.4%than that of 5.5 kN/m^(3),and the strength increased by 42%.The change of cement content and bubble group has significant influence on strength of the foamed lightweight soil.