含水量对加筋膨胀土强度与变形特性的影响

Effect of Water Content on Strength and Deformation Characteristics of Reinforced Expansive Soils

对双向格栅加筋膨胀土进行不同含水量下的无侧限压缩和固结不排水剪试验,研究了含水量对加筋膨胀土强度与变形特性的影响。无侧限试验表明,含水量显著影响加筋膨胀土的破坏模式,随含水量增大,加筋对应力应变曲线的影响减小,加筋后峰值强度和残余强度的变化减小,其分别对应应变的变化量减小。固结不排水剪试验表明,含水量对未加筋与加筋膨胀土的破坏模式并无影响,其应力应变曲线均呈应变硬化型,随含水量增大,加筋土的峰值强度急剧减小,加筋后峰值强度提高的数值减小,而含水量对初始屈服应力的影响与加筋层数有关。

Expansive soil samples reinforced with a biaxial geogrid are adopted to carry out a series of unconfined compression, consolidated and undrain tests at different water content. Effects of water content on the strength and deformation characteristics of reinforced expansive soils are studied. Water content has significant effect on the failure model of reinforced expansive soils; With increasing water content, the effect of reinforce on the stress-strain curves decreases, and the change of peak strength and residual strength decrease. Water content has little effect on the failure mode, in which all the stress-strain curves show strain-hardening; With increasing water content, both the peak strength, and increment after reinforcement decrease sharply. The effect of water content on the initial yield stress is related to the layers of reinforce.