不同含水率膨胀土的无侧限抗压强度-电阻率试验研究

Unconfined compressive strength and resistivity test of expansive soil with different water content

文章通过对不同含水率的合肥膨胀土无侧限抗压强度-电阻率试验,获取了不同含水率条件下合肥膨胀土的应力-应变-电阻率全过程变化曲线;分析了含水率对膨胀土强度的影响、膨胀土受压过程中应力-应变-电阻率的变化规律;探讨了膨胀土受压过程中导致电阻率变化的3种效应——压密效应、水连通效应和结构破坏效应,试验中不同含水率膨胀土试样电阻率的不同变化是3种效应的叠加和综合反映;探讨了不同含水率条件下,膨胀土初始电阻率、破坏电阻率与无侧限抗压强度之间的关系。研究结果有助于探索利用电阻率法评价膨胀土的强度特性,建立土体地球物理参数与强度特性之间的关系。

Through the unconfined compressive strength and resistivity test of expansive soil in Hefei with different water content, the whole change curves of stress-strain and resistivity of Hefei expan- sive soil under different water content conditions are obtained. The influence of water content on ex- pansive soil strength and the change rule of stress-strain and resistivity in the process of expansive soil compression are analyzed. Three effects that arouse the change of resistivity in the process of expan- sive soil compression are discussed, including compaction effect, water connection effect and structur- al damage effect. The different changes of resistivity of expansive soil samples with different water content are the superposition and comprehensive reflection of these three effects. Meanwhile, the rela- tionship between the initial resistivity, damage resistivity and the unconfined compressive strength of expansive soil under different water content conditions is discussed. The research results are helpful to explore the strength of expansive soil by using the electrical resistivity method, and establish the rela- tionship between soil body＇s geophysical parameters and strength characteristics.