掺入粉煤灰软黏土的复合碱渣土力学特性探究

Mechanical Properties of Composite Soda Residue Soil Mixed with Fly Ash and Soft Clay

为探究承载性能优良且经济适用的碱渣地基土方案,设计了24种掺入粉煤灰和软黏土的复合碱渣土,并且综合无侧限抗压强度与经济指标,通过模糊评价法确定了复合碱渣土的最优配合比,同时对其进行了劈裂抗拉试验、静力三轴试验和蠕变试验.结果表明:软黏土、粉煤灰均对碱渣有明显加固作用,软黏土的加入可减少粉煤灰的用量,具备较好的经济适用性;复合碱渣土的劈裂抗拉强度与其无侧限抗压强度之比为0.15;固结围压对复合碱渣土不排水强度的影响最大,超固结比次之,固结比最小;当上部荷载未达到长期强度时,复合碱渣土的蠕变特征较为稳定且数值极小.

To explore the economically suitable soda residue foundation soil with excellent bearing performance, 24 kinds of composite soda residue soil mixed with fly ash and soft clay were designed. Taking both unconfined compressive strength and economic factor into consideration, the optimal proportion was determined through fuzzy evaluation method. Splitting tensile test, static triaxial test and creep test were carried out for composite soda residue soil with optimal proportion. The results show that both soft clay and fly ash have obvious reinforcement effect on alkali slag. Addition of soft clay can reduce the amount of fly ash and has good economical applicability. The ratio of splitting tensile strength of composite soda residue soil to its unconfined compressive strength is 0.15. The consolidation confining pressure has the greatest influence on the undrained strength of the composite soda residue soil, followed by the over-consolidation ratio and the consolidation ratio is the least. When the upper load does not reach the long-term strength, the creep characteristics are relatively stable and the value is extremely small.