Laboratory study on elastic dynamic mechanics of AAFS-stabilized mucky soils by bender-extender elements method

Abstract Alkali-activated Fly Ash-Slag Geopolymer (AAFS) is a novel green and sustainable cementitious material with broad application prospects in soils stabilization, mucky soils foundation is prone to problems such as uneven settlement of the foundation and structural instability. However, most of the existing studies have focused on the static characteristics of stabilized soils while neglecting the research on its dynamic characteristics. Therefore, studying the variation law of elastic parameters of AAFS-stabilized mucky soils under extremely small strain is of great significance for its practical engineering application. In this study, the combined test of shear wave and compression wave for AAFS-stabilized mucky soils is carried out by bender-extender elements method. The propagation time of shear wave and compression wave is determined by initial arrival wave method and discrete frequency method, separately. Subsequently, the shear modulus( G 0 ), constrained modulus( M 0 ), and Poisson’s ratio( v 0 ) are derived. The effects of curing time, AAFS content, and confining pressure on the elastic parameters of soils are analyzed. The result shows that with the increase of curing time and confining pressure, both the G 0 and M 0 gradually increase, while v 0 gradually decrease. As the increase of AAFS content, the G 0 and M 0 initially increase, while v 0 decreased first and then increase, indicating that higher AAFS content does not necessarily lead to better performance. The sensitivity of the G 0 and M 0 to the three factors ranked from high to low as follows: confining pressure, AAFS content, and curing time. The sensitivity of v 0 to the three factors ranked as curing time, AAFS content, and confining pressure. Finally, the experimental results of this study are compared with those of other geotechnical materials, verifying the reasonableness of the data and the superiority of the performance. The research results provide a theoretical reference for the engineering application of AAFS-stabilized mucky soils.