Dynamic behavior of Haikou marine clay treated with cement

Abstract

The dynamic properties of cement-treated soil are important in evaluating the performance of both cement-treated ground and overlying infrastructure subjected to dynamic loads such as earthquake and traffic-induced impact. In this study, using the marine clays collected from Haikou, China, a series of cyclic triaxial tests were performed to investigate the dynamic behavior of both pure and cement-treated marine clays, with the investigation focus placed on the equivalent shear modulus and damping ratio of cement-treated marine clay. Some important factors, namely confining pressure, loading frequency and cycle, cement content, strain amplitude, and curing period, were systematically taken into consideration. The results suggested that, different from the pure clay, the loading frequency and confining pressure have slightly intensifying and alleviating effects on the equivalent shear modulus and damping ratio of cement-treated clay, respectively; the curing period had a similar influence on the dynamic behavior of cement-treated clay. Among the factors considered, the cement content and strain amplitude were found to be the most influential on the dynamic properties of cement-treated clay, albeit the influencing trends being exactly opposite. Regardless of other factors considered, the equivalent shear modulus and damping ratio were found to attenuate significantly within the first 5–10 loading cycles, beyond which they became relatively unchanged. In addition, multivariate regression analyses were conducted based on the experimental results, and two semi-empirical equations were established for reasonably correlating the equivalent shear modulus and damping ratio with the factors considered in this study, respectively, which can serve to provide first-order predictions of them for similar cement-treated clays.