STATISTICAL EVALUATION FOR STRENGTH OF PILE BY DEEP MIXING METHOD

摘要

This paper presents a statistical method to evaluate the strength of heterogeneous stabilized pile by deep mixing method using cement as an additive reagent. The cross-section of stabilized shaft is conceptually divided into small elements in order to examine the characteristics of its heterogeneity due to imperfect mixing. The properties of each element are treated as independently identical. Typically, the unconfined compressive strength of cemented clay is regarded as a random variable of which the probability density distribution is assumed as log-normal. Based on probabilistic and statistic theory, another random variable, denoted as the factor of mixing uniformity, is proposed to quantitatively assess the influences of mixing quality on the strength of pile shaft. The probability density function of this factor is studied, and its applications in conventional design and Reliability-Based Design (RBD) method are analyzed as well.