软土结构性定量化参数研究

土结构性研究的根本任务是寻找能全面反映土在应力作用下结构破损规律的定量化指标。对黄石、漳州、青岛地区软土进行单向与等向压缩试验,分析结构性土的压缩特性,探讨了不同试验条件对软土结构性的影响,结果表明:当压力低于结构屈服压力时,主要是初始结构的自我调整过程,结构存在少量的破损,压缩性较小;当压力大于结构屈服压力时,结构大量破坏,除了颗粒间的滑移,还伴随结构的塌陷,压缩性大大增加;重塑样在压缩过程中压缩性变化不大,这是由于重塑样已失去了结构性的影响。根据土样在压缩过程中结构破损情况提出了一个新的判别结构性强弱的定量化参数—结构破损系数,该值可通过AutoCAD软件简单获取,便于推广。利用该方法判别试验土样中结构性最强的为青岛软土,黄石软土次之,漳州软土最弱。最后利用结构破损系数解释了不同扰动程度对压缩曲线的影响。

Quantitative Parametric Analysis of Soft Clay Structure

It is a fundamental task for soil structure study to find a quantitative parameter that reflects structural damage under pressure. Based on the unidirectional compression and isotonic compression tests of soft clays from Huangshi, Zhangzhou and Qingdao, the compression properties of structure soil and the effect of different conditions on the properties were investigated. It is found that when the pressure is lower than structure yield stress, it is mainly the initial structure self alignment procedure and the structure is in few damage and the compressibility is small. When the pressure is bigger than the structure yield pressure, the structure destroys massively and the compressibility increases greatly not only from inter granular slipping but also from the collapse. With the damage properties in compression, a new coefficient was proposed to evaluate the structural behavior. And this parameter can be obtained simply through the software AutoCAD. With the proposed method, it is found that the soft clay in Qingdao is strongest in structural behavior, followed with that in Huangshi and Zhangzhou.