高含水率吹填淤泥固化土强度特性及预测模型

高淤泥初始含水率以及低固化剂掺量是吹填造陆工程和疏浚淤泥资源化利用工程的常见特点,形成的固化土含水率和强度与其关系密切。本文通过室内试验,探讨了吹填淤泥固化土含水率和强度与养护龄期、固化剂掺量、淤泥初始含水率之间的关系,并尝试选择合适的参数,建立固化土无侧限抗压强度预测模型。研究表明,各龄期的固化土含水率随固化剂掺量增加而呈现规律性减小,基本呈线性关系,尽管淤泥初始含水率不同,但固化土的含水率下降差异较小;当淤泥初始含水率较低时,固化土强度与固化剂掺量的线性拟合关系较为明显,但当初始含水率较高时,线性关系则不明显;固化土强度并非随着w₀/w_L呈线性下降,初始含水率大于一定的值后,各龄期的固化土强度下降幅度均减小;用水灰比w/A_w表征各龄期的淤泥固化土无侧限抗压强度具有较高的相关系数,而考虑龄期和固化剂掺量共同影响的综合参数EAT也能够用于建立高含水率淤泥固化土的强度预测模型,可为高含水率淤泥固化处理提供应用指导。

Strength Properties and Prediction Models of Solidified Dredger Filled Mud with High Water-content

High water-content and low solidified material content are main characteristics of foundation treatment works for land reclamation of dredger filled mud, and water content and unconfined compressive strength of the produced solidified soil are closely related to the two characteristics. In the paper, a series of laboratory tests were performed to investigate relationships between water content, unconfined compressive strength of the solidified soil and curing time, solidified material content, and initial water content of mud, and to propose strength prediction model with the appropriate parameters. The research results show that water content of the solidified soil at different curing time decreases regularly with the increase of solidified material content. The approximation is linear, but when the initial water content of mud is different, there is little difference in the decrease of water content of the solidified soil. When the initial water content of mud is low, the linear fitting relationships between strength of the solidified soil and solidified material content are obvious. However, when the initial water content continues to increase, the overall linear relationships are not obvious. The strength of the solidified soil does not decrease linearly with w₀/w_L, when the initial water content is higher than a certain value, the decrease of strength decreases in all curing times. The unconfined compressive strength of the solidified soil at different curing times characterized by w/A_w has a high correlation coefficient, and the comprehensive parameter EAT considering curing time and solidified material content can also be used to establish the strength prediction model. The research results can provide guidance for solidification treatment of sludge with high water content.