Abstract

This paper studied the strength growth characteristics of Tianjin Binhai dredger fill, considering the impact load, drainage condition, and loading way of the impact. Based on UU and scanning electron microscope tests, the strength growth mechanism of the dredger fill was studied from both macroscopic and microscopic perspectives. The results showed that there an optimal impact load under the combined action of impact load and drainage, which can enhance the strength of the dredger fill to the maximum extent, its value is close to the structural yield stress. Furthermore, the methods of ‘more impact rounds and fewer impact counts’ and ‘first light then heavy’ can obtain the best effect of foundation reinforcement. Microstructural analysis showed that, with the increase in impact loads, the pore complexity and the number of pores increased, while the porosity, the number of soil particles, the pore circumference, and the total pore area decreased. This research also showed that the increase in the strength of dredger fill was mainly reflected by the increase in the internal friction angle under the combined actions of impact load and drainage, while the change of cohesion was rather small. The mathematical relationship between the internal friction angle and the pore characteristic can be expressed by a unary function, which increases with increasing pore complexity.

摘要

本文研究了天津滨海挖泥船填料的强度增长特性，考虑了冲击载荷、排水条件和冲击加载方式。基于UU和扫描电镜测试，从宏观和微观两个角度研究了挖泥船填料的强度增长机制。结果表明，在冲击荷载和排水共同作用下，存在一个最优的冲击荷载，可以最大限度地提高挖泥船填料的强度，其值接近于结构屈服应力。此外，“多冲击次数少冲击”和“先轻后重”的方法可以获得最佳的地基加固效果。微观结构分析表明，随着冲击载荷的增加，孔隙复杂性和孔隙数量增加，孔隙度、土壤颗粒数、孔隙周长和总孔隙面积减小。本研究还表明，挖泥船填料强度的增加主要体现在冲击载荷和排水共同作用下内摩擦角的增加，而内聚力的变化较小。内摩擦角与孔隙特征之间的数学关系可以用一元函数表示，随着孔隙复杂度的增加而增加。而内聚力的变化很小。内摩擦角与孔隙特征之间的数学关系可以用一元函数表示，随着孔隙复杂度的增加而增加。而内聚力的变化很小。内摩擦角与孔隙特征之间的数学关系可以用一元函数表示，随着孔隙复杂度的增加而增加。