针对大规模的水利水电项目通常需要大量的土地用于建设水库、水电站等基础设施,导致了大量的工程弃土产生问题,本文利用开挖弃土制备土基可控性低强度材料,采用数字图像相关技术(DIC)和声发射技术(AE)监测试件破坏特征以及损伤演化机制,通过压汞法(MIP)和扫描电镜(SEM)观察试件内部孔隙分布特征。结果表明,试件受压破坏后呈现完全破碎形态,裂缝在贯穿试件的过程中沿着最初发展方向持续发展,荷载到达峰值后裂缝发展主要以延伸为主直至破坏,试件内部拉伸破坏和剪切破坏并无明显区别。试件内部孔隙率较高,孔隙较大,整体粘结性较低,部分孔隙有水化产物充填,在加载过程中起连结作用。本研究为科学调控弃土基可控性低强度材料力学性能提供参考。

For large-scale water conservancy and hydropower projects usually need a large amount of land for the construction of reservoirs, hydropower stations and other infrastructure, leading to a large number of engineering soil abandonment problems. In this paper, the controllable low-strength materials based on soil were prepared by using the engineering excavation residue. The failure characteristics and damage evolution mechanism of the specimens were monitored by using digital image correlation (DIC) and acoustic emission (AE) technology. The distribution characteristics of pore space in the specimens were observed by mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). The results show that the specimen is completely broken after compression failure, and the crack continues to develop along the initial development direction in the process of penetrating the specimen. After the load reaches the peak value, the crack development mainly extends to failure, and there is no obvious difference between tensile failure and shear failure in the specimen. The internal porosity of the specimen is high, the pores are large, and the overall cohesion is low. Some pores are filled with hydration products, which play a connecting role in the loading process. This study provides a reference for scientific control of mechanical properties of slag soil based controllable low strength materials.

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国家自然科学基金项目（面上项目，重点项目，重大项目）