水泥土材料的细观损伤机理

Meso-scale damage mechanism of cement soil

为了研究水泥土的细观损伤机理,在中国科学院武汉岩土力学研究所岩土力学重点实验室进行了一系列水泥土细观力学试验.基于细观力学实验结果,分析了实验进行过程中水泥土细观实时图像的表面变化以及水泥土应力-应变关系曲线的突变特征,探讨了水泥土的细观损伤破裂机理.结果表明:水泥土材料的结构组成具有不均匀性,且有初始损伤存在.在荷载作用下,材料的破坏是由其内部细观尺度的损伤演变并发展的,最终汇聚成宏观裂纹,宏观裂纹进一步扩展导致材料强度丧失、结构破坏.用细观力学和损伤力学基本原理来分析水泥土的承载性状及在第一承载阶段的损伤演变情况,可评定材料的承载能力及其工程结构的可靠性.

In order to study the meso-scale damage mechanism of cement soil,a series of meso-scale mechanical experiments for cement soil were performed at Key Laboratory of Rock and Soil Mechanics affiliated to Wuhan Institute of Rock and Soil Mechanics of Chinese Academy of Sciences.Based on the results of meso-scale mechanical experiments,the surface change of meso-scale real-time images for cement soil in the experimental process and the mutation characteristics of stress-strain curve for cement soil were analyzed.In addition,the meso-scale damage fracture mechanism of cement soil was investigated.The results show that the structural constituent of cement soil is inhomogeneous and has the initial damage.Under the loading condition,the damage process of material initiates from the evolution and development of internal meso-scale damage,and the meso-scale damage finally converges to form macroscopic cracks.The further propagation of macroscopic cracks will lead to the strength loss of material and the failure of structure.Obviously,the basic principles of meso-scale mechanics and damage mechanics can be used to analyze the load bearing performance of cement soil as well as the damage evolution at the first load bearing stage,and thus,the load bearing capacity of materials and the reliability of engineering structures can be evaluated.