沥青混凝土水力劈裂的细观机理研究  

Study on Meso-mechanism of Hydraulic Fracture of Asphalt Concrete

作　　者：武利强[1] 王良[1] 章晓桦[1] 朱晟[2] 

机构地区：[1]浙江省水利河口研究院,浙江杭州310020 [2]河海大学水工结构研究所,江苏南京210098

出　　处：《水力发电》2017年第2期47-50,59,共5页Water Power

基　　金：国家自然科学基金项目(51609215);浙江省水利河口研究院博士后基金项目(质检A15001)

摘　　要：以基于离散单元法的二维颗粒流程序(PFC^(2D))为平台,建立可模拟沥青混凝土水力劈裂的数值模拟方法,深入研究沥青混凝土水力劈裂机理。该方法可模拟水力劈裂裂缝出现、扩展直到破坏的全过程。在此基础上,对沥青混凝土水力劈裂的细观机理和发生条件进行了研究。水力劈裂为拉伸破坏,细观机理为颗粒间法向接触力(拉力)超过法向粘结强度时,产生微裂缝,导致渗透系数增大,水压力急剧增长,从而激发更多微裂缝产生,直至微裂缝贯通形成宏观裂缝。发生条件为存在弱接触面区,有利于微裂缝的产生,而微裂缝产生后又可诱发更多裂缝产生直至贯通形成宏观裂缝。For understanding the mechanism of hydraulic fracture of asphalt concrete, a numerical method used to simulate hydraulic facture of asphalt concrete is suggested based on Two-dimensional Partiele Flow Code （ PFC^2D） . The method can reproduce whole process of hydraulic facture which includes the appearance, propagation and fracture of crack. Then, the meso-mechanism and occurred conditions are studied. The results show that the hydraulic fracture fails in tension. When the normal contact force is larger than the bond strength, the micro crack appears which can lead to the increasing of permeability coefficient. As a result, water pressure adjacent to micro crack will increase, which induees more micro eraeks. Many connected micro cracks finally will form maerosopie eraeks. The occurred eondition of hydraulie fracture is the existenee of weak contact surface regions where the first micro crack will appear.

关 键 词：离散单元法 沥青混凝土 水力劈裂 细观机理 发生条件 

分 类 号：TV431.5[水利工程—水工结构工程]