动荷载下预设裂隙岩样疲劳试验研究  

Experimental Study on the Fatigue of Pre-fractured Rock Specimens under Dynamic Loading

作　　者：林媛媛[1] 李润[1] 

机构地区：[1]福建江夏学院,福建福州350108

出　　处：《福建建设科技》2016年第6期32-34,共3页Fujian Construction Science & Technology

基　　金：福建江夏学院大学生创新创业训练计划项目(201513763002);福建省自然科学基金(2015J05077);福建省中青年教师教育科研项目(JA15533)资助

摘　　要：采用相似材料制作含预设裂隙的类岩试样，分别对完整试样及30°、45°、60°的预设裂隙试样进行单轴循环加载，借助动态信号测试系统及数码相机、摄像机对类岩试样疲劳劣化过程进行试验研究。研究发现：试样轴向应变一循环次数比曲线存在较明显的规律：加载初期，持续时间较短，曲线上升较快；加载中期，持续时间长，曲线上升平缓；加载末期，持续时间短，曲线急剧上升。循环加载过程中，试样完整面的新生裂纹一般始于试样两端的受载面，主裂纹与加我方向呈30°～45°交角，大多呈现X形的破坏形态；试样预设裂隙面，都是在预设裂隙尖端处新生裂纹，同时产生翼裂纹，随着新生裂纹不断扩展、汇合，逐渐与预设裂隙一起形成主裂隙面，试样最终形成近似X形的裂纹破坏形态。The similar materials had been prepared to make pre -fractured rocklike specimens. The uniaxial cyclic loading tests were car- ded out for intact specimens and pre - fractured of 30°, 45°, and 60° rocklike specimens. The dynamic signal test system and digital cam- era and video camera were used for the experimental study on the fatigue degradation process of rocklike specimens. It was indicated that the curve of axial strain - cycle ratio for specimens obeys obvious laws： In the initial loading, the duration was shorter and the curve in- creased very quickly; in the middle loading, the duration was longer and the curve smoothly developed; in the late loading, the duration was short and the curve rapidly rose. During the process of cyclic loading, the new cracks on the intact surface of specimens were generally initiated in the both ends of loading surface, the main cracks presented 30° -45° intersection angle with the loading direction, most of them presented X - shaped failure mode ; pre - fractured surface of specimens always had new cracks at the tip of pre - fracture and genera- ted wing cracks at the same time. With the constant extension and coalescence, new cracks gradually formed main fracture together with pre -facture. Finally, specimens formed X -shaped failure mode.

关 键 词：动荷载 裂隙岩样 疲劳损伤 疲劳裂纹 

分 类 号：TU45[建筑科学—岩土工程]