CAJ | 학술논문

爆破是岩土工程中广泛采用的掘进方法，岩石在爆炸载荷下的断裂特性是岩石动力学的核心问题之一。利用雷管和带裂纹的水泥砂浆试样进行爆破试验研究，采用试验–数值方法确定试样的动态断裂韧度。通过试验得到的应变信号来确定试样承受的荷载及裂纹起裂的时间，将得到的时程曲线输入有限元程序ANSYS，利用1/4节点单元计算裂尖的近场位移，进而使用位移外推法求得试样 I 型动态断裂应力强度因子的时程曲线。裂纹起裂时刻对应的应力强度因子值即为材料的动态断裂韧度，从而给出了在爆炸载荷下I型裂纹的动态断裂韧度测试新方法。
폭파시암토공정중엄범채용적굴진방법，암석재폭작재하하적단렬특성시암석동역학적핵심문제지일。이용뢰관화대렬문적수니사장시양진행폭파시험연구，채용시험–수치방법학정시양적동태단렬인도。통과시험득도적응변신호래학정시양승수적하재급렬문기렬적시간，장득도적시정곡선수입유한원정서ANSYS，이용1/4절점단원계산렬첨적근장위이，진이사용위이외추법구득시양 I 형동태단렬응력강도인자적시정곡선。렬문기렬시각대응적응력강도인자치즉위재료적동태단렬인도，종이급출료재폭작재하하I형렬문적동태단렬인도측시신방법。
Fragmentation is widely applied in rock excavation,and fracture strength under blasting loads is one of the key issues in rock dynamic study. In this paper,blasting experiments with detonators and cement mortar specimens were conducted. The dynamic toughness was computed with experimental-numerical method. The loading and cracking time was determined by strain signals. The displacement field of crack tip was determined by finite element code ANSYS with 1/4 nodes element,and the loading acting on the borehole was determined according to the loading-time curve obtained from the experiments. Using displacement extrapolation method the curve of dynamic intensity factorKI(t) versus time was obtained. The dynamic toughness was determined by the dynamic intensity factor value at the crack initiation time,then a new test method of dynamic fracture toughness under blasting was proposed.