Indoor explosive fracturing simulation tests were carried out at atmospheric pressure and 20 Mpa confining pressure, respectively. The obtained explosive fracturing effects were compared. Comparisons show that confining pressure has a certain influence on crack propagation path, crack shape and crack curvature; and that the number of cracks induced by explosive fracturing at 20 Mpa confining pressure is less, the length is shorter and the curvature is clearer than those generated at atmospheric pressure. The fractal properties of the cracks were described by the fractal theory and the fractal dimensions of those cracks were derived. Results display that under the same test conditions, the fractal dimensions of the cracks at the surface of the same cement sample are not completely the same with each other, and that the fractal dimension of the cracks at 20 Mpa confining pressure is higher than those generated at atmospheric pressure.%通过室内爆炸压裂模拟实验,得到常压和20 MPa围压2种情况下的爆炸压裂效果,并对实验结果进行了对比分析,分析结果表明:围压对裂纹扩展路径、形状、弯曲度都有一定影响,与常压下的裂纹扩展情况相比,施加围压后得到的裂纹数量少、长度短、弯曲明显.在对爆炸压裂形成的裂纹进行定性描述的基础上,利用分形理论,对裂纹的分形特征进行了描述,并对裂纹的分形维数进行了求解.结果表明:同一实验条件、同一试样表面形成的裂纹,分形维数也不完全相同,围压条件下形成的裂纹维数高于常压下的裂纹维数.
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