球形装药内爆岩体破坏效应的准静态模型

Quasi-static Model for Rock Damage Caused by Closed Explosion of Spherical Charge

针对岩石介质封闭内爆问题,建立了球形装药爆炸破坏区域预测模型。基于岩体的弹性—裂纹—粉碎破坏模式,粉碎区采用Hoek-Brown准则,并结合爆炸前后爆生气体的绝热关系,得到了岩石介质的爆腔尺寸、粉碎区尺寸和裂纹区尺寸。与文献试验结果及已有相关准静态理论进行比较。结果表明:该文模型爆腔尺寸的预测结果与试验结果吻合良好,误差范围为-5.8%~5.5%,而基于Mohr-Coulomb准则的准静态模型计算结果均偏小,且柱形爆腔公式不适用于球形爆腔;Hoek-Brown准则中无量纲经验系数m值对爆腔尺寸有一定影响,m增大,爆腔尺寸减小;粉碎区尺寸和裂纹区尺寸预测结果受m值影响较小,且比较合理。

Aiming at the closed explosion in rock,a model for predicting breakage zones caused by spherical charges was established.The radii of explosion cavity,comminuted region and cracked region in rock were obtained based on the elastic-comminuted-cracked response model,and the adiabatic relation of the detonation gas before and after explosion was considered.The Hoek-Brown criterion was used to describe the material in comminuted region.The blasting cavity results from the proposed model agree well with the experiment in references with relative error range from-5.8%to 5.5%.The results of quasi-static model based on the Mohr-Coulomb criterion are smaller,and the formula of cylindrical blasting cavity is not applicable to the spherical blasting cavity.As the value of dimensionless coefficient min the Hoek-Brown criterion increases,the size of blasting cavity decreases.The predicted results in radius of comminuted region and crack region are reasonable and less affected by m.