爆破荷载作用下露天矿边坡稳定性的突变研究

基于二维斜坡平面滑动失稳力学模型，引入爆破荷载因素，建立了露天爆破荷载作用下岩质边坡失稳的尖点突变理论模型。根据建立的突变模型，探讨了爆破荷载幅值和爆破荷载频率对边坡稳定性的影响规律，导出了边坡的动态自稳临界高度，并提出了失稳的判据条件，结果表明：爆破荷载幅值越大，爆破荷载频率越小，后缘裂缝深度越大，边坡失稳的可能性越高；在爆破荷载作用下，边坡的稳定程度是动态变化的，且随着应力波入射角的增大，边坡失稳破坏的可能性不断提高。以大孤山露天矿内的两处边坡为例，计算了边坡的动安全系数及动态自稳临界高度，利用边坡当前实际的稳定情况验证了提出的边坡失稳判据的合理性，为预防露天矿爆破在开挖过程中边坡岩体的动力失稳提供了一定的理论支持。

Catastrophe analysis of open-pit slope stability under blasting load

Cusp catastrophe theory models of the rock slope instability under open blasting load were built based on the two-dimensional mechanical instability model considering the factors of blasting dynamic load. According to the established model, the influences of the amplitude and frequency of blasting dynamic load on the slope stability were discussed, and the dynamic critical instability height of the slope was derived, the criterion of the slope instability was also proposed. The result reveals that the possibility of slope instability increases with the increase of amplitude of the dynamic load, the decrease of frequency and the increase of trailing edge crack depth; the stability of slope is dynamic, and with the increase of incident angle of stress wave, the possibility of slope failure is increasing under blasting load. Taking two slopes in Dagushan Open-pit Mine as examples, the dynamic safety factor and the dynamic self-stability critical height of the slope are calculated, and the rationality of the proposed slope instability criterion is verified by the actual stability of the slope at present. It provides a certain theoretical support for preventing the dynamic instability of slope rock mass in the process of blasting excavation in open-pit mine.