露天矿支撑—回填动态作用下有限边坡力学模型研究

近水平内排露天煤矿其端帮演化是典型的有限边坡开挖-回填反复推进的过程,根据露天煤矿边坡特点,通过FLAC3D数值模拟软件揭示了压力拱动态发展规律,建立了有限边坡组合压力拱模型,给出了组合支撑拱失稳判据,结果表明：边坡地应力朝采掘槽中心卸载,表现为时效性的非对称压力拱形状,压帮内排及时跟进可以提高端帮边坡稳定性,其主要机理是内排台阶提供了有效支撑力,阻止了端帮边坡的蠕变发展,限制了地应力的卸载空间,掩埋了变形较大的坡脚位置,并使应力集中区域转移到内排台阶表面。

Study on Mechanical Model of Finite Slope under Dynamic Supporting-Backfilling Action in Open-pit Mine

Most of the slopes of open pit mines are finite slopes. The length of slopes is generally less than 200m. It is difficult to accurately evaluate slope stability by traditional two-dimensional slope analysis method. For the near-horizontal open pit mine, the end gang is a typical finite slope excavation-backfilling process. According to the characteristics of open-pit coal mine slope, the dynamic development law of pressure arch is revealed. The finite slope combined pressure arch model is established. The criterion of combined support arch instability is given. Through numerical simulation, the results show that the slope stress is toward mining. The center of the groove is unloaded, which is characterized by a time-sensitive asymmetric "pressure arch" shape. The timely follow-up of the inner tube can improve the stability of the end slope. The main mechanism is that the inner step provides effective support and prevents the end. The creep development of the slope limits the unloading space of the ground stress, buryes the position of the slope with large deformation, and transfers the stress concentration area to the inner step surface.