运用三维有限元数值模拟方法初步证实了笔者提出的凹陷露天矿边坡少剥离技术的时空原理中的空间原理 ,即小曲率半径原理和端部作用原理。计算了在自重应力作用下的均质岩体中 ,进行 10 0 m、5 0 0 m和 10 0 0 m的贯通和非贯通开挖 ,以及三种直径的倒截头圆锥开挖的应力分布 ,表明这些开挖是周围岩体应力降低的过程 ,随着开挖半径的扩大 ,压降范围和压降值增加 ,(σ1 - σ3 )值上升 ,岩体稳定性变差 ;开挖工程底部之下的厚大岩体 ,作为开挖工程的端部 ,对深部边坡的水平应力具有转移承载的作用 ,有利于下部边坡的稳定。上述原理的证实为深凹露天矿加陡下部边坡角以减少废石剥离量奠定了部分理论基础

Space Principles for Reducing Stripping in Furrow Pits Zhang Shixiong Peng Tao Wang Fushou Hu JianhuThe shorter curvature radius principle (or the smaller arching effect principle) and the bottom effect principle, which are the space principle of the space time principles for reducing stripping in furrow pits put forward by the first author of the paper, have been corroborated with 3 D Finite Element Method. The stress distribution of the excavated rock mass has been calculated under the following conditions: the rock mass is a homogeneous and elastic mass, which is only loaded by its dead weight; the cylinder excavation diameters are 100 m, 500 m and 1 000 m respectively; the bottom diameters of the reverse frustoconic excavations are the same size as above, their slope angle is 50°. The study result shows that, an excavation process is a process of the rock stress reducing. As the expanding of excavation diameters, the size and the value of rock stress reducing expand, and so does the value of ( σ 1- σ 3), the slope rock stability goes worse. The thick rock mass under an excavation engineering, as its bottom, can transfer and bear the virgin horizontal stresses of the lower slope, it is favorable for the stability of the latter. It is the bottom effect principle. The above principles give a part of the theory base for reducing stripping in furrow pits.furrow pit; slope stability; principle of shorter curvature radius; principle of bottom effect; finite element