大型金属矿体开采地应力场变化及其对采区岩体移动范围的影响分析

ANALYSIS ON IN-SITU STRESS FIELD CHANGE DUE TO UNDERGROUND MINING OF METAL ORE AND ITS INFLUENCE ON RANGE OF ROCK MASS DISPLACEMENTS

根据金属矿地下开采引起的地应力场变化对岩体移动变形范围影响的工程实际,采用现场实测和数值分析方法,对深埋破碎金属矿体开采引起的地应力场变化及其对地质环境影响并导致岩体移动变形范围不断扩大这一客观现象进行了具体计算分析。结果表明,矿体开采后,随着采深的增加地应力明显增大,岩体移动变形的影响范围也随之而增大。另一方面,地应力场变化,尤其是水平方向的构造应力场变化和影响是不可忽视的。

The change of in-situ stress field due to underground mining of metal ore has often resulted in major disasters in the metal mines. Stress change not only influences the stability of the deep tunnel, but also changes the range of rock mass displacements due to mining. Based on the results of numerical analysis for a large amount of measured results of in-situ stress in metal mine, the fundamental theoretical formulas of in-situ stress in horizontal and vertical direction are given. The results of the numerical analysis show that the in-situ stress, the range of rock mass displacements and deformations in overlying strata increase with the increment of depth of underground mining. The influence of the tectonic stress in the horizontal direction on range of rock mass displacements is evident, which is very important for deep underground excavation activities, especially for the metal ore mining.