安太堡露天煤矿排土场基底黄土的微结构演化与弱层的形成机理

MICROTEXTURE EVOLUTION OF THE DISCHARGED-MATERIAL STACK FIELD BASE LOESS OF ANTAIBAO OPENCUT COAL MINE AND THE FORMING MECHANISM OF THE WEAK INTERBED IN THE LOESS

本文根据安太堡露天煤矿排土场基底黄土的粘土矿物组成和微结构及其在分级荷载下微结构变化的研究,论述了排土场基底黄土内弱层的形成机理,提出弱层是在上覆排土压力下由于黄土的微结构变化而形成的演化弱层。并指出弱层的形成是导致排土场失稳滑坡的主要控制因素。这种弱层在新排土场设计时期并不存在,极具隐蔽性。但在设计时必须考虑在排土增至一定高度后,弱层的形成对排土场稳定性的影响,否则必将会存在重大滑坡隐患。

The formative mechanism of weak interbeds within the discharge material stack field base loess of the Antaibao Opencut Coal Mine is discussed in this paper, based on studies of clay minerals, microtextures and microtexture evolution under different load pressures. The research demonstrates that the weak interbeds are a kind of evolution ones formed by microtexture changes of the base loess under the load pressure of the overlying discharge materials, and constitute the controlling factor of the discharge material stack field landslides. They do not exist and cannot be detected during the time of designing a new discharge field. But their influence on the stability of the discharge field slope must be considered in order to avoid the danger of landslides.