The open pit slope is the mining boundary left after mining ore. From the perspective of economic exploitation, the angle of the open pit slope is larger (the steeper), the better the mining efficiency, the less the rock can be stripped and the mining cost is reduced. However, an excessively large slope angle will inevitably lead to an increased risk of damage such as slope landslides. As shown in Fig. 11-4, the open pit slope refers to a rock mass that is inclined to the stope formed by steps around the open pit. Open pit slopes are divided into work sloping slopes and non-working sloping slopes. A work-slope is a slope that is undergoing mining or rock-peeling operations, as shown in Figure 11-4. A non-work-assisted slope is a slope consisting of an open-pit mine boundary step (permanent step) that does not engage in mining or rock-peking operations, as shown in Figure 11-4, FG and BD. There are many steps on the non-work side slope that are necessary for mining operations and for maintaining slope stability. The slope stability study object refers to the non-working slope. With the open-pit mining, the open-pit mine will gradually deepen and eventually reach the design boundary FEAB of the open-pit mine. FEAB is also called the final boundary of open pit mines. FE and BA are called the final slopes of open pit mines. The slope angle is called the final slope angle of open pit mines, as shown in Figure 11-4. The open pit slope is the boundary of open pit mining. It is also the object of open pit mining operations. It also plays a role in providing the lower ore and rock transportation. Therefore, it has many characteristics compared with other rock slopes. (1) The formation of open pit slope is a dynamic excavation process The open pit slope is gradually formed as the mining project deepens. In the early stage of open pit mining, the slope problem is not serious due to the small height of the slope. However, for some mines, even small slopes often occur due to rock formation conditions and rock mass structures. Partial destruction. As a result, some open pit mines have experienced slope instability since the beginning of mining and have continued throughout the open pit mining process. (2) Non-selective geological conditions of slope engineering The open pit slope is the boundary of the open pit. Its formation can only be designed and excavated according to the condition of the ore body, the relevant national mineral demand, the economic level of the relevant industry, the technical conditions of the mining, etc., especially the slope. The formation position is not selective, but can only be formed around the mined ore body, that is, the engineering geological conditions, hydrogeological conditions, rock formation conditions, etc. of the slope are not selective, and the unfavorable engineering geological area cannot be avoided. It is not possible to fundamentally adjust the orientation of the slope. (3) The slope is tall and affected by daily blasting vibration The open pit slope is the largest of all types of artificially formed rock slopes, with a strike length of several kilometers. Thus disclosed the formation plurality of open pit slope, the slope portions of large differences in the geological conditions, steep slope, the slope angle of the final generally are between 400 ~ 500, or even more, such a steep rock tall The slope poses a certain threat to the safe mining of the lower part. At the same time, daily production and blasting operations of mining, relying on blasting, etc. also affected the stability of the slope. Despite the extensive use of millisecond blasting technology, the impact of the vibration on the slope is still huge, resulting in further fracture of the rock mass on the slope surface, blasting vibration induced slope sliding, rock rolling on the slope surface, partial collapse of the step. Protective Coatings,Protective Coatings With Modified Silica,Silica Fume For Protective Coatings,Marine Protective Coatings Henan Minmetals East New Materials CO. LTD. , https://www.eastspecialitysilica.com
Figure 11-4 Open pit slope and its composition