长期矿震作用对露天矿边坡岩体状态的影响研究

Study on the influence of long-term mine earthquake on rock mass state of open pit slope

为研究长期矿震作用对边坡岩体应力应变状态的影响及影响累积的可能性,通过设置矿震场景来模拟被研究边坡在矿震过程中的岩体状态变化。场景设定为45 a分9次模拟,周期为5 a,各周期中随机发生3次3级矿震,选取具有代表性的岩体状态表征量,包括塑性区、位移和最大主应力进行规律分析。研究了矿震对露天矿边坡的作用形式,分析了这些作用导致边坡岩体状态变化的原因,建立了塑性区、位移和最大主应力与矿震震动的关系。结果表明,矿震震动主要影响岩体位移,其次是塑性区,对主应力影响很小。对大高差边坡的岩体塑性区及位移影响较大,位移有累积作用,塑性区累积较小;对主应力影响很小且作用不累积。长期看矿震对边坡岩体的弱化是长时间的累积过程,岩体结构松散后矿震才能迅速导致滑坡失稳。

To study the influence of long-term mine earthquakes on the stress-strain state of slope rock mass and the possibility of influence accumulation,a mine earthquake scene was set to simulate the change of rock mass state in the process of mine earthquakes.The scene is set as 45 years,divided into 9 simulations,and the period is 5 years.In each period,there are 3 times mine earthquakes with magnitude 3 randomly.The representative rock mass state characterization quantities,including plastic zone,displacement and the maximum principal stress,are selected to analyze the law.This paper studies the action forms of mine earthquakes on open pit mine slope,analyzes the reasons for the change of rock mass state caused by these actions,and establishes the relationship between the plastic zone,displacement,the maximum principal stress and mine earthquake vibration.The results show that the displacement of rock mass is mainly affected by mine earthquakes,followed by the plastic zone,and the influence on the principal stress is very small.It has a great influence on the plastic zone and displacement of rock mass with large elevation difference,and the cumulative effect of displacement is obvious,while the cumulative effect of plastic zone is small.It has little effect on the principal stress and does not accumulate.In the long run,the weakening of slope rock mass caused by mine earthquakes is a long-term cumulative process.Only when the rock mass structure is loose can the mine earthquake quickly lead to landslide instability.