浅埋煤层顶板深孔预爆强制初放研究

Study on Forced Roof Caving to Hard Roof by Deep-Hole Pre-Blasting in Shallow Coal Seam

神府矿区覆岩属于亚坚硬顶板,由于煤层埋藏浅且基本顶分层厚度大,需避免工作面初采时出现基本顶大面积垮落而引发灾变。在采前相似模拟实验的基础上,探讨了爆破时基本顶的破坏机理。建立了基本顶破坏的力学模型,推导了基本顶初次破断距与爆孔深度关系的计算公式,计算了南梁煤矿不同爆破参数时基本顶的破断距。实验及理论研究所确定的参数在现场取得了良好的应用效果,为预爆强制初放时确定爆破参数提供了可靠的理论依据。

Overlying strata in Sheng-Fu mining area belong to inferior hard roof.Because of the shallow burial depth and thick layered of main roof,it needs to avoid the large area caving of the main roof during the first weighting period of working face.In this paper,based on the different physical simulation experiments,the failure mechanism of main roof is discussed when blasting is used.In addi-tion,the mechanical model of main roof failure is established,and the relationship between the first weighting step of main roof and the depth of blasting hole is deduced.Thus,the first weighting steps of main roof in Nanliang coal mine are calculated according to different explosion parameters.The pa-rameters which are determined by experimental and theoretical studies have achieved good application results in field testing,which can provide reliable theoretical basis for determining the explosive pa-rameters in implementing forced roof caving by deep-hole pre-blasting.