薄煤层硫化铁结核剥落的数值试验

Numerical test of spalling of iron sulfide concretions in thin seam

对典型结核不同出露状态与滚筒截齿着力点不同部位等状态进行了结核剥落的数值试验，分析了薄煤层硫化铁结核的剥落机理、形式及条件．结核在截齿作用下其周围煤体形成贯通式破坏区，声发射沿结核周围煤体密集分布，呈现平移剥落、旋转剥落、松动剥落及压入剥落等4种整体剥落形式．典型结核（200mm×150mm）整体剥落荷载为6．8～13．8kN．结核在煤壁的深度越小，剥落荷载越小；截齿着力点位于结核中部的剥落荷载大于端部．当结核厚度较小（≤45mm左右）时呈现截断剥落形式，在结核中线及周围形成破裂区，声发射沿结核中线及结核周围分布．

The numerical tests focused on typical concretions of different exposed status and drum pick focal points in different parts of concretions were carried on about the spalling of concretions. The spalling mechanism, forms and conditions were analyzed. Transfixion damaged areas were shaped when the concretions affected by pick. AE distributed along the coal around the concretions intensively, and there are translation spalling, rotating spalling loosing spalling and pressure spalling 4 overall spalling forms. The load to overall spall of typical concretions （200 mmx 150 ram） is 6. 8 - 13.8 kN. The required load to spall is less when the depth of concretions in coal wall is less. Pick focus in the central of concretions compared to near the end, the required load is smaller. When the thickness of concretions is smaller than 45 mm or less, the truncated form of spalling will appear, and there are fracture areas in the middle and surrounding area of concretions. AE distributes along the middle lane and around the concretions.