为掌握近距离煤层层间基本顶的损伤及破断规律，采用连续损伤模型对上煤层开采引起的底板损伤规律进行了研究，并依据层间基本顶在采空区损伤区域的层位对基本顶进行了分类，获得了损伤基本顶初次断裂长度计算公式。结果表明：底板损伤区域呈勺形分布，损伤量由损伤核区域向边缘区域递减；层间基本顶可分为无损伤、部分损伤以及完全损伤3类，3类基本顶对下煤层矿压显现的影响依次减弱；损伤基本顶的断裂长度随损伤量的增大而减小，存在极限损伤量，使得损伤基本顶的断裂长度趋近于0；损伤基本顶断裂形成的关键块高长比增大，砌体梁结构更易发生滑落失稳，其情况与斜沟煤矿现场矿压观测结果吻合。

This study aims to study the damage and rupture laws of the main roofs between coal seams with a close distance. A continuum damage model was adopted to investigate the damage laws of floor caused by mining the upper coal seam. Morever, the main roofs were clearly classified based on their positions in damage area of the floor in the goaf. Thus, an initial fracture span formula was obtained for the damaged main roofs. The numerical calculation results show that the damaged area in the floor is spoon-shaped and the damage value decreases from the damage core area to the marginal area. The main roofs between coal seams can be divided into three types, including no damage, partial damage and complete damage. In addition, the influence of three types of main roofs on the behaviours of the lower strata decreases successively. The fracture length declines with the increase of the damage value, until the limit damage value occurs, which results in the fracture length approaching to zero. The height-length ratio of critical blocks formed from the damaged main roofs increases and the voussoir beam slides easily to a great extent. The laws of damaged main roofs are verified in Xiegou coal mine.