综放工作面一次开采厚度和宽度大，顶板破坏条件和影响因素复杂。为分析综放工作面顶板破坏特征，将基本顶视作为原岩区、液压支架控顶区、采空区、破断垮落顶板充填体等4区支撑的板，建立综放工作面多区支撑的顶板力学模型，开发有限元计算程序，结合二分法反演基本顶作用荷载和周期垮落步距。利用模型研究陕西崔木煤矿综放开采过程中顶板弯矩和剪力分布，分析基本顶沿煤壁前方断裂、煤壁处断裂和采空区断裂的条件、影响因素及影响规律，结果表明:综放开采多区支撑基本顶的最大弯矩发生在煤壁前方;若基本顶在煤壁前方产生拉伸破断，基本顶边界条件改变，引起弯矩重分布，最大弯矩位置转移至煤壁处;若基本顶不在煤壁处断裂，随着工作面推进，基本顶内最大弯矩增大，最大弯矩位置向采空区方向偏移，基本顶将在采空区上方断裂;基本顶最大弯矩位置受支架刚度、基本顶抗拉强度和厚度影响较大，随着支架刚度、基本顶抗拉强度和厚度增大，最大弯矩发生位置向采空区方向偏移，更容易在采空区上方位置产生拉伸破断;基本顶最大剪力位置受周期垮落步距、支架刚度、基本顶厚度影响较大，随着周期垮落步距、支架刚度和基本顶厚度增大，最大剪力发生位置向采空区方向偏移，基本顶更容易在采空区上方产生剪切破断。

The excavation thickness and width of fully mechanized mining working face are large,and the roof failure conditions and influencing factors are complex. To research the fracturing characteristics of the roof in fully mechanized mining working face,the main roof was taken as the unite width plate supported by the four areas including the intact rock,hydraulic support,goaf and filling body formed by collapsed roof. Then the mechanical model of multi-area supporting roof in fully mechanized mining working face was set up,and the corresponding finite element program was de- veloped. The loads and periodic caving pace of main roof were deduced by the model combined with the dichotomy. The model in this paper was employed to investigate the distribution of the moment and shear force in fully mechanized caving working face of Cuimu coal mine. The conditions,influencing factors and laws of fracturing in front of coal wall, at the coal wall or in goaf were analyzed and researched. The results show that the maximum moment of multi-area sup- porting main roof happens in front of coal wall. If the tension failure of main roof happens in front of coal wall,the boundary condition of main roof is changed. Redistribution of the moment of main roof makes the maximum moment appear at coal wall,and the tension failure maybe happen. Otherwise,with the workface advancing,the maximum mo- ment of main roof increases. The position of the maximum moment offsets to goaf,and the main roof will fracture in goaf. The maximum moment position of main roof is influenced by the support stiffness,tension strength and thickness of main roof. With the increase of support stiffness,tension strength and thickness of main roof,the position of the max- imum moment offsets to goaf,which will easily lead to fracture in goaf. The maximum shear force position of main roof is influenced by the support stiffness,periodic caving pace and thickness of main roof. With the increase of support stiffness,periodic caving pace and thickness of main roof,the position offsets to goaf,which will easily lead to fracture in goaf.