【摘要】 以拖带坐标描述法和S－R分解定理的非线性几何场论为基础，分析了初始位形主断面上倾斜、曲率和水平变形计算公式的不合理性，建立了实时位形上的计算公式；利用平均整旋角概念和裂纹产生与扩张的几何准则，建立了确定实时位形上，水下采煤导水裂隙带高度的方法。与经典断裂判据相比，该方法计算简单，应用方便。更多还原

【Abstract】 On the basis of co-moving coordinate description method and S-R decomposition theorem. The authors analyze the unreasonableness of slope, curvature and horizontal strain on subsidence profiles on undeformed configuration. The accurate formulate are established on deformed configuration. Using the concept of mean rotation angle the authors present the fracture criterion of the process of initiation and propagation of microcrack. According to the new geometric criterion we can determine the height of crack band in mining under water body. Compared with the classical fracture criteria the new method is effective and applicable for analysis of engineering problems.更多还原