常规地表沉陷预计是对工作面回采结束、地表沉陷稳定后最终的静态移动变形预计;当涉及建(构)筑物下保护性开采与地面建(构)筑物加固及动态纠偏治理时，需要掌握该地质采矿条件下的地表动态移动变形规律，同时能够解决区域性变采高条件下的地表动态沉陷预计问题。首先对常见Knothe,Logistic,Weibull、分段Knothe、幂函数-Knothe与双曲线等时间函数的曲线形态、各时间段的地表动态下沉、下沉速度与下沉加速度进行了优缺点和适用性分析;其次基于东坡煤矿地表移动变形实测数据，针对特厚煤层综放开采条件下地表移动变形的特殊性，引入Bertalanffy时间函数，并基于此函数改进Bertalanffy三参时间函数;分析了各参数对改进Bertalanffy三参时间函数的影响规律，研究了各参数的物理意义以及与地质采矿条件的内在联系规律;最后将该函数用于平朔井工一矿特厚煤层综放开采条件下的地表动态下沉预计，并进行了拟合优度分析和现场应用效果检验。结果表明:基于改进Bertalanffy三参时间函数的各参数物理意义与地质采矿条件具有内在联系;该地表动态沉陷预计模型可塑性强、有着较好地预测精度和应用广度，能够较好地应用于煤矿地表动态变形的预计工作中;提出基于改进Bertalanffy三参时间函数结合影响函数法，该方法可有效地解决特厚煤层区域性限厚开采，如特厚煤层只采不放、煤层厚度赋存不稳定等区域性变采高条件下的地表动态沉陷预计问题。

Conventional surface subsidence prediction is the final static surface movement and deformation prediction after finishing the working face mining. When involving a protective mining under buildings or structures,buildings or structures reinforcement and their rectifying governance,it needs to understand the law of surface dynamic movement and deformation under its geological and mining conditions. Firstly,this paper analyzes the advantages,disadvantages and applicability of the common time function,such as Knothe,Logistic,Weibull,segmented Knothe,power functionKnothe and hyperbolic curve common time function,and analyzes the characteristics of their curve forms,dynamic surface sinking,sinking speed and sinking acceleration in each period. Secondly,based on the measured data of surface moving deformation in Dongpo Coal mine and in view of the particularity of surface movement and deformation for extra thick seam using fully mechanized caving mining method,the Bertalanffy time function is introduced,based on that,the Bertalanffy three-parameters time function is improved. Also,the paper analyzes the influence law of each parameter in the improved Bertalanffy three-parameters time function. Internal relation of the physical meaning for each paramete and its geological and mining conditions are studied. Finally,the time function is used for No.1 mine of Pingshuo mining region whose mining method is extra thick seam fully mechanized caving mining method,and its dynamic subsidence goodness of fit under this condition is tested. Results show that the physical significance of the parameters based on the improved Bertalanffy three-parameters time function is intrinsically related to the geological and mining conditions. This model has strong plasticity,good prediction accuracy and application breadth,and can be applied to the prediction of dynamic surface deformation of coal mine. Based on the improved Bertalanffy three-parameters time function combined with the influence function method,this method can effectively solve the problem of dynamic surface subsidence prediction under the regional variable mining height conditions,such as the limited thickness extraction in extremely thick coal seam and the unstable thickness of the coal seam.