Abstract: Based on ANSYS parallel software platform, and according to active tectonic block region division and distribution of active faults in North China, and combined with GPS data, the range of the numerical model is defined as 99.8°～121.4°E, 27.9°～42.3°N, which contains a majority of the North China active tectonic block region and parts of other block regions including the Tibetan plateau, the Xiyu, South China, and the Northeastern Asia. The model is divided into 416582 elements whose average side length is 25km with 582392 nodes. The main research results are: (1)Simulation of crustal movement velocity and analysis. The results show that the velocity of crustal movement in North China as a whole decreases from east to west and increases from north to south. It is an almost match between simulation results and GPS observed velocity field. (2)Simulation of the slip of faults and analysis. Considering all known late Quaternary active faults in North China in the model and according to the simulation results, the slip of faults obtained from simulation and that from geological survey are almost consistent. (3)Simulation of strain fields and analysis. By numerical simulation, the minimum strain and the maximum principal strain in North China in 1999-2004 and 2004-2007 are calculated. The horizontal strain direction in North China is in accord with the strain direction obtained from inversion of focal mechanism solutions, GPS observations, etc. by previous studies.

Key words: finite element, active fault, simulation, North China

摘要： 基于并行版ANSYS数值模拟软件平台，根据华北地区活动地块划分及活动断裂分布，结合GPS资料等，确定模型的几何边界范围是99.8°～121.4°E，27.9°～42.3°N，模型的边界范围包括华北活动地块区的绝大部分以及周边青藏、西域、南华和东北亚地块的部分地区。模型单元平均边长为25km，模型共划分为单元416 582个，节点582 392个。主要研究成果为：1）地壳运动速度模拟与分析对比：华北地区地壳运动速率的整体分布呈现由东向西逐渐减小、自北向南逐渐增大的特点，数值模拟结果与GPS观测运动速度大部分较吻合；2）断层运动性质模拟与分析对比：华北地区有限元模型考虑了华北地区已知所有晚更新世以来的活动断裂，模拟结果所得的断层运动性质与活动断裂地质调查的运动性质符合得较好；3）应变场模拟与分析对比：通过数值模拟，计算了1999—2004年和2004—2007年华北地区地表第1主应变和第3主应变（最大压应变）的大小和方向，与前人利用震源机制结果、GPS测量结果等资料反演得到的华北地区主应变场较一致。

关键词: 有限元, 数值模拟, 活动断裂, 华北地区