Abstract: The project of "Yinchuan active fault exploration and earthquake risk assessment" is aimed at strengthening the fundamental work of engineering construction for earthquake resistance and prevention in Yinchuan City.In order to achieve this general goal,a joint multi-disciplinary exploration of the Yinchuan buried fault and the Luhuatai fault has been carried out on the basis of collection and analysis of predecessors'data.This paper discusses the methods of constructing three-dimensional subsurface structure model of the project area of Yinchuan active fault exploration by using the achievements of the Yinchuan active fault exploration,and puts forward main work steps and suggestions for the model construction.The steps for 3D modeling of subsurface structure using active fault survey data are as follows:To collect and pre-process the data of seismic exploration of active fault;Using seismic interpretation software to interpret the fault and the bed position,draw bed plane structure map,and output the fault and bed position data,meanwhile,to further complete the 3D visual modeling with this software;To load fundamental data,bed plane and fault data into the 3D modeling software GOCAD,carry on the fault plane and the bed plane revision and reconstruct 3D model,construct three-dimensional cutting section,and demonstrate the three-dimensional model achievements.Since the seismic survey data are not standard,it increases the difficulty in earthquake data explanation and affects the explanation precision.Therefore,we propose to standardize the archiving of primary seismic survey data,add a cross line in the survey area of each active fault,and if possible,use the regional time-depth conversion used by petroleum sector to enhance the explanation precision of seismic section.

Key words: active fault survey, construct, three-dimensional subsurface structure model

摘要： 在收集与整理前人资料的基础上,"银川市活断层探测与地震危险性评价"项目对银川隐伏断层、芦花台隐伏断层等断层开展了多学科的联合探测。文中对如何以银川市活断层探测成果资料构建银川活断层探测区地下三维构造模型的方法进行了探索,总结出的步骤是:收集活断层地震探测资料并进行数据预处理;在地震解释软件中进行断层及层位的解释,绘制层面构造图并输出断层及层位数据,也可在该软件中进一步完成三维可视化建模;在三维建模软件GOCAD中加载基础数据、层面及断层数据,进行断层面及层面修正构建与展示三维模型。鉴于地震探测资料的不规范会增加地震数据解释工作的难度并影响到解释精度,建议:规范原始探测数据的归档要求,在每条活断层的探测区上增加1条联络测线,在可能的情况下采用石油单位的区域时深转换关系,提高地震剖面的解释精度。

关键词: 活断层探测, 构建, 地下三维构造模型