初至走时层析成像在工程勘探中的应用与研究  

Application and research of first arrival traveltime tomography in engineering exploration

作　　者：马婷[1] 唐国彬[2] 郭桂红[3] 周学明 侯爵 张智[2] MA Ting;TANG Guo-bin;GUO Gui-hong;ZHOU Xue-ming;HOU Jue;ZHANG Zhi(Tianjin Earthquake Agency,Tianjin 300201,China;Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration,College of Earth Sciences and Guilin University of Technology,Guilin 541004,China;Lanzhou University and The Key Laboratory of Mechanics on Disaster and Environmental in Western China,Lanzhou 730000,China;China Railway Design Corporation,Tianjin 300251,China;State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijng 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Geophysics,Chinese Earthquake Administration,Beijng 100081,China)

机构地区：[1]天津市地震局,天津300201 [2]广西隐伏金属矿产勘查重点实验室,桂林理工大学地球科学学院,桂林541004 [3]兰州大学,西部灾害与环境力学教育部重点实验室,兰州730000 [4]中国铁路设计集团有限公司,天津300251 [5]中国科学院地质与地球物理研究所,岩石圈演化国家重点实验室,北京100029 [6]中国科学院大学,北京100049 [7]中国地震局地球物理研究所,北京100081

出　　处：《地球物理学进展》2019年第6期2486-2492,共7页Progress in Geophysics

基　　金：国家自然科学基金(41504074,41804060)资助

摘　　要：工程勘探中由于技术手段限制和地质条件的复杂性,地面物探方法获得的反演结果与实际地质情况往往存在较大偏差.地面激发、隧道内接收的透射波由于直接穿过地质体,因而利用透射波初至走时进行层析成像具有更高的精度和可靠性.本文以某隧道勘探工程为例,对透射波初至走时层析成像的应用效果和影响因素进行了数值试验分析,详细探讨了初始模型和射线覆盖次数对反演效果的影响,试验结果表明:(1)由于具有直接穿透地质体的优势,透射波勘探相较于其他地面地震勘探方法具有更好的精度、可靠性和准确性;(2)虽然初始模型不准确,其在横向上的扰动仍然足以反映异常的存在,但是基于先验地质信息构建适当初始模型对于提升反演精度至关重要;(3)采用针对性的观测系统设计及井地联合反演方法可以提高数据投影角度和完备性,有效减少解的不确定性,从而逼近地质体真实的地球物理模型.数值试验表明透射波初至走时层析成像在工程物探中有广泛应用前景.Due to the limitation of technical means and the complexity of geological conditions in engineering exploration,the inversion results obtained by surface geophysical prospecting methods may be deviated from the actual geological situation.The transmitted wave which was shoot on the ground and received in the tunnel directly pass through the geological body,and the first arrival traveltime tomography using transmitted waves has higher accuracy and reliability.Taking a tunnel exploration project as an example,this paper analyzes the application effect and influencing factors of the first arrival traveltime tomography using transmitted waves by numerical experiments,and discusses the influence of the initial model and the number of ray coverage on the inversion effect in detail.The results showed that:(1)Because of the advantages of directly penetrating geological body,transmitted wave exploration has better accuracy and reliability than other surface geophysical survey.(2)Although the initial model is inaccurate and it is still sufficient to reflect the existence of anomalies in laterally,building an appropriate initial model based on prior geological information is crucial to improve the inversion accuracy.(3)By using the targeted observation system design and the combined drilling and surface seism inversion,the projection angle and completeness of data can be improved,and the uncertainty of the solution can be effectively reduced,so as to approach the real geophysical model of the geological body.Numerical experiments show that the application of the first arrival traveltime tomography using transmitted waves has broad application prospect in engineering geophysical exploration.

关 键 词：初至走时层析成像 透射波 工程勘探 

分 类 号：P631[天文地球—地质矿产勘探]