摘要
研究目的:跨海大桥、海底隧道等重大工程建设需要通过多道地震方法查明海域沉积层结构与厚度、断裂分布与活动性特征、基岩起伏与风化层厚度,以及特殊地质体分布范围等。但是在近海海域多道地震施工的条件受到诸多限制,如水深较浅、流速大、养殖区和渔业活动密集等,进而导致采集电缆较短且缺乏姿态控制,同时由于采集电缆较短产生覆盖次数少、速度分析困难等问题。最终获得的地震资料品质相对较差,存在信噪比低、多次波发育、电缆姿态不好等问题,需要进行针对性地分析和处理。研究结论:(1)地震数据经过联合噪声压制、多次波组合压制、提高覆盖次数、电缆时差校正等技术处理,显著提高了地震剖面的分辨率和信噪比;(2)处理后的地震剖面自浅至深各主要反射层的产状和构造形态清晰,地质现象清楚;(3)针对数据处理中遇到的噪声类型复杂、多次波压制难度大、速度分析困难等难点和挑战,总结出了一套适用于近海工程的多道地震数据处理技术流程,对后续近海工程高分辨率多道地震探测的数据处理工作具有一定的指导意义。
Research purposes:The construction of offshore engineering such as cross-sea bridges and subsea tunnels requires the identification of sedimentary layer structure and thickness,fault distribution and activity characteristics,bedrock relief and weathered layer thickness,as well as the distribution range of special geological bodies using a multi-channel seismic reflection method.However,offshore environments for multi-channel seismic data acquisition are subject to many constraints,such as shallow water depth,high flow rate,intensive aquaculture and fishing activities,which can result in short collection cables without attitude control.Additionally,due to the short collection cables,the coverage times are reduced,making speed analysis difficult.The quality of the seismic data obtained is relatively poor,with problems such as low signal-to-noise ratio,strong multiple waves,and cable attitude issues,which require targeted analysis and processing.Research conclusions:(1)Seismic data are significantly improved in resolution and signal-to-noise ratio through technical processing such as joint noise suppression,multiple wave combination suppression,increasing coverage times,and cable time difference correction.(2)The produced seismic profile after processing clearly shows the production state and structural morphology of each major reflection layer from shallow to deep,and the geological phenomena are clear.(3)In response to the difficulties and challenges encountered in data processing such as complex noise types,difficulty in multiple wave suppression,and difficulty in speed analysis,a set of multi-channel seismic data processing technical processes applicable to offshore engineering has been summarized,which has certain guiding significance for the data processing of subsequent high-resolution multi-channel seismic exploration in offshore engineering.
作者
刘振明
周学明
祁晓雨
LIU Zhenming;ZHOU Xueming;QI Xiaoyu(China Railway Design Corporation,Tianjin 300251,China)
出处
《铁道工程学报》
EI
CSCD
北大核心
2024年第6期17-22,共6页
Journal of Railway Engineering Society
基金
中国铁路设计集团有限公司科技开发课题(2023A0226406)。
关键词
近海工程
多道地震
噪声压制
多次波
offshore engineering
multi-channel seismic
noise suppression
multiple wave
