【作者】 王福海；

【导师】 刘怀山；

【作者基本信息】 中国海洋大学 ， 海洋地球物理， 2009， 博士

【摘要】 青岛海湾大桥桥位区地处胶州湾陆海连接的滩浅海地区,工程地质地球物理勘查条件特殊,数据处理也具有与常规海上和陆上数据处理方法不同的特点,论文通过调查研究桥区的地质资料,结合实际勘查条件综合分析各种地球物理勘查方法,选择了适合桥区情况有效的海洋地球物理勘查方法,研究了工程地质地球物理勘查的关键技术,获得了最佳的勘查效果。青岛海湾大桥位于胶州湾北部,连接胶州湾两侧,从区域地层位置来看,桥区属于诸城-胶州地层小区；从大地构造上来看,位于鲁东断块之中的胶南断块区北部。论文对区内的地层和侵入岩种类、构造特征、区内断裂进行了总结和分析。同时为分析桥区的潜在震源区,结合区内的区域重力异常特征、区域磁场特征、区域居里面莫霍面分布特征,对研究区的区域地球物理场进行了研究。研究了区域内各种滩浅海地球物理勘查方法,通过研究各种方法的原理与处理解释效果,结合研究区内的地质和地球物理特征,确定区内勘查采用的地球物理方法。多波束测深主要用于测量海湾大桥海底地形,浅地层剖面地震勘查技术是勘查海底浅层结构、海底沉积特征的重要手段,而海洋磁测对于研究海洋基底构造具有不可替代的作用。首次提出并实现了海湾大桥陆海地质工程高精度地震勘查方法,解决了海湾大桥桥位区陆海地质工程高精度地球物理资料的采集、处理、解释应用。建立和发展了陆海高精度地震勘查数据处理技术和完善处理流程,解决了海湾大桥滩浅海地震数据处理关键技术。为了克服激发接收条件的不同使地震勘查数据激发接收因素一致性较差,引起的子波在振幅、频率、相位上存在差异问题,利用了子波差异校正技术解决了上述问题的影响。利用地表一致性振幅补偿来消除由于波前扩散、地层吸收等原因引起的能量的损失以及地震道能量不均衡的影响；利用地表一致性校正子波能量谱；为消除震源对子波的影响以及检波点的子波差别,利用两步法统计子波反褶积减小震源和检波器引起的子波差异,使得子波相位得到校正,经过反褶积后陆上资料和海上资料相位一致性变好；最后利用匹配滤波进一步消除反射时差和子波差异的影响,消除炮点、检波点的差异以及同相轴间的时差,实现地震资料的有效连接和同相叠加,提高剖面的信噪比,使地震资料可以连续追踪,有利于构造解释。对于多次波的压制,采用优化组合多重压制的方法,经过分析研究实际地震资料中多次波的特征,提出利用预测反褶积、f-k滤波及加权混波结合的方法对资料进行处理,处理后多次波得到了有效的压制。为保证高保真,高分辨率成像采用叠前时间偏移技术,消除速度分析过程中倾角和位置的不同带来的影响。结合实际钻探、磁法、浅剖和多道地震勘查资料进行了综合分析和解释,对海湾大桥桥轴线附近的海底地形、覆盖层厚度、基岩顶板的埋藏深度及海域断裂破碎等地质构造等问题进行了分析和系统研究,获得了最佳的勘查效果,为青岛海湾大桥根据工程地质进行初步设计提供了可靠、详实的岩土物理力学参数。更多还原

【Abstract】 Qingdao gulf bridge is located in paralic zone of which geologic geophysics prospecting conditions are special and data processing also has the different characteristics of conventional marine seismic data and land seismic data. Through the investigation of geological data and combined with the actual survey to comprehensively analysis geophysical methods, this paper selects the effective marine geophysical exloration methods and appropriate processing mathods to get comprehensive results analysis ans explanation.Qingdao gulf bridge is in north of Jiaozhou Bay connecting Jiaozhou Bay on both sids. In view of statigraphy, the bridge belongs to Zhucheng-Jiaozhou formation, while from geostructure, it is located among north of Jiaonan block area. In this paper, the region types of strata and intrusive rock, structural features, fault blocks were summarized and analyzed. For the analysis of potential focal area, combined with the characteristics of regional gravity anomaly, magnetic signature and Moho-discontinuty, the regional geophysical field is studied.Because of the particularity of paralic zone surface condition, the construction work of different area, such as land, coastal mud flat, TZ zone and shallow water, has a big difference which will cause the larger seismice wave energy, frequence and pase difference. For the reason, we need study to obtain the wvaelet’s statistical attributes. And then, we can make the compatibility processing for the shotpoints and the receiving-points for the purpose of removing the divergence between the shot-points and receiving-points to get the higher quality seismic data. The use of surface consistent TAR to eliminate seismic energy losses. To liminate the impact of seismic source to wavelet, using two-step statistical wavelet deconvolution to make wavelet phase to be corrected. Finally the use of matched filter to further eliminate the impact of wavelet difference and achieve an effective connection of seismic data and in-phase superimposes.For the suppression of multiple wave , optinal combination multi-suppressed method is applied. After analysis of multiple wave characteristics in the actual seismic data, the multiple wave is suppressed effectively by using the predictive deconvolution and f-k filtering and other mehtods.This paper focuses on the migration imaging of how to make zero-offset profile. In order to ensure high fidelity, high-resolution imaging used time migration before stack to eliminate the impact of the difference between the inclination and location.Combined with actual drilling data and magnetic curves to analyse and explain the processing results. The geologic position is divided and base rock depth is analysed.Comprehensively analysis of the results obtained, this paper give an effective processing and interpretation method of geological and geophysical prospecting results in Qingdao gulf bridge, the difficulties of key geophysical techniques is solved.更多还原