地震勘探安全距离的标定方法研究          下载免费PDF全文

石双虎  丁向晖  齐永飞  杨阳  单启铜 《地震工程学报》2017,39(1):186-190

随着地震勘探的不断推进及人类活动范围的扩大,地震采集工作无法避免会涉及到越来越多的复杂地表条件和采集环境,如城区、油区等障碍物繁多的地区及环境高敏感区域。大量障碍物既影响地震采集质量和资料品质,也给施工安全造成威胁。在过渡带地震勘探中,由于激发方式多样化,安全距离的确定较为复杂,稍有不慎,很容易引起安全事故和造成资料缺失。本文基于振动效应的原理对混源激发中的安全距离进行理论探讨和实际测试,其结果对于复杂地区的地震勘探施工有着一定的指导意义。  相似文献   

COMPARISON STUDY OF TWO KINDS OF CODES TO MEASURE FAULT-OFFSETS BASED ON MATLAB: A CASE STUDY ON EASTERN ALTYN TAGH FAULT          下载免费PDF全文

KANG Wen-jun  XU Xi-wei  YU Gui-hua  LUO Jia-hong 《地震地质》1979,42(3):732-747

Geomorphic offsets displaced by coseismic surface rupture can be analyzed to identify earthquake recurrence behavior. Therefore, obtaining a sufficient and precise along-fault offset dataset is vital to identify long-term earthquake recurrence behavior. Furthermore, knowledge of along-fault slip distribution during a single-earthquake or multi-earthquakes is important for other reasons, including a better understanding of the relationship between earthquake size and coseismic displacements, fault kinematics and fault mechanics. A recent flourish of offsets-measuring software and high-resolution topographic data together offer an unprecedented opportunity to measure high-density fault offsets. Here, we introduce and compare two kinds of most popular software, LaDiCaoz and 3D_Fault_Offsets. We describe the workflow and principle of the two codes by taking a fault-offset example on the eastern Altyn Tagh Fault. LaDiCaoz iterates over the channel morphology and position parameters and determines the summed absolute elevation difference Σ[Δ(elevation)] between both transverse profiles. The optimal horizontal offset is defined by the parameter combination that results in the least mismatch between two profiles. Compared with LaDiCaoz, the principle of 3D_Fault_Offsets is more complicated by measuring the offset in three dimensions. It mathematically identifies and represents nine of the most prominent geometric characteristics of common sublinear markers along faults in three dimensions, such as the streambed(minimum elevation), top, free face and base of channel banks or scarps(minimum Laplacian, maximum gradient, and maximum Laplacian), and ridges(maximum elevation). By calculating best fit lines through the nine point clouds on either side of the fault, the code computes the lateral and vertical offsets between the piercing points of these lines onto the fault plane, providing nine lateral and nine vertical offset measures per marker. Through a Monte Carlo approach, the code calculates the total uncertainty on each offset. Although both 3D_Fault_Offsets and LaDiCaoz are developed based on the Matlab platform, there are significant differences in principles, linear marker, software interface, repeatability, input-file types, degree of automation, adaptability, output file types, etc. In this part, we compare and summarize their features, advantages, and disadvantages. Finally, we calculate the correlation of two groups of fault-offset data derived from the two methods along the eastern ATF. By doing this, we try to explore if the two methods can be crosschecked and to study how sinuosity of the linear geomorphic markers affect the measuring results. By discussing and comparing the accuracy of the two measuring methods, we consider that LaDiCaoz is better than 3D_Fault_Offsets in accuracy aspect. In our opinion, there exist some disadvantages in the both software, and higher automation and introduction of artificial intelligence will be the future development direction.  相似文献   

偏移距域/角度域共成像点道集与偏移速度的关系   总被引：3，自引：0，他引：3  

刘守伟  程玖兵  王华忠  马在田 《地球科学》2007,32(4):575-582

为了得到波动方程偏移距域共成像点道集(ODCIGs) 和角度域共成像点道集(ADCIGs) 与偏移速度的关系, 在匀速单层水平反射情况下, 对ODCIGs和ADCIGs随偏移速度的变化进行了定量的推导, 得到偏移速度偏小时ODCIGs与半偏移距成双曲关系, 反之成椭圆关系; 结合深度聚焦分析, 得到偏移速度偏大时, ADCIGs中视入射角大于真入射角, 反之, 小于真入射角; 在速度偏小时, ADCIGs上剩余时差(RMO) 与视入射角的正切值成椭圆关系, 反之成双曲关系.在地震有效入射角度范围内, ADCIGs对于偏大的偏移速度更加敏感.在偏移速度分析(MVA) 中, 从稍大的速度开始分析会对速度分析更加有利.   相似文献   

中国东部城市地区隐伏断裂上断点与最新活动时代关系的初步分析——以邢台、唐山地震区为例   总被引：4，自引：0，他引：4  

李传友  汪一鹏  王志才 《地震地质》2007,29(2):431-445

中国东部城市地区大多为较厚第四系松散物覆盖区,许多城市附近发育了具有相当规模的隐伏断裂。在这些第四系较厚覆盖区发育的隐伏断裂的上断点是否代表了断裂的最新活动时代?文中通过对邢台、唐山等发生过强震的中国东部城市附近地区地质、地球物理、地震活动、地形变等资料的综合分析,来讨论这些较厚第四系覆盖区隐伏断裂的上断点与断裂的最新活动年代的关系问题。初步分析表明,作为邢台地震和唐山地震发震断裂的新河断裂和唐山断裂带,并不象其上断点显示的为晚更新世不活动断裂或者为局部活动段,而均为大型活动断裂。由此认为,在中国东部沉积层较厚地区,不能完全根据断裂断错的最新地层确定断裂的最新活动时代。对于一条穿过新沉积较厚地区的断裂,其最新活动时代应根据构造背景、断裂对新地层的控制作用、断错最新地层、新地层沉积厚度、构造地貌、地震活动、地形变、现今构造应力场等综合判定  相似文献   

自升式平台水平偏移的数值模拟方法研究     

殷齐麟  董胜 《中国海洋大学学报(自然科学版)》2019,(4):137-143

自升式平台的水平偏移会增加作业难度,严重时降低平台的坐底稳定性。基于平台主体发生水平偏移U的原因,将水平偏移分成三部分:桩腿弯曲引起的水平偏移Ub,桩靴转动引起的水平偏移Ur以及桩靴平移引起的水平偏移Ud。利用有限元软件ABAQUS建立圆柱腿自升式平台-地基耦合模型,考虑桩土之间法向挤压、切向摩擦的接触关系,利用Coulomb定律计算摩擦力。利用子程序DLOAD实现波浪力的加载,波浪采用Airy波模型。针对桩周无回填土体、桩周土体未完全固结以及固结完成三个阶段,探究桩靴直径、回填土强度、以及埋置深度对U,Ud和Ub的影响。并与中国船级社《海上移动平台入级与建造规范》(2005)中推荐的方法进行对比。最后给出了相关的结论。  相似文献   

成组加密法宽方位三维观测系统设计方法及应用     

许崇宝  宁方助 《中国煤田地质》2000,12(4):60-62,65

三维地震勘探是一种面积勘探方法,观测系统形式很多,常用的线束型三维观测系统,由于其排列片狭片,存在方位角分布不均匀的弊端。为了改善面元的方位角分布特性,笔者于９９年８月提出了一种新型三维观测系统设计法,又称之为成组加密法宽方位三维观测系统设计方法。文中系统叙述了该方法的设计原理,并对共主要设计参数进行了理论分析。该设计方法在徐州张双楼煤矿三维地震勘探中首次投入使用,取得了很好的技术效果和显著的经济  相似文献   

双差定位法在三峡库区地震定位中的应用   总被引：12，自引：5，他引：7  

张爱民  李强 《大地测量与地球动力学》2006,26(3):73-77

基于三峡地震台网2003年5月19日至2005年8月的地震记录资料,用双差定位法对发生于三峡库区(30.5°～31.5°N、109.5°～111.5°E)的1676次地震进行了重新定位。重新定位后的地震最大偏移量为10.93km,最小为0.08km,平均偏移量为1.87km,平均震源深度为6.59km。  相似文献   

共偏移距地震反射波方法用于城市活断层探测   总被引：4，自引：0，他引：4       下载免费PDF全文

刘保金  姬继法  徐朝繁  袁洪克  廖旭  白云  万波 《地震地质》2006,28(3):411-418

在简要介绍共偏移距地震反射波勘探方法原理、现场数据采集和室内资料处理方法的基础上,结合福州和沈阳2个城市的活断层探测实例,探讨了采用共偏移距地震反射波方法进行活断层探测的有效性和局限性。结果表明,该方法具有分辨率高、对地下构造的重现性好、探测结果可实时分析解释等特点,在第四纪覆盖层较薄、基岩面起伏变化较大的地区采用该方法可快速对被测目标进行准确定位  相似文献   

Spectral accuracy of Jgm3 from satellite crossover altimetry     

J. Klokočník  C. A. Wagner  J. Kostelecký 《Journal of Geodesy》1999,73(3):138-146

A detailed accuracy assessment of the geopotential model Jgm3 is made based on independent single- and dual-satellite sea-height differences at crossovers from altimetry with Jgm3-based orbits. These differences, averaged over long time spans and in latitude bands, are converted to spectra (latitude-lumped coefficients) by least-squares estimation. The observed error spectra so obtained are then compared directly to error projections for them from the Jgm3 variance–covariance matrix. It is found from these comparisons that Jgm3 is generally well calibrated with respect to the crossover altimetry of and between Geosat, TOPEX/Poseidon (T/P), and Ers 1. Some significant discrepancies at a few lower orders (namely m=1 and 3) indicate a need for further improvement of Jgm3. A companion calibration (by order) of the geopotential model Jgm2 shows its variance–covariance matrix also to be generally well calibrated for the same single- and dual-satellite altimeter data sets (but based on Jgm2 orbits), except that the error projections for Geosat are too pessimistic. The analysis of the dual-satellite crossovers reveals possible relative coordinate system offsets (particularly for Geosat with respect to T/P) which have been discussed previously. The long-term detailed seasonally averaged Geosat sea level with respect to T/P (covering 1985–1996) should be useful in gauging the relative change in sea level between different parts of the ocean over the single 4-year gap between these missions (1988–1992). Received: 16 February 1998 / Accepted: 25 November 1998  相似文献   

应用T-A双重拟合进行多次波压制     

王辉  何兵寿 《物探化探计算技术》1999,21(1):9-13

本文介绍了多项式拟合零炮检距剖面的方法、原理,并提出了一种新的拟合方法,即时间—振幅双重拟合法（Ｔｉｍｅ－ＡｍｐｌｉｔｕｄｅＤｕａｌＦｉｔｉｎｇＭｅｔｈｏｄ）,用于地震波组的提纯和多次波的压制,并将其与其他多次波的压制方法进行了对比  相似文献