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固定式海洋平台利用TLD的减震研究 总被引：7，自引：0，他引：7
本文研究固定式海洋平台利用调谐液体阻尼器（ＴｕｎｅｄＬｉｑｕｉｄＤａｍｐｅｒ，简称ＴＬＤ）减小地震反应的方法。首先探讨了调谐频率比、激磁频率比对减震效果的影响，在此基础上建立了ＴＬＤ——平台系统的力学模型和运动方程，通过数值计算验证了该方法的有效性 相似文献
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地震与波浪联合作用下海洋平台动力特性分析 总被引：1，自引：0，他引：1
主要针对地震与波浪联合作用下空间导管架式海洋平台结构的动力响应特性进行研究。以春晓平台结构为例,利用ANSYS程序进行了动力响应的数值计算,分析中考虑了地震设防烈度、风浪条件及场地土类型等因素对结构响应的影响,并与地震单独作用下的结构响应进行了对比。分析结果表明,抗震设防烈度较低、中等及较大风浪条件下对海洋平台结构进行抗震分析时有必要考虑地震与波浪的联合作用。 相似文献
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珠江口盆地白云凹陷陆坡区10.5 Ma以来的沉积体系 总被引：1，自引：0，他引：1
通过对珠江口盆地白云凹陷陆坡区10.5Ma以来的地震相分析,共识别出席状平行亚平行地震相、透镜状前积地震相、深切河谷地震相、帚状地震相和杂乱地震相,不同的地震相分别代表不同的沉积体系类型。综合所识别的地震相类型,分析了陆架边缘下切谷、浊积扇和陆架边缘三角洲3种主要的沉积体系及其配置关系。物源供给是影响陆坡区沉积体系发育的最重要因素,是沉积体系发育的物质基础,海平面变化和构造运动为沉积体系发育提供了可容纳空间,3种影响因素共同影响了陆坡区沉积体系的发育。 相似文献
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位于马来盆地与西纳土纳盆地交汇处的研究区上新统?更新统发育复杂的浅海、海陆过渡相水下分支河道体系,常规的地震资料无法进行精细识别刻画。通过对叠后地震资料进行希尔伯特?黄变换,提取了地震资料高频分量,提高了地震资料的分辨率,有效识别了薄层砂泥岩交互特征和细微沉积体。通过对高频分量进行瞬时属性提取,明确了目的层段水下分支河道的平面展布特征。与常规叠后地震属性相比,经过希尔伯特?黄变换后的叠后地震资料提取的瞬时属性显示了更多沉积体系的细节特征,为水下分支河道的内部结构、发育期次、切割关系等时空演化研究提供了更高分辨率的地震数据。 相似文献
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In this study, the seismic response control of offshore platform structures with Shape Memory Alloy (SMA) dampers is investigated. A new SMA damper and its restoring force medel are introduced for the calculation of seismic response reduction. Based on an actual platform structure and its mechanical medel, the parameters which may affect the rate of shock absorption are analyzed, such as the number, position and characteristics of the SMA dampers and the condition of the site where the platform is located. The results show that the SMA damper is an effective control device for offshore platforms and satisfactory control can be achieved by proper selection of the parameters. 相似文献
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海洋平台结构动力响应优化设计与灵敏度分析 总被引：5，自引：1，他引：5
研究了海洋平台结构动力响应优化设计以结构动力响应的灵敏度计算方法。给出了结构稳态频率响应和瞬态时程响应的灵敏度分析算法，并通过数值试验讨论了瞬态响应灵敏度分析算法的精度和差分法中变量摄动量的影响。在JIFEX软件中实现了结构动力响应灵敏度计算，建立海洋平台结构优化模型和求解方法。数值算例表明了本文方法和程序的有效性。 相似文献
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为了研究海底防沉板—桩复合基础在地震荷载作用下的动力反应特性,以我国南海深水工程实例为研究对象,利用Flac3D有限差分仿真软件建立了计算模型,土体采用Mohr-Coulomb本构模型,模型底部输入EL Centro地震波,对不同桩长的复合基础进行分析计算.在该特定工程背景下,研究结果表明:随着桩长的增加,防沉板顶部加速度放大系数呈减小趋势;地震荷载下,复合基础发生震陷,沉降量在地震波加速度峰值过后趋于稳定;当桩长为6m时,复合基础的水平振动程度和震陷量最小;由于桩基础把震动能量传输到深部土层中,复合基础周围土体的加速度响应值小于远场土体.在动力时域内,防沉板与桩连接处弯矩最大,需要在此处增设加固装置. 相似文献
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深海微生物培养模拟平台温度控制技术研究 总被引：3，自引：0，他引：3
针对深海微生物培养系统对温度条件的苛刻要求,在分析系统构成及建模的基础上,介绍了一种对系统的两级滞后环节采用了PI控制和双Smith预估反馈的方法,通过内环和外环Smith预估控制,精确的消除了温度控制系统中滞后延迟环节的影响,提高了PI控制强度,减少了超调,提高了系统动态响应和稳态精度。在系统Matlab仿真和实际实验中得到了良好的效果,满足系统的精度要求。 相似文献
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S.A. Stewart 《Marine and Petroleum Geology》2011,28(5):959-965
Reflection seismic data is widely-used in industry and academia. It is often interpreted and displayed with considerable vertical exaggeration. Vertical exaggeration is defined as the vertical to horizontal aspect ratio of a reflection seismic cross section in depth. Recent literature is reviewed here to quantify for the first time the extent and typical values of vertical exaggeration in published work. Results are collated from 1437 papers published in 68 journals in the period 2006-2010. This broad scope is intended to provide a global view but it does not claim to be exhaustive. One example from each paper was analysed. Depth conversion was necessary in 74% of cases (every case of time-domain seismic with vertical exaggeration not stated). The main findings are that only 12% of papers use aspect ratios with vertical scale set approximately equal to horizontal scale (vertical exaggeration in the range 0.8-1.2). 75% of papers use reflection seismic with vertical exaggeration greater than 2. Splits of the data in terms of shallow high resolution seismic and deep, crustal imaging seismic were also obtained. The cause of this very widespread vertical exaggeration of reflection seismic cross sections is generally some form of display optimisation, such as emphasis of stratigraphic architectures or displaying long sections that would otherwise not fit on screen, or effects related to seismic sampling, but a specific reason is rarely stated. Angular relationships in stratigraphic and structural architectures are distorted so commonly that true geometries are rarely seen, which becomes an issue if readers are unfamiliar with these geometries. There is a clear opportunity for authors who display and publish reflection seismic data to annotate an estimate of vertical exaggeration alongside other standard annotation on seismic displays. 相似文献
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根据地震反射特征、古生物组合、湖水面变化及构造变动，应用层序地层学原理，对下第三系进行层序划分，分析了地震相类型，总结出主要的沉积体系特征及其展布规律 相似文献
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海洋平台结构抗震可靠性时程分析方法 总被引：3，自引：0，他引：3
将地震运动视为随机过程,建立海洋平台结构在地震作用任一时刻基于剪切变形控制的极限状态方程,应用JC法计算海洋平台结构在地震作用任一时刻的可靠度,得到海洋平台结构抗震可靠度的时程曲线。该方法可满足工程设计的要求,便于工程应用。 相似文献
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New high-resolution seismic reflection data collected along the eastern margin of Corsica have been analysed to describe the morphology of the turbidite systems located seaward of the Golo River mouth. The boomer data reveal that there is not only one turbidite system directly associated with the river, but four additional, non-coalescing systems which grew simultaneously. In the south, the system has the typical morphology of a turbidite deposit rich in mud and sand with a well-developed meandering canyon and channel morphology. In the north, they have the morphology of sand-rich turbidite systems with shorter straight channels. The southernmost deposits are interpreted to represent a more advanced stage of turbidite system development. Terraces, recognised by their particular seismic facies on boomer profiles which clearly differs from the surrounding levee facies, are observed in the channel meanders. They are interpreted as confined levees built by vertical accretion due to deposition from low-energy flows. Despite limited penetration, boomer seismics are demonstrated to be a useful complement to lower-resolution sparker data. The boomer data are superior (1) for the characterisation of fine-grained turbidite deposits by extending seawards the limits of the turbidite systems commonly defined by the acoustic response of sands, (2) in demonstrating the persistence of turbiditic processes farther towards the basin, and (3) for proposing conceptual models for the formation of terraces in fan valleys. 相似文献
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Igneous intrusions emplaced within the prospective intervals of sedimentary basins can exert a significant impact on petroleum systems and hence are of considerable interest particularly when risking exploration plays. A number of discordant high amplitude seismic anomalies (DSAs) with a range of geometries are documented in high resolution 3D seismic data in the northern South China Sea. Their distribution and seismic characteristics are analysed and compared with similar seismic anomalies documented within sedimentary basins in the Atlantic margins and other locations. The DSAs occur mainly within Early Miocene strata and are interpreted as igneous intrusions that were emplaced close to the palaeo-seabed and are dated as early Middle Miocene using seismic-stratigraphic methods. A number of vents are also identified above the intrusions within early Middle Miocene strata. Several geometrical forms are observed, referred to here as saucer-shaped, lensoid-shaped, stacked and composite intrusions. The seismic expression of these is increasing complex towards the palaeo-seabed, with a tendency for the saucer-shaped sills to be the deepest intrusive forms. The igneous intrusions observed in this study only could be identified using 3D seismic data and they are important for the future evaluations of petroleum systems, basin evolution and tectonic analysis in the Pearl River Mouth Basin. 相似文献
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Kuang Zhiping Cao Guoao Dr. Lecturer Tongji University Shanghai Dr. Professor Tongji University Shanghai 《中国海洋工程》1993,(2)
- An approximate method is presented to investigate the earthquake response of the fluid-single leg (shortened for S. L.) gravity platform-soil interaction system. By assuming a suitable form of the velocity potential of the radiation waves and by using the motion equation and the boundary conditions, the unknown coefficients can be obtained. Thereafter the function of frequency for the interaction system may also be obtained. In this paper, the difference of the system dynamic response between rigid foundation is analyzed and the influences of the various foundation geometric dimension and the various water-depth on the hydrodynamic loading and dynamic response of the system is illustrated. 相似文献
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Duennebier F.K. Harris D.W. Jolly J. Babinec J. Copson D. Stiffel K. 《Oceanic Engineering, IEEE Journal of》2002,27(2):212-217
The Hawaii-2 Observatory seismic system is currently transmitting high-quality seismic data from the ocean floor in the central NE Pacific Ocean through Hawaii to the IRIS Data Management Center. The system includes broad-band seismic, geophone, acoustic, and ocean current sensors. The seismic sensors are buried about 0.4 m below the ocean floor to improve coupling to the ocean bottom and to reduce noise levels. The system can be remotely calibrated, leveled and locked, and gains can be changed on command from shore. Data are temporarily stored in the seismic package for retransmission as needed to correct for transmission problems and to prevent loss of data. Data generated are valuable for studies of the Earth's structure and the dynamics of earthquakes 相似文献
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A pop-up bottom seismic recorder designed for seismic refraction experiments was built by the Institute of Oceanographic Sciences in 1968. The device is housed within a 71 cm diameter sphere weighing 270 kg when launched. signals picked up by a hydrophone are recorded in analogue form on magnetic tape in the band 2–100 Hz. The total continuous recording period is 12 hr but the lifetime of the system can be effectively extended by cycling the tape-recorders to allow shooting to go on for up to 3 days. Ballast release is by acoustic command or by pre-set clock. The instruments have been used in water depths from 150 to 4820 m making a total of 63 deployments with a 95% recovery rate. A new version with three-component geophones is being built. 相似文献
20.
Dynamic behavior of tension-leg platform with net-cage system subjected to wave forces 总被引：2，自引：0，他引：2
In this study a typical tension-leg platform with net cage system is presented, and a set of equations of motion for the platform with a net-cage system of a simplified two-dimensional case are derived. Subsequently a close form solution is obtained when the wave-structure interaction between the top platform structure and the incident wave is considered. The parameter of solidity as a ratio of the twine diameter and the mesh size of the cage is also taken into account in the analysis. The purpose of this study is to investigate the dynamic behavior for the tension-leg platform with a net-cage system and its pre-tensioned tethers when subjected to incident waves and flow drags, and furthermore, to understand the relationship between the structure behavior and the properties of the net-cages. Numerical examples are carried out and the results are discussed focusing on the motion of both the platform and net-cages when subjected to waves of a range of periods. It is found that there is a close relationship between the dynamic behavior of the platform and the net-cage features such as the solidity ratio between the twine diameter and the mesh size of the net-cage while the parameters related to waves are held constant. 相似文献