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111.
Salt tectonics in the Eastern Persian Gulf (Iran) is linked to a unique salt‐bearing system involving two overlapping ‘autochthonous’ mobile source layers, the Ediacaran–Early Cambrian Hormuz Salt and the Late Oligocene–Early Miocene Fars Salt. Interpretations of reflection seismic profiles and sequential cross‐section restorations are presented to decipher the evolution of salt structures from the two source layers and their kinematic interaction on the style of salt flow. Seismic interpretations illustrate that the Hormuz and Fars salts started flowing in the Early Palaeozoic (likely Cambrian) and Early Miocene, respectively, shortly after their deposition. Differential sedimentary loading (downbuilding) and subsalt basement faults initiated and localized the flow of the Hormuz Salt and the related salt structures. The resultant diapirs grew by passive diapirism until Late Cretaceous, whereas the pillows became inactive during the Mesozoic after a progressive decline of growth in the Late Palaeozoic. The diapirs and pillows were then subjected to a Palaeocene–Eocene contractional deformation event, which squeezed the diapirs. The consequence was significant salt extrusion, leading to the development of allochthonous salt sheets and wings. Subsequent rise of the Hormuz Salt occurred in wider salt stocks and secondary salt walls by coeval passive diapirism and tectonic shortening since Late Oligocene. Evacuation and diapirism of the Fars Salt was driven mainly by differential sedimentary loading in annular and elongate minibasins overlying the salt and locally by downslope gliding around pre‐existing stocks of the Hormuz Salt. At earlier stages, the Fars Salt flowed not only towards the pre‐existing Hormuz stocks but also away from them to initiate ring‐like salt walls and anticlines around some of the stocks. Subsequently, once primary welds developed around these stocks, the Fars Salt flowed outwards to source the peripheral salt walls. Our results reveal that evolving pre‐existing salt structures from an older source layer have triggered the flow of a younger salt layer and controlled the resulting salt structures. This interaction complicates the flow direction of the younger salt layer, the geometry and spatial distribution of its structures, as well as minibasin depocentre migration through time. Even though dealing with a unique case of two ‘autochthonous’ mobile salt layers, this work may also provide constraints on our understanding of the kinematics of salt flow and diapirism in other salt basins having significant ‘allochthonous’ salt that is coevally affected by deformation of the deeper autochthonous salt layer and related structures. 相似文献
112.
基于NAO99b全球海潮模型、NAO99Jb区域海潮模型、验潮站资料和SRTM地形数据确定的高空间分辨率海陆边界数据,构建我国沿海和岛屿高精度重力海潮负荷改正模型。以马祖岛为例介绍该模型,并采用实测的绝对重力测量资料进行验证。结果表明,经该模型改正后的重力观测精度明显提高。 相似文献
113.
针对近海区域海潮变化复杂且海潮负荷效应显著,而全球海潮模型在近海区域精度较低的问题,该文提出了将全球海潮模型NAO.99b和区域模型osu.chinasea.2010相结合,分析海潮对中国大陆及周边地区IGS站的影响。使用GAMIT软件解算IGS站实测数据,通过海潮负荷计算软件SPOTL对解算结果进行改正,并对改正效果进行对比和分析。结果表明,海潮负荷对中国及周边区域站点的影响主要体现在垂直方向,对一些站点的影响可以达到厘米级;海潮负荷对站点坐标的改正效果明显,特别是日本的种子岛站改正效果接近30%;站点改正效果从沿海到内陆逐渐减弱。 相似文献
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钢屈服—摩擦复合耗能器的性能研究 总被引:6,自引:1,他引:5
本文提出了“综合利用不同耗能原理和机制来设计新型耗能器”的思想,研究开发了钢屈服-摩擦复合耗能器,并对其进行了性能试验和对比试验,考察了耗能器的工作性能和耗能性能。给出了耗能器的恢复力模型,研究结果表明,钢屈服-摩擦复合耗能器利用钢屈服滞回和摩擦两种机制耗能,具有稳定的工作性能,耗能能力强且可调节,构造简单,形状紧凑,体积小,造价低,制作与安装方便,是一种有广阔应用前景的新型耗能减震装置。 相似文献
117.
嵌岩桩理论研究和设计中的几个问题 总被引:27,自引:0,他引:27
明确嵌岩桩的定义和分类,对嵌岩桩的承载机理、临界嵌入深度、设计理论和数值模拟方法等问题进行讨论,并对未来的工作进行论述。 相似文献
118.
DING Keqin DUAN Menglan FU Pinsheng LIU Chuntu
Ph. D. Associate Professor Research Department Center of Boiler Pressure Vessel Inspection Research Beijing P. R. China
Ph. D. Research Professor CCS Research Development Center China Classification Society Beijing P. R. China
Lecturer Yumen Petroleum School of Technique Technology Yumen P. R. China Research Professor 《中国海洋工程》1999,(4)
A simple probabilistic model for predicting crack growth behavior under random loading is pre-sented.In the model,the parameters c and m in the Paris-Erdogan Equation are taken as random variables,and their stochastic characteristic values are obtained through fatigue crack propagation tests on an offshorestructural steel under constant amplitude loading.Furthermore,by using the Monte Carlo simulation tech-nique,the fatigue crack propagation life to reach a given crack length is predicted.The tests are conducted toverify the applicability of the theoretical prediction of the fatigue crack propagation. 相似文献
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The disturbed state concept (DSC) model, and a new and simplified procedure for unloading and reloading behavior are implemented in a nonlinear finite element procedure for dynamic analysis for coupled response of saturated porous materials. The DSC model is used to characterize the cyclic behavior of saturated clays and clay–steel interfaces. In the DSC, the relative intact (RI) behavior is characterized by using the hierarchical single surface (HISS) plasticity model; and the fully adjusted (FA) behavior is modeled by using the critical state concept. The DSC model is validated with respect to laboratory triaxial tests for clay and shear tests for clay‐steel interfaces. The computer procedure is used to predict field behavior of an instrumented pile subjected to cyclic loading. The predictions provide very good correlation with the field data. They also yield improved results compared to those from a HISS model with anisotropic hardening, partly because the DSC model allows for degradation or softening and interface response. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献