海洋地震资料相位控制处理——东海研究实例     

陈茂根  郝晓红  赵秀莲  刘苗 《海洋地质译丛》2014,(2):1-6

为了满足定量解释的需要,地震资料处理必须是高分辨率、振幅保持和相位控制的.面向海洋地震资料的相位控制处理技术包括利用远场信号进行确定性零相位化、Q补偿、预测反褶积及剩余相位校正等.利用模拟远场信号求取确定性去气泡及零相位化算子.此文基于相位控制处理,讨论了海洋地震资料的相位和极性判别方法,探讨了大于24 ms算子长度的预测反褶积对于保持信号形状的必要性,介绍了东海三维地震资料相位控制流程.  相似文献   

琼东南盆地深水区断层垂向输导及成藏模式   总被引：2，自引：1，他引：1  

王振峰  刘震  曹尚  孙志鹏  左倩媚  王亚辉  何卫军 《海洋学报(英文版)》2014,33(12):96-106

In the Qiongdongnan Basin, faults are well developed.Based on the drilling results, the traps controlled two or more faults are oil-rich. However, when only one fault cut through the sand body, there is no sign for hy-drocarbon accumulation in the sandstone. In terms of this phenomenon, the principle of reservoir-forming controlled by fault terrace is proposed, i.e., when the single fault activates, because of the incompressibility of pore water, the resistance of pore and the direction of buoyancy, it is impossible for hydrocarbon to ac-cumulate in sandstone. But when there are two or more faults, one of the faults acts as the spillway so the hydrocarbon could fill in the pore of sandstone through other faults. In total five gas bearing structures and four failure traps are considered, as examples to demonstrate our findings. According to this theory, it is well-advised that south steep slope zone of Baodao-Changchang Depression, south gentle slope zone of Lingshui Depression, north steep slope zone of Lingshui Depression, and north steep slope zone of Baodao Depression are the most favorable step-fault zones, which are the main exploration direction in next stage.  相似文献   

山东烟台大季家地区海水入侵界面划分的意义     

宋希利  ;宋鹏  ;时彦芳  ;耿祥峰 《山东地质》2014,(6):58-61

在沿海地区划分海水入侵界线具有重大意义,在海水入侵范围内,地下水由于含盐量高,虽然工业生产、人畜生活不能利（饮）用,但深部海水可为海产品养殖业带来较高的利用价值。利用高密度电法和可控源音频大地电磁2种方法准确划分了浅、深部海水入侵界线,并根据电性特征分析探讨了海水入侵区域的由浅至深的侵入特点,推测了不同深度上岩石破碎及富水规律,为探讨沿海养殖业利用温度相对稳定或较高的深部入侵海水进行了积极、有益的探讨。  相似文献   

Displacement‐controlled method and its applications to material non‐linearity     

H. Zheng  D. F. Liu  C. F. Lee  L. G. Tham 《国际地质力学数值与分析法杂志》2005,29(3):209-226

For the analysis of non‐linear problems, the displacement‐controlled method (DCM) has a more extensive application scope and more powerful abilities than the load‐controlled method (LCM). However, difficulties of the DCM's procedure not amenable to most finite element implementations of the conventional LCM have restricted its applications in geomechanics. By means of Sherman–Morrison's theorem, the solution of DCM is improved. The improved procedure is characterized by high efficiency, good numerical stability and a programme structure similar to LCM. Two aspects of applications of DCM are illustrated. The first application is to compute the response of a structure under a given load level like the conventional finite element analysis. The second application is to trace the equilibrium path of a structure under a given load distribution type. A simple but effective algorithm is presented for automatically adjusting the step length in tracing the equilibrium path. Examples illustrate that the proposed procedures are suited for modelling complicated non‐linear problems in geomechanics. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

区段控制浓度的一种定量化模型研究     

李亚民  王路光  王靖飞  李慈君 《地理与地理信息科学》2004,20(6):109-112

该文就总量控制工作进行理论探讨,提出控制平均浓度的排污等效模型,同时对计算区段控制浓度的确定进行定量化模型研究。该模型简便、易操作、实用性强,具有一定的理论意义和实用价值。  相似文献   

Tectonic inversion assessed by integration of geological and geophysical data: The intracontinental Rio do Peixe Basin,NE Brazil     

David L. Vasconcelos  Fernando O. Marques  Francisco C. C. Nogueira  Yoe A. R. Perez  Francisco H. R. Bezerra  Rmulo C. Stohler  Jorge A. B. Souza 《Basin Research》2021,33(1):705-728

Common basin models assume that the post‐rift tectonic evolution of most basins is usually associated with tectonic quiescence. However, tectonic inversion during the post‐rift phase has been proposed for several sedimentary basins worldwide, but how and why it happens is still a matter of debate, especially in intracontinental settings where the lithosphere is old and thick. Here, we use geological and geophysical data from the Rio do Peixe Basin in NE Brazil to show evidence that intracontinental sedimentary basins can be tectonically inverted by far‐field compressive stresses acting on pre‐existing weakness zones of lithospheric‐scale where stresses can concentrate and inversion can occur. Geomorphological and field data combined with seismic reflection, gravimetric and borehole data show that: (a) inversion occurred along two main Precambrian lithospheric‐scale shear zones, the Patos (E‐W trending) and Portalegre (NE‐SW trending), which had already been reactivated as basin‐bounding faults during the earlier rift stage; (b) post‐rift reactivation affected (mostly) the original master normal faults with the largest rift displacements, and locally produced new reverse faults; (c) during contraction, deformation was partitioned between fault reactivation and buckling of the incompetent sediment pushed against the hard basement; (d) all these signs of inversion have been observed in the field and can be demonstrated on seismic reflection profiles; and (e) combined gravimetric and seismic data show that the main structures of the basin were followed by an inversion. These data are consistent with the operation of WSW‐ENE horizontal maximum compressive stress as a result of combined pushes of the Mid‐Atlantic Ridge (towards the W) and the Andes (towards the E), responsible for the post‐rift oblique inversion of normal faults inherited from the rift phase and formed with vertical maximum compressive stress.  相似文献   

新型预制装配式楼盖抗倒塌试验研究   总被引：2，自引：2，他引：0       下载免费PDF全文

韩春  袁大伟  李青宁  姜维山 《地震工程学报》2017,39(1):45-51

地震及爆炸荷载下的结构连续倒塌问题对人民的生命财产造成重大威胁,是土木工程领域研究的一个热门方向。为了提高新型预应力空心楼板结构的整体性,防止由于竖向支承构件的失效形成楼板的局部或者连续倒塌,对2块新型预应力空心板足尺模型进行四分点静力加载试验,研究新型预制装配式两跨连续楼板的抗连续倒塌能力。试件均由预应力空心短板通过板端伸出U形筋和胡子筋进行对接连接,板侧纵向拼缝通过胡子筋和植筋与边梁的纵筋进行连接,2个试件的计算跨度相同。本文采用在加载过程中突然拆除中间支座,得到楼板破坏形态、裂缝发展、承载能力、应变、最大变形等试验结果。对试件的受力过程、悬索作用机理进行分析,最后得到楼盖拼缝及板侧边梁连接构造的布置合理,新型预制装配式楼盖采用合适的周边连系和横向拼缝连接可以达到理想的抗倒塌能力。  相似文献   

Variation in the sediment deposition behind check‐dams under different soil erosion conditions on the Loess Plateau,China          下载免费PDF全文

Yanhong Wei  Zhong He  Juying Jiao  Yujin Li  Yixian Chen  Hengkang Zhao 《地球表面变化过程与地形》2018,43(9):1899-1912

To maintain a reasonable sediment regulation system in the middle reaches of the Yellow River, it is critical to determine the variation in sediment deposition behind check‐dams for different soil erosion conditions. Sediment samples were collected by using a drilling machine in the Fangta watershed of the loess hilly–gully region and the Manhonggou watershed of the weathered sandstone hilly–gully (pisha) region. On the basis of the check‐dam capacity curves, the soil bulk densities and the couplet thickness in these two small watersheds, the sediment yields were deduced at the watershed scale. The annual average sediment deposition rate in the Manhonggou watershed (702.0 mm/(km²·a)) from 1976 to 2009 was much higher than that in the Fangta watershed (171.6 mm/(km²·a)) from 1975 to 2013. The soil particle size distributions in these two small watersheds were generally centred on the silt and sand fractions, which were 42.4% and 50.7% in the Fangta watershed and 60.6% and 32.9% in the Manhonggou watershed, respectively. The annual sediment deposition yield exhibited a decreasing trend; the transition years were 1991 in the Fangta watershed and 1996 in the Manhonggou watershed (P < 0.05). In contrast, the annual average sediment deposition yield was much higher in the Manhonggou watershed (14011.1 t/(km²·a)) than in the Fangta watershed (3149.6 t/(km²·a)). In addition, the rainfalls that induced sediment deposition at the check‐dams were greater than 30 mm in the Fangta watershed and 20 mm in the Manhonggou watershed. The rainfall was not the main reason for the difference in the sediment yield between the two small watersheds. The conversion of farmland to forestland or grassland was the main reason for the decrease in the soil erosion in the Fangta watershed, while the weathered sandstone and bare land were the main factors driving the high sediment yield in the Manhonggou watershed. Knowledge of the sediment deposition process of check‐dams and the variation in the catchment sediment yield under different soil erosion conditions can serve as a basis for the implementation of improved soil erosion and sediment control strategies, particularly in semi‐arid hilly–gully regions. Copyright © 2018 John Wiley & Sons, Ltd.  相似文献   

Analytical and empirical models for predicting the drift capacity of modern unreinforced masonry walls          下载免费PDF全文

Bastian Valentin Wilding  Katrin Beyer 《地震工程与结构动力学》2018,47(10):2012-2031

Displacement‐based seismic assessment of buildings containing unreinforced masonry (URM) walls requires as input, among others, estimates of the in‐plane drift capacity at the considered limit states. Current codes assess the drift capacity of URM walls by means of empirical models with most codes relating the drift capacity to the failure mode and wall slenderness. Comparisons with experimental results show that such relationships result in large scatter and usually do not provide satisfactory predictions. The objective of this paper is to determine trends in drift capacities of modern URM walls from 61 experimental tests and to investigate whether analytical models could lead to more reliable estimates of the displacement capacity than the currently used empirical models. A recently developed analytical model for the prediction of the ultimate drift capacity for both shear and flexure controlled URM walls is introduced and simplified into an equation that is suitable for code implementation. The approach follows the idea of plastic hinge models for reinforced concrete or steel structures. It explicitly considers the influence of crushing due to flexural or shear failure in URM walls and takes into account the effect of kinematic and static boundary conditions on the drift capacity. Finally, the performance of the analytical model is benchmarked against the test data and other empirical formulations. It shows that it yields significantly better estimates than empirical models in current codes. The paper concludes with an investigation of the sensitivity of the ultimate drift capacity to the wall geometry, static, and kinematic boundary conditions.  相似文献   

武汉交通学校群楼爆破拆除塌落振动分析     

刘璇  杨永强  胡进军  谢礼立 《地震工程与工程振动》2019,39(1):158-165

为了分析一次性爆破拆除多栋建筑造成的地面振动的特征及对周边建筑物的影响,对武汉交通学校群楼爆破拆除中的地面振动进行了测量,并对实测的塌落振动的峰值、频谱特性进行分析。结果表明:此次监测记录到的峰值频率在5～10 Hz,对比高架桥以及单一高层结构爆破拆除数据,倒塌叠加使得振动能量在频谱上分布更加离散,其峰值频率与周边结构自振频率相差变大,周边建筑共振的危险性降低;对于周围的结构而言,水平振动持时大于竖向振动,但水平振动幅值明显小于竖向振动;爆破塌落振动的竖向分量对周围结构的威胁较大,应采取有效的缓冲及隔振措施;由《爆破安全规程》和周边建筑爆破前后主振频率分析可知,本次爆破拆除工作未对周边建筑造成破坏性影响,验证了群楼爆破拆除方案的高效性和安全性。  相似文献