Architecture,deformation style and petrophysical properties of growth fault systems: the Late Triassic deltaic succession of southern Edgeøya (East Svalbard)

The Late Triassic outcrops on southern Edgeøya, East Svalbard, allow a multiscale study of syn‐sedimentary listric growth faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The faults, characterized by mutually influencing deformation envelopes over space‐time, generally show SW‐ to SE‐dipping directions, indicating a counter‐regional trend with respect to the inferred W‐NW directed progradation of the associated delta system. The down‐dip movement is accommodated by polyphase deformation, with the different fault architectural elements recording a time‐dependent transition from fluidal‐hydroplastic to ductile‐brittle deformation, which is also conceptually scale‐dependent, from the smaller‐ (3rd order) to the larger‐scale (1st order) end‐member faults respectively. A shift from distributed strain to strain localization towards the fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho‐structural facies across and along the fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second‐ and third‐order listric fault nucleation points appear to be located above blind fault tip‐related monoclines involving cemented organic shales. Close to planar, through‐going, first‐order faults cut across this boundary, eventually connecting with other favourable lower‐hierarchy fault to create seismic‐scale fault zones similar to those imaged in the nearby offshore areas. The inferred large‐scale driving mechanisms for the first‐order faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine‐grained, water‐saturated, low‐accommodation, prodeltaic depositional environment. In synergy to this large‐scale picture, small‐scale causative factors favouring second‐ and third‐order faulting seem to be related to mechanical‐rheological instabilities related to localized shallow diagenesis and liquidization fronts.     

生态文明建设的路径依赖与互动关系变化——基于2003-2015年长江经济带地级市面板数据

基于路径依赖视角,采集长江经济带108个地级市的2003-2015年面板数据,运用皮尔逊相关系数、回归分析等方法,刻画长江经济带生态文明建设的路径依赖格局和演化,并初步探讨了影响因素与关系变化。结果表明：① 生态文明建设是一个长期且循序渐进的过程,短期内生态文明建设存在着较强路径依赖,80%以上的城市在相邻阶段内结构相似度的相关系数在中等相关以上,各地区应当具有生态文明建设的战略定力。② 生态文明建设要求新型良性互动关系的建立,出现结构锁定的地区在构建自然系统与其他系统的互动关系上要显著落后。在第二阶段与第三阶段,整个长江经济带的自然状态增长率对经济系统增长和社会系统增长的回归系数分别为0.139和0.061,而在结构锁定地区,回归系数则不显著。③ 在不同阶段自然响应（表征资源利用）、经济压力（表征经济增长）、社会响应（表征教育与社会保障）的增长率与结构相似度呈现显著负相关,表明资源利用效率、资金、教育与社会保障的提升可从手段、资金和意识三方面推动形成新型的良性互动关系,有利于突破当前的区域结构锁定。     

铁路工程地质勘察钻孔质量的层次-模糊综合评判

通过对铁路工程地质勘察钻孔质量评价因素的多层次、多因素研究,建立铁路勘察钻孔质量综合评判指标体系层次模型,运用层次分析法确定每个影响因素的权重,并采用模糊数学基本原理对铁路钻孔质量进行综合评判。在评判模型中,综合考虑影响铁路工程钻探质量的定量、非定量指标,以其成孔条件、钻探记录、原位测试为基本准则层,根据实际现场判断手段确立每个准则下的指标层,将指标层针对评判分级标准转换成隶属度矩阵,利用模糊数学原理综合评判铁路钻孔钻探质量等级。     

PLASTIC DESIGN OF SEISMIC RESISTANT STEEL FRAMES

A new method for designing moment resisting steel frames failing in a global mode is presented in this paper. Starting from the analysis of the typical collapse mechanisms of frames subjected to horizontal forces, the method is based on the application of the kinematic theorem of plastic collapse. The beam section properties are assumed to be known quantities, because they are designed to resist vertical loads. As a consequence, the unknowns of the design problem are the column sections. They are determined by means of design conditions expressing that the kinematically admissible multiplier of the horizontal forces corresponding to the global mechanism has to be the smallest among all kinematically admissible multipliers. In addition, the proposed design method includes both the influence of distributed loads acting on the beams and the influence of second-order effects. In particular, the influence of second-order effects, which can play an important role in the seismic design of steel frames, is accounted for by the mechanism equilibrium curves of the analysed collapse mechanisms. Moreover, in order to show the practical application of the proposed design procedure, a worked example is presented. Finally, the inelastic behaviour of the designed frame is compared to that obtained when the simple member hierarchy criterion or a similar rule is applied. © 1997 by John Wiley & Sons, Ltd.     

Distribution of glaciofluvial sediment within and on the surface of a high arctic valley glacier: Marthabreen,Svalbard

Marthabreen is a 7·8 km long valley glacier in SW Spitsbergen. The glacier is partially covered by a layer of angular debris derived from rockfall in its accumulation area, pierced in places by pinnacles and ridges of glaciofluvial sediment. These concentrations of glaciofluvial sediment fall into three categories: (1) debris pinnacles; (2) longitudinal sediment dykes; (3) longitudinal ridge accumulations. Debris pinnacles are slabs of sediment (predominantly sands, gravels and cobbles) elevated to the glacier surface along thrusts. Longitudinal sediment dykes are low (<0·5 m high) ridges of debris melting out of vertical sediment dykes within the body of the glacier. They are composed of a range of facies including sands, granule gravels, pebble gravels and diamiction. These dykes are sub-parallel to the longitudinal foliation on the glacier and form during folding of the stratification. Longitudinal ridge accumulations are higher (>1 m high) ridges of sorted sand and gravels which are not associated with penetrative ice structures. Their occurrence downglacier of sediment dykes and debris pinnacles suggests that they originate as supraglacial or englacial channels or tunnels filled by sediment derived from the dykes or thrusts. The presence of large quantities of glaciofluvial sediment on the surface of Marthabreen does not imply englacial water flow at high levels within the glacier, but is related to ice deformational processes such as thrusting and folding of debris-rich stratification. Copyright © 1999 John Wiley & Sons, Ltd.     

Probabilistic neural networks for seismic damage mechanisms prediction

The procedure commonly employed to assess the seismic vulnerability of buildings uses simplified qualitative and quantitative observations obtained from the measured data entered into report forms. In Italy, the data sheets adopted by the National Defence Group against Earthquakes (Gruppo Nazionale per la Difesa dai Terremoti—GNDT) play a unifying and reference role. This paper proposes a method for the processing of the data contained in such report forms which is based on probabilistic neural networks producing a Bayesian classification. The final goal is to exploit the fundamental learning and generalization capabilities of neural networks to obtain an estimate of the vulnerability of structural systems. In particular, the aim is to be able to predict the damage mechanisms which may be triggered in the macro-elements of public worship buildings. Copyright © 1999 John Wiley & Sons Ltd.     

济阳坳陷陈家庄凸起东南坡古冲沟沉积充填特征

利用最新的三维地震和钻井、测井等资料,对济阳坳陷陈家庄凸起东南坡古冲沟的地质特征和沉积充填特征进行了探索性研究。边界大断层——陈南断裂的活动控制冲沟的形成。边界断层活动初期,冲沟内充填有近源快速堆积的冲积扇扇根的粗碎屑砂体。断陷的扩张深陷期,靠近冲沟的底壁和测壁为稍长反射段的杂乱地震相,为扇三角洲根部较粗的砂质碎屑。湖盆收缩或萎缩期,冲沟内部发育有极强振幅、平行、高连续的反射相,冲沟的充填相与东营凹陷的河流一三角洲淤浅沉积相吻合,构成一个完整的沉积体系。在对古冲沟的地质特征和沉积充填特征进行研究的基础之上,对古冲沟的油气储集性能进行了概要评价,认为冲沟内由同沉积断层的逆牵引作用所形成的逆牵引背斜与冲沟内常见的前积相反射砂体和深湖相泥页岩相配置,可能构成有利的油气聚集部位。     

城市道路网面域层次结构特征的识别与表达

层次性是道路网一个重要的空间结构特征,文中提出一种城市道路网面域层次结构特征的识别与表达方法。首先以路链为基本单元对道路网数据进行重新组织,选取连通度、接近度、中介度和长度对路链的结构特征重要性进行评价;然后以道路网眼作为表达道路网面域层次结构特征的基本单元,依据路链的属性等级、结构特征重要性以及视觉对称性原则,依次选取路链对道路网最大包络区域进行层次剖分从而获得其包含的各级层次道路网眼;最后利用二叉树模型对道路网眼之间的层次关系和邻接关系进行结构化表达。实验结果表明,所提方法能够完整提取出道路网包含的全部道路网眼并准确建立它们之间的空间关系,其结果能较好地反映道路网面域的层次结构特征。     

FORMATION AND STRUCTURAL EVOLUTION OF INITIAL DISTURBANCE OF TYPHOON FUNG-WONG (2008)

The formation of a tropical cyclone is the result of a process in which an initial disturbance evolves into a warm-core low-pressure system; however, the origin of the initial disturbance and the features of the initial fields are overlooked in most existing theories. In this study, based on FY-2C brightness temperature data and the Japan reanalysis dataset, the origin and evolution of the tropical disturbance that became Typhoon Fung-Wong (2008) were examined. The results demonstrated that the initial disturbance emerged within a saddle-type field with large vertical tropospheric wind shear. The vertical wind shear decreased with the adjustment of the upper circulation; moreover, accompanied by convection over the warm section around the upper cold vortex, it provided favorable thermal and dynamic conditions for the development of a tropical vortex. During its development, the zone of associated positive relative vorticity strengthened and descended from the mid-troposphere to lower levels. This rapid strengthening of lower-level vorticity was due to increasing convergence related to the intensification of the pressure gradient southwest of the subtropical high. This indicated that the upper cold vortex and West Pacific subtropical high played very important roles in this case.