我国实验岩石力学与构造物理学研究的若干新进展   总被引：5，自引：2，他引：5       下载免费PDF全文

马胜利  马瑾 《地震学报》2003,25(5):528-534

简述了近年来我国学者在与地震学和地球内部物理学相关的实验岩石力学和构造物理学研究方面的进展．在此领域的进展主要体现在:大量实验以及数学模拟结果丰富了对岩石脆性破裂过程，特别是结构和介质非均匀条件下破裂过程的认识；在非均匀断层的摩擦行为与失稳成核方面取得了一些新结果，揭示了断层滑动行为的复杂性；在岩石脆塑性转换和塑性流变方面取得了一些新结果，特别是在下地壳和上地幔物质的流变性质方面取得了重要进展；在高温高压岩石物理方面取得了一批实验结果, 并应用于地球内部物质的组成和状态的研究．这些结果为深入理解地球内部物质的物理性质、变形机制及地震物理过程提供了有价值的参考资料.   相似文献   

华南地区岩石圈三维结构类型与演化动力学   总被引：9，自引：0，他引：9  

蔡学林  朱介寿  曹家敏  刘顺  郑圻森 《大地构造与成矿学》2003,27(4):301-312

从地球层块结构研究思路出发,对华南及邻区天然地震面波层析成像进行系统地构造解析,发现岩石圈中下部存在形态各异,大小不等的高速块体,结合地质学、地球化学、其它地球物理学标志等多学科综合研究,将其称为幔块构造。研究显示高速块体或幔块构造是华南地区岩石圈构造格局和岩石圈表层构造变形最基本条件之一。首次建立起华南地区岩石圈三种三维几何结构样式:克拉通陆根状结构、造山带楔状结构和碎块状结构,以及岩石圈三类构造演化类型:克拉通型岩石圈、增厚型岩石圈和减薄型岩石圈(弱减薄型岩石圈及强减薄型岩石圈)。本文在论述华南岩石圈三维结构构造类型基本特征基础上,首次探讨了华南地区软流圈三维结构以及该区岩石圈演化动力学特征。  相似文献   

外套框架加层结构利用摩擦和消能装置试验及构造措施研究     

殷永炜  李宏男 《地震工程与工程振动》2003,23(1):152-159

本文提出了在外套框架加层结构中采用摩擦阻尼器和砂垫层作为减震装置，进行增设摩擦和消能的加层结构模型的振动台试验，结果表明，采用摩擦和消能装置能有效地减小加层结构的地震反应。在此基础上，对采用摩擦和消能装置加层结构的构造措施进行了研究。  相似文献   

Morphological Characteristics of Till Formations in Relation with Mechanical Parameters     

Thomas Lebourg  Joëlle Riss  Richard Fabre  Bernard Clément 《Mathematical Geology》2003,35(7):835-852

The study of landslides stability on mountain slopes can become very difficult when materials in movement are heterogeneous: it is a current problem with the old glacial till formations presently under study (Aspe Valley, Pyrénées, France). Analysis of slope stability using numerical models necessitates accurate data about mechanical and physical properties. Because tills are very heterogeneous, a large sample is necessary but, unfortunately, data acquisition costs a lot of time and money. Therefore, we would like to estimate mechanical data from correlated parameters that are easier to acquire (morphological parameters using image analysis). Observations in the field and previous mechanical results in the laboratory have shown that differences between the behavior of tills seem to be related not only to their 3D structure but also to the morphological and petrographical characteristics of their components. The aim of this paper is first to illustrate how to classify the till formations textural and petrographical characteristics at the sample scales; these classifications are based on the distributions of size, shape of their constitutive elements (blocks, matrix, etc.). Significant statistical results are available by applying image analysis methods based on mathematical morphology. Next we show how these characteristics are related to the mechanical characteristics (friction angle, cohesion). Six specific till formations were collected, and we establish the relation between the effective internal angle of friction and the elongation factor.  相似文献   

带负摩阻力桩基的设计与检测   总被引：8，自引：0，他引：8  

夏力农  王星华 《岩土力学》2003,(Z2)

分析了带负摩阻力桩基的荷载传递特点,比较了带负摩阻力桩的实际工作状态与静载试压条件下的工作性状之间的差异。通过一个工程实例说明了带负摩阻力桩的承载力评价的缺陷,设计与检测之间的不协调。提出了带负摩阻力桩设计与检测的合理方法。  相似文献   

STUDY OF THE NONLINEAR MECHANISM ABOUT THE FORMATION OF BLOCKING HIGH^*          下载免费PDF全文

ZHENG Zuguang  LI Xiuling  LIU Lihong  WU Hong 《Acta Meteorologica Sinica》2004,18(4):423-440

In this paper,a nonlinear dynamical system considering the interactions among ultra-long wave,long wave and zonal flow in a baroelinic atmosphere was found.In this system,thermal forcing and frictional dissipation are regarded as the external parameters.The procedure,in which the maps of orbit in phase space,contour of stream function and section of Poincaré mapping are combined with each other,is used to determine the distributions of system states and circulation patterns and to draw the corresponding diagrams.The results show that by using the Galerkin method,there is no essential influence of the increasing of orders of truncated-spectrum in a certain range on the distributions of system states and circulation patterns,but it makes them somewhat complexities.By contrast,the changing of distribution of thermal forcing exerts a great influence on the system.Blocking high links closely with the oscillating of the atmospheric circulation and the meridional growing intensely,while the development of synoptic wave can promote the oscillating.  相似文献   

Predictive control of seismic structures with semi‐active friction dampers     

Lyan‐Ywan Lu 《地震工程与结构动力学》2004,33(5):647-668

In this paper a predictive control method especially suitable for the control of semi‐active friction dampers is proposed. By keeping the adjustable slip force of a semi‐active friction damper slightly lower than the critical friction force, the method allows the damper to remain in its slip state throughout an earthquake of arbitrary intensity, so the energy dissipation capacity of the damper can be improved. The proposed method is formulated in a discrete‐time domain and cast in the form of direct output feedback for easy control implementation. The control algorithm is able to produce a continuous and smooth slip force for a friction damper and thus avoid exerting the high‐frequency structural response that usually exists in structures with conventional friction dampers. Using a numerical study, the control performance of a multiple degrees of freedom (DOF) structural system equipped with passive friction dampers and semi‐active dampers controlled by the proposed method are compared. The numerical case shows that by merely using a single semi‐active friction damper and a few sensors, the proposed method is able to achieve better acceleration reduction than the case using multiple passive dampers. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

顶管施工中注浆减摩作用机理的研究   总被引：20，自引：1，他引：20  

魏纲  徐日庆  邵剑明  罗曼慧  金自力 《岩土力学》2004,25(6):930-934

长距离顶管施工中为减小顶进阻力通常采用注浆减摩措施。研究了注浆材料及其性能，对注浆过程中浆液与管道以及周围土体之间的相互作用机理进行了分析，探讨了浆液在土体中的渗流以及注浆对土层移动的影响，提出了注浆时应注意的几个问题。  相似文献   

开合构造环境下花岗岩体的构造样式与变形差异   总被引：1，自引：0，他引：1  

杨坤光徐亚军  杨奎锋刘强 《地质通报》2004,23(3):246-249

传统研究认为，大量花岗岩体的侵入发生于区域性伸展环境，是碰撞造山后应力松弛阶段侵位的，称之为造山后或非造山侵入体。近年来，对造山带和古岩浆弧的深入研究发现，花岗岩不但可以侵位于伸展构造环境，也可侵位于挤压构造环境(同构造侵入体)，两者在三维窄间形态、宏观尺度、露头尺度、显微尺度上的构造样式与变形往往是不同的。区分2类不同构造样式的岩体，对于分析区域构造和造山带演化有着重要的意义。  相似文献   

Chain-based polyline tessellation algorithm for cartographic rendering     

Mingguang Wu  Peibei Zheng  Guonian Lu  A-Xing Zhu 《制图学和地理信息科学》2017,44(6):491-506

ABSTRACT

Although the extrusion of 1D polylines into a 2D polygon and the tessellation of the polygon into primitives has been performed in the field of computer graphics, the efficient, robust, and high-quality tessellation of thick polylines that supports various cartographic styles for polyline rendering remains a practical challenge. We examined and compared existing vertex-, segment-, and polygon-based algorithms, and present a chain-based tessellation algorithm for cartographic rendering: points in the polyline are classified into abrupt and smooth points according to their point spacing, angle and thickness. The polylines are then divided into abrupt and smooth chains by clustering points that are adjacent and of the same type. An optimal algorithm is also presented to continuously tessellate the smooth chains into minimum geometric primitives and efficiently tessellate the abrupt chains into geometric primitives. We implemented the proposed algorithm and present the results of robustness, efficiency, quality, and cartographic styling tests conducted on real-world polylines. The results indicate that this approach has substantial advantages when considering all four requirements (robustness, efficiency, quality, and the support for various cartographic styles).  相似文献