Cyclic testing of unreinforced masonry walls in two‐way bending     

M. C. Griffith  J. Vaculik  N. T. K. Lam  J. Wilson  E. Lumantarna 《地震工程与结构动力学》2007,36(6):801-821

An experimental programme was conducted in which eight full‐scale unreinforced masonry walls were subjected to cyclic face loading using a system of airbags. Of the eight walls, six contained a window opening and four were subjected to vertical pre‐compression. Combined supports at the vertical and horizontal edges ensured that under face loading the walls underwent two‐way bending. The test walls were found to possess good post‐peak strength and displacement capacity as well as reasonable energy dissipation characteristics. Significant strength and stiffness degradation and non‐symmetry of strength in the positive and negative displacement directions were also evident. Discussion of the causes of the aforementioned trends and their implications towards the seismic response of masonry walls is provided. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Topography and palaeogeographic evolution of a middle Miocene foredeep basin plain (Northern Apennines, Italy)     

Claudio Corrado Lucente 《Sedimentary Geology》2004,170(3-4):107-134

The Marnoso–arenacea basin was a narrow, northwest–southeast trending, foredeep of Middle–Late Miocene age bounded to the southwest by the Apennine thrust front. The basin configuration and evolution were strongly controlled by tectonics.

Geometrical and sedimentological analysis of Serravallian turbidites deposited within the Marnoso–arenacea foredeep, combined with palaeocurrent data (turbidite flow provenance, reflection and deflection), identify topographic irregularities in a basin plain setting in the form of confined troughs (the more internal Mandrioli sub-basin and the external S. Sofia sub-basin) separated by an intrabasinal structural high. This basin configuration was generated by the propagation of a blind thrust striking northwest to southeast, parallel to the main trend of the Apennines thrust belt.

Ongoing thrust-induced sea bed deformation, marked by the emplacement of large submarine landslides, drove the evolution of the two sub-basins. In an early stage, the growth and lateral propagation of a fault-related anticline promoted the development of open foredeep sub-basins that were replaced progressively by wedge-top or piggy-back basins, partially or completely isolated from the main foredeep. Meanwhile, the depocenter shifted to a more external position and the sub-basins were incorporated within an accretionary thrust belt.  相似文献   

人工质量在砖混结构振动台试验中的作用   总被引：5，自引：0，他引：5  

黄维平  王连广 《地震工程与工程振动》2001,21(3):99-103

通过组合墙片的拟静力试验和模型房屋的振动台试验，分析研究了人工质量模拟对砖混结构振动台试验的作用和影响。研究表明，重力对结构的弯曲刚度有较大影响，但不影响结构的剪切刚度。在主拉应力破坏的条件下，结构的破坏荷载随重力的增加而增大。提出了不完全模拟的人工质量模型应满足的相似条件及如何根据模型试验结果估计原型结构的抗震能力。  相似文献   

组合墙结构房屋抗震性能的振动台试验研究   总被引：1，自引：0，他引：1  

黄维平  王连广 《地震工程与工程振动》2001,21(4):63-66

通过三个组合墙模型房屋的振动台试验，分析了组合墙结构体系房屋的动力性能和抗震能力，比较了底一层和底两层框架组合墙房屋和普通组合墙房屋的抗震性能。结果表明，八层组合墙房屋的抗震能力远远超过设计能力，可用于八度地区，底框架组合墙房屋的抗震性能优于普通组合墙房屋，底两层框架组合墙房屋也优于底一层框架组合墙房屋。  相似文献   

Mathematical modelling of an infilled RC frame structure based on the results of pseudo‐dynamic tests     

Matja Dol&#x;ek  Peter Fajfar 《地震工程与结构动力学》2002,31(6):1215-1230

In this paper, a technique is presented which employs the results of pseudo‐dynamic tests for the development of a mathematical model. This technique, described by means of the mathematical modelling of a three‐storey reinforced concrete frame building with infill in the bottom two storeys, which was tested at ELSA in Ispra, proved to be effective and to lead to a fairly accurate structural model. The results of analyses suggest that the global non‐linear seismic response of reinforced concrete frames with masonry infill can be adequately simulated by a relatively simple mathematical model, which combines beam elements with concentrated plasticity, simple connection elements, and equivalent strut elements representing the infill walls (provided that the infill does not fail out of plane and that no shear sliding failure occurs). Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Building damage from the Marmara, Turkey earthquake of August 17, 1999     

Michel Bruneau 《Journal of Seismology》2002,6(3):357-377

The objective of this paper is to provide a brief overview of damage as observed immediately following the earthquake. Detailed studies of structural seismic performance, conducted in the time elapsed since August 1999, are not the subject of this paper, but rather the object of other papers presented in this Special Issue of the Journal. Damage to reinforced concrete, masonry, and steel structures, is described. The mode the failure presented include: foundation failures; soft stories; strong beams and weak columns; lack of column confinement and poor detailing practice; buckling and fractures of steel members; and non-structural damage. Some general lessons learned from this earthquake are also formulated.  相似文献   

2-D rotation behavior of a rigid ellipse in confined viscous simple shear: numerical experiments using FEM     

R. Taborda  J. Antunes  F.O. Marques 《Tectonophysics》2004,379(1-4):127-137

The rotation behavior of rigid elliptical inclusions adherent to the viscous matrix in simple shear flow is investigated using a 2-D finite element numerical model. Several simulations were performed using different ratios (S) between shear zone width and inclusion's least principal axis. A computational strategy was devised to calculate pressure and viscous forces exerted on the inclusion and deduce its angular velocity. For large S values, results agree remarkably well with theoretical predictions, while for small S values results deviate significantly from theory but are in agreement with previous analogue experiments. The numerical model provided detailed and coherent information about the physical parameters involved in the process (e.g., pressure, strain rate and vorticity distributions within the model).  相似文献   

西安市地热水开采与地面沉降、地裂缝关系的分析   总被引：6，自引：1，他引：6       下载免费PDF全文

吴富春  方炜  宋立胜  王锋  朱兴国  景北科  董星宏  左永青 《地震地质》2002,24(2):234-240

西安市地面沉降和地裂缝在空间分布上有明显的一致性 ,它们的发展过程和强度变化在时间上也有明显的同步性。诱发地面沉降的主因是过量开采承压水导致承压水位下降 ,含水层介质的孔隙压力减小 ,黏性土层释水压密导致地面永久性的沉降 ,而且浅层的释水压密量大于深层 ;不均匀的地面沉降又诱发了地裂缝。无论是地热井水位或热水开采量的变化 ,还是分层沉降量的观测资料都表明 ,目前西安市深层热水开采还没有加剧西安市的地面沉降和地裂缝活动。控制并减少承压水的开采量 ,是减弱西安市地面沉降和地裂缝活动的最有效的方法  相似文献   

承压井水位对气压动态过程的响应   总被引：12，自引：0，他引：12  

张昭栋  郑金涵 《地球物理学报》1989,32(5):539-549

本文从气压影响承压井水位的偏微分方程出发,考虑到井孔和含水层之间相互渗流的边界条件,得出了方程的解。给出了承压井水位对气庄动态过程响应的气压效率和位相滞后。讨论了气压效率和位相滞后与水井含水层系统各参数的关系。并指出气压效率越大的承压井,其含水层对应力应变的敏感程度越差。  相似文献   

底框砌体滑移隔震结构的优化设计研究   总被引：2，自引：0，他引：2  

关罡 《世界地震工程》2004,20(2):61-63

针对底层框架砌体滑移隔震结构的特点，构建了系统的优化设计数学模型；通过计算分析，探讨了地震作用下结构的优化设计问题；给出了结构最大地震反应随设计参数的变化规律和设计变量的优化解。  相似文献