土工合成材料构造物的抗震性能     

李广信 《世界地震工程》2010,26(4)

文中介绍了日本阪神地震、美国北里奇地震、土耳其伊斯坦布尔地震、中美洲萨尔瓦多地震、台湾集-集地震以及我国四川的汶川地震中一些加筋挡土墙加筋边坡的震后调查。结果表明,看似柔弱的土工合成材料,具有良好的抗震性能。同时也介绍了用EPS(聚苯乙烯板块)作为填料的优异抗震性能。  相似文献   

Three‐dimensional beam–truss model for reinforced concrete walls and slabs – part 2: modeling approach and validation for slabs and coupled walls          下载免费PDF全文

Yuan Lu  Marios Panagiotou 《地震工程与结构动力学》2016,45(11):1707-1724

A three‐dimensional beam–truss model (BTM) for reinforced concrete (RC) walls that explicitly models flexure–shear interaction and accurately captures diagonal shear failures was presented in the first part of this two‐paper series. This paper extends the BTM to simulate RC slabs and coupled RC walls through slabs and beams. The inclination angle of the diagonal elements for coupled RC walls is determined, accounting for the geometry of the walls and the level of coupling. Two case studies validate the model: (1) a two‐bay slab–column specimen experimentally tested using cyclic static loading and (2) a five‐story coupled T‐wall–beam–slab specimen subjected to biaxial shake table excitation. The numerically computed lateral force–lateral displacement and strain contours are compared with the experimentally measured response and observed damage. The five‐story specimen is characterized by diagonal shear failure at the bottom story of the walls, which is captured by the BTM. The BTM of the five‐story specimen is used to study the effects of coupling on shear demand for lightly reinforced RC coupled walls. The effect of mesh refinement and bar fracture of non‐ductile transverse reinforcement is studied. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Numerically based proposals for the stiffness and strength of masonry infills with openings in reinforced concrete frames          下载免费PDF全文

Farhad Akhoundi  Paulo B. Lourenço  Graça Vasconcelos 《地震工程与结构动力学》2016,45(6):869-891

Aimed at investigating the effect of openings on the in‐plane behaviour of masonry infills in reinforced concrete frames, a parametric study is presented based on model calibration via experimental tests. Two types of openings are investigated: central window openings and different combinations of door and window openings based on the typologies of southern European countries. First, a finite element model of the structure is made using the DIANA software program. Then, after calibration with experimental results, a parametric analysis is carried out to investigate the effect of the presence and location of the different types of openings on the in‐plane behaviour of the infilled frame. Finally, different equations for predicting the initial stiffness and lateral strength of infilled frames with any types of openings were obtained. An α factor related to the geometry of the piers between openings is proposed to take into account the location of the openings in the developed equations. Subsequently, the masonry infill panel is replaced by a diagonal strut. An empirical equation is also proposed for the width of an equivalent strut to replace a masonry infill panel with openings in such a way that they possess the same initial stiffness. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

In‐plane and out‐of‐plane behavior of confined masonry walls for various toothing and openings details and prediction of their strength and stiffness          下载免费PDF全文

Vaibhav Singhal  Durgesh C. Rai 《地震工程与结构动力学》2016,45(15):2551-2569

Eight half‐scale brick masonry walls were tested to study two important aspects of confined masonry (CM) walls related to its seismic behavior under in‐plane and out‐of‐plane loads. Four solid wall specimens tested to investigate the role of type of interface between the masonry and tie‐columns, such as toothing varying from none to every course. The other four specimens with openings were tested to study the effectiveness of various strengthening options around opening to mitigate their negative influence. In the set of four walls, one wall was infilled frame while the other three were CM walls of different configurations. The experimental results were further used to determine the accuracy of various existing models in predicting the in‐plane response quantities of CM walls. Confined masonry walls maintained structural integrity even when severely damaged and performed much better than infill frames. No significant effect of toothing details was noticed although toothing at every brick course was preferred for better post‐peak response. For perforated walls, provision of vertical elements along with continuous horizontal bands around openings was more effective in improving the overall response. Several empirical and semi‐empirical equations are available to estimate the lateral strength and stiffness of CM walls, but those including the contribution of longitudinal reinforcement in tie‐columns provided better predictions. The available equations along with reduction factors proposed for infills could not provide good estimates of strength and stiffness for perforated CM walls. However, recently proposed relations correlating strength/stiffness with the degree of confinement provided reasonable predictions for all wall specimens. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

基于ACCRBF网络的多层砖房震害预测   总被引：1，自引：1，他引：0  

杨秀萍  程运平  陈克珩  丁大勇 《震灾防御技术》2013,8(1):90-96

针对传统震害预测方法逐栋抽样计算建筑物抗震性能的不足,本文提出了一种基于蚁群聚类径向基(ACCRBF)网络模型的建筑物震害预测方法。依据不同地震动峰值加速度下多层砖房的实际震害资料,对模型进行训练,在模型的输入和输出之间建立映射关系,并利用这种映射关系对未知样本进行分类,实现对多层砖房的震害分析和预测。模型的输入为反映结构的震害影响因子,输出为给定的地震动峰值加速度下结构震害等级。研究表明,基于ACCRBF网络模型的多层砖房震害预测结果与震害实例基本吻合,具有推广应用价值。  相似文献   

A new limit equilibrium method for the pseudostatic design of embedded cantilevered retaining walls     

《Soil Dynamics and Earthquake Engineering》2013

This paper describes a new pseudostatic limit equilibrium method for the design of cantilevered retaining walls under seismic actions. The method has been applied in a parametric study of the effects of the geometry of the wall, considering different excavated and embedded depths, of the strength of the soil, and of the contact between the soil and the wall. The pseudostatic predictions are in very good agreement, both in terms of horizontal contact stress and bending moment distributions, with the results of truly dynamic 2-D finite difference analyses and published experimental data. It is found that for increasing strengths of the soil–wall system both the critical acceleration and the maximum bending moment on the wall increase. In other words, a stronger soil–wall system will experience smaller displacements during the earthquake, but this is paid for by increasing internal forces in the wall.  相似文献   

农村住宅砌体结构地震破坏数值模拟研究   总被引：1，自引：1，他引：0       下载免费PDF全文

马宏旺  王兰民  陈龙珠  李庆松 《地震工程学报》2013,35(2):232-239

国内震害调查表明我国农村房屋在地震中破坏严重,主要原因是农村自建房屋大都缺乏基本抗震措施.近年来有关部门针对农村房屋的抗震性能提出一些改进措施,但这些措施实际抗震效果如何,除了极少数通过模型试验验证外,很少得到验证.本文建立了砌体结构非线性有限元分析模型,以一幢农宅为研究对象,通过地震时程反应来再现其在地震作用下的破坏状况.研究表明本文提出数值模型能够较好的模拟砌体结构在地震中破坏过程,发现结构抗震薄弱部位.通过对三种模型对比分析表明圈梁和构造柱可以有效提高砌体结构整体抗震性能,但对局部破坏影响不大,需要在以后抗震设计中加以考虑.  相似文献   

地连墙与自凝灰浆防水墙组合防渗新技术的应用及分析          下载免费PDF全文

陈晓飞 《探矿工程》2012,39(8):50-53

地连墙与自凝灰浆防水墙配套使用是一种新型的深基坑支护形式,相对传统的基坑支护形式具有经济节约和防渗效果佳等优点。结合南京华新城AB地块深基坑工程应用实例,根据其复杂的工程特点,从防渗、力学性能、造价等方面论证了地连墙与自凝灰浆防渗墙配套使用的可行性及优点,并结合工程实际对自凝灰浆防渗墙的施工工艺和技术要点做了详细的介绍。  相似文献   

Seismic lateral movement prediction for gravity retaining walls on granular soils     

J.C. Tiznado  F. Rodríguez-Roa 《Soil Dynamics and Earthquake Engineering》2011

At present, methods based on allowable displacements are frequently used in the seismic design of earth retaining structures. However, these procedures ignore both the foundation soil deformability and the seismic amplification of the soil placed behind the retaining wall. Thus, they are not able to predict neither a rotational failure mechanism nor seismic induced lateral displacements with an acceptable degree of accuracy for the most general case. In this paper, a series of 2D finite-element analyses were carried out to study the seismic behavior of gravity retaining walls on normally consolidated granular soils. Chilean strong-motion records were applied at the bedrock level. An advanced non-linear constitutive model was used to represent both the backfill and foundation soil behavior. This elastoplastic model takes into account both the stress dependency of soil stiffness and coupling between shear and volumetric strains. In unloading–reloading cycles, the non-linear shear-modulus reduction with shear strain amplitude is considered. Interface elements were used to model soil–structure interaction. Routine-design charts were derived from the numerical analyses to predict the lateral movements at the base and top of gravity retaining walls located at sites with similar seismic characteristics to the Chilean subduction zone. Thus, wall seismic rotation can also be obtained. The developed charts consider wall dimensions, granular soil properties, bedrock depth, and seismic input motion characteristics. As shown, the proposed charts match well with available experimental data.  相似文献   

基于MATLAB神经网络方法的多层砖房震害预测   总被引：1，自引：0，他引：1       下载免费PDF全文

姜伟  马令勇  刘功良 《地震工程学报》2011,33(2):155-158

提出利用MATLAB人工神经网络工具箱建立基于贝叶斯正则算法的BP神经网络模型,以地震区多层砖房震害调查数据为因子的震害预测方法.神经网络模型输入震害因子包括建筑的层数、施工质量、房屋整体性等,输出值为建筑物在地震作用下的破坏程度.结果表明,本方法可以对多层砖房的震害样本进行预测并达到较理想的效果.  相似文献