Download or read book A Comprehensive Study on Parameters Affecting Stiffness of Shear Wall frame Buildings Under Lateral Loads written by Nami Rokhgar and published by . This book was released on 2014 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lateral Stiffness is one of the most important properties of a building which not only defines resistance to displacements under lateral loads but it can also have a great impact on natural period of a structure. Different stiffness values can ultimately affect the behavior of a structure under seismic loads and lateral forces that will be applied to it. In this study several parameters that can affect lateral stiffness of shear wall-frame buildings have been studied. At first, different configurations of shear walls in plan were analyzed in both medium rise and high rise buildings. In both cases, models with a central concrete core showed higher stiffness and smaller lateral displacements but at the same time, higher story forces were applied to the structure in seismic analysis. Cracking in shear walls is the other parameter considered in this study. Results indicate that cracked modification factors introduced in ACI can greatly impact the stiffness and other related properties of a building. A more precise approach is used to identify cracked elements based on finite element methods. Openings in shear walls have also been studied. Analysis results showed that in the case considered, openings with an area up to 10% of the wall did not have a significant influence on stiffness of the structure but higher opening ratios eventually resulted into severe loss of stiffness and large displacements. Stiffness of walls not parallel to direction of load is also investigated. Results indicate that even small angles between direction of load and shear wall can considerably reduce the stiffness of a structure in a specific direction. In the end, two parameters affecting flexural capacity of shear walls have been studied, vertical reinforcement and wall thickness. Even though an increase in each of the two parameters can be helpful, results show that each of them can increase flexural capacity of a section more efficiently under different conditions. Analysis in all of the models is performed by ETABS 2013. The intention is not to get involved in too many complex calculations, but rather compare the behavior of buildings in different conditions as a practical guide.
Download or read book Experimental Investigation of Long Term and Lateral Load Behavior of CLT Shear Walls for Mid rise Wood Buildings written by Md Kobir Hossain and published by . This book was released on 2019 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a recognized need for tall building (8-20 story) construction in the United States due to growing population in the urban areas. In addition, there is a significant emphasis placed by the communities on sustainability. Wood is a sustainable construction material with a negative carbon footprint in comparison to steel and concrete, which are the traditional building materials used predominantly in tall buildings. Traditional Light Wood Frame Shear Wall system used in residential building construction in the U.S. cannot be used to construction tall building as it fails to provide necessary strength and stiffness. Mass timber panel such as Cross-Laminated Timber has been recognized as a promising building construction material in recent times and has been used in hundreds of building mostly in low seismic regions. However, to realize an all wood tall building in high seismic areas, lateral load resisting system (LLRS) using CLT needs to be developed and characterized before its implementation into building construction. This research focusses on addressing some of the issues in developing a robust LLRS using unbonded post-tensioned rocking CLT wall system for high seismic application. The parameters that affect the behavior of this system such as the compression, moisture diffusion and creep behavior of CLT material were studied by conducting laboratory testing. The performance of CLT rocking wall system was investigated through laboratory testing of four full scale specimens using different wall dimensions and detailing to gain a thorough understanding of this system behavior under reverse cyclic loading. The results show that this system can provide full recentering up to 3% drift with limited sustained damage at the rocking toes and limited energy dissipation capability. The rocking wall system can be designed as a robust LLRS but can be further improved by incorporating external energy dissipating elements into the system. To improve the system performance by including damping in the rocking wall system, o-connector and LiFS are used to connect two rocking walls. The coupled walls still provide the recentering while reduces the seismic displacement demand resulting from higher damping. Tests and finite element analysis of o-connectors were carried to understand its force-displacement behavior and energy dissipating capacity under reverse cyclic load. Design equations based on the test and FEA results are proposed. Laboratory tests were conducted on two CLT-LiFS hybrid walls in addition to component level tests on LiFS and CLT-LiFS connection. A load transfer mechanism in CLT-LiFS hybrid wall is proposed and used with a simplified calculation procedure to predict the force-displacement behavior of hybrid wall. The study shows that the analysis procedure predicts force capacity within 20% of the test results and can be conservatively used for practice. The test results show that the hybrid wall system has improved energy dissipation capacity while providing almost full recentering at 4% drift. The CLT building performance can be improved and the cost associated with LLRS may be reduced by taking into account the beneficial effect of non-rectangular shear walls (such as T-wall, I-wall). Non-rectangular walls can be achieved by connecting them at web-to-flange interface with high stiffness connections. Also, a high stiffness wall-to-foundation connection which can transfer the high base shear to foundation needs to be developed. Two connections, one for web-to-flange interface and another for wall-to-foundation interface, is developed by using grouted shear key incorporating ultra-high performance concrete and self-tapping screw. Laboratory tests on these two connection show that the connections have very high stiffness (4 times) compared to traditional bracket type ones and they have high strength as high as 3 to 4 times.
Download or read book Advances in Structural Engineering and Rehabilitation written by Sondipon Adhikari and published by Springer. This book was released on 2019-06-12 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises select papers presented at the International Conference on Trends and Recent Advances in Civil Engineering (TRACE 2018). The book covers a wide range of topics related to recent advancements in structural engineering, structural health monitoring, rehabilitation and retrofitting of structures, and earthquake-resistant structures. Based on case studies and laboratory investigations, the book highlights latest techniques and innovative methods for building repair and maintenance. Recent development in materials being used in structural rehabilitation and retrofitting is also discussed. The contents of this book can be useful for researchers and professionals working in structural engineering and allied areas.
Download or read book Wind and Earthquake Resistant Buildings written by Bungale S. Taranath and published by CRC Press. This book was released on 2004-12-15 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed as a resource for practicing engineers, while simultaneously serving as a text in a formal classroom setting, Wind and Earthquake Resistant Buildings provides a fundmental understanding of the behavior of steel, concrete, and composite building structures. The text format follows, in a logical manner, the typical process of designing a bu
Download or read book Study of Deflection of Single and Multi Storey Light Frame Wood Shear Walls written by Mohammad Mehdi Bagheri and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The behavior of wood shear walls has been the focus of researchers and engineers for many years due to their availability in the North American construction landscape. A review of the established literature showed that most of the research have focused on the shear wall behavior as a whole with no investigation specifically targeting the individual components of its deflection. Also, little to no attention has been given to the investigation of the cumulative effects especially when the out-of-plane diaphragm stiffness is considered. The current study aims at investigating the effects of construction details variation on the behavior of the shear walls and evaluating whether the current deflection equation, as per wood design standard (CSA 2014) can adequately predict the overall wall stiffness. A total of 27 full-scale single-storey walls, with different construction details and aspect ratios, were tested under either static or monotonic (as both are the same) loading. The parameters that were varied in the testing were the stud size and spacing, nail diameter and spacing, sheathing panel type and thickness and hold-down anchoring system/type. For the two-storey walls, two different loading cases were considered, namely where the load was applied at the top or bottom storey only. The results showed that the strength and stiffness correlated almost directly to the inverse of the wall aspect ratio. There was no clear trend when considering the effect of the walls' aspect ratios on ductility. Unexpectedly, walls with aspect ratios not permitted according to the wood design standard (4:1 and 6:1) followed similar strength and stiffness trends and had sufficient ductility ratios as those with smaller aspect ratios. This observation explains in part some of the discrepancies found between engineering calculations and behavior of actual building with light frame wood shear walls. Significant discrepancies were found when comparing the various deflection constituent with those estimated using the design expression. Adding more end studs and changing the size of the studs had no significant effect on the overall wall capacity and little effect on its stiffness. Reducing the stud spacing had, as expected, no effect on the wall capacity; however, the results showed that the bending stiffness was affected by the overall number of studs in the wall and not solely by the end studs. Shear walls sheathed with plywood panels exhibits slightly higher peak load and initial stiffness than those with OSB, which was mainly attributed to the greater panel thickness, and possibly density, of the plywood. Both sheathing types provided similar levels of ductility, as expected. Thicker sheathing increased the capacity and stiffness of the wall with no significant change observed in ductility ratio. The wall strength was significantly affected by the nail diameter and nail spacing, but no difference was observed when the nail edge/end distance was increased. The results also showed that discrete hold-down system behaved in a non-linear manner with a significantly greater initial stiffness than that assumed in design. The study also showed that having continuous hold-down connections has a positive effect on the capacity, stiffness and ductility of the wall when compared with discrete hold-downs. Having no hold-down adversely affects the wall capacity and stiffness, but did not affect the ductility of the wall. For the two-storey walls, the deflection estimated based on the cumulative effect assumption showed slight differences when compared with that observed in the experimental study. It was observed that the majority of the cumulative effect stems from the rigid body rotation due to deformation in the hold-down devices. A Computer shear wall model (through SAP2000) was developed using linear "frame" and "membrane" elements for the framing and sheathing members, respectively, whereas the sheathing to framing nails and hold-down were modeled using nonlinear springs. It was found that the model was capable of predicting the peak load, ultimate deflection and yield loads with reasonable accuracy, but overestimated the initial stiffness and ductility of the walls. In general, when the force-displacement curves were compared it was evident that the model was capable of predicting the wall behaviour with reasonable accuracy. When investigating the cumulative effects using the model, the results clearly showed that the assumption of cumulative effects due to rigid body rotation is valid for stacked shearwalls with no consideration for the floor diaphragm. The effect of the diaphragm on the behavior of the shear walls, in particular its out-of-plane rigidity was simulated by modeling the floors as beam. The out of plane stiffness of the shear walls was investigated for idealized (infinitely stiff or flexible) as well as "realistic". The results showed reductions in the shearwall deflection in the magnitude of approximately 80% considering the out of plane rigidity of the diaphragm. It was also concluded that considering conservative estimates of out of plane stiffness might lead to a very significant reduction in deflection and that assuming the floor diaphragm to be infinitely rigid out of plan seems reasonable. For diaphragms supported on multiple panels further reduction in the deflection was observed. More work, particularly at the experimental level, is needed to verify the finding obtained in the numerical investigation related to the effect of out of plane diaphragm stiffness.
Download or read book Manual for the Design of Concrete Building Structures to Eurocode 2 written by and published by . This book was released on 2006-01-01 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lateral Load Analysis of Shear Wall Frame Structures written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study is to model and analyze the nonplanar shear wall assemblies of shear wall-frame structures. Two three dimensional models, for open and closed section shear wall assemblies, are developed. These models are based on conventional wide column analogy, in which a planar shear wall is replaced by an idealized frame structure consisting of a column and rigid beams located at floor levels. The rigid diaphragm floor assumption, which is widely used in the analysis of multistorey building structures, is also taken into consideration. The connections of the rigid beams are released against torsion in the model proposed for open section shear walls. For modelling closed section shear walls, in addition to this the torsional stiffness of the wide columns are adjusted by using a series of equations. Several shear wall-frame systems having different shapes of nonplanar shear wall assemblies are analyzed by static lateral load, response spectrum and time history methods where the proposed methods are used. The results of these analyses are compared with the results obtained by using common shear wall modelling techniques.
Download or read book Hysteretic Response of Steel Clad Wood Framed Shear Walls Under Reverse cyclic Loading written by Khoi Duc Mai and published by . This book was released on 2016 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: FEA models were developed and validated to predict shear strength and effective shear modulus of SCWF shear walls under monotonic loading. Moreover, the hysteretic behavior of SCWF shear walls was predicted using hysteretic behavior of sheathing-to-framing connector elements. Analyses were performed to assess the shear strength, stiffness, ductility, equivalent energy elastic plastic (EEEP), and hysteretic parameters of tested SCWF shear wall specimens. Experimental tests also provided the seismic design coefficients of SCWF shear walls, which are currently lacking in the building codes.
Download or read book Factors Affecting Shear Wall Stiffness in Tall Buildings written by Michel Salim Slaiman and published by . This book was released on 1976 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shear Wall frame Interaction written by Iain A. MacLeod and published by . This book was released on 1971 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reinforced Concrete Design of Tall Buildings written by Bungale S. Taranath and published by CRC Press. This book was released on 2009-12-14 with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt: An exploration of the world of concrete as it applies to the construction of buildings, Reinforced Concrete Design of Tall Buildings provides a practical perspective on all aspects of reinforced concrete used in the design of structures, with particular focus on tall and ultra-tall buildings. Written by Dr. Bungale S. Taranath, this work explains t
Download or read book STESSA 2003 Behaviour of Steel Structures in Seismic Areas written by Federico Mazzolani and published by Routledge. This book was released on 2018-03-29 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting a comprehensive overview of recent developments in the field of seismic resistant steel structures, this volume reports upon the latest progress in theoretical and experimental research into the area, and groups findings in the following key sections: · performance-based design of structures · structural integrity under exceptional loading · material and member behaviour · connections · global behaviour · moment resisting frames · passive and active control · strengthening and repairing · codification · design and application
Download or read book Interaction Between Floor Slabs and Shear Walls in Tall Buildings written by Yang Chee Wong and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earthquake Engineering Handbook written by Charles Scawthorn and published by CRC Press. This book was released on 2002-09-27 with total page 1508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquakes are nearly unique among natural phenomena - they affect virtually everything within a region, from massive buildings and bridges, down to the furnishings within a home. Successful earthquake engineering therefore requires a broad background in subjects, ranging from the geologic causes and effects of earthquakes to understanding the imp
Download or read book Analysis of Shear Wall frame Structures Subjected to Lateral Loads written by G. Viswanathan and published by . This book was released on 1972 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lateral Resistance of Steel clad Wood framed Shear Walls with Openings written by Dustin G. Gatchalian and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PRO 8 1st International RILEM Symposium on Timber Engineering written by Lars Boström and published by RILEM Publications. This book was released on 1999 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:
