Download or read book Seismic Design and Testing of Rocking Cross Laminated Timber Walls written by Ryan S. Ganey and published by . This book was released on 2015 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mass timber is an attractive alternative to nonrenewable materials such as concrete and steel. High rise timber buildings have not been built in high seismic areas due to lack of ductile lateral force resisting systems that can have large seismic force reduction factors. Seismically resilient, lateral systems for tall timber buildings can be created by combining cross laminated timber (CLT) panels with post-tensioned (PT) self-centering technology. The concept features a system of stacked CLT walls where particular stories are equipped to rock against the above and below floor diaphragms through PT connections and are supplemented with mild steel U-shaped flexural plate energy dissipation devices (UFPs). Experiments were conducted to better understand rocking CLT wall behavior and seismic performance. The testing program consisted of five single wall tests with varying PT areas, initial tensioning force, CLT panel composition, and rocking surface and one coupled wall test with UFPs as the coupling devices. The walls were tested with a quasi-static reverse-cyclic load protocol. The experimental results showed a ductile response and good energy dissipation qualities. To evaluate the feasibility and performance of the rocking CLT wall system, prototype designs were developed for 8 to 14 story buildings in Seattle using a performance-based seismic design procedure. Performance was assessed using numerical simulations performed in OpenSees for ground motions representing a range of seismic hazards. The results were used to validate the performance-based seismic design procedure for tall timber buildings with rocking CLT walls.

Download or read book Large scale Dynamic Testing of Rocking Cross Laminated Timber Walls written by Sarah Wichman and published by . This book was released on 2018 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the recent development of engineered wood products such as cross laminated timber (CLT), tall mass timber buildings are becoming a feasible and attractive alternative to using nonrenewable materials such as concrete and steel. Using CLT panels in a post-tensioned rocking wall system shows great potential for creating reliable, cost-effective, and rapidly constructible ductile seismic load resisting systems. The design of these systems are supplemented with replaceable steel U-shaped flexural plate energy dissipation devices (UFPs). This system has opened the door to creating seismic resilience systems that sustain minor damage during large earthquakes. With this in mind, the NHERI TallWood Project funded by the National Science Foundation, is developing a rocking cross laminated timber wall seismic force resisting system and design procedure for tall timber buildings that enables seismic resilience by meeting rigorous performance requirements. The system is designed to have no damage during a frequent hazard (such as a 50% probability of exceedance in 50 years), limits damage to the easily replaceable UFP devices in less frequent earthquakes (such as a 10% probability of exceedance in 50 years), and has more considerable damage that may require CLT repair and PT replacement in an even less frequent hazard (such as a 2% probability of exceedance in 50 years). Experiments conducted by the NHERI TallWood group tested a full-scale two-story mass timer building, with CLT post-tensioned rocking walls as the lateral system, on the world's largest outdoor shake table in San Diego, California at the NHERI@UCSD facility. Fourteen dynamic ground motion tests were conducted on the specimen and experimental results showed a ductile response with low levels of damage. In addition, the performance-based design procedure and performance objectives for the specimen matched well with the observed and instrumented response.

Download or read book Numerical Modeling and Seismic Performance of Post tensioned Cross laminated Timber Rocking Wall Systems written by Alex William Wilson and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Both the high- and reduced-order model compared well against experimental tests for both single and coupled PT CLT rocking walls. Both archetypes were able to meet predetermined performance objectives and code acceptance criteria, while the assessed responses of the low- and mid-rise archetype proved to be more sensitive to ground motion pulses and far-field motions, respectively. For all assessed intensity levels, both buildings showed that nonstructural repair could be performed at a cost cheaper than total replacement. The low- and mid-rise building exhibited better nonstructural economic performance in high and low intensity level events, respectively

Download or read book Displacement based seismic design for multi storey cross laminated timber buildings written by Hummel, Johannes and published by kassel university press GmbH. This book was released on 2017 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Key Terms: cross laminated timber, displacement-based seismic design, time history analysis, multi-storey timber structures, hysteretic behaviour

Download or read book Construction and Seismic Testing of a Resilient Two story Mass Timber Structure with Cross Laminated Rocking Walls written by Daniel R. Griesenauer and published by . This book was released on 2018 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Test Setup Design and Cyclic Evaluation of Rocking CLT Wall and Floor Restoring Force Lateral System written by and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The introduction of the demand for mass timber buildings in areas with seismic hazards has called for new lateral systems. Lateral systems in mass timber building typically utilize a rocking shear wall with post-tensioned rods to provide system re-centering. These post-tensioned rods add axial load to the shear wall and potentially endure long term creep affects. Mass Timber buildings consist of cross laminated (clt) shear walls and floor slabs along with glulam beams. The flexural capacity of the CLT floor slabs along with dead load can provide an alternative source for the restoring force. This project developed a test setup to accommodate a full scale cyclic testing of this restoring force. Cyclic testing included determining the influence of dead load on the system and the influence of ductile hold-downs. Hold-downs properties can be varied to alter shape of the hysteric curve and to allow re-centering. The hold-downs will serve as sacrificial fuses with the goal all yielding occurs to them while mass timber members remain elastic.

Download or read book CLT Handbook written by Erol Karacabeyli and published by . This book was released on 2013-01 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book PROPERTIES OF CROSS LAMINATED TIMBER PANEL WITH LOW VALUE LUMBER AND PERFORMANCE OF CROSS LAMINATED TIMBER WALL SYSTEM SUBJECTED TO SEISMIC AND SEQUENTIAL SEISMIC WIND LOADINGS written by and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : The Cross laminated timber (CLT) panels extended the market of timber material in structural construction, while its laminated structure allows layup design for utilizing low-value lumber. Through mechanical tests and numerical simulation, the mechanical properties of CLT made with low-value sugar maple (Acer saccharum) was first examined. The CLT panels made with white spruce (Picea glauca) salvaged from dead standing trees were examined. The mixed-species panels were prepared with the low-value sugar maple and salvaged spruce. The CLT panels were tested with the third-point and mid-point bending tests following ASTM D198 for major-axis flexural and shear properties. The CLT panels provided adequate flexural performance per current standard PRG 320-2019. The mechanical properties of the hybrid CLT panels with sugar maple surface layers were improved. In the meanwhile, the finite element model built with orthogonal constitutive law and progressive damage criteria simulated the mechanical behaviors of the tested CLT panels. Overall, the simulation results compared favorably with test data and provided reasonable estimates. A decomposed model with equivalent springs and shell elements based on the connection properties was developed to estimate the nonlinear dynamic performance of the conventional CLT shear wall. Full-size building simulation results indicated that the developed model could accurately estimate the wall dynamic performance. The dynamic performance of PT CLT rocking wall was also evaluated with numerical simulation. The similar equivalent decomposed wall model was developed and calibrated. A full-scale platform structure was simulated and compared with test results subjected to different seismic excitations. Because of the concentrated connection damage, the impact of sequential seismic-wind hazards on CLT shear wall systems is severer than that on traditional steel or reinforced concrete structures. With the developed conventional and PT wall models, the structural dynamic responses of different CLT wall systems were evaluated in wind-only and sequential seismic-wind scenarios. The wind-excited peak story displacement and acceleration for both CLT structures were magnified in the sequential seismic-wind scenarios compared with wind-only scenarios. The simulation results indicated that the sequential seismic-wind scenarios caused large acceleration with damaged connections for the conventional CLT shear wall structure. The PT CLT wall structure had minor displacement and acceleration, which was linear to the wind loading factors. The study of mechanical properties of the CLT panels made with low-value sugar maple and salvaged spruce can promote the utilization of the low-value lumber and promote forest management. The developed panel model provided an approach to estimate the CLT mechanical properties based on the nondestructive lamination test result, which can be a tool for future layup design. The developed decomposed equivalent wall models can capture the wall behavior effectively and efficiently, which potentially be an aid for the performance assessment of CLT structures. The results demonstrated the necessity of considering sequential hazard cases for conventional CLT wall structures, which is a reference for future development of performance-based design for conventional CLT wall structures.

Download or read book Development of Seismic Performance Factors for Cross laminated Timber Shear Walls written by John W. Van de Lindt and published by . This book was released on 2018 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its initial introduction in Europe more than two decades ago, cross-laminated timber (CLT) has been established as a new-generation product (UNFAO 2016). Recent construction projects in both Canada and the United States (Pei et al. 2016) and research efforts in Europe, North America, and Japan on CLT-based lateral force resisting systems (Pei et al. 2014) have demonstrated that CLT can be a viable alternative to steel and concrete in mid-rise construction, particularly in seismic regions. However, CLT-based seismic force resisting systems are not included in current design codes and standards, meaning that any CLT seismic design can be conducted only through alternative methods. This approach is both costly and complicated, making CLT less competitive than other conventional structural systems such as light-frame wood and heavier materials such as steel and concrete. The purpose of this Forest Products Laboratory partnership with Colorado State University is to determine seismic performance factors for CLT, thereby enabling CLT to be used efficiently and competitively throughout the United States.

Download or read book Timber Engineering written by Sven Thelandersson and published by John Wiley & Sons. This book was released on 2003-03-14 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Timber construction is one of the most prevalent methods of constructing buildings in North America and an increasingly significant method of construction in Europe and the rest of the world. Timber Engineering deals not only with the structural aspects of timber construction, structural components, joints and systems based on solid timber and engineered wood products, but also material behaviour and properties on a wood element level. Produced by internationally renowned experts in the field, this book represents the state of the art in research on the understanding of the material behaviour of solid wood and engineered wood products. There is no comparable compendium currently available on the topic - the subjects represented include the most recent phenomena of timber engineering and the newest development of practice-related research. Grouped into three different sections, 'Basic properties of wood-based structural elements', 'Design aspects on timber structures' and 'Joints and structural assemblies', this book focuses on key issues in the understanding of: timber as a modern engineered construction material with controlled and documented properties the background for design of structural systems based on timber and engineered wood products the background for structural design of joints in structural timber systems Furthermore, this invaluable book contains advanced teaching material for all technical schools and universities involved in timber engineering. It also provides an essential resource for timber engineering students and researchers, as well as practicing structural and civil engineers.

Download or read book Materials and Joints in Timber Structures written by Simon Aicher and published by Springer Science & Business Media. This book was released on 2013-09-25 with total page 815 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the contributions from the RILEM International Symposium on Materials and Joints in Timber Structures that was held in Stuttgart, Germany from October 8 to 10, 2013. It covers recent developments in the materials and the joints used in modern timber structures. Regarding basic wooden materials, the contributions highlight the widened spectrum of products comprising cross-laminated timber, glulam and LVL from hardwoods and block glued elements. Timber concrete compounds, cement bonded wood composites and innovative light-weight constructions represent increasingly employed alternatives for floors, bridges and facades. With regard to jointing technologies, considerable advances in both mechanical connections and glued joints are presented. Self-tapping screws have created unprecedented options for reliable, strong as well as ductile joints and reinforcement technologies. Regarding adhesives, which constitute the basis of the jointing/laminating technology of modern timber products, extended options for tailor-made bonding solutions have to be stated. Apart from melamine-urea and phenolic-resorcinol adhesives, one-component-polyurethanes, emulsion isocyanate polymers and epoxies offer a wide range of possibilities. The contributions dealing with experimental and numerical investigations on static, cyclic and seismic behavior of structures clearly reveal the enhanced potential of modern timber construction for reliable and sustainable buildings and bridges of the new millennium. The book is structured in nine thematic areas, being I) Structures II) Mechanical Connections III) Glued Joints and Adhesives IV) Timber and Concrete/Cement/Polymer Composites V) Cyclic, Seismic Behavior VI) Hardwood, Modified Wood and Bamboo VII) Cross-Laminated Timber VIII) Properties and Testing of Wood IX) Glulam

Download or read book NEHRP Recommended Provisions National Earthquake Hazards Reduction Program for Seismic Regulations for New Buildings and Other Structures Commentary written by United States. Federal Emergency Management Agency and published by . This book was released on 2001 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rapid Visual Screening of Buildings for Potential Seismic Hazards Supporting Documentation written by and published by Government Printing Office. This book was released on 2015 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Rapid Visual Screening (RVS) handbook can be used by trained personnel to identify, inventory, and screen buildings that are potentially seismically vulnerable. The RVS procedure comprises a method and several forms that help users to quickly identify, inventory, and score buildings according to their risk of collapse if hit by major earthquakes. The RVS handbook describes how to identify the structural type and key weakness characteristics, how to complete the screening forms, and how to manage a successful RVS program.

Download or read book A Numerical Analysis of Seismic Performance of Cross laminated Timber Shear Wall Assemblies with Enhanced Anchor Tiedown Systems written by Tanner Louis Reijm 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 Introduction to Genetic Algorithms written by S.N. Sivanandam and published by Springer Science & Business Media. This book was released on 2007-10-24 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a basic introduction to genetic algorithms. It provides a detailed explanation of genetic algorithm concepts and examines numerous genetic algorithm optimization problems. In addition, the book presents implementation of optimization problems using C and C++ as well as simulated solutions for genetic algorithm problems using MATLAB 7.0. It also includes application case studies on genetic algorithms in emerging fields.

Download or read book Structures Congress 2013 written by Brian J. Leshko and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains 267 papers on subjects that are advancing structural engineering in the areas of bridges, buildings, and non-building structures.