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Seismic Assessment of a Three-Story Wood Building with an Integrated CLT-Lightframe System using RTHS

https://research.thinkwood.com/en/permalink/catalogue1293
Year of Publication
2018
Topic
Mechanical Properties
Seismic
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Shear Walls
Author
Nguyen, Tu
Dao, Thang
Aaleti, Sriram
van de Lindt, John
Fridley, Kenneth
Publisher
ScienceDirect
Year of Publication
2018
Country of Publication
Netherlands
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Shear Walls
Topic
Mechanical Properties
Seismic
Keywords
Post-Tensioned
Real Time Hybrid Simulation
Language
English
Research Status
Complete
Series
Engineering Structures
Summary
This paper presents the results of an experimental study whose objective was to investigate the behavior of a hybrid wood shear-wall system defined herein as a combination of traditional light-frame wood shear walls with post-tensioned rocking Cross-Laminated Timber (CLT) panels. The post-tensioned CLT panels in the hybrid system offer both vertical and lateral load resistance and self-centering capacities. The traditional Light-Frame Wood Systems (LiFS) provide additional lateral load resistance along with a large amount of energy dissipation through the friction of nail connections. Thus, a combination of these two types of structures, in which traditional light-frame wood shearwalls are utilized as structural partition walls, may provide an excellent structural solution for mid-rise to tall wood buildings for apartments/condos, where there is a need for resisting large lateral and vertical loads as well as structural stability. In this study, a real-time hybrid testing algorithm using a combination of time-delay updating and Newmark-Beta feed forward to reduce the undesirable effects of time delay was introduced. The top two-stories of a three-story building were modeled as a numerical substructure with the first story as the experimental CLT-LiFS substructure. The experimental results of the hybrid wall are presented and discussed in this paper.
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Real-Time Hybrid Seismic Simulation of a Three-Story Wood Building with an Integrated CLT-Lightframe System (CLT-LIFS)

https://research.thinkwood.com/en/permalink/catalogue1649
Year of Publication
2016
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Shear Walls
Author
Nguyen, Tu
Dao, Thang
Aaleti, Sriram
van de Lindt, John
Fridley, Kenneth
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Shear Walls
Topic
Mechanical Properties
Keywords
Post-Tensioned
Reverse Cyclic Loading
Simulation
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3479-3487
Summary
This paper presents the results of a study whose objective was to investigate the behaviour of a hybrid wood shearwall system defined herein as a combination of traditional light-frame wood shear walls with post-tensioned rocking cross laminated timber (CLT). The post-tensioned CLT panels in the hybrid system offer both vertical and lateral load resistance and self-centering capacities. The traditional light wood frame shearwalls (LiFS) provide additional lateral load resistance along with energy dissipation through the slip of nail connections. Thus a combination of these two types of structures will provide an excellent structural solution for mid-rise to tall wood buildings, where there is a need for resisting large lateral and vertical loads as well as structural stability. A conventional test on the hybrid system subjected to a reverse-cyclic loading protocol and a real-time hybrid simulation using the new algorithm were conducted. In real-time hybrid simulation, a three-story building was modelled as a numerical substructure. In the first story of the three-story building the experimental CLT-LiFS substructure was tested and integrated in real time with the numerical substructure as described herein. The experimental observation of the behaviours and damage of the hybrid shear wall are presented and discussed in this paper.
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Performance Based Design and Force Modification Factors for CLT Structures

https://research.thinkwood.com/en/permalink/catalogue928
Year of Publication
2012
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Walls
Author
Pei, Shiling
Popovski, Marjan
van de Lindt, John
Year of Publication
2012
Country of Publication
Sweden
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Walls
Topic
Seismic
Design and Systems
Keywords
Quasi-Static Tests
R-factors
Performance-Based Seismic Design
US
Canada
Language
English
Conference
CIB-W18 Meeting
Research Status
Complete
Notes
August 27-30, 2012, Växjö, Sweden p.293-304
Summary
In this paper, a performance-based seismic design (PBSD) of a CLT building was conducted and the seismic response of the CLT building was compared to that of a wood-frame structure tested during the NEESWood project. The results from the quasi-static tests on CLT walls performed at FPInnovations were used as input information for modelling of the CLT walls, the main lateral load resisting elements of the structure. Once the satisfactory design of the CLT mid-rise structure was established through PBSD, a force-based design was developed with varying R-factors and that design was compared to the PBSD result. In this way, suitable R-factors were calibrated so that they can yield equivalent seismic performance of the CLT building when designed using the traditional force-based design methods. Based on the results of this study it is recommended that a value of Rd=2.5 and Ro=1.5 can be assigned for structures with symmetrical floor plans in the National Building Code of Canada (NBCC). In the US an R=4.3 can be used for symmetrical CLT structures designed according to ASCE 7. These values can be assigned provided that the design values for CLT walls considered (and implemented in the material design standards) are similar to the values determined in this study using the kinematics model developed that includes the influence of the hold-downs in the CLT wall resistance. Design of the CLT building with those R-factors using the equivalent static procedures in the US and Canada will result in the CLT building having similar seismic performance to that of the tested wood-frame NEESWood building, which had only minor non-structural damage during a rare earthquake event.
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Development and Full-Scale Validation of Resilience-Based Seismic Design of Tall Wood Buildings: The NHERI Tallwood Project

https://research.thinkwood.com/en/permalink/catalogue1477
Year of Publication
2017
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems
Author
Pei, Shiling
van de Lindt, John
Ricles, James
Sause, Richard
Berman, Jeffrey
Ryan, Keri
Dolan, Daniel
Buchanan, Andrew
Robinson, Thomas
McDonnell, Eric
Blomgren, Hans-Erik
Popovski, Marjan
Rammer, Douglas
Year of Publication
2017
Country of Publication
New Zealand
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Tall Wood
Post-Tensioned
Rocking Walls
Resilience-Based Seismic Design
Shaking Table Test
Language
English
Conference
New Zealand Society for Earthquake Engineering Conference
Research Status
Complete
Notes
April 27-29, 2017, Wellington, New Zealand
Summary
With global urbanization trends, the demands for tall residential and mixeduse buildings in the range of 8~20 stories are increasing. One new structural system in this height range are tall wood buildings which have been built in select locations around the world using a relatively new heavy timber structural material known as cross laminated timber (CLT). With its relatively light weight, there is consensus amongst the global wood seismic research and practitioner community that tall wood buildings have a substantial potential to become a key solution to building future seismically resilient cities. This paper introduces the NHERI Tallwood Project recentely funded by the U.S. National Science Fundation to develop and validate a seismic design methodology for tall wood buildings that incorporates high-performance structural and nonstructural systems and can quantitatively account for building resilience. This will be accomplished through a series of research tasks planned over a 4-year period. These tasks will include mechanistic modeling of tall wood buildings with several variants of post-tensioned rocking CLT wall systems, fragility modeling of structural and non-structural building components that affect resilience, fullscale biaxial testing of building sub-assembly systems, development of a resilience-based seismic design (RBSD) methodology, and finally a series of full-scale shaking table tests of a 10-story CLT building specimen to validate the proposed design. The project will deliver a new tall building type capable of transforming the urban building landscape by addressing urbanization demand while enhancing resilience and sustainability.
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Hybrid System of Unbonded Post-Tensioned CLT Panels and Light-Frame Wood Shear Walls

https://research.thinkwood.com/en/permalink/catalogue757
Year of Publication
2017
Topic
Design and Systems
Mechanical Properties
Seismic
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Shear Walls
Author
Ho, Tu Xuan
Dao, Thang
Aaleti, Sriram
van de Lindt, John
Rammer, Douglas
Publisher
American Society of Civil Engineers
Year of Publication
2017
Country of Publication
United States
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Light Frame (Lumber+Panels)
Application
Shear Walls
Topic
Design and Systems
Mechanical Properties
Seismic
Keywords
Post-Tensioned
Cyclic Loadings
Dynamic Analysis
Numerical model
Language
English
Research Status
Complete
Series
Journal of Structural Engineering
Summary
Cross-laminated timber (CLT) is a relatively new type of massive timber system that has shown to possess excellent mechanical properties and structural behavior in building construction. When post-tensioned with high-strength tendons, CLT panels perform well under cyclic loadings because of two key characteristics: their rocking behavior and self-centering capacity. Although post-tensioned rocking CLT panels can carry heavy gravity loads, resist lateral loads, and self-center after a seismic event, they are heavy and form a pinched hysteresis, thereby limiting energy dissipation. Conversely, conventional light-frame wood shear walls (LiFS) provide a large amount of energy dissipation from fastener slip and, as their name implies, are lightweight, thereby reducing inertial forces during earthquakes. The combination of these different lateral behaviors can help improve the performance of buildings during strong ground shaking, but issues of deformation compatibility exist. This study presents the results of a numerical study to examine the behavior of post-tensioned CLT walls under cyclic loadings. A well-known 10-parameter model was applied to simulate the performance of a CLT-LiFS hybrid system. The posttensioned CLT wall model was designed on the basis of a modified monolithic beam analogy that was originally developed for precast concrete-jointed ductile connections. Several tests on post-tensioned CLT panels and hybrid walls were implemented at the Large Scale Structural Lab at the University of Alabama to validate the numerical model, and the results showed very good agreement with the numerical model. Finally, incremental dynamic analysis on system level models was compared with conventional light-frame wood system models.
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Performance-Based Seismic Retrofit of Soft-Story Woodframe Buildings

https://research.thinkwood.com/en/permalink/catalogue674
Year of Publication
2014
Topic
Seismic
Application
Wood Building Systems
Author
Bahmani, Pouria
van de Lindt, John
Pryor, Steven
Mochizuki, Gary
Gershfeld, Mikhail
Rammer, Douglas
Tian, Jingjing
Symans, Michael
Publisher
C3 Ink
Year of Publication
2014
Country of Publication
United States
Format
Magazine Article
Application
Wood Building Systems
Topic
Seismic
Keywords
Retrofit
Soft-Story
Performance Based Seismic Retrofit
Shake Table Test
Language
English
Research Status
Complete
Series
STRUCTURE
Summary
This article presents the first generation of Performance-based seismic retrofit (PBSR) and resulting retrofit design using a combination of wood structural panel sheathing and Simpson Strong-Tie® Strong Frame® steel special moment frames. PBSR is essentially the same as performance-based seismic design (PBSD) with the exception of additional constraints on the design due to existing structural and non-structural assemblies. The PBSD method is a design methodology that seeks to ensure that structures meet prescribed performance criteria under seismic loads. In the PBSR, retrofits were installed such that the building meets the performance criteria at the DBE and MCE level and its torsional response reduces to an acceptable range. In this retrofit design methodology, retrofits are not limited to the bottom story (like those of the FEMA P-807 retrofit methodology). They can also be applied to the upper stories to increase the strength of the building, leading to better overall performance of the structure.
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Seismic Design of Cross-Laminated Timber Buildings

https://research.thinkwood.com/en/permalink/catalogue1971
Year of Publication
2018
Topic
Seismic
Design and Systems
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Tannert, Thomas
Follesa, Maurizio
Fragiacomo, Massimo
González Soto, Paulina
Isoda, Hiroshi
Moroder, Daniel
Xiong, Haibei
van de Lindt, John
Publisher
Society of Wood Science and Technology
Year of Publication
2018
Country of Publication
United States
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Seismic
Design and Systems
Keywords
Seismicity
Design Standards
Platform-Type Construction
Ductility
Connections
Language
English
Research Status
Complete
Series
Wood and Fiber Science
Summary
The increasing interest in cross-laminated timber (CLT) construction has resulted in multiple international research projects and publications covering the manufacturing and performance of CLT. Multiple regions and countries have adopted provisions for CLT into their engineering design standards and building regulations. Designing and building CLT structures, also in earthquake-prone regions is no longer a domain for early adopters, but is becoming a part of regular timber engineering practice...
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Tall Cross-Laminated Timber Building: Design and Performance Session WW300 Experimental and Modeling Studies on Wood Frame Buildings

https://research.thinkwood.com/en/permalink/catalogue618
Year of Publication
2014
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems
Author
Dolan, Daniel
Bordry, Vincent
Pei, Shiling
van de Lindt, John
Organization
Structures Congress
Publisher
American Society of Civil Engineers
Year of Publication
2014
Country of Publication
United States
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Walls
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Damping
Multi-Story
Ductility
Cost
Fire Resistance
Language
English
Conference
Structures Congress 2014
Research Status
Complete
Notes
April 3-5, 2014, Boston, Massachusetts, United States
Summary
Cross-laminated timber (CLT) is widely perceived as the most promising option for building high-rise wood structures due to its structural robustness and good fire resistance. While gravity load design of a tall CLT building is relatively easy to address because all CLT walls can be utilized as bearing walls, design for significant lateral loads (earthquake and wind) can be challenging due to the lack of ductility in current CLT construction methods that utilize wall panels with low aspect ratios (height to length). Keeping the wall panels at high aspect ratios can provide a more ductile response, but it will inevitably increase the material and labor costs associated with the structure. In this study, a solution to this dilemma is proposed by introducing damping and elastic restoring devices in a multi-story CLT building to achieve ductile response, while keeping the integrity of low aspect ratio walls to reduce the cost of construction and improve fire resistance. The design methodology for incorporating the response modification devices is proposed and the performance of the as-designed structure under seismic is evaluated.
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Direct Displacement Design of Tall CLT Building with Deformable Diaphragms

https://research.thinkwood.com/en/permalink/catalogue1650
Year of Publication
2016
Topic
Design and Systems
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Bolvardi, Vahab
Pei, Shiling
van de Lindt, John
Dolan, James
Year of Publication
2016
Country of Publication
Austria
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Design and Systems
Seismic
Keywords
Inter-Story Isolation
Displacement-Based Design
Simulation
Language
English
Conference
World Conference on Timber Engineering
Research Status
Complete
Notes
August 22-25, 2016, Vienna, Austria p. 3506-3514
Summary
In order to cope with the speed of urbanization around the world especially in areas of high seismicity, researchers and engineers have always been investigating cost-effective building systems with high seismic performance. Cross Laminated Timber (CLT) is a wood based material that is suitable for tall building construction. However, the current CLT system is prone to connection damage in strong earthquakes due to the vast majority of the system ductility resides in connections. One solution is the concept of inter-story isolation to develop a potentially resilient system that can remain damage free during strong earthquakes. A generalized displacement-based design method was developed to design an inter-story isolation system for a tall wood building based on articulated damage expectations. A12-story CLT building with one isolation layer was used to illustrate the proposed design method. The building performance was validated through numerical simulation under different seismic hazard levels.
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Ductility Based Force Reduction Factors for Symmetrical Cross-Laminated Timber Structures

https://research.thinkwood.com/en/permalink/catalogue446
Year of Publication
2014
Topic
Mechanical Properties
Seismic
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Walls
Author
Popovski, Marjan
Pei, Shiling
van de Lindt, John
Karacabeyli, Erol
Organization
European Association of Earthquake Engineering
Year of Publication
2014
Country of Publication
Canada
Format
Conference Paper
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Walls
Topic
Mechanical Properties
Seismic
Keywords
Force Modification Factors
Ductility
National Building Code of Canada
Fasteners
Seismic Performance
Language
English
Conference
Second European Conference on Earthquake Engineering and Seismology
Research Status
Complete
Notes
August 25-29, 2014, Istanbul, Turkey
Summary
Cross-laminated timber (CLT) as a structural system has not been fully introduced in European or North American building codes. One of the most important issues for designers of CLT structures in earthquake prone regions when equivalent static design procedure is used, are the values for the force modification factors (R-factors) for this structural system. Consequently, the objective of this study was to derive suitable ductility-based force modification factors (Rd-factors) for seismic design of CLT buildings for the National Building Code of Canada (NBCC). For that purpose, the six-storey NEESWood Capstone wood-frame building was redesigned as a CLT structure and was used as a reference symmetrical structure for the analyses. The same floor plan was used to develop models for ten and fifteen storey buildings. Non-linear analytical models of the buildings designed with different Rd-factors were developed using the SAPWood computer program. CLT walls were modelled using the output from mechanics models developed in Matlab that were verified against CLT wall tests conducted at FPInnovations. Two design methodologies for determining the CLT wall design resistance (to include and exclude the influence of the hold-downs), were used. To study the effects of fastener behaviour on the R-factors, three different fasteners (16d nails, 4x70mm and 5x90mm screws) used to connect the CLT walls, were used in the analyses. Each of the 3-D building models was subjected to a series of 22 bi-axial input earthquake motions suggested in the FEMA P-695 procedure. Based on the results, the fragility curves were developed for the analysed buildings. Results showed that an Rd-factor of 2.0 is appropriate conservative estimate for the symmetrical CLT buildings studied, for the chosen level of seismic performance.
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10 records – page 1 of 1.