Showing papers by "John W. van de Lindt published in 2016"
22 Dec 2016
TL;DR: A unified theoretical methodology for the modeling of dependent/interdependent infrastructure networks and incorporates it in a six-step probabilistic procedure to assess their resilience and shows the importance of capturing the dependency between networks in modeling the resilience of critical infrastructure.
Abstract: Water and wastewater network, electric power network, transportation network, communication network, and information technology network are among the critical infrastructure in our communities; their disruption during and after hazard events greatly affects communities’ well-being, economic security, social welfare, and public health. In addition, a disruption in one network may cause disruption to other networks and lead to their reduced functionality. This paper presents a unified theoretical methodology for the modeling of dependent/interdependent infrastructure networks and incorporates it in a six-step probabilistic procedure to assess their resilience. Both the methodology and the procedure are general, can be applied to any infrastructure network and hazard, and can model different types of dependencies between networks. As an illustration, the paper models the direct effects of seismic events on the functionality of a potable water distribution network and the cascading effects of the dama...
159 citations
22 Dec 2016
TL;DR: The Centerville Testbed is introduced, defining the physical infrastructure within the community, natural hazards to which it is exposed, and the population demographics necessary to assess potential post-disaster impacts on the population, local economy, and public services.
Abstract: Enhancing community resilience in the future will require new interdisciplinary systems-based approaches that depend on many disciplines, including engineering, social and economic, and information sciences. The National Institute of Standards and Technology awarded the Center for Risk-Based Community Resilience Planning to Colorado State University and nine other universities in 2015, with the overarching goal of establishing the measurement science for community resilience assessment. The Centerville Virtual Community Testbed is aimed at enabling fundamental resilience assessment algorithms to be initiated, developed, and coded in a preliminary form, and tested before the refined measurement methods and supporting data classifications and databases necessary for a more complete assessment have fully matured. This paper introduces the Centerville Testbed, defining the physical infrastructure within the community, natural hazards to which it is exposed, and the population demographics necessary to...
124 citations
TL;DR: In this article, the majority of these buildings were constructed from the 1920s to the 1960s and are pro-posed as a disaster preparedness problem for decades, and they have been recognized as a soft-story wood-frame buildings.
Abstract: Soft-story wood-frame buildings have been recognized as a disaster preparedness problem for decades. The majority of these buildings were constructed from the 1920s to the 1960s and are pro...
117 citations
TL;DR: In this paper, the authors proposed a framework for loss estimation of steel structures subjected to mainshock-aftershock sequences, based on a typical 4-story steel frame with a deterioration model.
46 citations
TL;DR: In this paper, the performance of a masonry school building subjected to tornado wind loads is investigated using a fragility methodology, along with proposed damage states for consideration in loss estimation.
45 citations
01 Jan 2016
TL;DR: A brief overview of the current status of cross laminated timber (CLT) building development in North America, highlighting some recent U.S. and Canadian research efforts related to CLT system performance, and identifies future CLT research directions based on the needs of the North American market is presented in this article.
Abstract: Although not yet seen as common practice, building with cross laminated timber (CLT) is gaining momentum in North America. Behind the scenes of the widely publicized project initiatives such as the Wood Innovation Design Centre Building in Canada and the recent U.S. Tall Wood Building Competition, substantial research, engineering, and development has been completed or is underway to enable the adoption of this innovative building system. This paper presents a brief overview of the current status of CLT building development in North America, highlighting some recent U.S. and Canadian research efforts related to CLT system performance, and identifies future CLT research directions based on the needs of the North American market. The majority of the research summarized herein is from a recent CLT research workshop in Madison, Wisconsin, USA, organized by the USDA Forest Products Laboratory. The opportunity and need for coordination in CLT research and development among the global timber engineering community are also highlighted in the conclusions of this paper.
36 citations
TL;DR: In this article, a probabilistic analysis was performed in order to develop tornado hazard curves at select locations across the United States, which varied as a function of location-specific occurrence rates.
Abstract: Approximately 1,200 tornadoes impact the United States every year with a percentage of these resulting in significant damage, injuries, and fatalities. Initially, a probabilistic tornado hazard analysis was performed in order to develop tornado hazard curves at select locations across the United States. This analysis resulted in the annual probability of experiencing a tornado of any strength at the specific locations, which varied as a function of location-specific occurrence rates. Five different residential wood-frame building archetypes were designed at each of the locations based on current residential building code and/or practice. Fragilities for the roof sheathing and truss to wall top-plate connections were developed for each archetype. Because fragilities are independent of location, they were then convolved with the tornado hazard curves to compute annual failure probabilities for select roof components. This represents the first time absolute risk of roof failure due to tornadoes has b...
28 citations
TL;DR: In this article, a combined Eulerian-Lagrangian method for fluid-structure interaction was applied in order to compute forces on elevated coastal structures with a focus on bridges.
22 citations
TL;DR: The NEES-Soft project was a five-university multi-industry effort that culminated in a series of full-scale soft-story wood-frame building tests to validate retrofit philosophies proposed by as discussed by the authors.
Abstract: Soft-story wood-frame buildings have been recognized as a disaster preparedness problem for decades. There are tens of thousands of these multifamily three- and four-story structures throughout California and other parts of the United States. The majority were constructed between 1920 and 1970 and are prevalent in regions such as the San Francisco Bay Area in California. The NEES-Soft project was a five-university multiindustry effort that culminated in a series of full-scale soft-story wood-frame building tests to validate retrofit philosophies proposed by (1) Federal Emergency Management Agency’s recent soft-story seismic retrofit guideline for wood buildings and (2) a performance-based seismic retrofit (PBSR) approach developed as part of the NEES-Soft project. This paper is the first in a set of companion papers that presents the building design, retrofit objectives and designs, and full-scale shake table test results of a four-story 370-m2 (4,000-ft2) soft-story test building. Four different ...
21 citations
22 Dec 2016
TL;DR: In this article, the resilience of the community to different natural and man-made haz-homes is discussed. But the authors focus on the electrical power network (EPN) as a vital component of the nation's critical infrastructure.
Abstract: The Electrical Power Network (EPN) constitutes a vital component of the nation’s critical infrastructure. Additionally, the resilience of the community to different natural and man-made haz...
21 citations
01 Dec 2016-ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering
TL;DR: In this article, the effects of aftershocks and post-quake decisions on seismic performance are discussed, and an assessment procedure in accordance with other performance-based earthquake engineering (PBEE)-based methods, but also with the ability to consider after-shocks is proposed.
Abstract: Current seismic performance methodologies already have the ability to estimate the direct loss, downtime, and fatalities of buildings because of earthquakes using performance-based earthquake engineering (PBEE). However, earthquake aftershocks that have the potential to cause additional damage to buildings are not considered in these methodologies. Conversely, previous seismic performance assessments considering aftershocks, which were on the basis of simplified models that do not have the capacity to simulate details, cannot account for various post-quake decisions (e.g., evacuation, safety evaluation, and repair). In this study, the effects of aftershocks and post-quake decisions on seismic performance are discussed. An assessment procedure in accordance with other PBEE-based methods, but also with the ability to consider aftershocks, is proposed. A framework was developed according to the procedure. An illustrative case study also is presented using two nonductile reinforced concrete frame buil...
01 Jan 2016
TL;DR: The intent of this project is to support the development of updated building code criteria contained in such standards as ASCE 7 and ASCE 41.
Abstract: Nonlinear analysis has become an increasingly useful and important tool for evaluation, upgrade and design of structures for seismic resistance. However, despite steady improvements in analysis capability, most practice remains anchored to guidelines developed more than 20 years ago. Under its ATC- 114 project, the Applied Technology Council is developing updated hysteretic envelope models for use in seismic analysis of new and existing buildings. The intent of this project is to support the development of updated building code criteria contained in such standards as ASCE 7 and ASCE 41. Project support is provided by the National Institute of Standards and Technology.
TL;DR: In this paper, the evolution of seismic design for wood-frame buildings from 1959 through current state-of-the-art methodologies available as of 2015 is presented, including two performance-based seismic retrofit levels and a soft-story-only retrofit design that followed a recent guideline published by FEMA.
Abstract: Following natural disasters, major changes are often adopted in design codes, provisions, and guidelines that highlight existing or perceived deficiencies in design code calibration and sometimes design philosophy. The work presented herein chronicles the evolution of seismic design for wood-frame buildings from 1959 through current state-of-the-art methodologies available as of 2015. Included in the approaches in this study were two performance-based seismic retrofit levels and a soft-story-only retrofit design that followed a recent guideline published by FEMA. A brief background on the historical significance and major changes adopted in each provision or guideline is provided. Building performance was quantified and compared using multirecord fragilities for a range of wood-frame building types for the historical seismic provisions, demonstrating that the predicted seismic performance of wood-frame buildings has improved over time. It was also demonstrated that performance-based seismic retrof...
TL;DR: In this article, the authors presented the method and results of an experimental study of 18 walls installed with one, two, or three of the previously described wall finishes, and determined the best approach to add the sheathing layers numerically when combining the backbone curves for analysis and design.
Abstract: Woodframe buildings are unique in that the nonstructural finishes such as gypsum wall board and stucco provide significant stiffness and strength relative to the lateral force resisting system, e.g., wood shear walls. Wall finishes, or components within a woodframe wall subassembly, can consist of multiple layered modern and/or archaic elements such as wood planks, drywall, plaster on lathe, stucco, or plywood. There exist significant differences in ductility among these materials, raising questions about how best to superimpose single-degree-of-freedom hysteretic models or backbone curves during nonlinear time history analysis or when combining backbone curves for design and retrofit. This paper presents the method and results of an experimental study of 18 walls installed with one, two, or three of the previously described finishes. Testing was performed to determine the best approach to add the sheathing layers numerically when combining the backbone curves for analysis and design. Nonlinear dy...
TL;DR: In this paper, the performance-based earthquake engineering framework, introduced by the Pacific Earthquake Engineering Research (PEER) center, is combined with Monte Carlo Simulation to evaluate, in a probabilistic sense, the earthquake-induced economic losses for these structures.
01 Dec 2016
TL;DR: In this paper, community resilience depends on the performance of the built environment and on supporting social, economic and public institutions which are essential for the recovery of a community following a disaster.
Abstract: Community resilience depends on the performance of the built environment and on supporting social, economic and public institutions which are essential for the recovery of a community following a d...
TL;DR: In the last decade, there has been a renewed interest in timber buildings around the world, owing in part to the naturally optimal structural properties of timber and to the environmental advantages of building with timber.
Abstract: In the last decade, there has been a renewed interest in timber buildings around the world, owed in part to the naturally optimal structural properties of timber and to the environmental advantages of building with timber. Several midrise buildings have been constructed, including a nine-story building in London, a ninestory building in Milan, and a 10-story building in Melbourne. A 14-story building is being constructed in Norway, and even taller timber buildings have been designed in Sweden, Austria, and Canada. Timber is a lightweight material and, as such, performs particularly well in moderate to intense earthquakes. However wood itself is not ductile and can have brittle failure modes, such as splitting, if not addressed properly within the seismic design procedure. A large body of research has been completed, and a number of projects are under way worldwide on the seismic behavior of timber structures and buildings. Full-scale shake table tests have been conducted in Japan, the United States, and Europe on an array of designs. Extensive component and joint testing has also been completed, and advanced numerical models developed. An effort has been made to implement this new knowledge in codes of practice, such as the Eurocode and the New Zealand and the Canadian standards. This special issue brings together papers from the key researchers all over the world working on the seismic resistance of timber structures. It includes a forum paper and 17 technical papers presenting research carried out in the United States, Canada, Italy, Germany, Slovenia, China, Japan, and New Zealand. Five topics are addressed: (1) light-frame timber buildings, (2) retrofit of existing light-frame timber buildings, (3) cross-laminated timber buildings, (4) innovative rocking and hybrid heavy timber walls, and (5) alternative bracing systems.
01 Jan 2016
Abstract: This paper presents selected results of connector testing and wall testing which were part of a Forest Products Lab-funded project undertaken at Colorado State University in an effort to determine seismic performance factors for cross laminated timber (CLT) shear walls in the United States. Archetype development, which is required as part of the process, is also discussed. Connector tests were performed on generic angle brackets which were tested under shear and uplift and performed as expected with consistent nail withdrawal observed. Quasi-static cyclic tests were conducted on CLT shear walls to systematically investigate the effects of various parameters. Boundary constraints and gravity loading were both found to have a beneficial effect on the wall performance, i.e. higher strength and deformation capacity. Specific gravity also had a significant effect on wall behaviour while CLT thickness was less influential. Higher aspect ratio panels (4:1) demonstrated lower stiffness and substantially larger deformation capacity compared to moderate aspect ratio panels (2:1). However, based on the test results there is likely a lower bound of 2:1 for aspect ratio where it ceases to have any beneficial effect on wall behaviour. This is likely due to the transition from the dominant rocking behaviour to sliding behaviour.
01 Jan 2016
TL;DR: In this article, the impact of boundary condition, gravity loading, CLT grade, panel thickness, and panel aspect ratio (height:length) on the strength and stiffness of cross-laminated timber (CLT) panels was investigated.
Abstract: This paper presents recent progress in the development of seismic performance factors for cross-laminated timber (CLT) systems in the United States. A brief overview of some of other systematic studies conducted in Europe, North America, and Japan is also provided. The FEMA P695 methodology is briefly described and selected results from connector testing and CLT wall testing are discussed. Shear and uplift tests were performed on generic angle brackets to quantify their behavior. CLT walls with these connectors were then tested investigate the influence of various parameters on wall component performance. The influential factors considered include boundary condition, gravity loading, CLT grade, panel thickness, and panel aspect ratio (height:length). Results indicate that boundary condition and gravity loading have beneficial effect on strength and stiffness of the CLT panels. CLT grade is an important parameter while CLT panel thickness only has a minimal influence on wall behavior. Higher aspect ratio (4:1) panels demonstrated less stiffness but considerably more ductility than the panels with lower aspect ratio (2:1). This paper also provides details on some on-going efforts including additional tests planned, index buildings from which P-695 archetypes will be extracted, and nonlinear modeling for this project.
TL;DR: In this article, a viscous damper retrofit is designed based on conclusions drawn from parametric studies and validated via slow pseudodynamic hybrid testing of a full-scale three-story building.
Abstract: Recent earthquakes have demonstrated the vulnerability of soft-story wood buildings. A performance-based retrofit option focusing on stiffening/strengthening only the soft ground story, as regulated by FEMA guidelines, was proposed in an attempt to achieve collapse prevention of the ground story while at the same time ensuring damage control of the upper stories. This paper focuses on an alternative retrofit approach that focuses on energy dissipation, in order to achieve a performance that is essentially comparable to the inherent performance target defined in FEMA guidelines. A viscous damper retrofit is designed based on conclusions drawn from parametric studies. Then, the proposed retrofit is validated via slow pseudodynamic hybrid testing of a full-scale three-story building. The test data are presented, interpreted, and compared against both pretest numerical predictions and posttest simulation results after model calibration. It is demonstrated that a damping retrofit, as compared to a stif...
TL;DR: In this paper, the authors present the hybrid test results of a full-scale collapse test program that was carried out on a 3-story soft-story woodframe building with an over-retrofitted first story.
Abstract: Soft-story woodframe buildings have been identified as a disaster preparedness problem throughout California and are present in many other states of the United States. These buildings can be readily identified by their large openings at the ground floor, often for parking, which results in a soft and weak first story that is prone to collapse in moderate to severe earthquakes. This paper presents the hybrid test results of a full-scale collapse test program that was carried out on a 3-story soft-story woodframe building with an overretrofitted first story. The overretrofitted design was constrained to the soft story only, essentially representing a retrofit that would likely drive the soft-story failure mechanism into the upper stories. The objectives of the collapse testing were to (1) quantify the collapse shift into the upper stories when the first story is overstrengthened, (2) investigate the collapse mechanisms of a woodframe building constructed with archaic building materials and style in ...
TL;DR: In this article, a reinforcement system that utilizes unique geometries in order to improve reinforced concrete beam stiffness, shear strength, and reinforcement bond properties, as compared with conventional glass-fiber reinforced polymer (GFRP) bar-style reinforcement is introduced.
Abstract: In this paper a reinforcement system that utilizes unique geometries in order to improve reinforced concrete beam stiffness, shear strength, and reinforcement bond properties, as compared with conventional glass-fiber reinforced polymer (GFRP) bar-style reinforcement is introduced. The proposed GFRP reinforcement is formed into modular units intended for use in place of traditional flexural reinforcement. Prototype reinforcement units were manufactured and cast into eight concrete beam specimens. These specimens were tested and compared to similar specimens with conventional straight GFRP bars in order to document their behavior and assess the effect on beam performance of the new geometry under typical loading. Bond failures that occurred in the control specimens were not present in the prototype specimens. Ultimate shear capacity in one of the prototype variations was increased by 26% over the bar-reinforced control specimens. Flexural performance for one of the prototypes was also found to be c...
01 Jan 2016
TL;DR: In this paper, a general procedure for performance-based wind engineering is proposed, and research needs for development of wood-frame performance based wind engineering are also highlighted in this chapter.
Abstract: Residential buildings in coastal areas are often at risk to hurricanes, which can result in both wind and storm surge damages, while tornadoes are one of the most devastating natural hazards that have occurred in all 50 states of the USA and can happen during any season of the year. This chapter focuses on summarizing some past studies on the performance of wood-frame residential buildings in recent major hurricanes and tornadoes. Damage data collected from hurricanes shows that in most hurricanes the damage to residential wood-frame buildings often comes from high winds, hurricane surge, flooding, and rainwater intrusion due to damage in the building envelope. Roof systems experienced extensive damage either directly from wind or due to failure of the flashing and coping. Hurricanes are often accompanied by heavy rain that results in substantial water intrusion through the breached area of the building, which in turn results in substantial financial loss to the structure and its contents. On the other hand, data collected from recent tornadoes in Tuscaloosa, Joplin, and Moore show that, for an EF-4 or EF-5 tornado, damage levels increase from the outer edges toward the centerline of a tornado track. Residential building damage in tornados is caused by high wind loading or debris impact, or both. A general procedure for performance-based wind engineering is proposed, and research needs for development of wood-frame performance-based wind engineering are also highlighted in this chapter.
Dissertation•
01 Jan 2016
TL;DR: In this article, the authors evaluated two glass-fiber reinforced polymer concrete reinforcement systems, which have been designed to serve as a non-corrosive alternative to steel reinforcement in reinforced concrete bridge girders.
Abstract: This report evaluates two new glass-fiber reinforced polymer concrete reinforcement systems, which have been designed to serve as a non-corrosive alternative to steel reinforcement in reinforced concrete bridge girders. Due to the nature of the reinforcement geometry, these systems react in a way to introduce compressive confinement into the concrete in the inner regions of the system units. The introduction of this compressive confinement zone will increase particle interaction effects, which results in increased shear and tensile force resistance contributed by the affected concrete. The system is also well integrated into the surrounding concrete matrix, therefore eliminating the potential for debonding failures. A proof of concept is conducted in order to evaluate a set of alternative reinforcement system prototypes. Before the reinforcement systems are evaluated, technical literature pertaining to alternative reinforcements is reviewed. Select specimens provided evidence of mechanically constrictive behavior and enhancements in flexural capacity. Indications of good bond strength and shear strength contribution from the flexural reinforcement systems were also found. The overall finding is that these reinforcement geometries do show potential and should be the subject of further study in a more extensive project.