scholarly journals Seismic Performance of a Green Roof Structure

2021 ◽  
Vol 13 (8) ◽  
pp. 4278
Author(s):  
Svetlana Tam ◽  
Jenna Wong
Keyword(s):  
Green Roof ◽  
Time History ◽  
Green Roofs ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Roof Structure ◽  
Nonlinear Time History Analyses ◽  
Vegetated Roofs ◽  
Nonlinear Time History ◽  
The Impact

Sustainability addresses the need to reduce the structure’s impact on the environment but does not reduce the environment’s impact on the structure. To explore this relationship, this study focuses on quantifying the impact of green roofs or vegetated roofs on seismic responses such as story displacements, interstory drifts, and floor level accelerations. Using an archetype three-story steel moment frame, nonlinear time history analyses are conducted in OpenSees for a shallow and deep green roof using a suite of ground motions from various distances from the fault to identify key trends and sensitivities in response.

Modeling of Hysteretic Damper in Three-Story Steel Frame Subjected to Earthquake Load

2010 ◽  
Vol 163-167 ◽  
pp. 3981-3986
Author(s):  
Mohammad Saeed Masoomi ◽  
Siti Aminah Osman ◽  
Shahed Shojaeipour
Keyword(s):  
Response Spectrum ◽  
Time History ◽  
Base Shear ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Braced Frame ◽  
Vector Method ◽  
Hysteretic Damper ◽  
Earthquake Load ◽  
Nonlinear Time History

This paper presents the nonlinear time-history and response spectrum analysis for a three-story steel moment frame and a braced frame by hysteretic damper against earthquake load which analyzed by SAP2000 software. The mentioned frames were analyzed by Eigenvalue method for linear analysis and Ritz-vector method for nonlinear analysis. Simulation results were presented as a time-displacement graph based on dynamic analysis, the dynamic base shear force is also calculated.

scholarly journals Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Seismic Demands ◽  
Nonlinear Time History Analyses ◽  
History Of ◽  
Protection Devices ◽  
Nonlinear Time History ◽  
Better Than

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

Effect of bidirectional excitation on seismic performance of regular RC frame buildings designed for modern codes

2021 ◽  
pp. 875529302110478
Author(s):  
Payal Gwalani ◽  
Yogendra Singh ◽  
Humberto Varum
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Inelastic Behavior ◽  
Moment Frame ◽  
Frame Buildings ◽  
Bidirectional Excitation ◽  
Rc Frame Buildings ◽  
Nonlinear Time History ◽  
Hinge Model

The existing practice to estimate seismic performance of a regular building is to carry out nonlinear time history analysis using two-dimensional models subjected to unidirectional excitations, even though the multiple components of ground motion can affect the seismic response, significantly. During seismic shaking, columns are invariably subjected to bending in two orthogonal vertical planes, which leads to a complex interaction of axial force with the biaxial bending moments. This article compares the seismic performance of regular and symmetric RC moment frame buildings for unidirectional and bidirectional ground motions. The buildings are designed and detailed according to the Indian codes, which are at par with the other modern seismic codes. A fiber-hinge model, duly calibrated with the biaxial experimental results, is utilized to simulate the inelastic behavior of columns under bidirectional bending. A comparison of the estimated seismic collapse capacity is presented, illustrating the importance of considering the bidirectional effects. The results from fragility analysis indicate that the failure probabilities of buildings under the bidirectional excitation are significantly higher as compared to those obtained under the unidirectional excitation.

Investigation of Damages in RC Frames Under Near Field Earthquakes Using a Damage Index

2016 ◽  
Vol 16 (02) ◽  
pp. 1450094 ◽  
Author(s):  
Seyed Morteza Zinati Yazdi ◽  
Mohammad Taghi Kazemi
Keyword(s):  
Near Field ◽  
Damage Index ◽  
Time History ◽  
General Rule ◽  
Nonlinear Time History Analysis ◽  
Far Field ◽  
Moment Frames ◽  
Moment Frame ◽  
Rc Frames ◽  
Nonlinear Time History

Heavy damages on structures caused by near field earthquakes in recent years has brought serious attention to this problem. An examination of previous records has shown significant differences for near field earthquakes, including a large energy pulse, unlike far field earthquakes. But as a general rule, the effects of near field earthquakes have been ignored in most building codes. The purpose of this paper is to investigate the effect of near field earthquakes on reinforced concrete (RC) moment frames. To achieve this goal, the Erduran damage index, an efficient way to calculate damage, was employed to analyze two 4- and 8-story RC moment frame buildings. The buildings with moderate and high ductility were designed by the strength criteria. Seven pairs of near field and far field earthquakes were scaled and used for dynamic nonlinear time history analysis. Using Erduran’s beam and column damage index, respectively, based on rotation and drift, the results from both near and far field earthquakes were compared. Moreover, for better assessment, 4-story buildings were evaluated from the performance based viewpoint of design. We observe from the results that most of the components of the structures under near field earthquakes sustained severe damages and in some cases even component failure. Components of the structures under near field earthquakes suffered from 30% more of damage, on average, than that under far field earthquakes.

scholarly journals State-of-the-Art Green Roofs: Technical Performance and Certifications for Sustainable Construction

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 69 ◽  
Author(s):  
Alejandra Naranjo ◽  
Andrés Colonia ◽  
Jaime Mesa ◽  
Heriberto Maury ◽  
Aníbal Maury-Ramírez
Keyword(s):  
Environmental Assessment ◽  
State Of The Art ◽  
Green Roof ◽  
Green Roofs ◽  
Assessment Method ◽  
Assessment System ◽  
Sustainable Construction ◽  
Runoff Water ◽  
Technical Performance ◽  
The Impact

Green roof systems, a technology which was used in major ancient buildings, are currently becoming an interesting strategy to reduce the negative impact of traditional urban development caused by ground impermeabilization. Only regarding the environmental impact, the application of these biological coatings on buildings has the potential of acting as a thermal, moisture, noise, and electromagnetic barrier. At the urban scale, they might reduce the heat island effect and sewage system load, improve runoff water and air quality, and reconstruct natural landscapes including wildlife. In spite of these significant benefits, the current design and construction methods are not completely regulated by law because there is a lack of knowledge of their technical performance. Hence, this review of the current state of the art presents a proper green roof classification based on their components and vegetation layer. Similarly, a detailed description from the key factors that control the hydraulic and thermal performance of green roofs is given. Based on these factors, an estimation of the impact of green roof systems on sustainable construction certifications is included (i.e., LEED—Leadership in Energy and Environment Design, BREEAM—Building Research Establishment Environmental Assessment Method, CASBEE—Comprehensive Assessment System for Built Environment Efficiency, BEAM—Building Environmental Assessment Method, ESGB—Evaluation Standard for Green Building). Finally, conclusions and future research challenges for the correct implementation of green roofs are addressed.

Influence of Earthquake Attack Angle on Seismic Demands for Structures under Bi-Directional Ground Motions

2011 ◽  
Vol 255-260 ◽  
pp. 2330-2334 ◽  
Author(s):  
Yu Zhang ◽  
Quan Wang Li ◽  
Jian Sheng Fan
Keyword(s):  
Seismic Design ◽  
Ground Motions ◽  
Time History ◽  
Earthquake Excitation ◽  
Seismic Demands ◽  
3 Dimensional ◽  
Nonlinear Time History Analyses ◽  
Modification Factor ◽  
Structural Responses ◽  
Nonlinear Time History

The earthquake may attack the structural building from any angle, but in current seismic design codes, this type of uncertainty is seldom accounted. The uncertainty associated with the direction of earthquake excitation was considered in this paper, and its effect on structural responses was investigated. For this purpose, a simple 3-dimensional model with symmetric plan was established, which had fundamental periods ranged from 0.1s to 5.0s, and was subjected to a set of 30 ground motion pairs for which both linear and nonlinear time history analyses were performed. Analyzing results showed that, on average, the elastic roof acceleration is 32% underestimated, and the inelastic roof displacement is 18% underestimated if the variation of earthquake excitation direction is not consider. Recognizing this, a modification factor for the seismic demand was proposed thorough a statistical analysis, which guarantees a probability of 95% design safety

scholarly journals Is Smart Growth a smart adaptation strategy?: Examining Ontario's proposed growth under climate change

2004 ◽  
Vol 71 (424-426) ◽  
pp. 57-62
Author(s):  
Brad Bass
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Urban Areas ◽  
Green Roof ◽  
Smart Growth ◽  
Green Roofs ◽  
Adaptation Strategy ◽  
University Of Toronto ◽  
Conducting Research ◽  
The Impact

The author is a member of Environment Canada's Adaptation and Impact Research Group, located in the Centre for Environment at the University of Toronto. His primary research interests include the use of ecological technologies in adapting urban areas to atmospheric change, the impacts of climate change on the energy sector, and the characteristics of adaptable systems. His current work on ecological technologies includes green roofs, vertical gardens and living machines. Dr Bass has been involved in two major projects, in Ottawa and Toronto, to evaluate the impact of green roofs on the urban heat island, energy consumption, stormwater runoff and water quality. Currently, Dr Bass is conducting research on integrating green roof infrastructure with other vegetation strategies at a community scale, simulating the impact of a green roof on the energy consumption of individual buildings.

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