Application Of Sustainable Design Principles To Increase Energy Efficiency Of Existing Buildings

This study investigates the effectiveness of different energy retrofitting techniques and examines the impact of employing those methods on energy consumption of existing residential buildings. Based on the research findings, the most effective and practical method of retrofitting has been proposed in order to improve energy efficiency of existing buildings. In order to achieve this goal, an existing residential building has been simulated in FirstRate 5 software so as to determine the existing thermal performance of the building. Afterwards, considering sustainable design principles, different insulation layers, glazing, and construction materials have been employed to conduct a comprehensive thermal performance study. Based on the research outcomes, the best technique for increasing energy efficiency of existing buildings and reducing their environmental impact and footprint has been identified and proposed for practical purposes

Long-term structural behaviour of composite sandwich panels

© Avestia Publishing, 2017. New materials are great additions to the structural world dominated by concrete and steel creating sustainable products and low impact materials that can go head to head with concrete and steel. The new materials being discovered can often outperform traditional materials and have added benefits that improve the in-life performance such as thermal capabilities and sound insulation. One of these construction materials are sandwich panels made of two materials that are relatively weak in their separated state, but are improved when they are constructed together in a sandwich panel. Sandwich panels can be used for almost any section of a building. Polystyrene/cement mixed core and thin cement sheet facings sandwich panels are Australian products made of cement-polystyrene beaded mixture encapsulated between two thick cement board sheets. Long-term structural behaviour of these sandwich panels are relatively unknown. Therefore, in this study, in order to understand the creep and creep recovery behaviour and properties of those sandwich panels, a series of experimental tests have been performed and the outcomes have been explained and discussed. Based on the results of this study, values for immediate recovery, creep recovery and irrecoverable creep strain are determined and proposed. In addition, typical creep and creep recovery design charts have been developed and presented for practical applications in structural engineering

Timber Portal Frames vs Timber Truss-Based Systems for Residential Buildings

© 2019 Harry Far and Claire Far. A large number of structures have been built during or after the construction of a house or residential-zoned building, which are not built at the same time and/or integrally with the structural integrity of the residential dwelling. These include carports, pergolas, sheds, and barns. The typical method of constructing these structures is a general timber truss and column system. The aim of this study is to look at the feasibility and economic incentive that may be gained from using a timber portal frame system, similar to the steel or timber portal frames used for larger industrial constructions, over the traditional timber truss and column arrangement. In this study, designs for three cases of timber truss and timber portals were carried out using industry appropriate methods and standards. Using the design information and data gathered through talks with industry professionals, both methods of construction were compared on cost and overall time duration. From the comparison of the truss and portal designs, the use of timber portal frames over timber truss systems proved to have advantage in relation to overall cost and man power involved. This could certainly affect the current attitude towards the construction of small residential buildings in the future

Shaking Table Tests on Soil-Structure System to Determine Lateral Seismic Response of Buildings

In this study, a series of experimental shaking table tests were performed on a physical fixed based model (structure directly fixed on top of the shaking table) and a flexible base model (soil-structure system) under the influence of four scaled earthquake acceleration records (two near field and two far field records) and the results were measured. The soil-structure system includes a 15 storey structural model resting on a synthetic clayey soil mixture consisting of kaolinite, bentonite, class F fly ash, lime, and water. The selected soil model was placed into a laminar soil container, designed and constructed to realistically simulate the free field conditions in shaking table tests. Comparing the measured response of fixed base and flexible base models, it is noted that the lateral deflections of flexible base model have evidently amplified in comparison to the fixed base model. As a result, performance level of the structural model may change extensively (e.g. from life safe to near collapse level), which may be extremely dangerous and safety threatening. Thus, it is experimentally observed that dynamic soil-structure interaction plays a significant role in seismic behaviour of moment resisting building frames resting on relatively soft soil

A CRITERION FOR CONSIDERING SOIL-STRUCTURE INTERACTION EFFECTS IN SEISMIC DESIGN OF DUCTILE RC-MRFs ACCORDING TO IRANIAN CODES

During the last quarter of the 20th century, the importance of dynamic soil-structure interaction for several structures founded on soft soils was well recognized. If not accounted for in analysis, the accuracy in assessing structural safety in the face of earthquakes cannot be accounted for adequately. For this reason, seismic soil-structure interaction analysis has become a major topic in earthquake engineering. As the Iranian Code of Practice for Seismic Resistant Design of Buildings (Standard No. 2800-05) does not address the soil-structure interaction explicitly, the effects of such interaction on behavior of reinforced concrete buildings with ductile moment-resisting frames, loaded and designed according to the Iranian Building Codes, are studied in this research, using direct soil-structure interaction method. To achieve this objective, four types of structures consisting of 3, 5, 7 and 10 story buildings, which represent the typical buildings in a high risk earthquake prone zone, have been selected in conjunction with three types of soil, representing types II, III and IV, as classified in the Iranian Standard No. 2800-05. Ductile Reinforced Concrete Moment-Resisting Frames, as fixed-base structures, once without soil interaction and the next time considering their soil interaction by direct method are modeled and subjected to different earthquake records. The results of the two cases subjected each to different earthquake records are studied and compared. This Comparison led to a criterion indicate that consideration of soil-structure interaction for seismic design, in buildings higher than three stories on soil type IV (Vs<175 m/s) as well as buildings higher than seven stories on soil type III (175<Vs<375 m/s), is essential

Advanced computation methods for soil-structure interaction analysis of structures resting on soft soils

© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. Adopting the most accurate and realistic modelling technique and computation method for treatment of dynamic soil–structure interaction (SSI) effects in seismic analysis and design of structures resting on soft soil deposits is one of the most discussed and challenging issues in the field of seismic design and requalification of different structures. In this study, a comprehensive critical review has been carried out on available and well-known modelling techniques and computation methods for dynamic SSI analysis. Discussing and comparing the advantages and disadvantages of employing each method, in this study, the most precise and reliable modelling technique as well as computation method have been identified and proposed to be employed in studying dynamic SSI analysis of structures resting on soft soil deposits

Experimental Investigations on Behaviour of Steel Structure Buildings

In this study, a comprehensive procedure for design, building and commissioning of scale steel structure building models has been developed and presented for practical applications in shaking table test programmes. To validate the model, shaking table tests and numerical time history dynamic analyses were performed under the influence of different scaled earthquake acceleration records. Comparing the numerical predictions and experimental values of maximum lateral displacements, it became apparent that the numerical predictions and laboratory measurements are in a good agreement. As a result, the scale structural model can replicate the behaviour of real steel structure buildings with acceptable accuracy. It is concluded that the physical model is a valid and qualified model which can be employed for experimental shaking table tests

Dynamic behaviour of unbraced steel frames resting on soft ground

© 2019 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin Many recent earthquakes clearly illustrate the importance of local ground properties for the dynamic response of structures. The dynamic response of an engineering structure is influenced by the medium on which it is founded. On solid rock, a fixed-base structural response occurs which can be evaluated by subjecting the foundation to the free-field ground motion occurring in the absence of the structure. However, on deformable ground, a feedback loop exists. In other words, when a feedback loop exists, the structure responds to the dynamics of the soil, while the soil also responds to the dynamics of the structure. Structural response is then governed by the interplay between the characteristics of the ground, the structure and the input motion. This study involved a numerical investigation of the dynamic behaviour of unbraced steel frames resting on soft ground. Two types of mid-rise unbraced steel frame, including 5- and 15-storey buildings on a soft soil deposit, were selected and analysed under the influence of three different earthquake acceleration records. The above-mentioned frames were analysed under two different boundary conditions: i) fixed-base (no soil-structure interaction) and ii) flexible-base (considering soil-structure interaction). The results of the analyses in terms of structural forces and lateral displacements for the above-mentioned boundary conditions are compared and discussed

Significance of using isolated footing technique for residential construction on expansive soils

© 2017, Higher Education Press and Springer-Verlag Berlin Heidelberg. Expansive soils cause problems with the founding of lightly loaded structures in many parts of the world. Foundation design for expansive soils is one of the most discussed and problematic issues in Australia as expansive soils were responsible for billions of dollars’ worth of damage to man-made structures such as buildings and roads. Several studies and reports indicate that one of the most common and least recognized problems causing severe structural damage to houses lies in expansive soils. In this study, a critical review has been carried out on the current Australian standards for building on expansive soils and they are compared with some techniques that are not included in the current Australian standards for residential slabs and footings. Based on the results of this review, the most effective and economical method has been proposed for construction of footings on all site classifications without restriction to 75mm of characteristic movement. In addition, it has become apparent that as design procedures for footings resting on sites with extreme characteristic movements are not included in the current Australian standards, there is a strong need for well-developed and simplified standard design procedures for characteristic soil movement of greater than 75mm to be included into the Australian Standards

Portal steel trusses vs. portal steel frames for long-span industrial buildings

© 2018 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin Portal frames and portal truss structures are two of the most cost-effective and sustainable structural forms for the design and construction of long-span industrial buildings. Although the use of both structure types as steel-clad structures is widely accepted, due to frame complexity and variation of frame types for use in single-storey buildings with spans > 30 m, literature providing a comprehensive investigation of the concepts of portal trusses and portal frames is scarce. This study compares the behaviour of a portal truss configuration with pitched portal frames for use in industrial buildings with spans > 30 m, focusing on weight, costs and construction time. Furthermore, this study entails a numerical investigation that utilizes the SAP2000 computer program to model and structurally optimize the member properties for both portal frame and portal truss configurations. Based on the results obtained from the investigation, it has become apparent that, due to the smaller sections used, the portal truss configurations are lighter and cheaper to fabricate and construct in comparison to the pitched portal frames, which, however, require a shorter construction time