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Papers by Ahmed Diab
In bridge analysis, bridge designers require the maximum loads applied on bridge traffic lanes in... more In bridge analysis, bridge designers require the maximum loads applied on bridge traffic lanes in order to determine the appropriate structural design including materials, girder spacing, and cross-section sizes for the bidding procedure. In order to achieve that, designers have to go through an iterative trial and error process which takes a considerable amount of time and may result in overestimation at the bidding stage. In the case of bridge design, there are no such tables which hinders the preliminary assessment of project value and bid cost. As such, this paper outlines a research conducted to develop traffic load equations and tables based on the 2020 AASHTO LRFD Bridge Design Specifications. By utilizing this method, engineers will save time in the design process, and reduce project bid cost by minimizing overdesigned and overestimated structural section sizes for project tender documents. In this research, moving load equations and tables were created based on single-lane bridge models for single span and two-span bridge configurations in SAP2000 software. Truck load arrangements, based on AASHTO LRFD design specifications, were applied and results obtained using moving load approach. Finally, the data generated from the parametric study was used to develop empirical expressions for design moment (MT) and shear (VT) for the use by bridge designers.
With increased prices of steel, bridge owners and design engineers may have become reluctant to u... more With increased prices of steel, bridge owners and design engineers may have become reluctant to using steel in bridge superstructure, as it may be cost prohibitive. During the preparation of bid documents, bridge design engineers select a bridge geometry which complies with functional requirements of the highway. While preliminary section sizes for precast concrete girders are available in the literature for use in the bidding process, no similar data is available for structural steel girders. So, the objective of this research is to establish ready-to-use design tables of steel I-girder bridges based on simplified analysis and design procedure specified in the Canadian Highway Bridge Design Code. The bridge analysis and design procedure were performed through a developed graphical computer software. The optimum steel girder section sizes were reached through iterative process to satisfy the ultimate, serviceability and fatigue limit state design procedure. The computer software dis...
The First International Symposium on Jointless & Sustainable Bridges
The structural insulated panel (SIP) is a sandwich structured composite that is prefabricated by ... more The structural insulated panel (SIP) is a sandwich structured composite that is prefabricated by attaching a lightweight thick core made of Expanded Polystyrene (EPS) foam laminated between two thin, and stiff face skins made of Oriented Strand Board (OSB). The use of sandwich panels provides key benefits over conventional materials including: very low weight; high stiffness; durability and; production and construction cost savings. The facing skins of the sandwich panel can be considered as the flanges for the I-beam carrying bending stresses in which one face skin is subjected to tension, and the other is in compression. The core resists the shear loads and stabilizes the skin faces together giving uniformly stiffened panel. OSB is wood product that shrinks when dry and swells when adsorb moisture either due to liquid or vapor from the surrounding atmosphere. The relative combination of relative humidity and temperature is introduced into the equilibrium moisture content (EMC) that increases with the increase of the relative humidity and with decreasing temperature. Experimental test matrix includes testing 2.44 m (8’) and 4.88 m (16’) long SIPs for 5 years under different sustained loads and weather resistive barriers (WRBs), recording creep deflection, relative humidity and temperature. After creep recovery, the SIPs are loaded to-collapse to determine their flexural strength.
In bridge analysis, bridge designers require the maximum loads applied on bridge traffic lanes in... more In bridge analysis, bridge designers require the maximum loads applied on bridge traffic lanes in order to determine the appropriate structural design including materials, girder spacing, and cross-section sizes for the bidding procedure. In order to achieve that, designers have to go through an iterative trial and error process which takes a considerable amount of time and may result in overestimation at the bidding stage. In the case of bridge design, there are no such tables which hinders the preliminary assessment of project value and bid cost. As such, this paper outlines a research conducted to develop traffic load equations and tables based on the 2020 AASHTO LRFD Bridge Design Specifications. By utilizing this method, engineers will save time in the design process, and reduce project bid cost by minimizing overdesigned and overestimated structural section sizes for project tender documents. In this research, moving load equations and tables were created based on single-lane bridge models for single span and two-span bridge configurations in SAP2000 software. Truck load arrangements, based on AASHTO LRFD design specifications, were applied and results obtained using moving load approach. Finally, the data generated from the parametric study was used to develop empirical expressions for design moment (MT) and shear (VT) for the use by bridge designers.
With increased prices of steel, bridge owners and design engineers may have become reluctant to u... more With increased prices of steel, bridge owners and design engineers may have become reluctant to using steel in bridge superstructure, as it may be cost prohibitive. During the preparation of bid documents, bridge design engineers select a bridge geometry which complies with functional requirements of the highway. While preliminary section sizes for precast concrete girders are available in the literature for use in the bidding process, no similar data is available for structural steel girders. So, the objective of this research is to establish ready-to-use design tables of steel I-girder bridges based on simplified analysis and design procedure specified in the Canadian Highway Bridge Design Code. The bridge analysis and design procedure were performed through a developed graphical computer software. The optimum steel girder section sizes were reached through iterative process to satisfy the ultimate, serviceability and fatigue limit state design procedure. The computer software dis...
The First International Symposium on Jointless & Sustainable Bridges
The structural insulated panel (SIP) is a sandwich structured composite that is prefabricated by ... more The structural insulated panel (SIP) is a sandwich structured composite that is prefabricated by attaching a lightweight thick core made of Expanded Polystyrene (EPS) foam laminated between two thin, and stiff face skins made of Oriented Strand Board (OSB). The use of sandwich panels provides key benefits over conventional materials including: very low weight; high stiffness; durability and; production and construction cost savings. The facing skins of the sandwich panel can be considered as the flanges for the I-beam carrying bending stresses in which one face skin is subjected to tension, and the other is in compression. The core resists the shear loads and stabilizes the skin faces together giving uniformly stiffened panel. OSB is wood product that shrinks when dry and swells when adsorb moisture either due to liquid or vapor from the surrounding atmosphere. The relative combination of relative humidity and temperature is introduced into the equilibrium moisture content (EMC) that increases with the increase of the relative humidity and with decreasing temperature. Experimental test matrix includes testing 2.44 m (8’) and 4.88 m (16’) long SIPs for 5 years under different sustained loads and weather resistive barriers (WRBs), recording creep deflection, relative humidity and temperature. After creep recovery, the SIPs are loaded to-collapse to determine their flexural strength.