11-11-2014, 04:22 PM
Abstracts: Large span area is the area where the architectural plan of a structure requires a wide and unobstructed floor area. Thus, there is no column or any obstruction in between and there is a clear vision for the required long span. Necessity to cover large span area: Many structures (industrial buildings, community halls, stadiums, etc.) are such that they need a column-free area for their functional and aesthetic requirements. As a consequence of the size of the span, technical considerations are placed so high on the list of architectural priorities that, they significantly affect the aesthetic treatment of the building. Thus, mainly for functional and aesthetic requirements of the structure, large span areas are required. For large spans, the traditional method of beam-column frames sometimes becomes uneconomical as there is a large moment produced because of a long span and so the requirement of the dimensions of components will be high. The forms of longest-span structures are therefore those of the most efficient structure types which are durable, strong, economical as well as aesthetic. In the pre-industrial age, the structural form that was used for the widest spans was the masonry vault or dome. The development of reinforced concrete in the late 19th century allowed the extension of the maximum span possible with the compressive form-active type of structure. Now-a-days, different types of structural systems are used for covering large span area like R.C.C. beam-slab structure, truss, shell structure and folded plate, space frame, etc. In this project work, an attempt to study the structural aspects of 3-D space truss system which is mostly used for large span covering with aesthetic importance. In first phase of the project, various aspects regarding the behaviour and load distribution of forces with respect to constant structural member properties along with various geometry & varying support conditions has been studied. The comparison with conventional 2-D truss system is done. This will further lead by the second phase study which will be done for cost comparisons and optimizations of these space truss roofing systems. The attempt to study the behavior and the force distribution (analysis) along various members for various supporting conditions is done in the project phase-I. In this phase, the study for the manual optimization along with design and analysis tool from STAAD. Pro is carried out. More often used systems of 15 m x 15m and 20m x 2om is used for the optimization study. The design of various elements of the grid structure is done on STAAD and for the optimization is done using iterative calculation to choose the economical section from the excel spreadsheet prepared . 1. The weight in the case of the corner supported system is highest as the stress concentration is seen at the supporting columns. 2. Comparative study of weight for system supported on four sides is lowest and almost the 0.25% than the corner supported and 0.7% the system supported on 2 sides. 3. Comparative study of weight for system supported on four sides shows negligible difference as all the members are required to design for majorly for slenderness and not for the strength 3987 67 6 06 Civil Engineering 14394 9429627083 bhaumikgp[at]gmail.com 067 Sal Institute Of Technology & Engineering Research 110673106010 PATEL BHAUMIK GHANSHYAMBHAI 7 UDP DESIGN OF VARIOUS STRUCTURAL SYSTEMS TO COVER LARGE SPAN AREA Large span area is the area where the architectural plan of a structure requires a wide and unobstructed floor area. Thus, there is no column or any obstruction in between and there is a clear vision for the required long span. Necessity to cover large span area: Many structures (industrial buildings, community halls, stadiums, etc.) are such that they need a column-free area for their functional and aesthetic requirements. As a consequence of the size of the span, technical considerations are placed so high on the list of architectural priorities that, they significantly affect the aesthetic treatment of the building. Thus, mainly for functional and aesthetic requirements of the structure, large span areas are required. For large spans, the traditional method of beam-column frames sometimes becomes uneconomical as there is a large moment produced because of a long span and so the requirement of the dimensions of components will be high. The forms of longest-span structures are therefore those of the most efficient structure types which are durable, strong, economical as well as aesthetic. In the pre-industrial age, the structural form that was used for the widest spans was the masonry vault or dome. The development of reinforced concrete in the late 19th century allowed the extension of the maximum span possible with the compressive form-active type of structure. Now-a-days, different types of structural systems are used for covering large span area like R.C.C. beam-slab structure, truss, shell structure and folded plate, space frame, etc. In this project work, an attempt to study the structural aspects of 3-D space truss system which is mostly used for large span covering with aesthetic importance. In first phase of the project, various aspects regarding the behaviour and load distribution of forces with respect to constant structural member properties along with various geometry & varying support conditions has been studied. The comparison with conventional 2-D truss system is done. This will further lead by the second phase study which will be done for cost comparisons and optimizations of these space truss roofing systems. The attempt to study the behavior and the force distribution (analysis) along various members for various supporting conditions is done in the project phase-I. In this phase, the study for the manual optimization along with design and analysis tool from STAAD. Pro is carried out. More often used systems of 15 m x 15m and 20m x 2om is used for the optimization study. The design of various elements of the grid structure is done on STAAD and for the optimization is done using iterative calculation to choose the economical section from the excel spreadsheet prepared .