Analysis and Design of Truss and Rafter Roofing System at Peshawar Services Club

Abstract

Steel as a building material, is of vital importance for industrial progression, infrastructural developments and construction related projects. Steel market growth is greatly associated with the GDP of any country. Steel is well known for its inherent stiffness and material strength thus allowing construction of long span structural members. In particular, Steel roofing, in the world is a 19th century phenomenon; however, it started in Pakistan after the commencement of commercial operations of Pakistan Steel Mills in 1984. In Pakistan, it has always been a subject to difficulties, yet its significance can never be denied. Steel roofing, with its inherent advantages of longevity, durability, energy efficiency, aesthetics and environmental friendliness, provides a wide variety from box trusses, double cantilever, bowstring, vaults, dual pitch, double inverted, rafters and so on. In Pakistan, box trusses and rafter systems are more popular, with both being equally good, if designed properly. However, none is economic and robust than a rafter system, especially for longer spans. Taking lead from the aforementioned knowledge and the interest developed during Steel Structures course, our group chose to undergo a project in Steel Structures. As a case study, we were introduced to a real time Steel Structure problem in Peshawar Services Club. It was a marquee comprising of box truss roofing superstructure on a RCC substructure. Based on our initial visit several structural faults and design discrepancies were identified, which called for an immediate remedy. After study of its structural drawings in detail, consultation of various codes, analysis of the existing structure on ETABS various problems were identified which if not addressed timely could lead to structural collapse. Retrofitting of box truss superstructure was also considered for this project; but was cost and time prohibitive. Subsequently, basing on our civil engineering knowledge, literature review and guidance of our supervisor, it was recommended to adopt a Steel rafter roofing system with retrofitting of existing concrete columns to sustain the new roofing system. The timely recommendations of the group were highly appreciated and was implemented by Headquarters Corps Engineers 11 Corps, and we are privileged that the Marquee at Peshawar Services Club is now being retrofitted according to our design/recommendations.