a review - Acta Technica Corviniensis

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ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering [25.] Sinou, M., & Kyvelou, S. Present and Future of building Performance Assessment Tools. Management of Environmental Quality, 17(5), 570-586, 2006. [26.] BEAM Society. BEAM Plus New Buildings Version 1.1 (Guidelines): Hong Kong Green Building Council and Building Environmental Assessment Method (BEAM Society), 2010. [27.] Lee, W.L., & Burnett, J. Benchmarking Energy Use Assessment of HK-BEAM, BREEAM and LEED. Building and Environment, 43, 1882-1891, 2008. [28.] HK-BEAM Society. (2004). Hong Kong Building Environmental Assessment Method 4/04 'New Buildings': Hong Kong Building Environmental Assessment Method (HK-BEAM). [29.] BEAM Society. Building Environmental Assessment Method for New Buildings: Building Environmental Assessment Method (BEAM), 2009. [30.] BCA. (2010). BCA Green Mark for New Residential Buildings Version RB/4.0 (Certification Standard): Building and Construction Authority (BCA). [31.] UNEP SBCI. Buildings and Climate Change: Summary for Decision-Makers, 2009. ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERING ISSN: 2067-3809 [CD-Rom, online] copyright © UNIVERSITY POLITEHNICA TIMISOARA, FACULTY OF ENGINEERING HUNEDOARA, 5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIA http://acta.fih.upt.ro 96 2013. Fascicule 2 [April–June]
1. Ala’a M. DARWISH, 2. Wameedh G. ABDUL-HUSSEIN, 3. Zeena T. JALEEL ELIMINATING HALF OF THE CONSTRUCTIONAL DEFLECTIONS OF SIMPLY SUPPORTED STEEL BRIDGES BY USING TEMPORARY CONTINUITY 1-3. BUILDING AND CONSTRUCTION ENGINEERING FACULTY, UNIVERSITY OF TECHNOLOGY, BAGHDAD, IRAQ ABSTRACT: When it is required to cast a bridge over a valley, a river or a busy highway, it is difficult to use the required shoring for the concrete casting molds. In such cases, the heavy weight of fresh concrete will be directly subjected to the bridge girders. This situation will apply severe stresses to the bare supporting - normally long span - girders, leading to an un-favorite and uncorrectable permanent deflection. In this research, a simple test was done to simulate the mentioned critical case. It was found that; by constructing temporary joints for both ends of the steel girders of a simply supported bridge panel with its adjacent panels will apply reversal moments to the original panel. By reducing mid span moments due to the weight of fresh concrete of the deck slab during construction, a noticeable reduction–up to Fifty percent–of the expected mid span constructional deflection can be eliminated. KEYWORDS: Bridge construction, Steel bridges, Bridge deflection control, Constructional bridge deflection, Plate-Girder bridge, Deck slab construction INTRODUCTION A normal bridge is a long structure, usually consists of several spans. Each span is also considered as a long structure compared to other types of engineering constructions. Bridges are designed to sustain the safe passing of heavy traffic and pedestrians loading. Heavy loading in addition to long span result in greater stresses leading to the adaption of huge sections. These large scale formations and their extra weight require special precautions during manufacturing, transporting and erecting. Generally, it is impossible to construct a bridge panel within one stroke. Therefore; design and construction processes will follow suitable procedures to fulfill the required aim of building a safe, durable and nice looking bridge without making any destruction to the site surroundings. Mainly, bridges are designed to be constructed by the use of reinforced concrete, pre-stressed concrete, steel or their combinations to act in a composite manner. In most cases, each panel consists of a number of equally spaced supporting girders topped by a reinforced concrete deck slab. During design stages, supporting girders are analyzed and designed to carry its self-weight and the weight of the fresh concrete of the deck slab plus 20% of the bridge live loading to account for the weight of the casing moulds, the construction equipments and the workers. The design is cross checked under the full dead and live loading for composite action of the hardened concrete that will be fully attached by shear connectors to the supporting girders. In cases where a bridge has to be constructed over a deep valley/river or in a busy city, it is difficult to construct or to attain-for few weeks- for the removal of the required temporary deck slab casting molds and its shoring. In such situation the constructing engineer will face a trouble of supporting his unshored temporary molds directly over the supporting girders. This will lead to an inevitable expected deflection. The mentioned extreme loading case is embarrassing during design stages. If the fresh concrete load of the deck slab is considered to be held by the supporting girders alone, it will lead to larger sections, altering the aesthetic appearance of the bridge and certainly it will increase the cost. While, following the standard code procedures without taking construction stresses into consideration will lead to un- favorite deflections. To have a numerical idea regarding the problem; for 10m wide bridge spanning 30m and with a concrete deck slab thickness of 20cm, the total uniformly distributed load due to the weight of the fresh concrete only – without the 20% increment of the live load- will be 156 tons. This load alone is much greater than the design live load recommended by AASHTO standard truck {1} which is suggested to be applied after the completion of the bridge. Normally this temporary construction load is taken by the shoring system, but if there is no shoring a problem will certainly arise.{2} For suspension bridges there is no problem of deflection, because each hanger could be considered as a support transforming the total load to the main cables which directs its tensile force to the bridge towers and © copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 97
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ROLE OF METAMODELING Detailed resea
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Figure 5 presents the cross-recepta
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RESULTS AND DISCUSSION. Electrochem
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REFERENCES [1.] Velisek, J.; Cejpek
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