Stiffness and Strength of Metal Bridge Deck Forms

Abstract

Light gauge metal sheeting is often utilized in the building and bridge industries for concrete formwork. Although the in-plane stiffness and strength of the metal forms are commonly relied upon for stability bracing in buildings, the forms are generally not considered for bracing in steel bridge construction. The primary difference between the forming systems in the two industries is the method of connection between the forms and girders. In bridge construction, an eccentric support angle is incorporated into the connection details to achieve a uniform slab thickness along the girder length. While the eccentric connection is a benefit for slab construction, the flexible connection limits the amount of bracing provided by the forms. This paper presents results from the first phase of a research study investigating the bracing behavior of metal bridge deck forms. Shear diaphragm tests were conducted to determine the shear stiffness and strength of bridge deck forms, and modified connection details were developed that substantially improve the bracing behavior of the forms. The measured stiffness and strength of diaphragms with the modified connection often met or exceeded the values of diaphragms with conventional noneccentric connections. The experimental results for the diaphragms with the modified connection details dramatically improve the potential for bracing of steel bridge girders by metal deck forms.

Narin Çelik Kirişlere Stabilite Desteği Sağlayan Kayma Diyaframlarının Rijitlik Gereklilikleri

“…Bu çalışmada sayısal çözümlemeler yapmak için ANSYS [1] Tasarımcılar, Denklem (7)'de belirtilen rijitliğe sahip bir diyaframı literatürde mevcut olan tabloları veya deney sonuçlarını kullanarak seçebilirler [16,5,7]. Denklem (7)'de şu tasarım katsayıları kullanılmalıdır kullanılmalıdır: (a) Yük ve dayanım katsayıları ile tasarımda as ϕ = 0.65; (b) Güvenlik katsayıları ile tasarımda ϕ = 0.65 (16,4].…”

“…Bu eksantriklik ise diyafram destek siteminin rijitliğini azaltır. Ancak son yıllarda yapılan çalışmalarda, basit bir bağlantı modifikasyonu sayesinde eksantrik bağlantının sebep olduğu rijitlik kaybının önüne geçilebildiği görülmüştür [7,8,9]. Bu araştırmaların sonuçları Houston'da (Teksas, ABD) üç yüz ellişer adet 50 metre serbest açıklıklı ve basit mesnetli çelik kirişten oluşan 2 adet köprü inşaatında uygulanmıştır [10].…”

Analysis of Steel Girder Bridges

“…For example, Fisher (5) noted that the effects of stay-in-place metal deck forms were significant in predicting deflections of steel plate girder bridges. Meanwhile, Egilmez et al (18) have been exploring the possibility of using stay-in-place metal deck forms as formal girder bracing by modifying the connection details to make them more robust and reliable. Modeling of the effects of stay-in-place metal deck forms directly in the analysis model would likely require a 3-D FEM approach.…”

Contribution of perforated steel ribs to load-carrying capacities of steel and concrete composite slabs under negative bending

“…Stay-in-place steel forms are now used for cast-in-place reinforced concrete deck slabs in girder bridges after their successful and wide applications for floor slabs in buildings (AASHTO, 2014;Marimuthu et al, 2007;Matsui, 2007;Wrigley, 2001). They can reduce the labor cost and construction time, and improve the construction quality (Egilmez et al, 2007(Egilmez et al, , 2011Knight, 2009). Moreover, if proper shear connectors are used to obtain the composite action between steel form and concrete, the steel forms can partially act as a tensile reinforcement, and then the cross-sectional area of the so-called steel and concrete composite (SCC) slab can be somewhat reduced.…”