（節(jié)選）橋梁外文翻譯--論傾斜角度對(duì)連續(xù)組合梁橋的影響（原文）

1、See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/273025406Influence of Skew Angle on ContinuousComposite Girder BridgeArticle in Journal of Bridge Engineerin

2、g · July 2012DOI: 10.1061/(ASCE)BE.1943-5592.0000273CITATIONS4READS62 authors, including:Gholamreza NouriKharazmi University42 PUBLICATIONS 41 CITATIONS SEE PROFILEAll in-text references underlined in blue are l

3、inked to publications on ResearchGate,letting you access and read them immediately.Available from: Gholamreza NouriRetrieved on: 26 August 2016specifications underestimated the bending moments by as much as 28% for exter

4、ior girders in normal bridges and that for a skew angle of 60°, the maximum moment in the interior girder was approxi- mately 71% of that in a normal bridge. Helba and Kennedy (1994) tested continuous-skewed composi

5、te bridges to define col- lapse loads. The results were presented for both simply supported and continuous, two-span, skewed composite bridges. Ebeido and Kennedy (1996a, b) investigated the influence of the skew angle,

6、as well as other design parameters, on the shear and reaction distri- bution factors of continuous, two-span, composite steel-concrete bridges. Khaloo and Mirzabozorg (2003), using the finite-element analy- sis (FEA) met

7、hod, analyzed three-dimensional (3D), simply sup- ported, skewed bridges with various span lengths, skew angles, girder spacings, and arrangements of internal transverse dia- phragms. They showed that the load distributi

8、on factor of exterior girders was reduced by 24% for a skew angle of 60° compared with nonskewed bridges. In addition, the study showed the sensitivity of the load distribution factors of the interior girders with r

9、espect to the skew angle. For decks with a skew angle of 60°, the distribution factors decreased by 26.3% compared with nonskewed bridges. It was concluded that the load distribution factors of the AASHTO standard s

10、pecifications were up to 43.1% higher than those found by FEA. Khaloo and Mirzabozorg (2003) suggested that girder live-load distribution factors should be reevaluated for skewed bridges. Huang et al. (2004) carried out

11、field tests and theoretical analyses using FEA for two-span continuous slab-on-steel girder composite bridges with a skew angle of 60°. Ashebo et al. (2007) studied the effect of dynamic loads on a skew-box girder c

12、ontinuous bridge. It was found that the influence of skew in both the static and dynamic behaviors of the bridge within the skew an- gle range of 0°–30° was very small Menassa et al. (2007) conducted FEA on a s

13、imply supported one-span multilane skew reinforced concrete slab bridge. They concluded that the ratio between the FEA longitudinal moments for skewed and straight bridges was almost 1 for bridges with a skew angle less

14、than 20°. This ratio decreased to 0.75 for bridges with skew angles between 30° and 40°, and further decreased to 0.5 as the skew angle of the bridge increased to 50°. In those studies, the effects of

15、 transverse dia- phragm arrangement and span ratio have not been considered. In this paper, the effect of the skew angle and other design parameters on the bending moment, shear force, and distribution factor of two-span

16、 continuous composite steel-concrete bridges are studied using FEA. The results of the FEA for skewed bridges are compared with the reference straight bridges as well as the AASHTO standard specifications and AASHTO LRFD

17、 specifica- tions. In addition, the accuracy of a simple equation for skewed bridges in a previous study is examined and the effects of the trans- verse diaphragm arrangement and span ratio are studied. Seventy- two mode

18、l cases are analyzed with various span ratios (1, 1.55, and 1.82), skew angles (0°–60°), and two arrangements of internal transverse diaphragms.Description of Bridge Models and AssumptionsTwo-lane bridges with

19、an overall width of 11.8 m with six I-section girders were considered. The structure was idealized using the fol- lowing assumptions: 1. The skewed decks were slab on girder and consisted of six steel I-sectioned longitu

20、dinal girders that are spaced at 2 m, center to center. 2. All materials were elastic and homogeneous.3. The deck slab and longitudinal I-girders were simply sup- ported at the abutment and were continuous over the piers

21、. The length of the first span was 24 m, with span ratios (N = second span length/first span length) of 1, 1.55, and 1.82. Two different arrangements for the intermediate transverse dia- phragm were studied: in the first

22、 pattern, a transverse diaphragm was perpendicular to the longitudinal girders; and in the second one, a transverse diaphragm was parallel to the supporting line of the deck. The skew angle varied 0–45° for the firs

23、t pattern and 0–60° for the parallel one. The girders were steel I-sections with a height of 2 m and section modulus of Sx ¼ 0:046 m3. We used L80 × 8 mm for the X-type intermediate diaphragm with a top an

24、d bottom cord cross frame. For all bridges, 25-cm-thick con- crete deck slabs of 30-MPa compressive strength were used and were reinforced on the top and bottom by a 400 mm2∕m area of steel mesh (Ebeido and Kennedy 1996a

25、, b). Fig. 1 shows the cross section of finite-element model (FEM) and two arrangements of transverse diaphragms.Finite-Element AnalysisMany variations have been used in the literature to formulate the girder-slab model.

26、 Hays et al. (1986) developed a model using quadrilateral shell elements for the bridge deck and space frame elements for the girders. This type of model is similar to the eccen- tric beam model except the elements are s

27、imply connected at the center of gravity and a rigid link is not required. A true eccentric beam approach was presented by Imbsen and Nutt (1978). The model utilized shell elements and beam elements connected by rigid li

28、nks to represent the deck and girders, respectively. Brock- enbrough (1986) used a detailed beam approach and divided the beam into three parts. Each flange was modeled as a beam element, and the web was modeled as a she

29、ll element. The slab utilized shell elements connected through a rigid link to the centroidal nodes of each element. The solid deck approach was presented by Tarhini and Frederick (1992), who used the solid element for t

30、he deck and the shell element for the girders. The eccentric beam model was identified as the most economical model while still accurately predicting girder behavior. We use the general FEA program, SAP2000 (CSI 2000), f

31、or the 3D FEM. The concrete slab was mod- eled using four-node 3D elastic shell elements with six degrees of freedom at each node. The longitudinal steel girders were modeled using two-node 3D elastic beam elements with

32、six degrees of free- dom at each node. The shell and beam elements were connected by rigid link elements. These elements were used to model the composite action between the deck and the girders by connecting the nodes of

33、 the deck elements with the beam and shell elements. The transverse diaphragms across the frames were modeled using the beam elements. The connections between the girder and diaphragm elements were fixed. Simple supports

34、 at the ends of bridges were modeled using boundary constraints in which the translational displacements were restricted except in the longitudi- nal direction, and there were no rotational constraints. It was shown that

35、 simple support boundary condition may provide more uniform results (Eom and Nowak 2001). Furthermore, the intermediate pier supports were modeled using boundary constraints in which all the translational displacements w

36、ere restricted.Loading and FEA ResultsThe standard truck HS20-44 was used according to the AASHTO standard specifications. The moving load option of SAP2000 (CSI 2000) was used for loading. To verify the FEM in the case6

37、18 / JOURNAL OF BRIDGE ENGINEERING © ASCE / JULY/AUGUST 2012J. Bridge Eng., 2012, 17(4): 617-623 Downloaded from ascelibrary.org by University of Liverpool on 11/26/15. Copyright ASCE. For personal use only; all rig