Testing of the Manitou bridge to determine its safe load carrying capacity

1981 ◽  
Vol 8 (2) ◽  
pp. 218-229 ◽  
Author(s):  
Baidar Bakht

The anatomy of a test to realistically determine the safe load carrying capacity of a bridge is presented. Analytically the bridge was declared to be unsuitable for carrying unrestricted traffic and yet the test showed that the bridge was capable of safely sustaining normal loads. The test points out the significance of the structure's response to varying temperatures, and shows that the load carrying capacity of the bridge depends substantially on such interaction of the various components as was not intentionally provided for in the original design.The test was helpful not only in determining the safe load carrying capacity of the bridge but was also instrumental in diagnosing the possible source of distress in the bridge deck slab.

Author(s):  
Sarah Jaber ◽  
Mounir Mabsout ◽  
Kassim Tarhini

Bridge specifications do not consider the effect of parapet stiffness in the analysis and design of reinforced concrete slab bridges. This paper performs a parametric investigation using finite element analysis (FEA) to study the effects of parapet stiffness on live load-carrying capacity of two-span, three-and four-lane concrete slab bridges. This study analyzed 96 highway bridge cases with varied parameters such as span-length, bridge width, and parapet stiffness within practical ranges. Reinforced concrete parapets or railings, built integrally with the bridge deck, were placed on one and/or both sides of bridge deck. The longitudinal bending moments calculated using the FEA results were compared with reference bridge cases without parapets, as well as AASHTO Standard and LRFD specifications. The FEA results presented in this paper showed that the presence of concrete parapets reduces the negative bending moments by 15% to 60% and the positive bending moments by 10% to 45%. The reduction in longitudinal bending moments can mean an increase in the load-carrying capacity of such bridges depending on the parapet stiffness. This investigation can assist engineers in modeling the actual bridge geometry more accurately for estimating the load-carrying capacity of existing concrete bridges. Hence, new bridges can be designed by considering the presence of concrete parapets. Parapets can be used as an alternative for strengthening existing one and two-span reinforced concrete slab bridges.


2005 ◽  
Vol 10 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J. Kala ◽  
Z. Kala

Authors of article analysed influence of variability of yield strength over cross-section of hot rolled steel member to its load-carrying capacity. In calculation models, the yield strength is usually taken as constant. But yield strength of a steel hot-rolled beam is generally a random quantity. Not only the whole beam but also its parts have slightly different material characteristics. According to the results of more accurate measurements, the statistical characteristics of the material taken from various cross-section points (e.g. from a web and a flange) are, however, more or less different. This variation is described by one dimensional random field. The load-carrying capacity of the beam IPE300 under bending moment at its ends with the lateral buckling influence included is analysed, nondimensional slenderness according to EC3 is λ¯ = 0.6. For this relatively low slender beam the influence of the yield strength on the load-carrying capacity is large. Also the influence of all the other imperfections as accurately as possible, the load-carrying capacity was determined by geometrically and materially nonlinear solution of very accurate FEM model by the ANSYS programme.


2005 ◽  
Vol 10 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Z. Kala

The load-carrying capacity of the member with imperfections under axial compression is analysed in the present paper. The study is divided into two parts: (i) in the first one, the input parameters are considered to be random numbers (with distribution of probability functions obtained from experimental results and/or tolerance standard), while (ii) in the other one, the input parameters are considered to be fuzzy numbers (with membership functions). The load-carrying capacity was calculated by geometrical nonlinear solution of a beam by means of the finite element method. In the case (ii), the membership function was determined by applying the fuzzy sets, whereas in the case (i), the distribution probability function of load-carrying capacity was determined. For (i) stochastic solution, the numerical simulation Monte Carlo method was applied, whereas for (ii) fuzzy solution, the method of the so-called α cuts was applied. The design load-carrying capacity was determined according to the EC3 and EN1990 standards. The results of the fuzzy, stochastic and deterministic analyses are compared in the concluding part of the paper.


2005 ◽  
Vol 33 (4) ◽  
pp. 210-226 ◽  
Author(s):  
I. L. Al-Qadi ◽  
M. A. Elseifi ◽  
P. J. Yoo ◽  
I. Janajreh

Abstract The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.


2020 ◽  
Vol 2020 (21) ◽  
pp. 146-153
Author(s):  
Anatolii Dekhtyar ◽  
◽  
Oleksandr Babkov ◽  

2019 ◽  
Vol 129 ◽  
pp. 1-4 ◽  
Author(s):  
Jun Cheng ◽  
Yuan Yu ◽  
Jie Guo ◽  
Shuai Wang ◽  
Shengyu Zhu ◽  
...  

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