Secondary Settlements of Structures Subjected to Large Variations in Live Load

1966 ◽  
pp. 460-471 ◽  
Author(s):  
Laurits Bjerrum
Keyword(s):  
Live Load

The Live Load Capacity of Rectangular Precast Reinforced Concrete Stick Plates

2018 ◽  
Vol 9 (5) ◽  
pp. 174
Author(s):  
Agus Maryoto ◽  
Han Ay Lie ◽  
Nanang Gunawan Wariyatno
Keyword(s):  
Reinforced Concrete ◽  
Load Capacity ◽  
Live Load

Live-Load Girder Distribution Factors for Bridges Subjected to Wide Trucks

2000 ◽  
Vol 1696 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Sami W. Tabsh ◽  
Muna Tabatabai
Keyword(s):  
Finite Element ◽  
The United States ◽  
Live Load ◽  
Wheel Load ◽  
Element Analysis ◽  
Load Effect ◽  
Design Specifications ◽  
Girder Bridges ◽  
Girder Distribution Factors ◽  
Modification Factor

An important problem facing engineers and officials in the United States is the constraint imposed on transportation due to limitations of bridges. These limitations typically constrain vehicles to minimum heights and widths, to minimum and maximum lengths, and to a maximum allowable weight. However, with current demands of society and industry, there are times when a truck must carry a load that exceeds the size and weight of the legal limit. In this situation, the trucking company requests from the state departments of transportation an overload permit. For a truck with a wheel gauge larger than 1.8 m (6 ft), the process of issuing a permit for an overload truck requires a tremendous amount of engineering efforts. This is because the wheel load girder distribution factors (GDFs) in the design specifications cannot be used to estimate the live-load effect in the girders. In some cases, an expensive and time-consuming finite element analysis may be needed to check the safety of the structure. In this study, the finite element method is used to develop a modification factor for the GDF in AASHTO’s LRFD Bridge Design Specifications to account for oversized trucks with a wheel gauge larger than 1.8 m. To develop this factor, nine bridges were considered with various numbers of girders, span lengths, girder spacings, and deck slab thicknesses. The results indicated that use of the proposed modification factor with the GDF in the design specifications can help increase the allowable load on slab-on-girder bridges.

Field Determined Live Load Distribution Factors for Modular Press-Brake-Formed Tub Girders

2021 ◽  
pp. 036119812098375
Author(s):  
Karl E. Barth ◽  
Gregory K. Michaelson ◽  
Adam D. Roh ◽  
Robert M. Tennant
Keyword(s):  
West Virginia ◽  
Experimental Testing ◽  
Field Performance ◽  
Live Load ◽  
Steel Bridge ◽  
Testing Procedures ◽  
Bending Capacity ◽  
Short Span ◽  
And Performance ◽  
Live Load Distribution

This paper is focused on the field performance of a modular press-brake-formed tub girder (PBFTG) system in short span bridge applications. The scope of this project to conduct a live load field test on West Virginia State Project no. S322-37-3.29 00, a bridge utilizing PBFTGs located near Ranger, West Virginia. The modular PBFTG is a shallow trapezoidal box girder cold-formed using press-brakes from standard mill plate widths and thicknesses. A technical working group within the Steel Market Development Institute’s Short Span Steel Bridge Alliance, led by the current authors, was charged with the development of this concept. Research of PBFTGs has included analyzing the flexural bending capacity using experimental testing and analytical methods. This paper presents the experimental testing procedures and performance of a composite PBFTG bridge.

Reliability Analysis of Prestressed Concrete Bridges in Mexico: Assessment and Live Load Factors Proposal

2021 ◽  
Author(s):  
Rolando Salgado-Estrada ◽  
Sergio A. Zamora-Castro ◽  
Agustín L. Herrera-May ◽  
Yessica A. Sánchez-Moreno ◽  
Yair S. Sánchez-Moreno
Keyword(s):  
Reliability Analysis ◽  
Prestressed Concrete ◽  
Concrete Bridges ◽  
Live Load ◽  
Prestressed Concrete Bridges ◽  
Load Factors

Redistribution of Internal Force under Structural Defect and Non-Linear Spatial Stability under Live Load and Wind of Tied-Arch Bridge

2013 ◽  
Vol 477-478 ◽  
pp. 640-645
Author(s):  
Qian Hui Pu ◽  
Hu Zhao
Keyword(s):  
Safety Factor ◽  
Mechanical Performance ◽  
Influence Factors ◽  
Internal Force ◽  
Structural Defects ◽  
Live Load ◽  
Positive Contribution ◽  
Arch Bridge ◽  
Initial Defect ◽  
Tied Arch Bridge

To study the mechanical performance and stability of tied-arch bridge under structural defects and damages, limited element modal of Panzhihua Luoguo Jinshajiang Bridge was established and analyzed. Firstly, some typical damage models and their influence factors were presented. Then, based on the model established, change of suspender force caused by arch rib lineation defect, hanger lineation defect and boom failure was calculated respectively. The stability safety factor under the load group composed of dead load, live load and wind was calculated as well as the second-class nonlinear stability safety factor under structural initial defect. Calculation results shows that, suspender forces were more sensitive to archs vertical defect than to transverse defect. While, short hangers were more sensitive to lineation defect than long ones, and secondary inner force in short booms were bigger than in long ones. The result also tells that lateral wind is bad to lateral stability. Lift wind, somehow, makes positive contribution to structures in-plane stability. Structural initial defect can draw down the second-class stability safety factor under geometric nonlinear condition.

Statistical Analysis of Live Load in Column Design

1972 ◽  
Vol 98 (8) ◽  
pp. 1803-1815
Author(s):  
Ross B. Corotis
Keyword(s):  
Statistical Analysis ◽  
Live Load ◽  
Column Design

Safe Platooning Headways on Girder Bridges

2021 ◽  
pp. 036119812110363
Author(s):  
Bowen Yang ◽  
Joshua S. Steelman ◽  
Jay A. Puckett ◽  
Daniel G. Linzell
Keyword(s):  
Prestressed Concrete ◽  
Limit State ◽  
Live Load ◽  
Load Effect ◽  
Operational Strategies ◽  
Reliability Indices ◽  
Girder Bridges ◽  
Legal Limits ◽  
Weigh In Motion ◽  
Load And Resistance Factor

Truck platooning—digitally linking two or more trucks to travel in a closely spaced convoy—is an emerging technology with the potential to save fuel and reduce labor. A framework is described to determine how much a platoon permit load might be increased above Federal Bridge Formula B legal limits, given strict control over the load characteristics and operational tactics. Soon, platoons are expected to advance not only with respect to traffic operations but also in their ability to weigh and report axle weight and spacing, functioning as mobile weigh-in-motion vehicles. Consequently, platoon live load statistics (bias and coefficient of variation) can differ from code assumptions, and are perhaps controllable, which poses a significant opportunity with respect to operational strategies. A parametric study is presented that examined safe headways between platooning trucks, considering different girder spacings, span lengths, numbers of spans, types of structure, truck configurations, numbers of trucks, and adjacent lane loading scenarios. The Strength I limit state was evaluated for steel and prestressed concrete I-girder bridges optimally designed using load and resistance factor design. Reliability indices, β, were calculated for each load case based on Monte Carlo simulation. Summary headway guidance was developed and is presented here to illustrate potential safe operational strategies for varying truck weights and platoon live load effect uncertainties.

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