The impact of measurement uncertainty from experimental load distribution factors on bridge load rating

2018 ◽  
Author(s):  
Michael V. Gangone ◽  
Matthew J. Whelan
Keyword(s):  
Measurement Uncertainty ◽  
Load Distribution ◽  
Load Rating ◽  
Load Distribution Factors ◽  
The Impact ◽  
Bridge Load Rating

scholarly journals Improved Live Load Distribution Factors for Use in Load Rating of Older Slab and T-Beam Reinforced Concrete Bridges

2021 ◽  
Author(s):  
Faezeh Ravazdezh ◽  
Julio A. Ramirez ◽  
Ghadir Haikal
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Load Distribution ◽  
Load Rating ◽  
Flat Slab ◽  
3D Finite Element ◽  
On Demand ◽  
Load Distribution Factors ◽  
The Impact ◽  
T Beam

This report describes a methodology for demand estimate through the improvement of load distribution factors in reinforced concrete flat-slab and T-beam bridges. The proposed distribution factors are supported on three-dimensional (3D) Finite Element (FE) analysis tools. The Conventional Load Rating (CLR) method currently in use by INDOT relies on a two-dimensional (2D) analysis based on beam theory. This approach may overestimate bridge demand as the result of neglecting the presence of parapets and sidewalks present in these bridges. The 3D behavior of a bridge and its response could be better modeled through a 3D computational model by including the participation of all elements. This research aims to investigate the potential effect of railings, parapets, sidewalks, and end-diaphragms on demand evaluation for purposes of rating reinforced concrete flat-slab and T-beam bridges using 3D finite element analysis. The project goal is to improve the current lateral load distribution factor by addressing the limitations resulting from the 2D analysis and ignoring the contribution of non-structural components. Through a parametric study of the slab and T-beam bridges in Indiana, the impact of selected parameters on demand estimates was estimated, and modifications to the current load distribution factors in AASHTO were proposed.

scholarly journals Live Load Distribution Factors for Skew Stringer Bridges with High-Performance-Steel Girders under Truck Loads

2018 ◽  
Vol 8 (10) ◽  
pp. 1717 ◽  
Author(s):  
Iman Mohseni ◽  
Yong Cho ◽  
Junsuk Kang
Keyword(s):  
Load Distribution ◽  
Shear Force ◽  
High Performance ◽  
Structural Parameters ◽  
Highway Bridges ◽  
Live Load ◽  
High Performance Steel ◽  
Live Load Distribution Factors ◽  
Live Load Distribution ◽  
Load Distribution Factors

Because the methods used to compute the live load distribution for moment and shear force in modern highway bridges subjected to vehicle loading are generally constrained by their range of applicability, refined analysis methods are necessary when this range is exceeded or new materials are used. This study developed a simplified method to calculate the live load distribution factors for skewed composite slab-on-girder bridges with high-performance-steel (HPS) girders whose parameters exceed the range of applicability defined by the American Association of State Highway and Transportation Officials (AASHTO)’s Load and Resistance Factor Design (LRFD) specifications. Bridge databases containing information on actual bridges and prototype bridges constructed from three different types of steel and structural parameters that exceeded the range of applicability were developed and the bridge modeling verified using results reported for field tests of actual bridges. The resulting simplified equations for the live load distribution factors of shear force and bending moment were based on a rigorous statistical analysis of the data. The proposed equations provided comparable results to those obtained using finite element analysis, giving bridge engineers greater flexibility when designing bridges with structural parameters that are outside the range of applicability defined by AASHTO in terms of span length, skewness, and bridge width.

scholarly journals Benefits of implementing IT tools and procedures for the estimation and measurement uncertainty in testing laboratories

2020 ◽  
Vol 2 (7) ◽  
pp. 317-323
Author(s):  
Maria Cristina Dijmarescu
Keyword(s):  
Measurement Uncertainty ◽  
Rapid Expansion ◽  
Market Demand ◽  
Destructive Testing ◽  
Continuous Increase ◽  
Testing Laboratories ◽  
Quality Of Products ◽  
The Impact ◽  
Non Destructive

Destructive and non-destructive testing of materials present a rapid expansion given by the increase in market demand caused by the desire to obtain an increasingly better quality of products. The continuous increase in quality demands leads directly to the need to implement and modernize the techniques, methods, and equipment used for quality control. Consequently, the need for product testing services has a rapid growth. This paper presents the strength and weaknesses of implementing IT tools for the estimation of the measurement uncertainty in testing laboratories and the impact of these tools on the economic part

scholarly journals Pedographic assessment of the impact of off-the-shelf orthopedic shoes on the load distribution under the feet in patients with a high risk of developing diabetic foot syndrome

2021 ◽  
Vol 23 (5) ◽  
pp. 442-451
Author(s):  
Vadim B. Bregovskiy ◽  
Oleg V. Udovichenko ◽  
Anastasia G. Demina ◽  
Eugenia Aleksandrovna Berseneva ◽  
Irina A. Karpova
Keyword(s):  
High Risk ◽  
Diabetic Foot ◽  
Load Distribution ◽  
Objective Assessment ◽  
Daily Basis ◽  
Diabetic Foot Syndrome ◽  
Lateral Part ◽  
Plantar Surface ◽  
The Impact ◽  
Orthopedic Shoes

BACKGROUND: It is known that the so-called “rocker” outsole helps to reduce the load on the forefoot and toes. Such an outsole is available in ready-made orthopedic shoes of some Russian manufacturers, however, an objective assessment of their impact on the load distribution under the foot during walking has not been carried out.AIMS: To study the pressure distribution inside the off-the-shelf orthopedic shoes“Sursil-Ortho” in comparison with the load inside the shoes used by patients on a daily basis.METHODS: We studied 20 patients (40 feet) with a high risk of diabetic foot syndrome. According to clinical data, a risk regions were determined on the plantar surface of the feet. In-shoe pedography (pedar, novel,Germany) was performed in shoes usually worn by the patients, and in orthopedic shoes“Sursil-Orto”(Moscow). The maximum peak pressure (MPP) was calculated. Criterion of efficiency: MPP in the risk region<200 kPa or reducing it by 25% or more.RESULTS: There was a significant decrease of the median MPP in the forefoot and in the risk region. The percentage of feet with MPP >200 kPa in the risk region decreased from 58% to 30% (p=0,014), in any area of the forefoot — from 63% to 30% (p=0,04). The increase in MPP under the midfoot and hindfoot did not exceed +14% (ns). Tested footwear was effective in 71% of cases. Predictors of the insufficient effect were: higher initial MPP in the risk region, risk region on the hallux or in the lateral part of the forefoot.CONCLUSIONS: Shoes with a rigid rocker outsole significantly reduce the pressure under the forefoot and under the toes during walking. The degree of load reduction varies: the lateral part of the forefoot and 2-5 toes are most unloaded, and the hallux and medial forefoot are slightly less.

scholarly journals Comparison of Numerical Analyses with a Static Load Test of a Continuous Flight Auger Pile

2014 ◽  
Vol 22 (4) ◽  
pp. 1-10 ◽  
Author(s):  
Michal Hoľko ◽  
Jakub Stacho
Keyword(s):  
Load Distribution ◽  
Static Load ◽  
Numerical Models ◽  
Load Test ◽  
Numerical Analyses ◽  
Static Load Test ◽  
Material Models ◽  
The Common ◽  
Constitutive Material ◽  
The Impact

Abstract The article deals with numerical analyses of a Continuous Flight Auger (CFA) pile. The analyses include a comparison of calculated and measured load-settlement curves as well as a comparison of the load distribution over a pile's length. The numerical analyses were executed using two types of software, i.e., Ansys and Plaxis, which are based on FEM calculations. Both types of software are different from each other in the way they create numerical models, model the interface between the pile and soil, and use constitutive material models. The analyses have been prepared in the form of a parametric study, where the method of modelling the interface and the material models of the soil are compared and analysed. Our analyses show that both types of software permit the modelling of pile foundations. The Plaxis software uses advanced material models as well as the modelling of the impact of groundwater or overconsolidation. The load-settlement curve calculated using Plaxis is equal to the results of a static load test with a more than 95 % degree of accuracy. In comparison, the load-settlement curve calculated using Ansys allows for the obtaining of only an approximate estimate, but the software allows for the common modelling of large structure systems together with a foundation system.

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