Nonlinear analysis of cable-stayed bridges at ultimate load level

1996 ◽  
Vol 23 (5) ◽  
pp. 1111-1117 ◽  
Author(s):  
M. S. Khalil
Keyword(s):  
Ultimate Load ◽  
Load Level ◽  
Load Factor ◽  
Nonlinear Behaviour ◽  
Safety Index ◽  
Nonlinear Load ◽  
Cable Stayed Bridge ◽  
Load Factors ◽  
Analysis Design ◽  
Cable Stayed Bridges

Cable-stayed bridges have unique characteristics which require unique treatment in their analysis, design, and construction. This paper discusses some of these characteristics and presents proposed means of solving the associated problems. The paper discusses the nonlinear behaviour of the cable-stayed system, the load factors required for the analysis of that type of bridge, the manner of application of the loads, and the analysis under factored loads. The paper presents the results of the analysis of the ALRT cable-stayed bridge in Vancouver, Canada. Key words: cable-stayed, bridges, nonlinear, load factor, safety index.

Development of loading-truck model and live-load factor for the Canadian Standards Association CSA-S6 code

1987 ◽  
Vol 14 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Akhilesh C. Agarwal ◽  
Moe S. Cheung
Keyword(s):  
Highway Bridges ◽  
Load Level ◽  
Load Factor ◽  
Live Load ◽  
Limit States ◽  
Load Factors ◽  
Loading System ◽  
Using Data ◽  
Council Of Ministers ◽  
Level Loading

Studies have shown that the MS-200 loading model in the Canadian Standards Association standard CAN3-S6-M78 for design of highway bridges no longer represents modern-day heavy trucks in Canada. For the new edition of the CSA-S6 code, based on the limit states philosophy, a new loading-truck model was developed based on the Council of Ministers' loading, which is the legal load limit for interprovincial transportation in Canada. The loading model, designated as the "CS-W loading truck," provides the flexibility to adopt a multiple-level loading system appropriate to various jurisdictions.The live-load factor was determined from a statistical approach using data from a truck survey conducted across Canada in seven provinces. Responses in simple-span bridges were determined by running one or more trucks from the survey across the bridge. Based on this study, a live-load factor of 1.60 was determined and CS-600, with a gross weight of 600 kN, was selected as the standard load level. As well, the validity of the truck model and the live-load factors were checked for continuous-span bridges. Key words: highway bridges, design loads, codes and standards, live-load models, load factors, load surveys, vehicle weight regulations.

scholarly journals Effect of blast loading and resulting progressive failure of a cable-stayed bridge

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Ravi Mudragada ◽  
S. S. Mishra
Keyword(s):  
Progressive Failure ◽  
Blast Resistance ◽  
Progressive Collapse ◽  
Building Structures ◽  
Structural Elements ◽  
Blast Loads ◽  
Cable Stayed Bridge ◽  
Bridge Performance ◽  
Cable Stayed Bridges

AbstractMany researchers have carried out experimental and numerical investigations to examine building structures’ response to explosive loads. Studies of bridges subjected to blast loads are limited. Hence, in this study, we present a case study on a cable-stayed bridge, namely, Charles River Cable-Stayed Bridge-Boston, to assess its robustness and resistance against the progressive collapse resulting from localized failure due to blast loads. Three different blast scenarios are considered to interpret the bridge performance to blast loads. To monitor the progressive failure mechanisms of the structural elements due to blast, pre-defined plastic hinges are assigned to the bridge deck. The results conclude that the bridge is too weak to sustain the blast loads near the tower location, and the progressive collapse is inevitable. Hence, to preserve this cable-stayed bridge from local and global failure, structural components should be more reinforced near the tower location. This case study helps the designer better understand the need for blast resistance design of cable-stayed bridges.

The effect of finite deformations in the elastic stability of plane frames

1962 ◽  
Vol 266 (1324) ◽  
pp. 47-67 ◽  
Keyword(s):  
Critical Load ◽  
Failure Load ◽  
Elastic Stability ◽  
Load Level ◽  
Load Factor ◽  
Proportional Loading ◽  
Arbitrary Load ◽  
Plane Frames ◽  
The Difference ◽  
Rigid Joints

The circumstances are discussed under which orthogonal relations exist between the elastic critical modes of plane frames subjected to proportional loading. Orthogonal relations may be obtained provided the loading does not produce any components of deformation associated with any of the critical modes at arbitrary levels of the load factor, and provided no part of the structure remains statically indeterminate due to bar forces when all rigid joints are replaced by pin joints. When at arbitrary load factors, the structure deforms with components associated with any of the buckling modes, the elastic failure load is not identical with the lowest elastic critical load, although for many frames the two loads may be very close. A general expression is obtained which reveals the relation between the deformations at an arbitrary load level and the deflexions given by linear analysis. The difference between the elastic failure load and the elastic critical load is discussed, and an approximate treatment applicable to certain types of frame and associated loading is developed.

Study on the Effective Slab Width of Composite Cable-Stayed Bridge under Axial Force

2012 ◽  
Vol 568 ◽  
pp. 200-203
Author(s):  
Xiang Nan Wu ◽  
Xiao Liang Zhai ◽  
Ming Min Zhou
Keyword(s):  
Axial Force ◽  
Shear Lag ◽  
Distribution Law ◽  
Slab Width ◽  
Cable Stayed Bridge ◽  
Stay Cables ◽  
Transmission Angle ◽  
Effective Flange Width ◽  
Width Coefficient ◽  
Cable Stayed Bridges

There exist evident shear-lag phenomena in large-span composite cable-stayed bridges under the action of axial force, especially in the deck with double main girders. In order to discuss the distribution law of the effective flange width coefficient along the span, caused by axial force, finite element computations of five composite cable-stayed bridges and theoretical analysis have been performed. The transmission angle of axial force caused by the axial compression of stay cables was given, meanwhile the formulas for computation effective slab width coefficient under axial force were suggested.

A prediction method for cable forces of cable-stayed bridges using fuzzy processing and Bayes estimation

2021 ◽  
Author(s):  
Li Dong ◽  
Bin Xie ◽  
Dongli Sun ◽  
Yizhuo Zhang
Keyword(s):  
Prediction Method ◽  
Practical Method ◽  
Bayes Estimation ◽  
Primary Data ◽  
Force Estimation ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
Input Parameters ◽  
Cable Forces ◽  
Cable Stayed Bridges

<p>Cable forces are primary factors influencing the design of a cable-stayed bridge. A fast and practical method for cable force estimation is proposed in this paper. For this purpose, five input parameters representing the main characteristics of a cable-stayed bridge and two output parameters representing the cable forces in two key construction stages are defined. Twenty different representative cable-stayed bridges are selected for further prediction. The cable forces are carefully optimized through finite element analysis. Then, discrete and fuzzy processing is applied in data processing to improve their reliability and practicality. Finally, based on the input parameters of a target bridge, the maximum possible output parameters are calculated by Bayes estimation based on the processed data. The calculation results show that the average prediction error of this method is less than 1% for the twenty bridges themselves, which provide the primary data and less than 3% for an under-construction bridge.</p>

Analysis of Robin Hood and Other Hashing Algorithms Under the Random Probing Model, With and Without Deletions

2018 ◽  
Vol 28 (4) ◽  
pp. 600-617
Author(s):  
P. V. POBLETE ◽  
A. VIOLA
Keyword(s):  
Search Algorithm ◽  
Recurrence Equation ◽  
Constant Time ◽  
Collision Resolution ◽  
Load Factor ◽  
Hash Tables ◽  
Search Cost ◽  
Robin Hood ◽  
Small Constant ◽  
Load Factors

Thirty years ago, the Robin Hood collision resolution strategy was introduced for open addressing hash tables, and a recurrence equation was found for the distribution of its search cost. Although this recurrence could not be solved analytically, it allowed for numerical computations that, remarkably, suggested that the variance of the search cost approached a value of 1.883 when the table was full. Furthermore, by using a non-standard mean-centred search algorithm, this would imply that searches could be performed in expected constant time even in a full table.In spite of the time elapsed since these observations were made, no progress has been made in proving them. In this paper we introduce a technique to work around the intractability of the recurrence equation by solving instead an associated differential equation. While this does not provide an exact solution, it is sufficiently powerful to prove a bound of π2/3 for the variance, and thus obtain a proof that the variance of Robin Hood is bounded by a small constant for load factors arbitrarily close to 1. As a corollary, this proves that the mean-centred search algorithm runs in expected constant time.We also use this technique to study the performance of Robin Hood hash tables under a long sequence of insertions and deletions, where deletions are implemented by marking elements as deleted. We prove that, in this case, the variance is bounded by 1/(1−α), where α is the load factor.To model the behaviour of these hash tables, we use a unified approach that we apply also to study the First-Come-First-Served and Last-Come-First-Served collision resolution disciplines, both with and without deletions.

The Strength of the Pigeon's Wing Bones in Relation to Their Function

1967 ◽  
Vol 46 (2) ◽  
pp. 219-233 ◽  
Author(s):  
C. J. PENNYCUICK
Keyword(s):  
Shoulder Joint ◽  
Ultimate Load ◽  
Lift Coefficient ◽  
Load Factor ◽  
Forward Motion ◽  
Air Speed

1. Simple methods are described for applying known bending and twisting moments to pigeon bones. The ultimate bending and torsional strengths of the humerus and radio-ulna are determined. 2. Lift distributions are calculated from a strip diagram on the assumption that local lift coefficient is constant across the span. The position of the centre of lift is calculated for (a) gliding, in which the relative air speed is entirely due to the forward motion of the bird; and (b) hovering, in which it is entirely due to rotation of the wing about the shoulder joint. 3. Estimates of the ultimate load factor of the humerus in bending and twisting yielded 8.8 and 9.0 respectively in gliding, and 5.7 and 5.6 in hovering. Corresponding figures for the radio-ulna were 6.9 and 9.1 in gliding, and 4.0 and 5.1 in hovering. 4. The pectoralis insertion is strong enough to apply 4.2g in gliding and 2.9g in hovering, so the muscles would be forcibly extended before any danger could arise of the bones being broken by excessive lift. 5. A lift coefficient of at least 3.4 is achieved during the downstroke of hovering.

scholarly journals Static Experiment and Finite Element Analysis of a Multitower Cable-Stayed Bridge with a New Stiffening System

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaowei Wang ◽  
Yingmin Li ◽  
Weiju Song ◽  
Jun Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Force ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
Practical Engineering ◽  
Static Experiment ◽  
Stiffening Effect ◽  
Better Than ◽  
Cable Stayed Bridges

Based on the stiffness limitations of the midtower in multitower cable-stayed bridges, a new stiffening system (tie-down cables) is proposed in this paper. The sag effects and wind-induced responses can be reduced with the proposed system because tie-down cables are short and aesthetic compared with traditional stiffening cables. The results show that the stiffening effect of tie-down cables is better than that of traditional stiffening cables in controlling the displacement and internal force of the bridge based on a static experiment and finite element analysis. Therefore, the proposed system can greatly improve the overall stiffness of a bridge, and its stiffening effect is better than that of traditional stiffening cables in controlling the displacement and internal force. The results provide a reference for the application of such systems in practical engineering.

scholarly journals Numerical Models used for The Calculation of The Cable-Stayed Bridge at Km 0+540 over Danube-Black Sea Canal

2016 ◽  
Vol 5 (2) ◽  
pp. 37-49
Author(s):  
Costin Stelian Mutu ◽  
Ionuţ Radu Răcănel
Keyword(s):  
Black Sea ◽  
Strain State ◽  
Numerical Models ◽  
Global Analysis ◽  
Order Effects ◽  
Nonlinear Behaviour ◽  
Calculation Methods ◽  
Stress Strain ◽  
Stress Strain State ◽  
Cable Stayed Bridges

Abstract Cable-stayed bridges are complex structures and for their design, the traditional calculation methods are hard, even impossible to use for a global analysis. Separate analyses for the each component of the bridge in a simplified manner can be conducted, but in this case the concurrence of the elements into the structure is not taken into account, leading to errors in estimating the structural response. For these structures, the construction method and the presence of the stays, which are elements having a nonlinear behaviour, implies to consider a nonlinear staged analysis including the second order effects in order to transmit form one stage to the other the stress-strain state. In the present time, thanks to the evolution and development of the calculation methods and computer analysis, cable-stayed bridges can be accurate analysed so that the obtained response is close to the behaviour of the structure during erection and later, in service. The aim of this paper is to present the results obtained using one of the finite element models and nonlinear staged analysis of the bridge at km 0+540 over Danube-Black Sea Canal near Agigea. Inside the paper, results related to the evolution of stress-strain state in principal structural elements of the bridge - pylons, stays and deck - during the execution and in final stage, in service are to be presented.

scholarly journals Calibration of models for pile settlement analysis using 64 field load tests

2008 ◽  
Vol 45 (1) ◽  
pp. 59-73 ◽  
Author(s):  
L. M. Zhang ◽  
Y. Xu ◽  
W. H. Tang
Keyword(s):  
Hong Kong ◽  
Prediction Models ◽  
Limit State ◽  
Design Guidelines ◽  
Load Level ◽  
Soil Parameters ◽  
Model Bias ◽  
Nonlinear Load ◽  
Settlement Prediction ◽  
Pile Settlement

Due to the presence of uncertainties, errors inevitably arise with the estimations of pile settlement. To properly consider serviceability requirements in limit state design, it is necessary to characterize the performance of commonly used settlement prediction models. In this work, information from 64 cases of long driven steel H-piles from field static loading tests in Hong Kong is utilized to evaluate the errors of three settlement prediction models for single piles: two elastic methods and a nonlinear load–transfer method. Commonly adopted soil parameters recommended in two Hong Kong design guidelines are used to reflect the uncertainty arising from evaluation of soil properties. The model error is represented by a bias factor. A conventional statistical analysis was first conducted to study the variability of model bias. A regression analysis method was then proposed as a supplemental analysis of model bias when only limited test data were available or when the measured settlement data distribute in a large range. Both methods result in very similar mean biases. The mean bias of each prediction model tends to vary with the load level and the bearing stratum at the pile toe; while the coefficient of variation of model bias only varies in narrow ranges.

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