Serviceability reliability analysis of cable-stayed bridges

Jin Cheng,Ru-Cheng Xiao 국제구조공학회 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.20 No.6

Fatigue reliability assessment of a three-tower four-span suspension bridge under stochastic traffic loads

Jin Cheng,Cheng Li 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.2

This paper aims to study the fatigue performance of three-tower four-span suspension bridges. For this purpose, the Oujiang River North Estuary Bridge which is a three-tower four-span suspension bridge with two main spans of 800m under construction in China is taken as an example in this study. This will be the first three-tower suspension bridge with steel truss girders in the world. This paper uses a random traffic load model to evaluate the fatigue reliability of the orthotropic steel bridge decks of three-tower four-span suspension bridges. In the study traffic load is simulated by random variables, and Monte Carlo simulation method is used to calculate the fatigue reliability index of the steel bridge deck. The parametric analysis is also carried out to clarify the influence of traffic growth rate, target reliability index and axle lateral distribution coefficient. It is found that the growth of traffic volume has the greatest impact on the evaluation results of the fatigue life, and the growth of traffic volume can result in a decrease of fatigue reliability of orthotropic steel bridge decks. The research results can provide a reference for the fatigue life and reliability assessment of three-tower four-span suspension bridge.

Backward Orientation Tracking Control of Mobile Robot with N Trailers

Jin Cheng,Bin Wang,Yong Zhang,Zhonghua Wang 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.2

A feedback control law for orientation tracking problem of a mobile robot with N on-axle trailers isproposed in this paper. Based on a recursive designing process, the orientation tracking problem is converted intostabilizing the including angles on the designed reference value. The designing process of the control law is simpleand can be easily extended to any given N trailers system. With input-to-state stability on cascade form system, theclosed-loop system is proven to be asymptotically stable. Simulation experiment on a mobile robot with 4 trailersis implemented and the results demonstrate that the proposed control law works successfully.

Simplified Method for Predicting the Deflections of Cable-stayed Suspension Bridges Considering Live Loads

Jin Cheng,Ying Li 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.5

A simplified method for predicting the deflections of cable-stayed suspension bridges considering live loads is presented. In the proposed method the governing equation of the cable-stayed suspension bridge, based on potential energy method, is derived. A Fourier series is used to describe the defections of the bridge deck. It has been shown from the numerical investigation of two different cable-stayed suspension bridges that the iteration procedure has a very high convergence rate. Only a few iterations are needed and a small number of series terms are sufficient for achieving the solutions of the problems. The predictions of the proposed method show good agreement with finite element results.

Development of computational software for flutter reliability analysis of long span bridges

Jin Cheng 한국풍공학회 2012 Wind and Structures, An International Journal (WAS Vol.15 No.3

The flutter reliability analysis of long span bridges requires use of a software tool that predicts the uncertainty in a flutter response due to uncertainties in the model formulation and input parameters. Existing flutter analysis numerical codes are not capable of dealing with stochastic uncertainty in the analysis of long span bridges. The goal of the present work is to develop a software tool (FREASB) to enable designers to efficiently and accurately conduct flutter reliability analysis of long span bridges. The FREASB interfaces an open-source Matlab toolbox for structural reliability analysis (FERUM) with a typical deterministic flutter analysis code. The paper presents a brief introduction to the generalized first-order reliability method implemented in FREASB and key steps involved in coupling it with a typical deterministic flutter analysis code. A numerical example concerning flutter reliability analysis of a long span suspension bridge with a main span of 1385 m is presented to demonstrate the application and effectiveness of the methodology and the software.

Serviceability Reliability Analysis of Prestressed Concrete Bridges

Jin Cheng 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.2

An effective method for serviceability reliability analysis of prestressed concrete bridges is presented in this paper. The method integrates the advantages of the Artificial Neural Network (ANN) method, First Order Reliability Method (FORM) and the importance sampling updating method. A distinctive feature of the present method is the introduction of an explicit approximate limit state function. The explicit formulation of the approximate limit state function is derived by using the parameters of the developed ANN model. Once the explicit limit state function is obtained, the failure probability can be easily estimated by using a hybrid reliability method consisting of the FORM and the importance sampling updating method. The accuracy and efficiency of the robust method is demonstrated through two numerical examples. As a practical engineering example, the serviceability reliability of a prestressed concrete bridge is illustrated. The obtained results clearly show the applicability and merits of the present method.

Random Field-based Reliability Analysis of Prestressed Concrete Bridges

Jin Cheng 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.5

A method for reliability assessment of prestressed concrete bridges accounting for the spatial variability of structural parametersis presented in this paper. The spatial variability of these parameters is modeled by means of random fields and the reliabilityestimates were determined by a generalized first-order reliability algorithm. The main feature of the random field-based reliabilitymethod is to consider the spatial variability of structural parameters that is disregarded in the traditional reliability method forprestressed concrete bridges. The accuracy and efficiency of the random field-based reliability method is demonstrated throughtwo numerical examples. A software strategy for interfacing the random field-based reliability method with ANSYS is developedvia a freely available MATLAB software tool (FERUM). As a practical engineering example, the reliability of a prestressedconcrete bridge is illustrated. The obtained results clearly show the applicability and merits of the random field-based reliabilitymethod and the associated software strategy.

Reliability based analysis of torsional divergence of long span suspension bridges

Jin Cheng,Q.S. Li 한국풍공학회 2009 Wind and Structures, An International Journal (WAS Vol.12 No.2

A systematic reliability evaluation approach for torsional divergence analysis of long span suspension bridges is proposed, consisting of the first order reliability method and a simplified torsional divergence analysis method. The proposed method was implemented in the deterministic torsional divergence analysis program SIMTDB through a new strategy involving interfacing the proposed method with SIMTDB via a freely available MATLAB software tool (FERUM). A numerical example involving a detailed computational model of a long span suspension bridge with a main span of 888 m is presented to demonstrate the applicability and merits of the proposed method and the associated software strategy. Finally, the most influential random variables on the reliability of long span suspension bridges against torsional divergence failure are identified by a sensitivity analysis.

Reliability analysis of steel cable-stayed bridges including soil-pile interaction

Jin Cheng,Xiao-luan Liu 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.13 No.2

An efficient and accurate algorithm is proposed to evaluate the reliability of cable-stayed bridges accounting for soil-pile interaction. The proposed algorithm integrates the finite-element method and the response surface method. The finite-element method is used to model the cable-stayed bridge including soilpile interaction. The reliability index is evaluated based on the response surface method. Uncertainties in the superstructure, the substructure and load parameters are incorporated in the proposed algorithm. A long span steel cable-stayed bridge with a main span length of 1088 m built in China is considered as an illustrative example. The reliability of the bridge is evaluated for the strength and serviceability performance functions. Results of the study show that when strength limit states for both girder and tower are considered, soil-pile interaction has significant effects on the reliability of steel cable-stayed bridges. Further, a detailed sensitivity study shows that the modulus of subgrade reaction is the most important soil-pile interaction-related parameter influencing the reliability of steel cable-stayed bridges.

Mechanical performance study and parametric analysis of three-tower four-span suspension bridges with steel truss girders

Jin Cheng,Mingsai Xu,Hang Xu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.32 No.2

This paper aims to study the mechanical performance of three-tower four-span suspension bridges with steel truss girders, including the static and dynamic characteristics of the bridge system, and more importantly, the influence of structural parameters including the side-main span ratio, sag-to-span ratio and the girder stiffness on key mechanical indices. For this purpose, the Oujiang River North Estuary Bridge which is a three-tower four-span suspension bridge with two main spans of 800m under construction in China is taken as an example in this study. This will be the first three-tower suspension bridge with steel truss girders in the world. The mechanical performance study and parametric analysis are conducted based on a validated three-dimensional spatial truss finite element model established for the Oujiang River North Estuary Bridge using MIDAS Civil. It is found that a relatively small side-main span ratio seems to be quite appropriate from the perspective of mechanical performance. And decreasing the sag-to-span ratio is an effective way to reduce the horizontal force subjected to the midtower and improve the antiskid safety of the main cable, while the vertical stiffness of the bridge will be reduced. However, the girder stiffness is shown to be of minimal significance on the mechanical performance. The findings from this paper can be used for design of three-tower suspension bridges with steel truss girders.