scholarly journals Analysis of the dynamic response of long span bridges with GNSS under typhoon loading

2021 ◽  
Vol 4 (3) ◽  
pp. Manuscript
Author(s):  
Hongbo Wang ◽  
Xiaolin Meng ◽  
Chaohe Chen
Keyword(s):  
Dynamic Response ◽  
Real Time ◽  
Deformation Monitoring ◽  
Bridge Management ◽  
Time Data ◽  
Engineering Structures ◽  
Long Span Bridges ◽  
Long Span ◽  
Long Span Bridge ◽  
Cross Correlation Analysis

Nowadays, real-time bridge deformation monitoring has attracted more attention due to the development of bridge management system and land transportation safety. Huge civil engineering structures, such as long-span bridge, is susceptible to dynamic deflection caused by various loadings. Hence, precise dynamic response measurement becomes necessary to make structure more reliable and integrated. Currently, Global Navigation Satellite System (GNSS) positioning technology has been commonly used in this field to detect the dynamic displacement of long-span bridges. According to this, real-time data were collected from the Forth Road Bridge to observe the dynamic response of lang span bridges under extreme wind load conditions and this report has also verified the data processing technique of the real-time bridge deformation monitoring system. Compared with other monitoring methods, the method used in this report which combines GNSS and anemometer together has features of high frequency with low lag. Moreover, it also shows the superiority of post-processing and synchronization, background noises could be reduced by embedded software. Finally, according to the cross-correlation analysis, it was found that wind speed and bridge displacement in y-axis have the highest correlation. Also, the reliability of combining method to monitor the dynamic response of long-span bridge and noise reducing method proposed in this report has also been verified.

Super-long span bridge aerodynamics: on-going results of the TG3.1 benchmark test – Step 1.2

2019 ◽  
Author(s):  
Giorgio Diana ◽  
Stoyan Stoyanoff ◽  
Andrew Allsop ◽  
Luca Amerio ◽  
Tommaso Argentini ◽  
...  
Keyword(s):  
Numerical Models ◽  
Experimental Tests ◽  
Numerical Comparison ◽  
Aeroelastic Stability ◽  
Turbulent Wind ◽  
Long Span Bridges ◽  
Buffeting Response ◽  
Long Span ◽  
Long Span Bridge ◽  
Sectional Model

<p>This paper is part of a series of publications aimed at the divulgation of the results of the 3-step benchmark proposed by the IABSE Task Group 3.1 to define reference results for the validation of the software that simulate the aeroelastic stability and the response to the turbulent wind of super-long span bridges. Step 1 is a numerical comparison of different numerical models both a sectional model (Step 1.1) and a full bridge (Step 1.2) are studied. Step 2 will be the comparison of predicted results and experimental tests in wind tunnel. Step 3 will be a comparison against full scale measurements.</p><p>The results of Step 1.1 related to the response of a sectional model were presented to the last IABSE Symposium in Nantes 2018. In this paper, the results of Step 1.2 related to the response long-span full bridge are presented in this paper both in terms of aeroelastic stability and buffeting response, comparing the results coming from several TG members.</p>

Numerical Simulation of Wind-Driven Rain on a Long-Span Bridge

2019 ◽  
Vol 19 (12) ◽  
pp. 1950149
Author(s):  
Shenghong Huang ◽  
Qiusheng Li ◽  
Man Liu ◽  
Fubin Chen ◽  
Shun Liu
Keyword(s):  
Numerical Simulation ◽  
Wind Engineering ◽  
Multiphase Model ◽  
Rain Intensity ◽  
Long Span Bridges ◽  
Long Span ◽  
Long Span Bridge ◽  
Extreme Rain ◽  
Section Model ◽  
Bridge Spans

Wind-driven rain (WDR) and its interactions with structures is an important research subject in wind engineering. As bridge spans are becoming longer and longer, the effects of WDR on long-span bridges should be well understood. Therefore, this paper presents a comprehensive numerical simulation study of WDR on a full-scale long-span bridge under extreme conditions. A validation study shows that the predictions of WDR on a bridge section model agree with experimental results, validating the applicability of the WDR simulation approach based on the Eulerian multiphase model. Furthermore, a detailed numerical simulation of WDR on a long-span bridge, North Bridge of Xiazhang Cross-sea Bridge is conducted. The simulation results indicate that although the loads induced by raindrops on the bridge surfaces are very small as compared to the wind loads, extreme rain intensity may occur on some windward surfaces of the bridge. The adopted numerical methods and rain loading models are validated to be an effective tool for WDR simulation for bridges and the results presented in this paper provide useful information for the water-erosion proof design of future long-span bridges.

A generalized Pareto distribution–based extreme value model of thermal gradients in a long-span bridge combining parameter updating

2016 ◽  
Vol 20 (2) ◽  
pp. 202-213 ◽  
Author(s):  
Guang-Dong Zhou ◽  
Ting-Hua Yi ◽  
Bin Chen ◽  
Huan Zhang
Keyword(s):  
Pareto Distribution ◽  
Generalized Pareto Distribution ◽  
Extreme Value ◽  
Thermal Gradients ◽  
Long Span Bridges ◽  
Long Span ◽  
Generalized Pareto ◽  
Long Span Bridge ◽  
Extreme Value Model ◽  
Value Model

Estimating extreme value models with high reliability for thermal gradients is a significant task that must be completed before reasonable thermal loads and possible thermal stress in long-span bridges are evaluated. In this article, a generalized Pareto distribution–based extreme value model combining parameter updating has been developed to describe the statistical characteristics of thermal gradients in a long-span bridge. The procedure of excluding correlation and the approach of selecting a proper threshold are suggested to prepare samples for generalized Pareto distribution estimation. A Bayesian estimation, which has the capability of updating model parameters by fusing prior information and incoming monitoring data, is proposed to fit the generalized Pareto distribution–based model. Furthermore, the Gibbs sampling, which is a Markov chain Monte Carlo algorithm, is adopted to derive the Bayesian posterior distribution. Finally, the proposed method is applied to the field monitoring data of thermal gradients in the Jiubao Bridge. The extreme value models of thermal gradients for the Jiubao Bridge are established, and the extreme thermal gradients with different return periods are extrapolated. The results indicate that the generalized Pareto distribution–based extreme value model has a strong ability to represent the statistical features of thermal gradients for the Jiubao Bridge, and the Bayesian estimation combining parameter updating provides high-precision generalized Pareto distribution–based models for predicting extreme thermal gradients. The predicted extreme thermal gradients are expected to evaluate and design long-span bridges.

Detection of Shifts in GPS Measurements for a Long-Span Bridge Using CUSUM Chart

2016 ◽  
Vol 16 (04) ◽  
pp. 1640024 ◽  
Author(s):  
Ting-Hua Yi ◽  
Hong-Nan Li ◽  
Gangbing Song ◽  
Qing Guo
Keyword(s):  
Deformation Monitoring ◽  
Experimental Results ◽  
High Rate ◽  
Cumulative Distribution ◽  
Control Technique ◽  
Cusum Chart ◽  
Shewhart Chart ◽  
Long Span ◽  
Long Span Bridge ◽  
Shift Detection

Timely and correctly evaluating the quality of Global Positioning System (GPS) data is essential for reduction in the number of false alarms and missed detection of a GPS-based bridge deformation monitoring system. This paper investigates how to use the statistical process control technique, known as the cumulative sum (CUSUM) chart, for the detection of small but persistent shifts in the high-rate GPS carrier-phase measurements. First, a mathematical model for the shift detection based on the continuous hypothesis testing is established. The main features and implementation procedure of the CUSUM chart for the shift detection are then summarized, and the corresponding parameter selection method is discussed in detail. To meet the normality requirement of the CUSUM chart, a novel method that transfers the data to the Q-statistic by the estimated cumulative distribution functions is proposed according to the probability integral transform theory. This is followed by a simulation carried out to evaluate the detection performance of the CUSUM chart and exploit its advantages to the commonly used Shewhart chart for the high-rate GPS monitoring data with different shift sizes. Experimental results have showed that the CUSUM chart is sensitive to small persistent shifts compared to the Shewhart chart although it has a delay problem. The integration of CUSUM chart and Shewhart chart would be a reliable approach for the shift detection. Finally, an on-site dynamic monitoring experiment is carried out on a long-span bridge to validate the proposed approach’s effectiveness in detecting an actual deformation shift, and the experimental results proved to be very encouraging.

Research on Design Vehicle Load for Long-Span Bridges

2011 ◽  
Vol 90-93 ◽  
pp. 909-914
Author(s):  
Da Lin Hu ◽  
Ding Ding ◽  
Long Gang Chen ◽  
Chun Mei Xia
Keyword(s):  
Simulation Analysis ◽  
Extreme Value Distribution ◽  
Bending Moments ◽  
Long Span Bridges ◽  
Long Span ◽  
Vehicle Load ◽  
Long Span Bridge ◽  
Load Effects ◽  
Vehicle Loads ◽  
Characteristic Values

This paper presents simulation analysis of load effects of bridges under random fleet. Based on actual data of vehicle loads on Guangzhou-Shenzhen Expressway and relevant statistical results, mid-span bending moments of long-span virtual simple-supported beams are calculated. Then probability distribution of the bending moments and extreme value distribution of the load effects within design reference period are obtained. Finally, characteristic values of mid-span bending moments and recommended values of design lane load are calculated, sequentially. The results studied in this paper can be as a reference for long-span bridge design, and also can be a reference for overloading control or weight charge policy.

scholarly journals Damage detection of long-span bridge structures based on response surface model

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1497-1504 ◽  
Author(s):  
Shujun Fang
Keyword(s):  
Damage Detection ◽  
Response Surface ◽  
Element Model ◽  
Response Surface Model ◽  
Surface Model ◽  
Long Span Bridges ◽  
Long Span ◽  
Long Span Bridge ◽  
The Finite Element Model ◽  
Fourth Order Polynomial

In order to solve the problem of high risk and low precision of existing damage detection methods for long-span Bridges, a new method based on fourth-order polynomial response surface model is proposed. Response surface model is constructed by using fourth order polynomial function. The parameters of the finite element model of the bridge are modified according to the response surface model. Based on the finite element model, the modal strain energy before and after the damage of the element was calculated, and the damage index of the element was obtained, so as to realize the damage detection of the long-span bridge structure. Experimental results show that the proposed method can accurately detect the damage location of long-span Bridges under different damage conditions, and the detection error of damage degree is less than 1%, which has a broad application prospect.

Feasibility Study of Super-Long Span Bridges Considering Aerostatic Instability by a Two-Stage Geometric Nonlinear Analysis

2020 ◽  
pp. 2150033
Author(s):  
Jiunn-Yin Tsay
Keyword(s):  
Wind Speed ◽  
Nonlinear Analysis ◽  
Two Stage ◽  
Long Span Bridges ◽  
Critical Wind Speed ◽  
Long Span ◽  
Main Cable ◽  
Geometric Nonlinear ◽  
Long Span Bridge ◽  
Geometric Nonlinear Analysis

To meet the need of constructing fixed cross strait links, super-long span bridge with a main span over 2 000[Formula: see text]m is considered as a candidate for their ability to cross deep and wide straits. To this end, some super-long span bridges with proper cable and girder systems were previously proposed and studied. The major design considerations are aimed at adopting new cable material, increasing the entire rigidity of the bridge, stabilizing the dynamic characteristics, strengthening the deck sections, etc. In this paper, a brief review of main cable and girder system is first given of the concepts previously proposed for the design of super-long span bridges. Then some typical examples are studied, focused on various issues related to the design of super-long span bridges, including composite cable, the unstressed length and tension force of the main cable, the stiffness and mass effects of the deck on critical wind speed, and the critical wind speed of various cable systems. The most challenges in super-long span bridges are to solve aerostatic and aerodynamic instability at required design wind speed. In this connection, the wind-induced aerostatic instability of super-long span bridges is studied by a two-stage geometric nonlinear analysis for dead loads and wind loads. The developed program adopted herein for geometric nonlinear analysis was verified and confirmed before. The proposed methods (i.e. composite cable, slotted girder, increasing deck stiffness and mass, cable layout, etc.) obtained for all the examples are in agreement with this study, which indicates applicability of the design approaches presented.

EVALUATION OF ENGINEERING STRUCTURES DEFORMATION (ACCURACY)

2019 ◽  
pp. 77-82
Author(s):  
T. Malik ◽  
Ya. Bryk ◽  
V. Zatserkovnyi ◽  
V. Belenok
Keyword(s):  
Real Time ◽  
Monitoring System ◽  
Structure Prediction ◽  
Optoelectronic Devices ◽  
Deformation Monitoring ◽  
Automated System ◽  
Control Panel ◽  
Engineering Structures ◽  
Engineering Structure ◽  
Accuracy Of Measurements

The construction of the model of accuracy of the measuring processes of the automated monitoring system of engineering structures deformations from the point of the theory of accuracy is considered in the article. From the point of view of the generalization of the accuracy of measurements by the automated system of engineering structures monitoring, the construction of the model of the measuring process is considered, resulting in separate characteristics and properties of the object to be investigated. In this case these are values of deformations of engineering constructions' structures. The brief acquaintance with the automated system of monitoring of engineering structures deformations, which represents a chain of optoelectronic devices-deformation marks, which are installed on constructions of structures and fix the created line is given. The use of this system allows to solve the problem of the preventive assessment of the dynamics of local technogenic deformation in the engineering structure and thus to increase the level of technogenic safety of the personnel of the engineering structure. Compared with modern well-known methods and means for determining the engineering structures deformation, an automated deformation monitoring system has the following advantages: 1. Cross-section geodetic control of deformations (position) of elements of the full volume of engineering structure with increased accuracy. 2. Automated control of engineering structures deformations in real time, including in limited or inaccessible for visual measurements places. 3. Control of the technogenic safety of the engineering structure, prediction of the moment of the emergency, warning about the upcoming critical state (moment) of the engineering structure in real time with the accurate definition of a certain area. 4. Installation of the entire monitoring system occurs during the construction of the structure, pre-installation sites of optoelectronic devices - deformation marks are agreed with the designers and architects. 5. The mean square error of measurement of relative deviations of deformations is not less than 0,1-0,5 mm at distances between optoelectronic devices up to 10 m. 6. Information on the magnitude of deviations from the nominal (initial) position goes to the remote central control panel of the system in real time scale. 7. In the case of upcoming moment of dangerous deviation (deformation), the command from the main control panel receives a signal for rapid response with the accurate designation of the place of dangerous deformation.

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