Bridge Engineering Practice Research Articles

Semiactive Control of Nonlinear Parametric Vibration of Super‐Long Stay Cable in Cable‐Stayed Bridge Installed with Magnetorheological Fluid Damper

As the stay cables of cable‐stayed bridges become longer, parametric resonance with a large amplitude is more easily triggered, which becomes a vibration hazard of super‐long stay cables. An increasing number of practical applications of vibration mitigation on stay cables demonstrate that vibration control strategies can effectively facilitate hazard mitigation and improve cable‐stayed bridge reliability and service life. This study proposes a semiactive control approach to reduce the parametric vibration of super‐long stay cables in cable‐stayed bridges installed with magnetorheological fluid damper (MRFD). First, using the cable’s gravity sag curve equation, an equation governing the combined stay cable‐bridge deck‐damper control system was established to consider the effect of the chordwise force of cable gravity. Subsequently, a targeted LQR‐based optimal active control law is proposed to provide the target control force in the semiactive control. The parametric influences on the performance of the LQR‐based optimal active control were analysed to provide insight into the proposed control strategy. Since the semiactive control could achieve almost the same control efficacy of the targeted optimal active control, a semiactive control strategy employing MRFD is proposed to mitigate the parametric vibration of a super‐long stay cable. Based on the proposed semiactive control strategy, the system was attached with the MRFD of the longest cable, S36, in the designed prototype long cable‐stayed bridge. The efficacy of the established semiactive control system was also analysed. The analysis results confirm that the proposed semiactive control strategy and designed semiactive control system can perform similar to the LQR‐based optimal active control. The semiactive control system attached to the MRFD can mitigate the parametric vibration of super‐long stay cables in cable‐stayed bridge engineering practice.

Development of residual stress model of orthotropic steel decks using measurements

Orthotropic steel decks are widely used in the bridge engineering practice due to light weight, high performance and high ultimate strength-to-weight ratio. Purpose of the current paper is developing the first residual stress model for orthotropic steel decks (OSDs) with U-shaped stiffeners based on residual stress measurement results. The proposed simplified residual stress model is valid for OSDs with single-bevel butt welds, manufactured from steel grade up to S355. Distribution and magnitude of manufacturing-induced residual stresses due to hot rolling, thermal cutting, cold-forming, welding, etc. are determined using contour method with thin-plate smoothing spline. It makes it possible to interpret two-dimensional full-map residual stresses, instead of conventional pointwise residual stress measurement techniques, resulting in higher spatial resolution. Longitudinal residual stress patterns are evaluated in representative cross-sections clearly indicating high stress peaks near the welds, even exceeding yield strength of the base material, while the influence of thermal cutting and cold-forming can be addressed as well. Statistical evaluation of measurement results is carried out, which resulted in mean standard deviation of 22 MPa and 34 MPa in the stiffener and deck plate, respectively, which is comparable with the accuracy of other measurement techniques, e.g., X-ray diffraction method or hole-drilling technique.

Bridge’s Overall Structural Scheme Analysis in High Seismic Risk Permafrost Regions

The mechanism of pile-soil reaction in frozen ground is not clear at present, but it is obvious that the reduction of dead weight will be beneficial to the seismic resistance of bridges. In view of the limited bridge engineering practice in high seismic risk permafrost regions, the paper addressed the structural performance of the superstructure and its effect on piles in these special regions. Four superstructures with different dead weights were compared, and bored piles were designed. Numerical simulations were implemented to investigate the refreezing time of the bored pile foundation. The concrete pile cooled rapidly in the first two days. The refreezing times of the GFRP, prestressed concrete T-girder, integrated composite girder, and MVFT girder were 15d, 37d, 39d, and 179d, respectively. The refreezing time of a pile in the same soil layer is mainly affected by the pile’s diameter, and it is significantly correlated to the square of the pile diameter. It reflects that the selection of bridge superstructures in the permafrost region is very important, which has been ignored in previous studies. The pile length and pile diameter of the lighter superstructure can be shorter and smaller to reduce the refreezing time and alleviate the thermal disturbance. Doi: 10.28991/CEJ-2022-08-07-01 Full Text: PDF

Value engineering analysis of RC roadway bridges assimilating environmental impact

ABSTRACT Bridges construction is one of the most challenging industries around the world as it necessitates a lot of experience, equipment and high budgets. Selection process of bridges’ structural system is mainly based on skill, knowledge base and experience that needs specified references helping in this process. There is a crucial need to manipulate a holistic Value e Engineering (VE) framework into the structural analysis/design of roadway bridges taking into consideration construction cost, construction time and environmental impacts. Unfortunately, the reported work on such an important field is still ecologically limited. The present research has two folds: (1) organize survey on VE related to structural-ecological prospective in bridge construction and (2) conduct a parametric study on analysis and design factors influencing VE outputs. For this purpose, a questionnaire was prepared to determine the extent of VE awareness among stakeholders and to test the controlling parameters. This survey has targeted a focus group of professional engineers in bridge engineering companies satisfying pre-determined characteristics. Setting the main VE parameters, study cases have been accounted for medium to large span simply supported and continuous roadway bridges with several cross sections using particular international code provisions. The VE included Embodied Carbon Emission (ECE) resulting from all activities thus estimating the cost of the carbon capture system. The total cost of each design case is estimated and compared to reach the minimum cost approach, thus enabling to recommend the most efficient structural system for Roadway Bridge. Hence, filling the gap between previous researches and bridge engineering practice.

Probabilistic assessment of a design truck model and live load factor from weigh-in-motion data for Mexican Highway bridge design

This study is focused on the statistical characterization of live load effects on bridges using weigh-in-motion data from a Mexican highway. A truck load model that is simpler than the design truck model implemented in the current Mexican requirements is suggested for design. The statistics are employed in target-reliability based calibration and verification of load factors in Mexican bridge design. Suggestions that could be useful for the Canadian bridge engineering practice are included.

Bridge Monitoring with Wavelet Principal Component and Spectrum Analysis Based on GPS Measurements: Case Study of the Mansoura Bridge in Egypt

AbstractDeformation and expansion joint movement of bridges are among the problems that widely exist in bridge engineering practice. Therefore, it is very important to monitor deformation of bridges and to timely process and analyze the measured data to ensure their safety. Mansoura Bridge, located at El-Mansoura City in Egypt, is selected to demonstrate the utilization of bridge deck deformation monitoring data to analyze and evaluate its safety based on global positioning system (GPS) measurements. The wavelet principal component analysis (WPCA) and spectrum methods are used to establish the time and frequency domain of bridge deformation and analyze the behavior and movement of the bridge under working traffic loads. The following conclusions are obtained in this study: (1) the WPCA can be used to eliminate the GPS observation errors; (2) the three-dimension spectrum gives much richer information for dynamic response; and (3) the deformation and expansion joint movement of Mansoura Bridge are safe unde...

Simulation of Composite Strengthening Technique in Prestressed Concrete Continuous Box Beam Bridges

The damage features of concrete continuous box beam bridges are summarized combined with three prestressed concrete continuous box beam bridges on ZhengLuo highway. There are four common strengthening methods in bridge engineering practice, i.e. bonded steel plates, strengthening with R.C, carbon fiber reinforced polymer (CFRP) and external prestressed strands. By numerical analysis technique of three dimension finite element (3D FE), the stresses of the damaged bridge are compared with the results of the strengthened one which is strengthened by one of the former methods. The strengthening effectiveness of those methods is ascertained. Therefore, the composite strengthening technique (CST) is established, which is effective to improve the bearing capacity and crack resistance of the strengthened bridge. An optimal strengthening process is put forward in the paper. So the CST is reasonable and effective to strengthen a damaged prestressed concrete continuous box beam bridge, which provides a significant reference for other similar strengthening projects.

Higher-order stiffness matrices in nonlinear finite element analysis of plane truss structures

There are enormous number of steel truss bridges in the U.S. and around the world. Elementary theory of structural analysis or linear elastic small displacement finite element method is typically used for analysis and design of these bridges. However, steel bridges may face large deflections and inelastic displacements due to unexpected live loads and/or unfavorable environmental conditions. Therefore, there is a need for the second- or higher-order elastic and/or inelastic analysis of these bridges. This article presents a methodology for the elastic large displacement analysis of plane trusses that are novel in bridge engineering practice. Higher-order stiffness matrices are derived and implemented in conjunction with the finite element procedure and updated Lagrangian description for the nonlinear analysis of plane truss structures. A numerical method, a modified Riks–Wempner approach, is used for the solution of geometric nonlinear plane truss problems. Numerical examples and results are presented to check the accuracy of the software developed by comparing the results of numerical examples with theoretical results and examples published by other authors. In this research, the concept of Object-Oriented technology and C++ programming language are used for coding and software developed.

George Shattuck Morison and the Development of Bridge Engineering

George Shattuck Morison (1842–1903) was one of the major contributors to the development of modern bridge engineering practice. His career spanned the era from design by empirical “rules of thumb” to the use of mathematical analysis techniques. Morison pioneered innovations in bridge engineering practice, including the introduction of materials testing and inspection, the development of design and construction specifications, and production of project reports. His major bridges included many crossings of the Missouri River, the great cantilever railroad bridge at Memphis, Tenn., and the Boone, Iowa viaduct. Morison served as President of the American Society of Civil Engineers and was an influential member of the Isthmian Canal Commission, which selected the location of the Panama Canal.

Multilevel algorithms for 3D simulation of nonlinear elasticity problems

This study is devoted to the numerical solution of 3D elasticity problems in multilayer media. The problem is described by a coupled system of second-order nonlinear elliptic partial differential equations with strongly varying coefficients. The boundary value problem is discretized by trilinear finite elements. The goal of the paper is to analyze the performance of three hierarchical algorithms for the arisen discrete problems. The secant method is applied as a general outer nonlinear iterative procedure. The two-level block-size reduction block-incomplete LU (BSR BILU) algorithm, and the algebraic multilevel iteration (AMLI) algorithm are implemented as preconditioners to the linearized problems into the framework of the conjugate gradient method. The BSR BILU is a special case two-level algorithm while the AMLI preconditioner is based on a regular multilevel mesh refinement. A simple patched local refinement in combination with the BSR BILU algorithm is considered at the end, as an efficient approach for problems with localized zones of active interactions. The developed FEM codes are applied for 3D simulation of pile systems in weak multilayer soil media. The benchmark problem is taken from the real-life bridge engineering practice. The presented test data illustrate the abilities of the proposed methods and algorithms as well as the robustness of the codes.

Condition Assessment for Bridge Management

Integrated analytical and experimental research, conducted for exploring objective, global condition assessment and evaluation of bridge serviceability and safety, is summarized. A related terminology with definitions for critical terms is offered. Nondestructive and destructive field testing and structural identification of seven actual bridge test specimens enabled formulating a bridge condition assessment and reliability evaluation methodology. Field-calibrated analytical models, developed by structural identification, are studied to understand the real behavior and performance of actual bridges and to quantify relative contributions of different stiffness and resistance mechanisms. While our heuristic knowledge base has served us well, further rationalizing our bridge engineering practice is needed to achieve the optimum management of the highway transportation infrastructure necessary for continued advances in the next century.

Shakedown Tests of One-Third–CALE Composite Bridge

This paper presents shakedown and plastic collapse test results for a one-third–scale bridge system. The bridge was a three-span, four-girder composite bridge comprising compact and noncompact sections. Experimental results are compared to analytical results from an inelastic grillage analysis. Inelastic force distribution in the longitudinal and transverse directions was examined along with inelastic deformations, reactions, and moments. The results show that bridge systems have a significant ability to redistribute force effects. However, the behavior of bridge systems is very complex and involves many characteristics that are difficult to incorporate into current modeling techniques. This paper discusses current research targeted to advance bridge engineering practice in the area of inelastic design and evaluation techniques.

Evaluation of System‐Reliability Methods for Cable‐Stayed Bridge Design

Probabilistic system-reliability methods have the potential to assist designers in better understanding the ultimate global behavior of bridges, thus leading to more economical, rational, and reliable structures. Nonetheless, these techniques are not currently broadly used in North American bridge engineering practice. Using a sample cable-stayed bridge design, a study is conducted to assess the practicability of system-reliability analytical methods to assist in the design of cable-stayed bridges. Ductile and brittle cables are considered in series and mixed system analyses, respectively. The sample bridge selected is found to be very reliable; the most likely failure mode identified is somewhat counterintuitive. More importantly, considerable insight into global ultimate behavior is provided by these analyses, and the effect of various design assumptions on global structural safety can be assessed. Some obstacles to the transfer of system-reliability procedures to the state of practice are identified.