Application Strategies of Shotcrete Anchor Support Technology in Highway Bridge and Tunnel Engineering

This article analyzes the application strategies of shotcrete anchor support technology using a highway bridge-tunnel construction project as an example.The article covers various strategies,including support plan formulation,mortar shotcrete anchor construction,grid steel frame construction,steel mesh construction,and concrete support construction.This analysis aims to provide a guideline for those interested in applying this technology and improving the quality and safety of highway bridges and tunnels construction.

Technical Analysis of Highway Bridge Static Load Test

Highway bridges are an important part of the transportation industry and can promote social economic construction and development.In actual operation,highway bridges are often damaged due to overload and natural factors,which tend to affect the safety and shorten the service life of these bridges.Assessing the overall state and performance of highway bridges is therefore a key element.Static load test,which is a type of sustainable detection experiment,has many advantages,including low cost,high efficiency,and high accuracy.In this paper,the bridge structure is analyzed through the application of theoretical calculations and relevant comparisons,so as to judge the operating state of the bridge.

Research on Highway Bridge Inspection

Highway bridges are important transportation infrastructures in our country,and their quality is related to the people's lives.Highway bridge inspection,identification and test are measures to evaluate the quality of highway bridges.Through the comprehensive application of various technologies,quality problems of highway bridges can be found early,thereby ensuring traffic safety.This paper first summarizes the role and the types of highway bridge inspection and test.Then the problems and solutions in highway bridge inspection and test are analyzed and studied,and some examples are given,in hopes of providing reference for future testing.

Seismic damage of highway bridges during the 2008 Wenchuan earthquake

Many highway bridges were severely damaged or completely collapsed during the 2008 Wenchuan earthquake. A field investigation was carried out in the strongly affected areas and over 320 bridges were examined. Damage to some representative highway bridges is briefly described and a preliminary analysis of the probable causes of the damage is presented in this paper. The most common damage included shear-flexural failure of the pier columns, expansion joint failure, shear key failure, and girder sliding in the transversal or longitudinal directions due to weak connections between girder and bearings. Lessons learned from this earthquake are described and recommendations related to the design of curved and skewed bridges, design of bearings and devices to prevent girder collapse, and ductility of bridge piers are presented. Suggestions for future seismic design and retrofitting techniques for bridges in moderate to severe earthquake areas are also proposed.

Seismic fragility analysis of highway bridges considering multi-dimensional performance limit state

Fragility analysis for highway bridges has become increasingly important in the risk assessment of highway transportation networks exposed to seismic hazards. This study introduces a methodology to calculate fragility that considers multi-dimensional performance limit state parameters and makes a first attempt to develop fragility curves for a multi-span continuous (MSC) concrete girder bridge considering two performance limit state parameters: column ductility and transverse deformation in the abutments. The main purpose of this paper is to show that the performance limit states, which are compared with the seismic response parameters in the calculation of fragility, should be properly modeled as randomly interdependent variables instead of deterministic quantities. The sensitivity of fragility curves is also investigated when the dependency between the limit states is different. The results indicate that the proposed method can be used to describe the vulnerable behavior of bridges which are sensitive to multiple response parameters and that the fragility information generated by this method will be more reliable and likely to be implemented into transportation network loss estimation.

Experimental study of a highway bridge with shape memory alloy restrainers focusing on the mitigation of unseating and pounding

This paper presents an experimental study to investigate the performance of shape memory alloy(SMA) restrainers for mitigating the pounding and unseating of highway bridges when subjected to seismic excitations.Mechanical property tests of the SMA wire used in the restrainers are conducted first to understand the pseudo-elastic characteristics of the material.Then,a series of shaking table tests are carried out on a highway bridge model.The structural responses of the highway bridge model equipped with SMA restrainers,installed in the form of deck-deck and deck-pile connections,are analyzed and compared with the uncontrolled structures.The test results of this study indicate that the SMA restrainers are not only effective in preventing unseating but also in suppressing the seismic-induced pounding of the highway bridge model used in this study.

Polynomial friction pendulum isolators(PFPIs)for seismic performance control of benchmark highway bridge

The seismic response of a benchmark highway bridge isolated with passive polynomial friction pendulum isolators （PFPIs） is investigated and subjected to six bidirectional ground motion records. The benchmark study is based on a lumped mass finite-element model of the 91/5 highway overcrossing located in Southern California. The PFPI system possesses two important parameters; one is horizontal flexibility and the other is energy absorbing capacity through friction. The evaluation criteria of the benchmark bridge arc analyzed considering two parameters, time period of the isolator and coefficient of friction of the isolation surface. The results of the numerical study are compared with those obtained from the traditional friction pendulum system （FPS）. Dual design performance of the PFPI system suppressed the displacement and acceleration response of the benchmark highway bridge. The dual design hysteresis loop of the PFPI system is the main advantage over the linear hysteresis loop of the FPS. The numerical result indicates that the seismic performance of the PFPI system is better than that of the traditional FPS isolated system. Further, it is observed that variations of the isolation time period and coefficient of friction of the FPS and PFPI systems have a significant effect on the peak responses of the benchmark highway bridge.

The effect of different intensity measures and earthquake directions on the seismic assessment of skewed highway bridges

In this study the probable seismic behavior of skewed bridges with continuous decks under earthquake excitations from different directions is investigated. A 45° skewed bridge is studied. A suite of 20 records is used to perform an Incremental Dynamic Analysis （IDA） for fragility curves. Four different earthquake directions have been considered： -45°, 0°, 22.5, 45°. A sensitivity analysis on different spectral intensity measures is presented; efficiency and practicality of different intensity measures have been studied. The fragility curves obtained indicate that the critical direction for skewed bridges is the skew direction as well as the longitudinal direction. The study shows the importance of finding the most critical earthquake in understanding and predicting the behavior of skewed bridges.

Analysis of Key Issues in Design Codes for Long-Span Highway Bridges

In recent years,with the continuous expansion of China's infrastructure construction,related construction work,including highway and bridge construction,has been steadily progressing.Among them,bridges are an important component of infrastructure construction,and their safety and stability are related to the travel of the masses and even the safety of their lives.China has a strict management system for bridge design specifications.This article mainly takes long-span highway bridges as an example to study the key issues of its design specifications and proposes countermeasures for related work.

Common Problems and Maintenance Management of Highway Bridges

China is currently undergoing rapid urbanization,and highway and bridge construction projects are increasing in both quantity and scope.They are one of the important infrastructures in urban construction.The requirements for the construction of bridge engineering projects are relatively high,but due to the influence of various factors,problems are bound to occur,which affects the aesthetics and functionality of the bridge.Therefore,it is necessary to strengthen the analysis of common problems of highway bridges,understand the causes,and put forward corresponding countermeasures.

Simulation Analysis on Navigation Indexes of Wanzhou Yangtze River Highway Bridge after the Anti-Collision Device Construction by Ship Model Test

After the anti-collision facility construction of Wanzhou Yangtze River Highway Bridge, the conditions of navigation in bridge area are complex. In order to study the navigation conditions of the reach and layout optimization measures, ensuring the safety of the ship navigation test has been carried out on the ship model navigation in the bridge area. According to the requirements of the maximum safety limit of the ship model test, the paper puts forward the best route, the control method and the difficulty of navigation through the analysis of the test results, and finally gives the recommendations and suggestions.

Load Testing in Bridge Maintenance

Highway bridges are a crucial component in road transportation networks.These bridges must be maintained according to usage requirements regularly.Test results must be considered before devising a maintenance plan.Load testing is a vital method of assessing the quality and performance of highway bridges.The outcomes of these tests facilitate the formulation of maintenance plans.This article examines the definition of load testing,its significance,and the process of execution,with the goal of providing support for bridge inspection and maintenance.

Application Strategy of BIM Technology in Highway and Bridge Design

For the highway and bridge construction industry,the traditional management model has been difficult to adapt to the current information management background.In recent years,in order to comprehensively improve the information management level of highway and bridge engineering,the highway and bridge industry advocates the use of emerging technologies to achieve full-cycle dynamic management of highway and bridge engineering management,and try to ensure the quality of highway and bridge engineering management while improving The efficiency of highway and bridge design management.In view of this,this article is mainly based on the background of information management,researching and analyzing the application strategy of BIM technology in highway bridge design for reference.

Experimental verification of bridge seismic damage states quantified by calibrating analytical models with empirical field data

Bridges are one of the most vulnerable components of a highway transportation network system subjected to earthquake ground motions. Prediction of resilience and sustainability of bridge performance in a probabilistic manner provides valuable information for pre-event system upgrading and post-event functional recovery of the network. The current study integrates bridge seismic damageability information obtained through empirical, analytical and experimental procedures and quantifies threshold limits of bridge damage states consistent with the physical damage description given in HAZUS. Experimental data from a large-scale shaking table test are utilized for this purpose. This experiment was conducted at the University of Nevada, Reno, where a research team from the University of California, Irvine, participated. Observed experimental damage data are processed to identify and quantify bridge damage states in terms of rotational ductility at bridge column ends. In parallel, a mechanistic model for fragility curves is developed in such a way that the model can be calibrated against empirical fragility curves that have been constructed from damage data obtained during the 1994 Northridge earthquake. This calibration quantifies threshold values of bridge damage states and makes the analytical study consistent with damage data observed in past earthquakes. The mechanistic model is transportable and applicable to most types and sizes of bridges. Finally, calibrated damage state definitions are compared with that obtained using experimental findings. Comparison shows excellent consistency among results from analytical, empirical and experimental observations.

基于可靠度的组合桥梁设计及维护策略(英文)

Currently,the design practice of highway bridges around the world are moving towards limit states design,a reliability-based design procedure.Canadian Highway Bridge Design Code(CHBDC)is the first design code entirely developed based on limit states design philosophy,including foundations and FRP components.However,reliability of a structure decreases in service due to environmental attacks and material deterioration such as fatigue,corrosion and many other reasons.Therefore,the structure should be inspected periodically,and the reliability of the structure should be evaluated according to its age and field data.If its reliability is reduced to a certain level,a repair should be scheduled as well as some preventive maintenance measures should be implemented to prevent further deterioration.Recently,many research works have been conducted to investigate reliability-deterioration mechanisms for each type of infrastructure and its components,optimize the inspection and maintenance strategy,predict remaining service life,estimate its life cycle cost.This paper is focused on the study of reliability-deterioration mechanisms of slab on steel girder bridges due to fatigue and corrosion of steel girders as well as corrosion of reinforcement in the deck slab.Examples will also be given to illustrate the proposed life cycle management strategy for composite slab on steel girder bridges.