Load Rating of Al Halfaia Bridge over the Nile

Applied Technologies and Innovations, 2010

The most common approach to assess the safety of a bridge is load rating. Load rating of bridges is an important task that needs more attention and to be exercised with care. A prior knowledge base is highly essential in performing such a forbidden task. In this paper load rating practices carried out globally is reviewed with special emphasis on fatigue effect. The behaviour of members and materials under fatigue loading, various models proposed to simulate fatigue loading are highlighted.

An integrated load-test technique has been developed to test load carrying capacity of bridges. The technique has been illustrated with a case study implemented on one of the bridges at NH 24 near Hapur. This methodology can also be used for performance evaluation, developing load ratings and for detecting possible degradation or damage in bridges.

2016

The most dynamic of all the loads for a bridge structure are the live loads that play a vital role in determination of strength of the structure. Bridge is a structure that has to bear the combined effect of all the axle loads traversing it and therefore it is very necessary for the structure to be carefully designed for the heavy live loads, it is expected to be traversed in its life time. Bridge unlike pavements (designed to withstand millions of application of such axle loads) may not withstand even a single such heavier load for which it is not designed. Overloading of vehicles on state highway has been monitored and properly analyzed in this research study. The effects of vehicular live load models as dictated by “West Pakistan Code of Practice for Highway Bridges (WPCPHB)”and “American Association of State Highway and Transportation Officials (AASHTO)” have been compared with the traffic data collected and statistically analyzed from weigh-in-motion (WIM) station. The WIM stat...

Civil and Environmental Engineering

In frame of global European standardization and as consequence of new knowledge concerning the existing bridge reliability, the need for revision of the Technological Standard No. 104 “Load-carrying capacity of road bridges and footbridges” [1] (hereinafter referred to as TS 104) had started up. In the first stage of the revision, the preparation and analysis in the form of Analysis Task (hereinafter referred to as AT) has been worked up by the collective of the Department of Structures and Bridges from the University of Zilina in cooperation with Slovak Road Administration (SRA), National Motorway Company (NMC) and other co-operators among academicians and designers. In the presented paper, the attention is paid to the general concept and basic assumptions of the AT and revised TS 104 for determining the road bridge load-carrying capacity.

MATEC Web of Conferences, 2018

New segmental concrete bridge has been built near the city Žilina, aligned on European highway corridor E 50. The bridge is composed of the two separate precast prestressed box girder structure constructed by balanced cantilever method. The total length of both structures is 1042 m. The similar superstructure consists of a total of eighteen continuous spans with main spans of 60.5 m. The construction process, load carrying capacity and monitoring of the bridge has been investigated before the opening of the bridge. The paper presents verification of the structural behaviour of the bridge under static load compared to predicted model for both precast prestressed structures.

IOP Conference Series: Materials Science and Engineering

A rapid growth of development in our country has demanded our road network to be expanded over the last few decades. To cope with rapid development, the transport industry has deployed larger vehicles with heavier axle loads. In many instances, the level of services of our road network governed by the bridge load capacity. Since pre-independence era, our bridges have been designed based on the British Code. Begin with British developed code of DSIR at early 20s to British Code (BS) and eventually to Eurocode, our bridge loadings have been evolved substantially. In the midst of foreign code, our National Axle Load study conducted in mid 80s has also marked a significant finding to our local bridge capacity in which three major groups of load carrying capacity have emerged from namely STAL, MTAL and LTAL. This paper presents the journey of our local bridge loading code of practice and the corresponding impact to the structural design and construction. Comparisons are made as early as in 20s at the time where the code was based on British Department of Scientific and Industrial Research (DSIR) to the early age of British Code and to the migration of Eurocode. A typical concrete bridge deck spanning of 20m to 60m are modeled and analyzed with respective live loading derived from these established code of practice. Discussion on the way forward of implementing the Eurocode into our local design practices are also included.

Procedia Engineering, 2014

This paper is about the analysis of a prestressed highway bridge and its strengthening. The bridge wassimply supported I' Girder structure with four-lanes and itwas heavily loaded than its capacity; therefore, bridge was analysed in flexure using software "SAP 2000" for the actual or modified vehicular loading present over the bridge. Flexural analysis was performed in two stages: initially, the bridge was analysed for the loads for which it was originally designed and then the same bridge was checked for the modified vehicular load present over it. Analysis resultsrevealed that the stresses in the I-girders were exceeding in tension side and therefore bridge had a problem in serviceability due to heavy vehicular load (modified load) and therefore required strengthening. After strengthening the bridge using plate bonding strengthening technique, bridge was reanalysed against the modified loading which showed that the flexure capacity of the bridge is sufficient to withstand the heavy vehicular loads.

2015 UBT International Conference, 2015

This study consists on a structural analysis comparison of a typical highway bridge between KTP, EN and AASHTO based on load capacity. The Eurocodes are currently in the process of national implementation towards becoming the Europe wide means for structural design of civil engineering works. A team from M ott M acdonald inspected 562 bridges and the main causes of the defects are figured out in the study as traffic load, nature force, and aging, lack of maintenance and design deficiencies. As design codes are advancing with time, the need of Albania to upgrade its code has become a must. This paper presents the deficiencies of KTP when compared to the other design codes in order to help identify the areas which KTP is prone to problems and defects. A typical highway bridge with three spans (60, 80 and 60m) was selected to be compared. CSi Bridge was used as the tool to do a structural analysis of this bridge. The bridge was designed three times according to each code. M aximum moment is compared for the maximum load combinations of each code, on the columns and beams supporting the highway. Due to the design of the bridge the only members giving a cross-section of the load effect from the main deck are the one chosen. KTP is 40%-90% lower than EN and 20%-80% lower than AASHTO when compared for maximum moment at mid span of the beam and column. These refer to the biggest areas of deficiency KTP faces when compared with EN and AASHTO.

Engineering Structures, 2021

Efficient and reliable load-carrying capacity evaluation of deficient bridges is essential for bridge maintenance and management. Based on load-carrying capacity evaluation of an existing bridge, operator can formulate strategies and implement countermeasures such as repair, strengthening or traffic regulation. Currently, static load test is used widely for evaluation of bridge load-carrying capacity. The test, however, is often considered expensive and requires massive traffic closure that hinders frequent implementation on highway or bridges in the rural area. In this paper, an efficient method for load-carrying capacity evaluation of girder bridges based on displacement under moving vehicle is proposed. The method consists of three main procedures, namely, radarbased dynamic displacement measurement under truck pass-by test, influence line extraction, and estimation of the displacement under the static load test scenario. Based on these procedures, evaluation of load-carrying capacity is conducted following the AASHTO manual. The method was verified in numerical simulations using three-dimensional finite element model of typical girder bridge under vehicle loading. Effects of vehicle weight, vehicle speed, and road roughness on the accuracy of displacement estimation were investigated in the numerical simulations. Full-scale implementation of the method was conducted on a simply supported prestressed concrete girder bridge to investigate feasibility of the proposed method and to provide guidance for practical application. The results reveal that load rating factor of the girders can be reliably evaluated. The evaluation process was also more effective and economical than the conventional method.

– Among the impermanent loads on bridge structures, the most frequent one is a vehicular live load and plays a key role in design of the bridge components Most of the developed countries have a comprehensive highway bridge design specification while other countries adopt certain renowned design codes but with certain adjustments to meet their demands. Live Load Models are either modified or calibration factors are proposed for them. In Pakistan two different codes are being followed for highway bridge design i.e. West Pakistan Code of Practice for Highway Bridge (1967) and AASHTO LRFD. Both the codes live load models do not represent the actual load and traffic pattern in Pakistan. In this study a WIM data is analyzed, extrapolated to the design period and HL93 live load model is calibrated to represent the true traffic condition of Pakistan. I. INTRODUCTION Bridges are the most essential part of transportation system and they need to be designed for all sorts of necessary loadings. The most essential load section among all is the live load in bridge design especially vehicular traffic loads. Traffic loads are the most multifarious variable loads that affect the design of bridges. Every country has different traffic pattern from one another and therefore it is necessary to develop a unique live load model for each of them. But in some countries two or more bridge design codes are used, for instance in Pakistan both West Pakistan Code of Practice for Highway Bridges (WPCPHB, 1967) & AASHTO LRFD or Standard specifications are used. A traffic live load models are developed to represent the actual traffic of the country or region and are meant to be conservative for new structures during their design life. The live load model should periodically be updated with the advancement of trucks industry & overloading for the safety of highway bridges. In Pakistan, current live load models in WPCPHB (1967) [1] were taken from British code (BS 153, 1937) introduced in India (in 1935) and is also based upon AASHTO standard of 1961 [2]. Since that time traffic pattern and truck loads have significantly changed especially vehicles GVW, axles weight and axles configuration while this code has not been updated since than to cater with the current load condition.