Pedestrian Bridge Evaluation and Modelling Subjected to Running Load Cases

<p>This paper presents the dynamic measurements performed at two pedestrian bridges in Sweden subjected to different loading scenarios. Using accelerometers, the natural frequencies, the experimental mode shapes, and damping properties were determined for each bridge. Analysis were performed using the generalized single degree of freedom theory, the finite element method and the coupled system approach taking into account the flying phase of the running load. Additionaly, a simplified sensitivity analysis is presented in terms of accelerations due to the pedestrian transient event of a running load case. Results indicate that there is an excellent agreement between the aforementioned modelling strategies and, that it is possible to have human structure interaction under running load scenarios.</p>

Live Load Factors for Military Traffic in Bridge Evaluation

Military vehicles are sometimes required to transit bridges owned and operated by civilian bridge authorities. Using available data regarding the gross vehicle weight and associated axle loads of military traffic, live load factors, calibrated to the Canadian Highway Bridge Design Code, are proposed for bridge design and evaluation. This paper recommends live load factors for three categories military vehicles: (1) Wheeled-Transport vehicles; (2) Wheeled-Fighting vehicles; and (3) Tracked-Fighting vehicles. The values are derived for interior girders of a simply supported slab-on-girder bridges subjected to a single lane of traffic loading and are believed to be generally applicable for other structural elements and bridge types. Inherent differences between fighting vehicles, which are heavily armoured, and transport vehicles, which although armoured have high payloads, suggest that highway bridges should be evaluated separately for military fighting vehicles and military transport vehicles using distinct live load factors. Keywords: Bridge Evaluation, Code Calibration, Military Vehicles.

Review of annual progress of bridge engineering in 2019

Bridge construction is one of the cores of traffic infrastructure construction. To better develop relevant bridge science, this paper introduces the main research progress in China and abroad in 2019 from 13 aspects, including concrete bridges and the high-performance materials, the latest research on steel-concrete composite girders, advances in box girder and cable-supported bridge analysis theories, advance in steel bridges, the theory of bridge evaluation and reinforcement, bridge model tests and new testing techniques, steel bridge fatigue, wind resistance of bridges, vehicle-bridge interactions, progress in seismic design of bridges, bridge hydrodynamics, bridge informatization and intelligent bridge and prefabricated concrete bridge structures.

A CASE FOR ADDING AN INSPECTION LEVEL RELATED TO SHM FOR BRIDGE EVALUATION

The Canadian Highway Bridge Design Code (CHBDC) uses the concept of a target reliability index for evaluating the load carrying capacity of existing bridges. This index, which is based on risk to human life, relates to three aspects of uncertainties inherent in a bridge; (a) element behaviour, (b) system behavior, and (c) inspection level, where the inspection level currently refers to only manual inspections. Citing examples of tests on many instrumented bridges, the paper proposes an additional inspection level for inspections done with the help of electronic instruments and tests under controlled vehicle loads. The paper proposes simple additions to clauses of the CHBDC, for use when determining the optimum load carrying capacities of existing bridges where structural health monitoring (SHM) information is available.

EVALUASI PENYEBAB KEGAGALAN DAN PERBAIKAN STRUKTUR JEMBATAN RANGKA BAJA DENGAN BENTANG 54 m = EVALUATION OF THE CAUSES OF FAILURE AND REPAIR OF 54 M SPAN TRUSS BRIDGE STRUCTURE

In this paper the evaluation and repair of a bridge failure are presented. The method is of analytical bridge evaluation, which consists of in-situ visual inspection, measurement of the bridge dimensions and quality test of the steel material. The data were used as input in structure modeling using SAP 2000 in order to calculate the required strength (Ru) of each structural members. Calculation were done to obtain the design strength (ØRn) of structural members and connections.The bridge components are in a safe condition if its design strength is greater than or equal to the required strength or ØRn ≥ Ru, If not, the bridge is categorized as failed and then a repair method and strengthening shall be be performed. The result showed that all of structural members and connections are in a safe condition. Bridge failure is caused by such factors as less precise execution in the field, combination of a large bolt holes and tightening bolts that have not reached the minimum tensile strength.The proposed bridge repair method is to provide two pieces of plates. The plates were welded at the end of the rod and drilled at the position of the existing bolt holes in order to avoid the bolt shifting.Keywords : bridge failure, bridge evaluation, required strength, design strength, , repaired method AbstrakPada makalah ini disajikan evaluasi dan perbaikan dari kasus kegagalan sebuah jembatan. Metode yang digunakan adalah evaluasi jembatan secara analitis yang terdiri dari pemeriksaan secara visual di lapangan, pengukuran dimensi jembatan dan pengujian mutu bahan baja. Data tersebut sebagai input dalam pemodelan struktur dengan SAP 2000 dan diperoleh kuat perlu (Ru) masing-masing batang. Perhitungan juga dilakukan terhadap kuat rencana (ØRn) baik batang maupun sambungan. Komponen jembatan dikatakan aman jika kuat rencana lebih besar atau sama dengan kuat perlu atau ØRn ≥ Ru. Kemudian dilakukan penentuan kegagalan jembatan serta metode perbaikannya. Hasil penelitian menunjukkan bahwa semua batang dan sambungan aman sehingga penyebab kegagalan jembatan bukan karena kekuatan batang maupun sambungannya melainkan faktor pelaksanaan di lapangan yang tidak tepat yaitu kombinasi antara adanya lubang baut yang besar dan pengencangan baut yang belum mencapai gaya tarik minimumnya. Metode perbaikan jembatan yang diusulkan adalah dengan memberi dua buah pelat penguat yang dilas pada ujung batang dan dilubangi sesuai dengan posisi lubang baut yang ada agar tidak terjadi pergeseran baut.Kata kunci : kegagalan jembatan, evaluasi jembatan, kuat perlu, kuat rencana, , metode perbaikan