Bridge Engineering

Felieton jest jednym z cyklu poświęconego krakowskim mostom. Opisuje historię powstania i modyfikacji Mostu Dębnickiego - ważnego elementu krakowskiej infrastruktury komunikacyjnej na kierunku wschód-zachód. Most ten został pierwotnie zbudowany jako most kolejowy dla dostaw wojskowych, ale potem przebudowano go na most drogowy. Przy tej przebudowie podjęto brzemienną decyzję, o której wzmianka jest w tytule: Zbudowano most nisko nad wodą (w wyniku czego jest zagrożony przy każdej powodzi), żeby zachować widok na Wawel.

The purpose of this study is to evaluate the long-term vertical deformations of segmented pre-tensioned concrete bridges by a new approach. It provides a practical and reliable method for calculating the amount of long-term deformation based on creep and shrinkage in segmented prestress bridges. There are various relationships for estimating the creep and shrinkage of concrete. The analytical results of existing models can be very different, and the results are not reliable. In this paper, the different existing relationships are written in MATLAB software. After calculation, the values of the creep and shrinkage are stored. Then a sample bridge is simulated in the CSI-Bridge software, and different values of creep and shrinkage are allocated separately. Therefore, the data are analyzed, and its maximum deformation value is extracted at a critical span (Dv-max). Assigning different amount of creep and shrinkage to the model results in different values of Dv-max. In the next step, al...

The purpose of this research is to evaluate and compare the relative merits of the two coating systems for reinforcing bars in concrete. A review is given of the nature and characteristics of both epoxy coated and galvanized steel for use as reinforcement in concrete. Also presented is an overview of the results from recent experimental work on the comparative corrosion behavior of uncoated black steel, epoxy coated steel, and galvanized steel in concrete.

Network arches are tied arch bridges with inclined hangers, which have multiple intersections. In contrast to tied arch bridges with vertical hangers they are mainly subject to axial forces and only little longitudinal bending, leading to possible savings of more than 50% of structural steel. Despite or maybe because of this amazing claim, few network arches have been built. It is the professional experience of the authors that when a network arch is proposed as an alternative to the conventional tied arch bridge with vertical hangers, the responsible persons request an extensive demonstration of its benefits. In this article the authors present a comparative study of conventional tied arch bridges and network arch bridges. Subsequently, the basic structural behavior of a network arch is explained by means of a parametric study of the radial hanger arrangement. This paper concludes that the longitudinal bending moments are about ten times smaller in a network arch than in a tied arch bridge with vertical hangers, leading to important material savings.

A simply supported bridge is modelled to investigate the effect of a strain rate dependent modulus of elasticity on the dynamic response of the structure to a moving load. The bridge is modelled as a one-dimensional discretized finite element beam and the moving load is represented by a point force. A constant modulus of elasticity is traditionally employed when simulating the dynamic response of structures under moving loads. In this paper, a time-variant modulus is used to calculate strains and displacements and compare them to the traditional approach for different speeds and bridge spans. The time-variant modulus is obtained from the strain rate of the structure which is used in turn to update the strain. The results show significant changes in the modulus and in the resulting load effect as load magnitude and speed increase.

... mechanism, this paper presents a precise comparison between the results obtained by an analytical model for a simple geometrically non-linear cable-stayed beam [12] and those obtained by both finite element analysis and experiments on a physical model. ...

— Designing an efficient Distributed Database System (DDBS) is considered as one of the most challenging problems because of multiple interdependent factors which are affecting its performance. Allocation and fragmentation are two processes which their efficiency and correctness influence the performance of DDBS. Therefore, efficient data fragmentation and allocation of fragments across the network sites are considered as an important research area in distributed database design. In this paper presents an approach which simultaneously fragments data vertically and allocates the fragments to appropriate sites across the network. Bond Energy Algorithm (BEA) is applied with a better affinity measure that improves the generated clusters of attributes.

Network arches have inclined hangers that cross each other at least twice. It seems
to happen more often for railway bridges than for road bridges that structural elements above
the bridge deck are acceptable, which justifies investigations of the applicability of network
arches.
The tie can be a longitudinally prestressed concrete slab. This gives less noise, and the
additional self-weight favours the structural behaviour. Alternatives with steel and composite
bridge decks are discussed. For double track railway bridges spanning up to 100 metres the
arches can be rolled H-sections. For larger spans welded box sections are applicable.
For the design of network arches the hanger arrangement is important. Small bending
moments in the arches and small hanger forces are obtained when the upper hanger nodes
are placed equidistantly and all hangers cross the arch with the same angle. The cross
angle’s size depends on several parameters. Hints for a good choice are given. The maximum
hanger forces vary little, thus all hangers have the same cross-section.
To ensure passenger comfort and the stability and continuity of the track, deformations of
railway bridges are constricted. A network arch is a stiff structure with small deflections and
therefore suitable to comply with such demands even for high speed railway traffic.
A network arch railway bridge with a concrete tie usually saves more than half the steel
required for tied arches with vertical hangers and concrete ties.

ABSTRACT: Availability of good quality local construction materials is a major component of road construction as it contributes greatly to the cost of construction. Reserves of good quality construction material may be readily available in some parts of Zambia while in some parts like the Western Province,  sources of suitable construction materials are scarce. The lack of suitable construction materials in the Province has affected the construction, rehabilitation and maintenance of roads in this area as materials have to be hauled from distant sources to site. Plans to construct an all-weather road to ease the transport challenges and ensure development for the people of Western Province started as far back as 1966 but were first effected in 2002 when the first attempt to construct an all-weather paved road embankment across the flood plain was made.
This paper discusses some of the challenges faced in road construction projects in Zambia’s Western Province, specifically focusing on the Mongu-Kalabo road construction project as a case study. The various challenges faced on this project include financing (high construction cost), challenging terrain (deep Kalahari sands and seasonal flooding and lack of suitable road construction materials are discussed. The Government of the republic of Zambia has prioritized infrastructure  development and ha thus embarked on the construction of the 34 km of the Mongu-Kalabo  Road  Embankment  which will include twenty five bridges across the Barotse Flood Plain at a cost of US$ 286 million. The potential benefits of constructing the Mongu-Kalabo road to the people of Western Province and the country at large which include opening up trade with neighboring Angola, are also discussed.

This paper sets down an approach for analysing the transverse stiffness properties of multicellular bridge decks. Established methods to represent the flexural stiffness, torsion and distortion of the transverse cell section are presented. The paper is a technical literature review and is intended for students of bridge engineering to ensure that the analytical techniques developed in the early 1970s by Professor F. Sawko & Dr E.C. Hambly remain visible to a modern generation of bridge designers.

Kangaroo Auto is offering free credit on a new $10,000 car. You pay $1000 down and then $300 a month for the next 30 months. Turtle Motors next door does not offer free credit but will give you $1000 off the list price. If the rate of interest is 10% a year, which company is offering the better deal To be able to compare those offers, we need to calculate the present value of each offer. For Kangaroo Auto: The $300 monthly payment represent an annuity. Number of periods = 30 Discount Rate = 10% / 12 = 0.833% monthly. (0.833% = 0.00833) PV = = $7,934.11 Add: The $1,000 down payment = $8,934.11 For Turtle Motors: The Present Value = $10,000-$1,000 = $9,000 Since the PV of the Kangaroo option is lower, then it offers the better deal

The Tees (Newport) Bridge officially opened in February 1934 to much fanfare and public celebration, the event receiving extensive local, regional and national media attention. The bridge provided a crucial link across the River Tees to the emerging industrial works on the north bank of the river and beyond, and similarly provided access to the industrial, commercial and retail businesses on the Middlesbrough side of the river. However, delays in the project meant approximately fourteen years had elapsed from initial discussions of a crossing to its fruition in the form of the world’s largest vertical-lift bridge.

ABSTRACT: The present paper examines how statistics of extremes can be used to enhance the assessment and performance prediction of monitored highway bridges. This is achieved by proposing an approach to obtain a monitoring-based live-load for use in a reliability analysis. Time effects that correlate observed data to code required return periods are considered. Additionally, a method to identify, minimise and properly account for the epistemic uncertainty inherent to any monitoring record within a reliability analysis is presented. The approach can be utilised to plan data collection efforts or to maximise the utility of a limited amount of data. The extension of extreme value statistics to the monitoring of highway bridges is developed first using simulations and is then demonstrated on a case study using 90 days of in-service data collected from a bridge located in Pennsylvania, USA.

KEYWORDS: monitoring; statistics of extremes; reliability assessment; uncertainty; live loads; highway bridges

Two novel demountable shear connectors for precast steel-concrete composite bridges are presented. The connectors use high-strength steel bolts, which are fastened to the steel beam with the aid of a special locking configuration that prevents slip of bolts within their holes. Moreover, the connectors promote accelerated construction and overcome typical construction tolerances issues of precast structures. Most importantly, the connectors allow bridge disassembly, and therefore, can address different bridge deterioration scenarios with minimum disturbance to traffic flow, i.e. (1) precast deck panels can be rapidly uplifted and replaced; (2) connectors can be rapidly removed and replaced; and (3) steel beams can be replaced, while precast decks and shear connectors can be reused. A series of push-out tests and a beam test were conducted to assess the behavior of the connectors and quantify the effect of important parameters. The experimental results showed that shear resistance and...

A recent project by Cork County Council has allowed the compilation and analysis of detailed inventory and inspection data of 1,400 bridges on its regional and local road network. Each bridge and its constituent components or elements have been visually inspected and their structural condition rated based on a defined scale of deterioration and damage. This paper presents data on bridge structure type and geometry as well as condition ratings for each bridge component. The worst performing bridge components and the most recurrent damage types are identified. Conclusions are drawn on the overall condition of the bridge stock, the critical structural components and the deterioration mechanisms that impact upon them.

The paper presents the new bridge over the river Acheloos in Greece. The position of the bridge poses several construction and design challenges, mostly due to the soil characteristics at the foundation, the increased seismicity of the region and the high flow of the river. The project involves the construction of a small balanced cantilever bridge with three spans of length 47.5m – 80m – 47.5m. The main innovation in the structure is that the deck is supported exclusively on high damping rubber bearings, a technique not commonly encountered in such bridges. The selection of this structural system was a result of the poor geotechnical / foundation conditions, which differed considerably among the piers, as well as their low height. This led to the design of special deck stabilizing systems for the various construction stages. The design included application of the principles of earthquake engineering, an advanced construction schedule and a displacement monitoring procedure. Informa...

Shear walls are incorporated in building to resist lateral forces and support the gravity loads. RC shear wall has high in plane stiffness. Positioning of shear wall has influence on the overall behaviour of the building. For effective and efficient performance of building it is essential to position shear wall in an ideal location. This paper presents the response of building with different positioning of shear wall using both Equivalent Static Method (Seismic Coefficient Method) and Response spectrum Analysis. Five different Model of RCC building, one with no shear wall and other four models with different position of shear wall which is subjected to earthquake load in zone V has been studied .This study also incorporates how the bending moment, shear force for beam and axial force for column vary with change in positioning of RC shear wall. Building are modelled and analysed using standard package ETABS 2013.

Abstrak Studi ini membahas tentang analisis respon dinamik perilaku gempa pada jembatan rangka pelengkung sebagai akibat dari pengaruh pergerakan tanah dan patahan. Data gempa didapat dari integral waktu gelombang respon percepatan gempa Jiji Taiwan pada tahun 1999 yang kemudian diaplikasikan kepada struktur jembatan rangka pelengkung untuk diteliti perilaku responsnya. Analisis respons dinamik dibuat menggunakan gerakan tanah pada saat gempa pada arah transversal dan longitudinal, bersamaan dengan pergerakan patahan pada arah vertical dan transversal, untuk meneliti perilaku gempa dari model jembatan baja pelengkung yang digunakan. Model analitis dengan sejarah waktu (time history) disimulasikan menggunakan model 3D dengan program ABAQUS. Berdasarkan hasil analisis, perilaku respons dari kedua kasus pada arah transversal dan longitudinal akibat akselerasi menunjukkan bentuk respons yang sedikit berbeda. Selain, itu juga ditemukan bahwa elemen struktur yang mengalami plastis berkumpul pertemuan antara rangka utama jembatan pelengkung dan girder pengakunya.

The scope of this paper is to introduce multiway analysis into structural engineering research and to outline methodology used in tensor decomposition of finite element analysis (FEA) data. More specifically, the example evaluated herein evaluates the stress distribution of two different highway bridge structural components (girders and cross frames), being subjected to incrementally increasing forces. Additionally, the paper shows potential advantages of using multiway methods in interpretation of FEA data and makes recommendations for future investigations on the use of multiway methods in FEA post-processing of structural engineering data.

Bridge collapse has dramatic consequences in transportation systems. Bridges are constructed with little adherence to the
quality design, mostly in developing countries. Engineers need reliable methods for accurate estimation of the scour
depth and location to design the bridge footing foundation safely. Scouring at the contracted section of approaching
flow is a significant cause of bridge abutment failure. The main objective of this study was to estimate the geometry of
the equilibrium contraction scour at a protruding abutment bridge in the compound channel, using parametric analysis
(PA). Data from clear-water contraction scour experiments in uniform sand were collected for PA modelling methods. The
main variables investigated were the abutment protrusion ratio, the contraction degree and the ratio of the maximum
contraction scour owing to approaching flow depth. Results from PA were compared with those of the existing empirical
methods for predicting the maximum contraction scour geometry. Statistical and graphical tests indicated that the PA
method gives reliable prediction of the contraction scour depth around a protruded abutment in a compound channel.

There are many old stone masonry arch railway bridges in Iran which are more than 70 years old, still under service. Need for capacity enhancement of railway transportation in recent years, particularly in freight railways, has made Iranian railway authority decide to enhance the axle load of trains from 200 KN to 250 KN. Condition survey for one of the most remarkable of these stone masonry arch bridges showed stone falling damage from middle of spans. In this paper, a theory for relating this type of damage to railway impacts has been developed and an innovative method for reduction of impact effects on railway bridges has been introduced.

Synopsis The Howe truss was patented in USA initially in 1840 and again in 1842 and went on to become one of the primary timber truss designs used in North America. The adaptation of the Howe truss in NSW into the two distinct forms known as the " Allan " and " Dare " trusses is well documented, though its usage elsewhere in Australia is largely ignored. This paper will briefly describe the extent of this usage and suggest the manner in which some of the bridge engineering knowledge required for their construction was transmitted.