Velich.Andrea.Bridging Gaps.London Bridges.ELTE.BTK.SEAS.2017.01.

This paper targets to explain different types of bridges that exists and how they are benefit to countries economy. This paper explains different types of bridges and their applications. It also explains the need of a particular bridge at a particular place. Introduction: A bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. There are many different designs that each serve a particular purpose and apply to different situations.

The Guidebook 2 is written in a user-friendly way employing only basic mathematical tools, supplemented by examples and case studies developed in detail. A wide range of potential users of the Guidebooks and other training materials includes practising engineers, designers, technicians, experts of public authorities, young people-high school and university students. The target groups come from all territorial regions of the partner countries. However, the dissemination of the project results is foreseen to be spread into all Member States of CEN and other interested countries.

A raised structure that allows the movement of vehicles or pedestrians over an obstacle. Introduction For millennia bridges have been used to cross barriers, typically a river, stream, or valley, by using locally available materials, such as stones, timber. Originally, cut trees were simply placed across streams to allow crossing. Later, pieces of wood were lashed together to make the improvements in functionality of the bridges. Such bridges are known as frame bridges. Since these early times bridge engineering has evolved into a major discipline in itself, one that benefits from the advances made in other engineering disciplines, such as engineering geology, water resources engineering, geotechnical engineering, and structural engineering. Based on these disciplines, modern bridge engineering mainly deals with (a) planning, (b) analysis, (c) design, (d) construction, (e) maintenance, and (f) rehabilitation. In modern society, bridges facilitate in surface transportation for roads and railways and carry facilities such as water/ sewer supply pipelines or electric/telephone communication lines across streams or gorges. In congested city centers, flyovers/overbridges serve to cross roads without mixing of the traffic moving across in different directions. Therefore, they are an essential part of daily life that aids a prospering trade and commerce in a city. Maintenance and repair of bridges, therefore, has consequences on the economy of the region, which mandates finding technological solutions for increasing their longevity. Bridgesarecalledlifelinestructuresbecauseapartfromthe day-to-day services, during natural calamities such as earthquakesor floods,they facilitate in providing emergency relief by enabling supply of food, medicine, etc., into hazard affected areas. Typically, structural redundancy in bridges is relatively low.

GLA Economics provides expert advice and analysis on London's economy and the economic issues facing the capital. Data and analysis from GLA Economics form a basis for the policy and investment decisions facing the Mayor of London and the GLA group. The unit is funded by the Greater London Authority, Transport for London and the London Development Agency. GLA Economics uses a wide range of information and data sourced from third party suppliers within its analysis and reports. GLA Economics cannot be held responsible for the accuracy or timeliness of this information and data. GLA Economics, the GLA, LDA and TfL will not be liable for any losses suffered or liabilities incurred by a party as a result of that party relying in any way on the information contained in this report. Working Paper 32: Building Bridges-Some lessons from the Middle Ages on the long-term economic impact of bridges over the Thames GLA Economics 1

Bridges, 2019

This is a collection of beautiful, critical, supporting, and loving articles written by graduate students. The authors in this first issue grapple with the realities of our current moment in ways that both acknowledge the significance of past scholarship while also mapping new pathways that put Foundations to work in (more) public ways.

Advantage Steel, 2014

We know that the condition of bridges and viaducts should answer the requirements of developing traffic loads. However, also the infrastructure or area under the bridge can develop and generate requirements for that bridge. As a result, the existing space under the bridge needs to be widened or heightened. This paper presents three modification and reconstruction projects in the Netherlands, which have resulted in heightening and widening of the navigation clearance under existing bridges. Inland navigation – carrying cargo, passengers or just recreational – constitutes an important branch of the Dutch economy. Additionally, the discussed projects comprised substantial improvements of technical condition, which extended the service life of the bridges.

The areas and infrastructures crossed by bridges or viaducts can develop. As a result, existing space under the bridge may need to be widened or heightened. This paper presents some modification and reconstruction projects in the Netherlands, which have resulted in widening and heightening of the navigation clearance under existing bridges. Inland navigation, both cargo vessels and recreational, generates important requirements for the Dutch bridge crossings.

In general a bridge project can be considered to have three major stages. They are, 1. Investigation stage 2. Design stage & 3. Construction stage Unlike the building structure constructions, bridge projects require an intensive investigation based on the feasibility, requirement or necessity, population benefited, economic development expected, topography, hydraulic data and soil characteristics prior to the approval and design stages. After all such investigations being over, the design stage commences. The design stage, consists of mainly three elements; hydraulic design, geometric design and structural design. Hydraulic design accounts for calculation of flood discharge, scour action near the bridge supporting structures, characteristics of river channel to fix the level of the bridge, clear water way of the bridge and thus the bridge spans. Foundation depth based on hydraulic characteristics is also a point to be considered. In geometric design, vertical and horizontal alignment and curvatures required are to be established. Traffic flow characteristics, projected traffic over one or two decades are to be considered. Thus the geometric design concerns more with transportation engineering point of view. Structural design involves the selection of component types and providing an economical solution for the purpose intended based on strength and serviceability point of view. At the end of design stage estimations, drawings and approvals are vital roles to be performed. At the construction stage, one cannot start the construction of bridge all of a sudden without certain preparatory works. Apart from primary construction surveys, river training works, coffer dam construction, approaches for machinery and equipments, storage and security for materials are important elements of bridge project under construction stage. Material and manpower management are also vital tasks for construction managers at this stage. There are design specific and bridge type specific construction technologies that could be adopted at this stage (like slip form, cantilever form techniques etc.). 2.3 DESIGN OBJECTIVES The general objective of bridge design is to provide economic, viable and safe solution to cross an obstacle such as river, valley and other traffic flow, by means of proper selection of site, material, type, technology and design. Specific objectives can be listed as follows: 1. to provide economic, strong and durable design of bridge 2. to provide the shortest structure across the obstacle 3. to forecast and decide the expected traffic flow in the future decades to come and to finalize the structural dimensions 4. to study the hydraulic data and fix economic spans for the bridge superstructure 5. to include applicable load combinations to design the structural components with the help of appropriate design code DESIGN WORKING LIFE Concrete, stone and steel bridges shall be designed for 100 years working life. Concrete and Steel culverts with an opening or diameter less than 2.0 m and all timber bridges shall be designed for 50 years working life.