Bridges and Their Studies

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.

Advantage Steel, 2014

Roads and bridges infrastructure are important factor in development of a region, as it provides land connectivity for transportation of people and goods. Since the sign of peace treaty in 2005, Aceh Province is continuously upgrading its roads and bridges capacity in order to increase the safety and quality of land. In 2014, surveys had been conducted in Cental Aceh to assess the condition of existing bridges, and also detail engineering design for the rehabilitation of old bridges or construction of new bridges had been proposed. Several typical problems of existing bridges were found, such as poor design, poor quality of construction, damages due to river flow and geotechnical problems. This paper summarizes some of the problems along with the proposed solution, and also intended as a documentation that can be used as reference for future road/bridges infrastructure improvement not only in Aceh Province, but also in other part of Indonesia.

2021

Bridges are structures that connect two places or two points separated by natural bodies like sea, ocean, hills, etc. These bridges are mainly constructed for different vehicles to move on but even pedestrians can also use. In West Bengal there are many bridges but among them four major ones are: Howrah Bridge, Second Hooghly Bridge, Bally Bridge and Nivedita Bridge. All these four bridges serve as the lifeline for the entire state. This paper deals with the overview and case study of Howrah Bridge and Second Hooghly Bridge; their history, constructional details and materials, impact on social, economical and cultural life, etc.

2013

The sustainable development of bridges is mainly based on meeting the three pillars of sustainability (economic, social and environmental factors) which have different goals. Each main criterion groups a large number of subcritera. Therefore, achieve a sustainable bridge is a complicate problem that involves a high number of factors in each stage of bridge life-cycle. For this reason, decision-making is a helpful process to solve the sustainability problem. The objective of this work is to review the bridge life-cycle decision-making problems that involve criteria that represent the pillars of the sustainability. While some works only consider criteria related to one or two of these pillars, the most current works consider criteria that involve all the pillars of sustainability. Furthermore, most of the works reviewed only study one stage of bridge life-cycle. This study shows the criteria used in some revised journal articles in each bridge life-cycle phase and, the multi-attribute decision-making used to achieve the sustainability. In addition, a small explanation of the obtained information will be carried out.

IJTSRD, 2020

A bridge is a structure built to span a valley, road, body of water, or other physical obstacle, for the purpose of providing passage over the obstacle. Nowadays suspension bridges are the pioneers in bridge technology. Of all the bridge types in use today, the suspension bridge allows for the longest span ranging from 2,000 to 7,000 feet. This type of bridge has cables suspended between towers & the cables support vertical suspender cables that carry the weight of the deck below. This arrangement allows the deck to be level or to arc upward for additional clearance. They are ideal for covering busy waterways. In this paper limitation, assumption analysis, how it can be constructing and loads acting on the bridge is described.

Structural Bridge Engineering, 2016

The chapter is a voice in the discussion concerning sustainable bridge development. Nowadays, the term has rather been abused, and therefore the presented approach refers to these elements of design, construction and maintenance of bridges-with regard to their role in transport and social life-which have been present in bridge construction for a long time and can be easily incorporated into the concept of sustainable bridge construction. Sustainable development, sustainable construction and so on are multidimensional. In the considered bridge construction area, looking at construction processes as interfering with the environment and which could and should be restricted is a new element. Nevertheless, other proven constructional solutions and technologies are characterised by their reliability. Assuming that the constructed bridges are to serve the next two or three generations of users, we can try to extrapolate current technical conditions on the next 30 or 60 years, i.e., up to three generations. We can do it if we know and are able to critically assess the history of bridge construction. Following this reasoning, the history in question is referred to in this paper, although rather subjectively and with the omission of numerous important personalities and technologies as well as instructive failures due to the publishing limitations.

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.