Review of Literature on Bridges Infrastructure Issues

Yozo Fujino (2017) found that civil infrastructure supports our everyday life and social activities. He also included that most of the bridges is built during our high economic growth period. As time goes by, maintenance and expenditures increased. He also included that condition of infrastructure is vary depend on the time and condition they were built. Infrastructure that is in the high risk of accident due to damage are those infrastructure that has been used for many years. Infrastructure that aging is at risk of a serious accident and he also included example of what happened in sasago tunnel accident 2012.

The study also of Bruce R. Ellingwood (2007) According to him, the risk of aging of an infrastructure is can lead to deterioaration of bridges from aggressive chemical attack, corrosion and other physical mechanisms. Like Bruce r. Ellingwood, our bridges get weak because they are aging. As time goes by, our bridge got breakable.

Deterioration. M. W Gewertz (1958) found that deterioration of structural parts as a outcome of growth of central corrosion on steel bar augmentation in a marine atmosphere and the consequent fracture of the nearby concrete is discussed. Susan C. Vallejo (2015) found that Philippines has a large percentage of transportation. 90% of passenger and 50% freight transportation respectively. Transportation has possible changes that can contribute to our development of civilization. Which some bridge has weight capacity and when the bridge cannot hold it anymore there will be a chance a bridge got wrecked. While Y. -J. Lee, P. Gardoni, H. -W. Lim (2010) also found that flow of the capacity of a transportation network can be reduced significantly if its constituent bridges are damaged by natural or man-made hazards. They also included that those are for rapid risk-informed decision making on hazard mitigation and response is essential to predict the post-hazard of the network efficiently and accurately. Bridge structure may experience deterioration over their life cycle.

ScourAyres (2016) found that scour is the erosion of soil surrounding a bridge foundation (piers and abutments). They included the cause of scour in bridges. Scour occur because fast-moving water around the bridge removes sediment from the bridge foundation and leaving a scour hole. Those holes can compromise bridge’s integrity. Most of the bridge that is built over active stream are those at risk of experience a problem with scour bank erosion, and channel instability during their useful life. Len Wright, Paul Chinowsky, Kenneth Strzepek, Russell Jones, Richard Streeter, Joel B. Smith, Jean-Marc Mayotte, Anthony Powell, Lesley Jantarasami, William Perkins (2012) found that the cause of instability of a bridge’s foundation is because of the scour. While scour causes stabilizing material, that is, riverbed that move away from the substructure.

Bridge Masters (2017) also found that a bridge above the river and streams is built on a bed of gravel. When flood happens, the racing floodwater the bed downstream from its piers, the flood wakening their ability to hold up the structure. Pressure on the bridge is the effect of flood and elements. Fernando de Falco, Raffaele Mele (2002) found that one of the major causes of bridge failure is scour. They said that suddenly and without prior warning or sign distress to the structure are those scour failure tend to occur. They said that taking examination into scour on existing structures has been limited and of doubtful effectiveness.

L. J. Prendergast, K. Gavin (2014) also found that scour is a common soil-structure interaction problem and they included that current changing of climate, increasing frequency of flooding, couple with the increasing magnitude of these flood events, will lead to a higher risk of bridge failure. Also scour known as excavation and removal of material from bed and banks of the stream as a result of flowing water. They included those three main forms of scour: general scour, contraction scour and local scour. Forde et al., (1999) study about The General scour occurs naturally in river channels and includes the aggradation and degradation of the river bed that can result of changes in hydraulic parameters control the channel form such as changes in the flow rate or changes in the quantity of sediment in the channel. While study about contraction scour happens as a result of the trimming in the channel’s cross-sectional area that arises because of the construction of the structure such as bridge pier and abutments. It can increase in flow of velocity and resulting bed shear stresses, caused by a reduction in the channel’s cross-sectional are at the location of the bridge. Increasing shear stresses can overcome the channel’s bed thresholds shear stress and mobilize the sediments.

Lastly, study about local scour happens around individuals bridge piers and abutments. It can lead to very localized erosion in the direct zone of the structure. They also included that monitoring the scour is important to guarantee the safe operation of the aging bridge advantage network.