International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 03 | Mar -2017
p-ISSN: 2395-0072
www.irjet.net
A Review on Blast Analysis of Reinforced Concrete Viaduct Pier Structures Aswin Vijay1, Dr. K Subha2 1PG
Student, Department of Civil Engineering, NSS College of Engineering, Palakkad
2Professor,
Department of Civil Engineering, NSS College of Engineering, Palakkad
-------------------------------------------------------------***---------------------------------------------------------Abstract - The world population, as we know, is increasing at an exponential rate. To cater the needs of this increase in population, huge development in the infrastructure is happening all over the world. Large numbers of bridges, metros, viaducts, flyover etc. are emerging at various locations of the globe every day. These structures may be made of reinforced concrete, steel, composites etc. Major portion of these structures are still made up of concrete. Even in composite bridges and viaducts, the ducts may rest over piers made up of reinforced concrete. As there is an increase in population, there has also been an increase in accidents. Likewise, there has also been an increase in vandalism and terrorist activities across the globe. Both these events may lead to blasts happening at various locations. One of the key locations where these blasts may occur is near the piers of these viaducts, metros, bridges etc. The failure of these reinforced concrete piers may result in a large number of causalities, especially when the piers of the viaduct structures like bridges, fly overs, metros etc. fail due to the blasts. Various types of loads are generated during the event of a blast. These loads act on the piers and the piers may be damaged partially or it may completely fail.
running on either side of these piers, as the metros are constructed over the roads. Any accident involving a blast can damage the pier structures resulting in serious injuries and loss of life. Designing the piers to be blast resistant can help in reducing the casualties to a great extent. By understanding the loads generated during a blast and its effects on the structure, we can design the structure to withstand these loads. However, designing these structures to completely resist the blast forces is a tedious process and may not be economical. Designing these structures so that damages may occur to a certain level but the total collapse of the structure does not take place is advisable. As science is evolving, the chemicals used for creating the explosions are also evolving. Some of the new chemical explosives cannot be detected even by using state of the art explosive detection technique. So, it is better that we stay prepared to face such a scenario.
2.EXPLOSIONS Explosion is a sudden increase in volume and release of large amounts of energy in an extreme manner, usually with the generation of high temperatures along with the release of gases. There are three types of explosions namely unconfined explosions, confined explosions and explosions caused by explosives attached to the structure. Unconfined explosions may occur as an air burst or a surface burst. Unconfined explosions can occur as an air-burst or a surface burst. In an air burst explosion, the detonation of the high explosive occurs above the ground level and intermediate amplification of the wave caused by ground reflections occurs just before the arrival of the initial blast wave at a building. (Fig. 1) As the shock wave propagates outwards along the ground surface, a front commonly called a Mach stem which is formed by the interaction of the initial wave and the reflected wave.
Key Words: Blast, Explosion, Blast Waves, Explosive Effects, Blast Loading
1. INTRODUCTION The increase in population over the years have led to a rapid increase in the number of accidents that are occurring in various parts of the world. Also, the number of activities of terror are climbing up. Due to these reasons, blasts, both accidental and planned, are all over the world. Many structures are affected due to these blasts. A large number of these structures are constructed elevated from the ground level by means of piers. These piers generally do not have any protection except for a small crash barrier. The failure of the piers of the structure can cause to structure to fail and topple over. In the modern metros, roads are
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