Blast Protection Techniques: A Review

In the past few years, many countries have suffered severely from the attacks in form of blasts and other terrorist activities. These attacks have caused a major loss to infrastructure, human lives as well as economic losses. When the explosive occurs intentionally, it is called blast and if the explosive explodes accidentally then it an explosion. In India, the blast resistant design of structures is categorized as explosion above ground, IS 4991 (Indian standard criteria for blast resistant design of structures for explosions above ground, New Delhi, India, 1969) and underground blasts, IS 6922 (Indian Standard criteria for safety and design of structures subject to underground blast, New Delhi, India, 1973). In addition, different international codes and regulations namely NATO (Department of Defense in Structures to resist the effects of accidental explosions, UFC 3-340-02, DC, United States of America, Washington, 2008), FEMA (NATO in Manual of NATO safety principles for the storage of NATO ammunition and explosives, AC/258-D/258, Bonn, Germany, 1993) and DOD (FEMA 428 in Primer to design safe school projects in case of terrorist attacks, Federal Emergency Management Agency, United States of America, 2003) provide guidelines to mitigate blast induced effects on structures. A brief sketch on the development of blast pressure time history generated from detonation of manmade explosions is discussed. Factors affecting the intensity of blast load and its effects on various structural components both experimentally and analytically are also summarized. Theoretical and empirical approaches proposed by various researchers for the prediction of realistic blast load are also studied. The review also includes blast mitigation strategies proposed by various investigations for an improved structural performance against blast. The studies presented in the literature review are broadly categorized under two sections namely studies on air and surface blast loading and studies on underground mine blast loading.