Design and Analysis of Blast Load on Structures (original) (raw)
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DETERMINATION OF BLAST LOAD PARAMETERS FOR A MULTI STOREY STRUCTURE
Blast resistant analysis explores non linear Two Dimensional dynamic responses of tall building (G+10) storey. Tall reinforced concrete structural buildings have been designed for normal loads like dead, live, and wind. As all of us are aware that in today's world terrorist's attacks are common and not a single country is completely safe. High-Explosive detonations propagate blast energy in all directions, causing extensive damage to both the target structure and nearby buildings. These blast loads are of high intensity and these loads acts on the structure for short durations. Hence blast loading is nothing but impulsive loading. These loads are analyzed by TM-5 1300. In there comes the major challenge for civil engineers to design the structure for blast loads. In the Impact from the blast loads damages the target structure as well as the surrounding structures. Hence the structure should be designed for the blast loads along with normal loads, so that can be resist shock waves due to blast (impact) loading. The blasting energy releases high intensity pressure waves which are called as incident pressure waves. Then the incident waves affect the surrounding structures along with target structure. Those waves touches the structure and rebounds to the source after which they gets combined with the incident waves forming high intensity waves called reflected pressure waves. With that the reflected pressure waves a mach front is formed with the summation of the both incident pressure as well as reflected pressure. The dynamic blast loads are needed to be carefully calculated just like wind loads and earthquake loads. In this paper the blast load parameters are calculated for 2-D G+10 structural frame which is done manually. Columns are key load bearing elements in the frame structure.
Analysis of Blast Loading Effect on High Rise Buildings
This paper presents the dynamic response of a High Rise Structure subjected to blast load. The fundamentals of blast hazards and the interaction of blast waves with structures are examined in this study it is about the lateral stability of a high rise building modeled using SAP2000. The model building was subjected to two different charge weights of 800lbs and 1600lbs TNT at a two different standoff distances of 5m and 10m.The blast loads are calculated using the methods outlined in section 5 of TM5-1300 and a nonlinear modal analysis is used for the analysis of the dynamic load of the blast. The primary performance parameters that will be used to evaluate the behavior of the building from a global perspective are the total drift and the inter-storey drift. They are good indicators of nonstructural damage, collapse and ability of the structure to resist P-delta effect. Behavior of R.C frame and concrete infill frame will be computed in Dynamic condition 1. Introduction In the past few years, a structure subjected to blast load gained importance due to accidental events or natural events. Generally conventional structures are not designed for blast load due to the reason that the magnitude of load caused by blast is huge and, the cost of design and construction is very high. As a result, the structure is susceptible to damage from blast load. Recent past blast incidents in the country trigger the minds of developers, architects and engineers to find solutions to protect the occupants and structures from blast disasters Special attention has been given to explosive loads on landmark structures, such as high rise buildings in metropolitan cities, The explosion of bombs in and around buildings can cause catastrophic impacts on the structural integrity of the building, such as damage to the external and internal structural frames and collapse of walls. Moreover, loss of life can result from the collapse of the structure. Understanding the performance of high-rise buildings under explosion is of great importance to provide buildings which eliminate or minimize damage to building and property in the event of explosion. The analysis and design of blast resistant structures require a detailed understanding of explosives, blast phenomena and blast effects on buildings.
Prediction of Blast Loading and Its Impact on Buildings
A bomb explosion within or immediately nearby a building can cause catastrophic damage on the building's external and internal structural frames, collapsing of walls, blowing out of large expanses of windows, and shutting down of critical life-safety systems. Loss of life and injuries to occupants can result from many causes, including direct blast-effects, structural collapse, debris impact, fire, and smoke. The indirect effects can combine to inhibit or prevent timely evacuation, thereby contributing to additional casualties. In addition, major catastrophes resulting from gas chemical explosions result in large dynamic loads, greater than the original design loads, of many structures. The analysis and design of structures subjected to blast loads require a detailed understanding of blast phenomena and the dynamic response of various structural elements. This paper presents a comprehensive overview of the effects of explosion on structures. An explanation of the nature of explosions and the mechanism of blast waves in free air is given. This paper also introduces different methods to estimate blast loads and structural response.
The paper describes the process of determining the blast load on structures and provides a numerical example of a fictive structure exposed to this load. The aim was to become familiar with the issue of blast load because of ever growing terrorist threat and the lack of guidelines from national and European regulations on the verification of structures exposed to explosions. The blast load was analytically determined as a pressure-time history and numerical model of the structure was created in SAP2000. The results confirm the initial assumption that it is possible with conventional software to simulate an explosion effects and give a preliminary assessment of the structure.
2013
This technical report describes a procedure that can be followed for the calculation of the loads to be applied to a structure as a consequence of a blast. The report considers explosions taking place outside a building, which are not addressed directly at the relevant European Standards (Eurocode EN1991-1-7) dealing with accidental loading scenarios. The aim is the production of a simple, self-contained guide enabling the structural engineer to conduct a preliminary design of buildings for possible terrorist attacks. Aspects of the theory of blast waves have been included at an introductory level. The approach of the empirical methods for the prediction of blast loads has been chosen, which is more straightforward and has resulted from extensive experimental testing. For the determination of the main blast parameters, several graphs and diagrams have been included, which have been collected and properly adapted from several authoritative sources. This should make the load calculati...
Blast Loading and Blast Effects on Structures – An Overview
Electronic Journal of Structural Engineering
The use of vehicle bombs to attack city centers has been a feature of campaigns by terrorist organizations around the world. A bomb explosion within or immediately nearby a building can cause catastrophic damage on the building's external and internal structural frames, collapsing of walls, blowing out of large expanses of windows, and shutting down of critical life-safety systems. Loss of life and injuries to occupants can result from many causes, including direct blast-effects, structural collapse, debris impact, fire, and smoke.The indirect effects can combine to inhibit or prevent timely evacuation, thereby contributing to additional casualties. In addition, major catastrophes resulting from gas-chemical explosions result in large dynamic loads, greater than the original design loads, of many structures. Due to the threat from such extreme loading conditions, efforts have been made during the past three decades to develop methods of structural analysis and design to resist b...
COMPUTATION OF BLAST LOADING FOR A MULTI STOREYED FRAMED BUILDING
The number and intensity of domestic and international terrorist activities have heightened our concerns towards the safety of our infrastructure systems. Due to different accidental or intentional events, related to important structures all over the world, explosive loads or blast loads have received considerable attention in recent years. The development in this field is made mostly through publication of the U.S. Army Corps of Engineers, Naval Facilities Engineering Command (NAVFAC), and Air Force Civil Engineer Support Agency. In India also, the guidelines for the blast loading are published in IS 4991. In the present study, blast pressures for different weights of surface blast or TNT and varying stand-off distances are computed for a multi-storeyed framed building adopting wave scaling laws given by U.S Army technical manual (UFC3-340-02). Blast pressures for different cases are computed using correlation between blast pressure and blast scaled distance based on charts given in U.S manual. Time history loading is also obtained with parameters of reflected total over pressure and duration of positive phase of blast.
"Comparative Analysis of Blast Load on Multi Storey R.C.C. Building at Different Locations"
IRJET, 2023
The increase in terrorist acts in recent years has made it clear that the effects of blast load on the structure are an important factor to be considered during the design phase. The primary goal of this article is to shed light on the comparative analysis of the building subjected to blast load is done by using Etabs software. Here 32 different load cases are taken, in which for external load with special emphasis placed on different standoff distances of blast that is 20m and 30m with incorporation of various TNT charge weights that is 50kgs, 100kgs, 200kgs and 300kgs in accordance with IS code 4991(1968). For internal load TNT charge of 50kgs, 40kgs, 30kgs and 20kgs are applied on corner column and central column of the building at various storeys. Response of models when subjected to blast load, in terms of storey displacement, storey drift and storey shear are analyzed using Time history analysis.
Analytical Investigation of High rise Building under Blast Loading.pdf
This paper presents the dynamic response of high rise building subjected to blast loading. It is about understanding the explosion phenomena and investigating the dynamic response of a concrete frame structure by using SAP2000. Building is of 10 storey is exposed to 30kg TNT and 60kg TNT with three different standoff distances of 10m, 12.5m and 15m respectively. A non-linear three Dimensional is used for analyzing the dynamic response of a structure. In the present scenario, structures under blast loading (i.e. bomb explosion) are acting in short duration with high pressure intensity of shock wave which is outlined in section of TM-5 1300.The aim of this paper is to investigate the performance of high rise buildings under blast loading, blast phenomena and dynamic response of a concrete frame structure under blast loading by using SAP2000 software. Blasting vibration responses are simulated by using MATLAB program. The result obtained in terms of time history function, displacements and influence of the parameter considering the resistance of structure. Therefore, for decreasing the facade on surrounding buildings, moderate explosive energy is used to control the structural damages due to explosion.
Structural Design for External Terrorist Bomb Attacks Blast Loading
2004
Events of the last ten years have greatly heightened the awareness of building owners and designers of the threat of terrorist attacks using explosives. The United States government has funded extensive research into blast analysis and protective design methods and has produced a number of guidelines for its own facilities. The private sector is increasingly considering similar measures, especially for socalled "icon buildings" that are perceived to be prime targets, as well as nearby structures that are vulnerable to collateral damage. This article summarizes the methods available to define an external terrorist bomb threat and estimate structural design loads and element responses using simple dynamic system models and principles.