blast loading

1. PATEL INSTITUTE OF ENGG. & SCIENCE
BHOPAL (M.P.)-462021, INDIA
Department of Civil Engineering
Presented by:-Vinay Kumar Singh Chandrakar Guide name:- Prof. P.D Porey
Roll No. :- 0509CE13MT18 Department:- Structural Engineering

3. 1. Abstract
2. Introduction
3. Literature Survey
4. Objectives And Methodology
5. Problem Description
6. Need For Research
7. Result And Discussion
8. Conclusion & Future Scope
9. References

4. The response of a concrete industrial building subjected to load, load and lateral blast
masses was examined. INVENTOR was used for generating the 3D model. The finite
component package ALTAIR was wont to analyze with radially symmetrical boundary
conditions. For the response calculations, transient structural analysis was simulated in
STAAD PRO and for that a undulation within the sort of uniform pressure was applied.
The analysis of structures subjected to blast pressure needs an in depth understanding
of blast phenomena and also the dynamic response of varied structural parts. this
provides a comprehensive summary of the consequences of explosion on different
grade of reinforced concrete structures.
Key words: Blast Pressure, Inventor, Altair, Staad Pro, Transient, Structural Analysis

5. Basic reactions to impact stacking have turned out to be progressively essential issues
for governments and specialists who try to minimize destruction to both open and
private structures. Surface blast creates both ground stun and air impact pressure on
close-by structures. Harm to the death toll and social frenzy are components that must
be minimized if the danger of blast activities can not be ceased. Outlining the structures
to be completely safe is not an efficient and practical alternative.
The main target of this study is to provide guidance to engineers where there is a
necessity of protection against the explosions caused by the detonation of high
explosives.This work incorporates data about explosives, diverse sorts of blast and
impact stacking parameters. The impact stacking on a structure brought about by a
high-dangerous explosion is based upon a few factors.
a) The extent of the blast
b) Dangerous area with respect to the structure being referred to, that is, unconfined or
limited blasts. Unconfined blasts incorporate free air burst blast and surface burst blast.

6. c) The geometrical design of the structures
Blast on the structure and the ground surface. To assess the impact on a structure, a
charge set on or extremely close to the ground surface. The Figure 1 and Figure 2
demonstrates how the reflected wave proliferates through the environment.
Figure 1 Figure 2

7. The basic characteristics of ground shocks induced by surface explosions are short
duration, large amplitude and high-frequency excitations. The response in the force
vibration phase includes high-frequency vibration modes with small displacements but
large acceleration, thus inducing high inertial shear force. The free vibration response
is however, dominated by lower frequency modes with larger displacements but
smaller accelerations.
Explosion and impact phenomenon :-
Close to the source of explosion the blast wave is formed and violent hot and
expanding gases will exert intense loads which are difficult to quantify precisely.
There are three impacts have been recognized; Air stun wave, Element pressure and
Ground stun wave.
1.) The air stun wave creates a quick increment pressure over the surrounding
environment at a point separate from the source.

8. 2.) This is regularly alluded to as overpressure. As an outcome, a pressure differential
is produced between the ignition gasses and the air, bringing an inversion toward
stream, back towards the focal point of the blast, known as a negative pressure stage.
3.) This negative pressure is in respect to the air, as opposed to irrefutably the negative
pressure. The structure reaches to the original stage when the air come back to its
unique state.
Exponential Decay of Pressure-Time History
Figure 3

9. Blast Wave Scaling Law:-
The impact wave scaling law characterized by Hopkins in (1915) states two distinct
pressures of the same dangers and has same impact qualities at some scaled separations
in comparable barometrical conditions. The Hopkins scaling separation is:
R
Z = —
W1/3
Z is the scaling separation R is the range
W is the pressure of charge

10. Alexander Stolz et al (1) examined bearing resistance of plate components made of the
bendable cement DUCON, under impact stacking conditions. He inferred the resistance
offered by plate component and figured iso-harm bends.
Broad chips away at the subject have been studied by [2] Ellis et al (2) and Mao et al
(3) on Ultra High Performance Concrete (UHPC) and Ultra High Performance Fibre
Reinforced Concrete (UHPFRC) separately and re-enacted uprooting and break
examples produced by the multi scale models with exploratory perceptions subjected to
impact stacking. Lei Mao et al (3). researched the execution of UHPFRC under impact
stacking with a solid material model which considers the strain rate impact.
Lei Mao et al (4) researched the execution of UHPFRC under impact stacking with a
solid material model which considers the strain rate impact. He likewise completed
parametric studies to research the impact of steel support and steel fiber in expanding
UHPFRC imperviousness to impact stacking.

11. Sung-Hwan Yun et al (5) researched the impact harm practices for solid boards
retrofitted with steel plates subjected to impact stacking. The plan incorporated the rate-
subordinate versatility and harm softening; the non-direct strain and strain-rate
solidifying and non-straight strain softening. They found that greatest avoidance and
most extreme redirection proportion are lessened when utilizing the retrofitted solid
boards when compared with the non-retrofitted solid board. They additionally found
that scabbing could be avoided with steel plates.
Siddiqui et al (9) completed trial tests to decide connections of synchronous ground
stun and air impact parameters against rash stacking. They added to a procedure of
investigation to assess the impact of an outer blast on the fortified solid controls of
different reactors. They set up exact connections of crest gaseous tension, top reflected
air impact pressure along the stature of the structure, top ground speeding up, arriving
stun of ground stun, span of ground stun and the time slack between ground stun and
air impact pressure coming to the solid structure et cetera on a fortified bond solid
regulation scaled model attributable to a surface blast at a sure separation. Tests were
conveyed with TNT charge pressures of 25, 30, 35, 40 and 50kg individually with
charge separations from 5m to 25m. In Blast stacking and impact consequences for
structures Mendis, Gupta and Ramsay (2007) presented clarification of the way blast
and the system of impact wave spread in free air, and additionally distinctive strategies
with appraisal impact load and basic reaction.

12. Objective:-
1. To study the blast resistance and response of a reinforced concrete structure and
its Components under blast pressure.
2. To study the deformation distribution in the structure during the positive and
negative phase of the blast pressure.
3. To compare the effects of blast pressure due to standoff of 5m and 6m.
Methodology:-
The work taken up is analytical work. AUTOCAD INVENTOR PROFESSIONAL
2014 is used for drafting the geometrical model. STAAD Pro is used for
analyzing the general load conditions of the structure and ALTAIR for analyzing
the structure for blast loads with self-pressure only and also with the live loads.

13. Reinforced Concrete building: The building is of the measurement 49.8m x 37.8m. The
floor to floor stature is 4m. The dividers are made of .254m thick solid pieces. In this
concentrate, level RCC rooftop is considered. Hazardous stacking is connected as a
uniform pressure of 40750 Pa and 57725 Pa acting ordinary to the askew front external
divider appearances discharged from an impact blast at standoff separations of 6m and
5m individually.
The analyses carried out are:
i. Dead load alone
ii. Dead load + Live Load
iii. Dead load + Live Load + 40750 Pa
iv. Dead load + Live Load + 57725 Pa
There are two types of materials used in the analysis – Concrete and Steel. The grade of
concrete is taken to be M20, M25, M30 & M35 for all the slabs, beams & columns for

14. Auxiliary reaction under unstable burden is a noteworthy worry in basic building. It's
difficult to anticipate huge numbers of the risky occasions that can happen in
structures: gas spills, terrorist assaults, an object affecting a building to give some
examples. What's more, in light of the fact that mishaps can't generally be avoided,
fabricating creators, city authorities and executives need to consider the likelihood of
these occasions when they are planning and building another structure. Proceeded with
usefulness instantly taking after an impact occasion of the base concerned will permit
administration powers to mount salvage endeavors, and on account of a blast on an
interstate scaffold, to adjust movement ways whilst keeping up an intersection at the
extension area.

15. Outlining a building considering these dangers can enhance the auxiliary uprightness of
the building, and it can likewise make a more protected and agreeable environment for
the individuals who utilize the structure regularly .In numerous calamity situations,
pulverization is severe to the point that remaking the occasion is troublesome. Be that
as it may, the learning picked up from sorting out what happened can advantage
planners and specialists. In this work, a numerical reenactment methodology of the trial
functions has been studied. To exhibit the proposed issue, a three story business
building is displayed in INVENTOR and is examined utilizing ALTAIR. The blast is
thought to be from standoff separations of 5m and 6m from the front inclining corner of
the building separately.

16. Start with description M20

17. Total deformation due to 6m standoff at 0.0094s

18. Total deformation due to 5m standoff at 0.0094s

20. Total deformation due to 6m standoff at 0.0094s

21. Total deformation due to 5m standoff at 0.0094s

23. Total deformation due to 6m standoff at 0.0094s

24. Total deformation due to 5m standoff at 0.0094s

26. Total deformation due to 6m standoff at 0.0094s

27. Total deformation due to 5m standoff at 0.0094s

28. Material/Time
5m Standoff
Deformation
Min
5m Standoff
Deformation
Max
6m Standoff
Deformation
Min
6m Standoff
Deformation
Max
M20/0.0094s 0 11.49 0 11.42
M20/0.0135s 0 11.72 0 11.67
M20/0.015s 0 11.63 0 11.61
M25/0.0094s 0 11.40 0 11.38
M25/0.0135s 0 11.70 0 11.65
M25/0.015s 0 11.61 0 11.59
M30/0.0094s 0 11.26 0 11.21
M30/0.0135s 0 11.68 0 11.63
M30/0.015s 0 11.58 0 11.55
M35/0.0094s 0 11.21 0 11.16
M35/0.0135s 0 11.60 0 11.64
M35/0.015s 0 11.54 0 11.51

30. Conclusion:-
For offices, open and business structures, set up thought for unbelievable time is
crucial. visible of the results of all four grade material utilized in an equivalent structure
is accessible within the writing, a definitive target is to form accessible the system for
problem solving the impact load on the structures. to both to admit the dynamic
properties of invigorating steel and cement underneath high strain rates often deliver by
the impact load.
After performing analysis on all the four structures of different grade I found the M35
material structure is safer then the others.
The limited component investigation uncovered that, for pivotally stacked sections, the
force of anxiety and distortion is higher at the shaft segment intersection than in
whatever is left of the segment length.

31. The segment reaction at distinctive floor levels demonstrated that the force of effect
reductions as the separation from the surface of impact increments.
The examination amongst of all four materials used in building at 6m standoff impact
stacking and 5m standoff impact stacking demonstrated that the aggregate distortions
and additionally the anxiety qualities are higher for lower standoff separations.
Future Scope:-
1.Cases in which the axial load does not remain constant during the response time are
possible. These include situations where the bomb is located within the structure and
the blast excites the girders connected to the column. The effect of this time-varying
axial load should be studied.
2. Cases should be studied when the explosions within a structure can cause failure of
interior girders, beams and floor slabs.
3. Tests and evaluation of connections under direct blast loads.
4. More material and combination can be used for better result.

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34. THANK - YOU