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The Masonry SocietyAIA Provider: 50119857

AIA Course:

Resilience-Based Blast Design of Reinforced Concrete Masonry Systems

November 6th,2019

Shady SalemAssistant professor

Civil Engineering Department

Faculty of Engineering

The British University in Egypt

The Masonry Society is a registered Provider with the American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of completion for non-AIA members are available upon request.

This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing or dealing in any material or product.

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

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ARE YOU REALLY SAFE?

3Global terrorism index 2016

World map for terrorism impact

WHY BLAST?

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Terrorism weapons 

Explosives/ Bombs/ Dynamite

Firearms

Other

Global terrorism index 2015

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CURRENT BLAST DESIGN STANDARDS

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Design base threat (DBT)

Damage classification for individual elements

Determine the building LOP

ASCE 59‐11

CSA 850‐12

Ignores the probabilistic 

nature

Ignores the wavefront variation

Ignores the system’s functionality and 

downtime

OBJECTIVES

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Street hardware

Target building

Buffer zoneSusceptible ground zero

Unsecured area

Secured areas

Building exterior(hazard mitigation design)

Building interior(localized hardening)

Blast building envelop(perimeter securing)

Threat

Schematic blast defensive lines (adapted from (FEMA 427)

• Develop a tool to assess the post‐blast functionality.

• Estimate the structure’s down time .

• Blast mitigation measures optimization. 

• Quantification of  the blast performance of 

reinforced concrete masonry systems

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MAIN OBJECTIVE

Resilience triangle

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Time (t)t0 tf

Functionality  (Q)

Robustness

Rapidity

Recovery rate

(Downtime)

Target Functionality

Hazard event

Initial Functionality

End of repair

100 %

METHODOLOGY

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Functionality loss

Time (hrs)

Functionality loss uncertainty

Repair time uncertainty

Ir

Mean functionality 

loss

Mean robustness

Mean repair timeDensity

Dynamic Response Resilience Frameworks

Blast assessment

Blast uncertainty propagation

RM 

out‐of‐plane 

assessment

Resistance functions

Influence of vertical rft. and axial load

Resilience assessment

Static Response

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RESILIENCE IS THE ABILITY TO WITHSTAND AND RAPIDLY RECOVER FROM DISRUPTIONPPD‐8

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Static ResponseS A L EM ,   S . ,  E Z Z E L D I N ,  M . ,   E L ‐DA KHA KHN I ,  W. ,  &   TA I T,  M .   ( 2 0 1 9 ) .  OUT ‐OF ‐ P LANE  B EHAV I OR  O F  LOAD ‐ B EAR I NG  R E I N FORCED  MASONRY   S H EAR  WAL L S . J O U RNA L  O F   S T RU C TUR A L  E NG I N E E R I N G , 1 4 5 ( 1 1 ) ,  0 4 0 1 9 1 2 7 .

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EXPERIMENTAL PROGRAM

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Vertical reinforcement: 6#3 (Walls L‐00 and L‐10)

Vertical reinforcement: 6#4 (Walls M‐00, M‐05, M‐10 and M15) 

Vertical reinforcement: 15#3 (Wall H‐10)

Test setup

LOAD‐DISPLACEMENT HYSTERETIC RELATIONSHIP

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0

50

100

150

200

0 25 50 75 100

0

50

100

150

200

0 25 50 75 100 0 25 50 75 100

0

50

100

150

200

0 25 50 75 100

0

50

100

150

200

0 25 50 75 100

0

50

100

150

200

0 25 50 75 100

L‐10L‐00

M‐00 M‐05 M‐10 M‐15

H‐10

Total load

 (P)(kN

)

Total load

 (P)(kN

)

Total load

 (P)(kN

)

P

PA

θ

θ

Δ

Mid‐height displacement (Δ) (mm)

Mid‐height displacement (Δ) (mm) Mid‐height displacement (Δ) (mm)

0 25 50 75 100

Low VL rft ratio

Mid‐height displacement (Δ) (mm)

Medium VL rft ratio

High VL rftratio

Mid‐height displacement (Δ) (mm) Mid‐height displacement (Δ) (mm) Mid‐height displacement (Δ) (mm)

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SELECTED EXPERIMENTAL RESULTS

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0 1 2 3 4 5 6 7

0

20

40

60

80

100

120

140

160

180

200

0 20 40 60 80 100

Chord rotation (degrees)

Total load

 (P) (kN)

Mid‐height displacement (Δ) (mm)

L‐00 L‐10 M‐00 M‐05 M‐10 M‐15 H‐10

Resistance functions for the tested walls

P

PA

θ

θ

Δ

L‐00

M‐15M‐05 M‐00

M‐10L‐10

L‐00

OUT‐OF‐PLANE RESISTANCE FUNCTIONS

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Total load

(P)(kN

)

Mid height displacement (Δ)(mm)

Plastic Elastic‐Plastic Elastic 

Pu

Pe

ΔeΔep

Ke

Kep

Mp

Mp 

Mp

Δm

Mp

Mp/2

Mp

Idealized resistance function of the USACE (2008)/USDOD (2014) Idealized resistance function of the USACE (2008)/USDOD (2014)

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RESISTANCE FUNCTIONS VALIDATION

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Models assessment

0

20

40

60

80

100

120

140

0 10 20 30 40 50 60

Total load

 (P) (kN)

Mid‐height displacement (Δ) (mm)

L‐10

Proposed model

UFC

Experimental vs Analytical (L‐10)

∆e

∆ep ∆u*

0

20406080

100120140

L‐00 L‐10 M‐00 M‐05 M‐10 M‐15

Deviation (%

)

USACE/USDOD Proposed model

At Δep

02040

6080

100120

140

L‐00 L‐10 M‐00 M‐05 M‐10 M‐15

Deviation (%

)

USACE/USDOD Proposed model

At Δu*

0

20406080

100120140

L‐00 L‐10 M‐00 M‐05 M‐10 M‐15

Deviation (%

)

USACE/USDOD Proposed model

At Δe

Dynamic ResponseSALEM , S . , E Z Z E L D I N , M . , TA I T, M . J . & E L ‐DAKHA KHN I , W. W. B LA S T F RAG I L I T Y A S S E S SMENT FOR LOAD ‐ B EAR I NGR E IN FORCED MA SONRY SH EAR WAL L S . A S C E JOU RNA L O F S T RU C TU R E ENG IN E E R I NG , SU BM I T T ED FOR PUB L I C AT I ON INAUGU S T 2 0 1 8

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NUMERICAL MODEL

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Zero length element

Elastic beam‐column element

Zero length element

Rotational spring (steel01 material)

Rotational spring (steel01 material)

Rotational spring (steel01 material)

Elastic beam‐column element

Fixed support

Fixed support

φy

My

Curvature

Moment

ky

Schematic diagram of the developed model

Start

Define geometry, material, load, n

My , θy , ky

i=1.0

My , θy , ky

i=n

Dispalcement history

hy

hy

Noi = i+1

Yes

M > My

hy

Dynamic analysis

hy

DIFs DIFs =1.0

Yes

Fiber analysis

No

Fiber analysis

Dynamic analysis

DIFs =1.0

(a)

(b)

Developed model: (a) framework; (b) iterative subroutine

EFFECT OF WAVEFRONT PARAMETERS

UNCERTAINTY/VARIABILITY ON RMSWS

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Is=1000 kpa.ms

Mid‐height displacement (m

m)

Mid‐height displacement (m

m) Pr=500 kpa

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BLAST FRAGILITY SURFACE

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200

330

400

500600

700800

9001000

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

50

100

110

120

130

140

150

160

170

180

190

200

0.9‐1

0.8‐0.9

0.7‐0.8

0.6‐0.7

0.5‐0.6

0.4‐0.5

0.3‐0.4

0.2‐0.3

0.1‐0.2

0‐0.1Is (kPa.ms)

Pr (kPa)

Probability P(DS2)

Blast fragility surface for wall L12 (θ=2°): (a) 3D view; (b) elevation (c) side view; (d) plan

(a)

(b) (c)

(d)

Deterministic Resilience AssessmentSALEM , S . , C AMP I D E L L I , M . , E L ‐DAKHAKHN I , W. W. , & TA I T, M . J . ( 2 0 1 8 ) . R E S I L I E NCE ‐BA S ED D ES I GN OF URBANC ENT R ES : A P P L I C AT I ON TO B L A S T R I S K A S S E S SMENT . S U S TA I N AB L E AND R E S I L I E N T I N F R A S T RUC TUR E , 3 ( 2 ) , 6 8 ‐ 8 5 .

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POST‐BLAST FUNCTIONALITY

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Functionality loss indicator (λ)

Superficial

Moderate

Heavy

Hazardous

Blowout*

λ = 0

λ = 1

Pressure (Kpa)

Impulse (Kpa.ms)

DS1 DS2 DS4DS3

Deterministic performance

λ = 0

λ = 1

*  Check for progressive collapse

DOWNTIME ESTIMATION

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𝐵𝑎𝑠𝑒𝑙𝑖𝑛𝑒 𝑒𝑠𝑡𝑖𝑚𝑎𝑡𝑒 ℎ𝑟𝑅𝑒𝑝𝑎𝑖𝑟 𝑐𝑜𝑠𝑡 $ 𝑙𝑎𝑏𝑜𝑟 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑐𝑜𝑚𝑚𝑒𝑛𝑐𝑒𝑚𝑒𝑛𝑡 𝑡𝑖𝑚𝑒 %

𝐸𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒 ℎ𝑜𝑢𝑟𝑙𝑦 𝑟𝑎𝑡𝑒 $ ℎ𝑟⁄

θ

Repair cost ($)

Replacement cost (CRPL)

LS LRPL Lh

Baseline estimate (FEMA P58)

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Deterministic Framework (case study)

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Case study elevation

3200

3200

3200

3200

3200

3200

3200

3200

3200

3200

3200

Ground floor

1st floor

2nd floor

3rd floor

4th floor

5th floor

6th floor

7th floor

8th floor

9th floor

10th floor

Roof

3200

6400

9600

12800

16000

19200

22400

25600

28800

32000

35200

0

23000

8000 7000 8000

35200

A B C D E F G H

A B C D E F G H

4

3

2

1

4

3

2

1

11000 11000 11000 11000 11000 11000 11000

77000

10000

3000

10000

23000

200 mmcast‐in‐place

 slab

200 mmcast‐in‐place

 slab

8000

7000

8000

500 kg TNT

40m

Case study plan

Deterministic Framework (continued)

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Deterministic damage mapping

Non‐functional 

area(f  = 1)

Functional area(f  = 0)

Time (t)t0 t0+110days

IR =7.89 unit 

System functionality  (Q)

IF = 14.3%

Repair time

110 Days

Deterministic resilience triangle

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Probabilistic Resilience AssessmentSALEM , S . , S I AM , A . , E L ‐DA KHA KHN I , W. W. , & TA I T, M . J . P ROBAB I L I S T I C R E S I L I ENC E ‐ I N FORMED R I S K MANAGEMENT:A P P L I C AT I ON TO B LA S T HA ZARD S . A S C E J OU RNA L O F MANAG EMEN T I N ENG IN E E R I NG S P EC I A L CO L L E C T I ON :MANAGEMEN T O F R E S I L I E N C E I N C I V I L I N F R A S T RUC TU R E S Y S T EMS : AN I N T E RD I S C I P L I N AR Y A P P ROACH , SU BM I T T EDFOR PU B L I C AT I ON I N J U LY 2 0 1 9 .

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Probabilistic Loss Quantification 

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Probabilistic performance

DS1 DS2

Pr[DS]

1.0

0.0 Impulse (kPa.ms)

DS3 DS4

λ = 0

$

$$$...

λ = 1

Pr[superficial]

Pr[moderate]

Pr[heavy]

Pr[hazardous]

Pr[blowout]

10P ( ) Pr rP Function loss G X LS Ι Ι dΙ

1

1 1

%

$

P ( ) .Pnf q

rs k k rs ksk

is

LS Ι G X LS Ι Ι .Q LPCT Repair time hr

Effective hourly rate hr

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Probabilistic Framework (case study)

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67.0

3000

0

6000

9000

Ground floor

1st floor

2nd floor

3rd floor

12.0 10.0 15.0 10.0 12.0

120004th floor

4.0 4.0

1 2 3 4 5 6 7 8

D

C

B

A

1 2 3 4 5 6 7 8

D

C

B

A

67.012.0 10.0 15.0 10.0 12.04.0 4.0

10.0

3.0

10.0

23.0

1 2 3 4 5 6 7 8

500 kg TNT

40m

Probabilistic case study

1 2 3 4 5 6 7 8

100%

100%

100%

100%

100%

100%

100%

100%

100%

100%

100%

100%

96.5%

96.1%

95.5%

94.8%

54.8%

54.3%

53.6%

52.5%

54.8%

54.3%

53.6%

52.5%

96.5%

96.1%

95.5%

94.8%

Fragility curves for the façade components: (a) RMSW; (b) 6mm toughened glass (adapted from Campidelli et al. (2016) Stewart and Netherton (2008)

0.00

0.20

0.40

0.60

0.80

1.00

0 2000 4000 6000

Probability

I (kPa.ms)

DS1 DS2 DS3 DS4

0.00

0.20

0.40

0.60

0.80

1.00

50 75 100 125 150 175 200

Probability

I (kPa.ms)

50 kg  500 kg 

Dysfunctional probabilities

(a) (b)

Probabilistic Framework (continued)

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Probabilistic case study

Functionality loss Time (hrs)

Functionality loss uncertainty

Repair time uncertainty

IrMean 

functionality loss

Mean robustnes

s

Mean repair time

Density

Probabilistic resilience triangleTime (t)

t0 tf

Mean resilience indicator (IR)

Functionality  (Q)

mean

 robustness

100 %

Mean

 functionality 

index (IF)

Mean Repair time

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The Masonry Society

This concludes The American Institute of Architects Continuing Education Systems Course

Shady SalemAssistant Professor, Civil Engineering DepartmentFaculty of EngineeringThe British University in EgyptEl Sherouk City ‐ 11837, Cairo, EgyptShady.salem@bue.edu.eg

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