hunter bldg test 2008
TRANSCRIPT
-
8/8/2019 Hunter Bldg Test 2008
1/70
ABSG Consulting Inc. 14607 San Pedro Avenue, Suite 215 San Antonio, TX 78232 USA
Tel: 210-495-5195 Fax: 210-495-5134
www.absconsulting.com
1
Hunter Building and Manufacturing
Standard BuildingFull Scale Explosive Testing
Prepared For:
Hunter Buildings and Manufacturing
Houston, TX
Final Report
Project Number 1749999
Prepared By:
Ben Harrison, P.E.
Darrell Barker, P.E.
Jerry Collinsworth
July 9, 2008
-
8/8/2019 Hunter Bldg Test 2008
2/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
i
Executive Summary
ABS Consulting conducted two full scale field tests utilizing 1,250 pounds of ANFO explosive
on a standard 8 psi, 200 msec Heavy Response Hunter blast resistant modular building. The
purpose of the explosive testing was to determine performance of the building at the upper limitof Medium Response (Test I) and the upper limit of High Response (Test II). Testing consisted
of the detonation of a 1,250 lbANFO charge at a range of 100 feet for Test I and 75 feet for Test II.
The ANFO charge was placed on the door side of the building for Test I and the opposite wall
for Test II. Peak side-on pressures were 9.7 psi for Test I and 17.4 psi for Test II.
Test I - Medium Response
Performance of the structure in Test I was consistent with ASCE Medium Response. While
primary components exhibited some plastic deformation, structural integrity was not
compromised. Test I resulted in a peak wall panel deformation of 6.3 inches which corresponds
to 6 degrees of support rotation, consistent with ASCE Medium Response limits for steel plates.Material strain data was not collected during the test but post-test evaluation of the response
indicated peak strains on the order of 4% which is also consistent with the selected design strain
limit for ASCE Medium Response. Peak wall accelerations were approximately 400 g. Peakbuilding sliding varied between 2 and 3 inches with a peak sliding acceleration of approximately
25g. Tipping was not observed.
An instrumented Hybrid III 50th percentile male car crash dummy was placed in the building for
Test I with the back of the Hybrid IIIs chair placed against the reflected wall. The peak
acceleration measured in the Hybrid III was 8 g. This acceleration is due to overall building
movement with some decoupling provided by the chair. Although the Hybrid III was situated
directly against the reflected wall only of the peak kinematic building acceleration wastransmitted to the Hybrid III. Relatively light damage was observed inside the building. Interior
furnishings and suspended items were dislodged. Acoustical ceiling tiles were down in some
sections of the building. The main ceiling grid components remained intact, but some of the
ceiling grid cross members were dislodged. Items placed on shelves were dislodged. Two fireextinguishers located on the blast wall came free from the mounting brackets.
Blast doors manufactured by Booth Industries were installed on the reflected wall facing theblast in Test I. Door latches were damaged during the test. One door rebounded open during the
test and the other door was jammed in the opening; therefore, the doors were found to be Intact
but Inoperable. There was no apparent structural deformation of the door beams. Hunter hasbeen manufacturing and installing its own blast doors which have been analyzed in separate
evaluation and testing.
-
8/8/2019 Hunter Bldg Test 2008
3/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
ii
Test II - High Response
Test II resulted in approximately 17.5 inches of deformation on the wall facing the blast as
integrated from the reflected wall accelerometer. Peak measured acceleration on the wall was onthe order of 2,000 g. Post-test evaluation indicated peak strains on the order of 10% which is
below the 15% value used for design. The peak wall deformation of 17.5 inches corresponds toa support rotation of 17 degrees. This response exceeds the ASCE support rotation limits forHigh Response for plates (12 degrees); however, damage to the structure was less than the
qualitative building damage description for High Response in the ASCE guideline. While
significant deformation occurred, the primary components were not at incipient collapse andwere not in danger of collapsing under environment loads (wind, etc.) as described by the ASCE
guideline for High response. Interior objects from the reflected wall including the desk, shelf,
cabinets and drywall had significant movement. The high debris velocity was evidenced by
penetrating impacts of desk coping into the veneer of the interior doors. The instrumenteddummy was not used for this test.
Both Booth blast doors on the rear face of the building, away from the charge, rebounded openduring Test II; however, the latches on the doors were damaged in Test I and thus did not have
the restraining capacity of an undamaged door.
Pressures were measured inside the building and were 3.7 psi during Test I and 4.5 psi during
Test II. Interior pressures did not appear to be the result of blast infiltration into the building but
may be attributed to the deformation of structural components. Sliding during Test II variedfrom 13-20 inches at the corners. Tipping was not observed in the high speed video.
Analysis of Results
Post-test modeling of the structure revealed that it was more flexible than predicted in theoriginal building analysis due to eave strut deformation. A revised model was prepared whichbetter matched the test results. This model results in greater wall deformation and support
rotation than the original analysis for the same strain value.
For Test I, the observed deflections were consistent with strain and rotation limits for Medium
Response in the ASCE guideline.
For Test II, deformations were less than High Response based on strain limits but observed
deformations were greater than High Response for support rotation limits. Thus if the design is
based on strain limits, deflections at maximum capacity will be greater than observed in the test.
If the design is based on support rotation, response at maximum capacity will be less thanobserved in the test.
Designing to the ASCE Building Damage descriptions in Table 5.B utilizing stain limits for thewall panels can be an appropriate approach; however, design based on support rotation limits is a
more common approach. In either approach, it is important for the user to understand the
deformations associated with the design and determine which is appropriate for the intended use.
-
8/8/2019 Hunter Bldg Test 2008
4/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
iii
The utilization of support rotations is incorporated in blast design as a simplified measure ofdamage. However, with the advent of more powerful computing and modeling techniques more
sophisticated measures of damage may be utilized. This includes the use of plastic strain, rather
than support rotation response criteria. Plastic strains occur as a component is deformed beyondits elastic capacity. The amount of deformation required to cause a given amount of plastic
strain is a function of several variables, many of which can be non-linear. Examples of variablesthat affect the level of plasticity and deformation a component can withstand include the materialproperties, level of fixity provided at the component supports and the stability of the cross-
section.
Using strain limits, a revised structural model based on the test, and incorporating clearingeffects, the free-field blast capacity at the limit of High Response is consistent with the 8 psi
value. For a design based on ASCE support rotation limit criteria and including clearing, the
free-field blast capacity at High Response is 7.3 psi with the short wall facing the blast and 8.0psi with the long wall facing the blast.
Using strain limits, with the revised structural model based on the test and incorporating clearingeffects, the free-field blast capacity at the limit of Medium response is consistent with the 5.6 psi
value. For a design based on ASCE support rotation limit criteria and including clearing, the
free-field blast capacity at Medium Response is 5.9 psi, which is consistent with the design
value.
When selecting the appropriate response level and design criteria, vulnerability of occupants to
debris and dislodged objects should be considered in addition to the response of structuralcomponents. Assessment of vulnerability was beyond the scope of this test program.
If the Booth blast doors are used, at least one should be facing away from a potential blast.
/
-
8/8/2019 Hunter Bldg Test 2008
5/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
iv
Executive Summary......................................................................................................................... i
List of Figures................................................................................................................................. v
List of Tables ................................................................................................................................ vii1. Purpose.................................................................................................................................... 1
2. Building Layout and Construction.......................................................................................... 13. Test Configurations................................................................................................................. 33.1. Explosive Charge Siting ................................................................................................. 4
3.2. Instrumentation ............................................................................................................... 5
3.3. Test I Configuration...................................................................................................... 10
3.3.1. Range and Explosive Charge................................................................................ 103.3.2. Building Instrumentation Placement..................................................................... 12
3.4. Test II Configuration..................................................................................................... 17
3.4.1. Range and Explosive Charge................................................................................ 173.4.2. Building Instrumentation Placement..................................................................... 18
4. Test I Results......................................................................................................................... 22
4.1. Free Field and Applied Pressures ................................................................................. 224.2. Observed Damage......................................................................................................... 27
4.3. Structural Response Measurements .............................................................................. 38
4.3.1. Sliding and Tipping............................................................................................... 39
4.3.2. Wall Panel............................................................................................................. 404.3.3. Roof Joists............................................................................................................. 42
5. Test II Results ....................................................................................................................... 43
5.1. Free Field and Applied Pressures ................................................................................. 435.2. Observed Damage......................................................................................................... 48
5.3. Structural Response Measurements .............................................................................. 555.3.1. Sliding and Tipping Response .............................................................................. 56
5.3.2. Wall Panel Response............................................................................................. 57
5.3.3. End Wall Eave Strut Response ............................................................................. 596. Summary............................................................................................................................... 60
-
8/8/2019 Hunter Bldg Test 2008
6/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
v
List of Figures
Figure 1. Hunter Building Floor Plan ............................................................................................ 1
Figure 2. Hunter Building Exterior Elevations .............................................................................. 2Figure 3. Test Building Framing Plans and Framing Elevations................................................... 3
Figure 5. PCB 102A07 Pressure Transducer ................................................................................. 5Figure 6. Typical Reflected Pressure Gauge Mount...................................................................... 6Figure 7. PCB 350B23 Shock Accelerometer ............................................................................... 6
Figure 8. Wall Typical Accelerometer Mount............................................................................... 7
Figure 9. Sliding and Tipping Accelerometer Mount.................................................................... 7Figure 10. HYBRID III 50th Percentile Male Crash Test Dummy................................................ 8
Figure 11. Yokogawa DL750 Oscilloscope................................................................................... 9
Figure 12. Instrumentation Bunker................................................................................................ 9Figure 13. Concrete Footing and Spray Paint Marker ................................................................. 10
Figure 14. Test I - Range Layout................................................................................................. 11
Figure 15. Test I - Skirted Building............................................................................................. 11
Figure 16. Test I - Explosive Charge........................................................................................... 12Figure 17. Test I - Building Layout Relative to Explosive Charge ............................................. 13
Figure 18. Test I - Reflected Wall Instrumentation (Elevation 2) ............................................... 13
Figure 19. Test I - Rear Wall Instrumentation (Elevation 1)....................................................... 14Figure 20. Test I - Sidewall Instrumentation (Elevation 3) ......................................................... 14
Figure 21. Test I - Roof Instrumentation ..................................................................................... 15
Figure 22. Test I - Instrumented Hybrid III Placement ............................................................... 16Figure 23. Test I - Interior Cameras and Instrumentation ........................................................... 16
Figure 24. Test II - Explosive Charge.......................................................................................... 17
Figure 25. Test II - Unskirted Building ....................................................................................... 18
Figure 26. Test II - Range Layout................................................................................................ 18
Figure 27. Test II - Building Layout Relative to Explosive Charge............................................ 19Figure 28. Test II - Reflected Wall Instrumentation (Elevation 1).............................................. 19
Figure 29. Test II - Rear Wall Instrumentation (Elevation 2)...................................................... 20
Figure 30. Test II - Sidewall Instrumentation (Elevation 3)........................................................ 20
Figure 31. Test II - Roof Instrumentation.................................................................................... 21Figure 32. Test II - Interior Cameras and Instrumentation .......................................................... 21
Figure 33. Test I Crater................................................................................................................ 22
Figure 34. Test I - Free-Field Pressure Time History.................................................................. 23Figure 35. Test I - Reflected Wall Pressure Time History #1 ...................................................... 24
Figure 36. Test I - Reflected Wall Pressure Time History #2 ...................................................... 24
Figure 37. Test I- Applied Roof Pressure Time History.............................................................. 25Figure 38. Test I - Applied Rear Wall Pressure History.............................................................. 25
Figure 39. Test I - Interior Pressure Time History (Occupied Volume)...................................... 26
Figure 40. Test I - Interior Pressure Time History (Plenum)....................................................... 26
Figure 41. Test I - Reflected Wall Damage (Weld Cracks Spray Painted Magenta) .................. 28Figure 42. Test I - Rear Wall Damage......................................................................................... 28
Figure 43. Test I - Roof Damage ................................................................................................. 29
Figure 44. Test I - Passive Building Sliding Measurements........................................................ 30Figure 45. Test I - Damage to HVAC: (a) Exterior and (b) Interior........................................... 31
-
8/8/2019 Hunter Bldg Test 2008
7/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
vi
Figure 46. Test I - Booth Blast Door Response: (a) Leftmost Door and (b) Rightmost Door ... 32Figure 47. Test I - Booth Door Latch Damage: (a) Pre-Test and (b) Post-Test ......................... 32
Figure 48. Test I - HYBRID III: (a) Pre-Test and (b) Post-Test................................................. 33
Figure 49. Test I - HYBRID III Measured Accelerations ........................................................... 34Figure 50. Test I - Mannequin: (a) Pre-Test and (b) Post-Test.................................................. 35
Figure 51. Test I - Building Interior: (a) Pre-Test and (b) Post-Test Damage............................ 35Figure 52. Test I - Cabinet Movement on Reflected Wall........................................................... 36Figure 53. Test I - Lavatory Fixtures: (a) Pre-Test and (b) Post-Test Damage.......................... 36
Figure 54. Test I - Interior Wall Damage: (a) Drywall Pulling Away and (b) Metal Stud
Damage ................................................................................................................................. 37
Figure 55. Test I - Fire Extinguisher Throw................................................................................ 38Figure 56. Test I Measured Sliding Time History .................................................................... 39
Figure 57. Test I - Measured Tipping Time History.................................................................... 40
Figure 58. Test I - Total Wall Panel Response Time History (Includes Sliding)........................ 41Figure 59. Test I - Relative Wall Panel Response Time History................................................. 41
Figure 60. Test I - Roof Joist Response Time History ................................................................ 42
Figure 61. Test II Crater............................................................................................................... 43Figure 62. Test II - Free-Field Pressure Time History................................................................. 44
Figure 63. Test II - Reflected Wall Pressure Time History #1.................................................... 45
Figure 64. Test II - Reflected Wall Pressure Time History #2.................................................... 45
Figure 65. Test II - Applied Roof Pressure Time History ........................................................... 46Figure 66. Test II - Applied Rear Wall Applied Pressure Time History ..................................... 46
Figure 67. Test II - Interior Pressure Time History (Occupied Volume) .................................... 47
Figure 68. Test II - Interior Pressure Time History (Plenum) ..................................................... 47Figure 69. Test II - High Speed Video Capture of Peak Wall Panel Response........................... 48
Figure 70. Test II - Reflected Wall Damage................................................................................ 49Figure 71. Test II - End Wall Damage......................................................................................... 49
Figure 72. Test II - Roof Deck Damage ...................................................................................... 50
Figure 73. Test II - Floor Deck Damage...................................................................................... 50Figure 74. Test II - Passive Building Sliding Measurements ...................................................... 51
Figure 75. Test II - Damage to HVAC: (a) Exterior and (b) Interior ......................................... 52
Figure 76. Test II - Damage to HVAC Duct................................................................................ 52Figure 77. Test II - Office Room: (a) Pre-Test and (b) Post- Test............................................. 53
Figure 78. Test II - Desk Debris Impacts: (a) Door Scarring and (b) With Impacting Debris ... 53
Figure 79. Test II - Central Work Room: (a) Pre-Test and (b) Post Test ................................... 54
Figure 80. Test II - Interior Debris............................................................................................... 54Figure 81. Test II - Light Fixture Damage................................................................................... 55
Figure 82. Test II - Measured Sliding Time History ................................................................... 56
Figure 83. Test II - Measured Tipping Time History .................................................................. 57Figure 84. Test II - Total Wall Panel Response Time History (Includes Sliding)....................... 58
Figure 85. Test II - Relative Wall Panel Response Time History ............................................... 58
Figure 86. Test II - End Wall Eave Strut Response Time History .............................................. 59
-
8/8/2019 Hunter Bldg Test 2008
8/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
vii
List of Tables
Table 1. Test Structure Component Cut List ................................................................................. 2Table 2. ASCE Response Range Descriptions .............................................................................. 4
Table 3. Test I - Deformation Limits............................................................................................. 4Table 4. Test II - Deformation Limits............................................................................................ 5Table 5. Test I - Measured and Applied Load Summary............................................................. 23
Table 6. Test I - Measured Response Summary .......................................................................... 39
Table 7. Test II - Measured and Applied Load Summary ........................................................... 44Table 8. Test II - Measured Response Summary......................................................................... 55
-
8/8/2019 Hunter Bldg Test 2008
9/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
1
1. Purpose
Hunter Buildings and Manufacturing LLC. (Hunter) manufactures blast resistant portable
buildings for the petroleum and chemical process industries. The purpose of a blast resistantmodular building is to provide increased protection to occupants over that which would be
provided by portable trailers of conventional construction.
Hunter Buildings contracted ABSG Consulting Inc (ABS Consulting) to perform two full scale
tests utilizing 1,250 pounds of ANFO. The purpose of the explosive testing was to test the
design and manufacturing of Hunter Buildings standard building at the upper limit of MediumResponse and the upper limit of High Response as defined by the American Society of Civil
Engineers (ASCE)Design of Blast Resistant Buildings in Petrochemical Facilities.[i]
2. Building Layout and Construction
The Hunter standard building utilized in the test measured 40 feet by 12 feet in plan and had an
eave height of 11 feet. A floor plan of the tested building is shown below in Figure 1 and
exterior elevations are provided in Figure 2. The building was constructed with the componentsshown in the framing plans and elevations in Figure 3 and specified in the cut list presented in
Table 1. Blast doors were manufactured by Booth Industries.
Figure 1. Hunter Building Floor Plan
i ASCE, Design of Blast Resistant Buildings in Petrochemical Facilities, Task Committee on Blast Resistant
Design, American Society of Civil Engineers, NY, NY, 1997.
-
8/8/2019 Hunter Bldg Test 2008
10/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
2
Figure 2. Hunter Building Exterior Elevations
Table 1. Test Structure Component Cut ListItem DimensionsTolerance No. of Pieces
CL1 HSS 6 x 6 x .625 A500B 11'-2" +0/-.125 4
CL2 HSS 6 x 6 x .500 A500B 10'-0" +0/-.125 7
B1 HSS 6 x 6 x .500 A500B 39'-0" +0/-.125 2
B2 HSS 6 x 6 x .500 A500B 11-0" +0/-.125 2
R1 HSS 6 x 6 x .500 A500B 39'-0" +0/-.125 2
R2 HSS 6 x 6 x .500 A500B 11'-0" +0/-.125 2
W1 HSS 6 x 6 x .500 A500B 3-0 +0/-.125 0
D1 HSS 6 x 6 x .500 A500B 3-1 1/2 +0/-.125 2
FJ1 HSS 6 x 2 x .3125 A500B 11'-0" +0/-.125 21
RJ1 C 6 x 13# A-36 11'-0" +0/-.125 19
RA1 Angle 2" x 2" x 1/8" A-36 39' +0/-.125 12
HRS 10 GA 17
HRS 12 GA 872" x 240"
84" x 120"
A1011-36
Description
A1011-36
-
8/8/2019 Hunter Bldg Test 2008
11/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
3
Figure 3. Test Building Framing Plans and Framing Elevations
3. Test Configurations
ABS Consulting tested a single standard Hunter Building two times. The building was not
manufactured specifically for this test but was pulled from the rental fleet at random. Therefore,
the building was representative of dimension, material, and fabrication of Hunters fleet ofbuildings and was not manufactured with the knowledge that it was for testing.
The purpose of Test I was to test the building at the upper limit of Medium Response in order tovalidate analysis methods and building response mechanisms. The purpose of Test II was to
determine potential failure mechanisms at the upper limits of capacity. Therefore, the building
was sited at a standoff predicted to cause a wall panel deformation at the upper limit of High
Response.
The following sections describe the instrumentation and instrumentation placement utilized to
achieve the goals for each test.
-
8/8/2019 Hunter Bldg Test 2008
12/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
4
3.1.Explosive Charge SitingThe goal of the test program was to perform two full scale high explosive tests utilizing 1,250 lbsof Ammonium Nitrate and Fuel Oil (ANFO). ANFO has a TNT equivalency of 0.82 for both
pressure and impulse which produces a TNT equivalent charge weight of 1,025 lbs TNT[ii]
. Thefirst explosive charge was configured to test the upper limit of Medium Response and the secondexperiment, with the charge placed on the opposite side of the structure, was configured to test
the upper limit of High Response. The design basis response levels are defined by ASCEs 1997
Design of Blast Resistant Buildings in Petrochemical Facilities[i]
. Response limits in Table 3were utilized for Test I and response limits in Table 4 were utilized for Test II. These support
rotation limits are more conservative than the strain limit criteria used for the design. Support
rotations were used because they are a more conservative approach and are commonly used inthe industry. Table 2 provides ASCEs written descriptions for the ASCE response levels. The
original design basis utilized these written descriptions and assigned strain limits to each
response level to quantify the design utilizing a strain limit of 7.5% for Medium Response and a
strain limit of 15% for High Response. A standoff of 100 ft was chosen for the first test and astandoff of 75 feet was chosen for the second test.
Table 2. ASCE Response Range DescriptionsResponse Range Description
Low
Localized building/component damage. Building can be used,
however repairs are required to restore integrity of structural envelope.Total cost of repairs is moderate.
Medium Widespread building/component damage. Building cannot be used
until repaired. Total cost of repairs is significant.
High Building/component has lost structural integrity and may collapse due
to environmental conditions. Total cost of repairs approach
replacement cost of building
Table 3. Test I - Deformation Limits
Test Target Deformation LimitComponent
(deg) (in)Wall Panel
*Designed for plasticity only and qualitativedescriptions in Table 2.
Roof and Floor Deck 6 10 1.2 in
Roof Joist 6 10 6.9 in
Floor Joist 6 10 6.9 in
End Wall Eave and
Sill Struts
6 10 6.9in
Door Column (Low) 2 3 2.1 in*Corrugated panel response criteria were not adopted as they were intended for thin gauge
(< 1/8-inch) panels. Plasticity limit criteria via FEA were utilized.
**Design of Columns supporting doors were limited to Low Response in order to aide
egress.
ii ConWep, Conventional Weapons Effects Program, Structures Laboratory, U.S. Army Engineer Waterways
Experiment Station, Vicksberg, Mississippi, V. 2.1.0.8.
-
8/8/2019 Hunter Bldg Test 2008
13/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
5
Table 4. Test II - Deformation Limits
Test Target Deformation LimitComponent
(deg) (in)Wall Panel* Designed for plasticity only and qualitative
descriptions in Table 2.Roof and Floor Deck 12 20 2.5 in
Roof Joist 12 20 14 in
Floor Joist 12 20 14 in
End Wall Eave and
Sill Struts
12 20 14 in
*Corrugated panel response criteria were not adopted as they were intended for thin gauge
(< 1/8-inch) panels. Plasticity limit criteria via FEA were utilized.
**Design of Columns supporting doors were limited to Low Response in order to aide
egress.
3.2.InstrumentationIn order to measure free-field and applied pressures nine PCB 102A07 pressure transducers, see
Figure 4, were utilized. These transducers measure pressure in the presence of shock and
vibration. The pressure probe consists of the Model 112A high sensitivity acceleration
compensated quartz element and an IC source follower amplifier joined together as aninseparable assembly and can measure pressures up to 50 psi utilizing 5 v output and has a useful
over range of 100 psi utilizing 10v output.
Figure 4. PCB 102A07 Pressure Transducer
-
8/8/2019 Hunter Bldg Test 2008
14/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
6
Figure 5. Typical Reflected Pressure Gauge Mount
Three PCB 350B23 accelerometers, see Figure 6, and one PCB 350B02 accelerometer wereutilized for structural response measurements. The equations of motion are characterized bythree main variables: acceleration, velocity and displacement and these three variables can be
mathematically derived from the measurements of acceleration. The PCB 350B02
Accelerometer has a range of 50,000 g and the PCB 350B23 accelerometers have a range of
10,000 g. The accelerometers are characterized by the following features:
Fixed voltage sensitivity, regardless of cable type.
Low-impedance output signal, which can be transmitted over long cables in harshenvironments with virtually no loss in signal quality.
Two-wire operation with low cost coaxial cable.
Requires only constant current signal conditioning.
Figure 6. PCB 350B23 Shock Accelerometer
-
8/8/2019 Hunter Bldg Test 2008
15/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
7
Figure 7. Wall Typical Accelerometer Mount
Figure 8. Sliding and Tipping Accelerometer Mount
A HYBRID III 50th Percentile male crash test dummy, representing the average adult male, was
utilized to measure occupant response. The HYBRID III, see Figure 9, is the most widely used
dummy in frontal crash and automotive safety restraint testing. The Hybrid IIIs height is 5 feet
9 inches and weights 172.3 pounds. Originally, the Hybrid III 50th male was developed byGeneral Motors for vehicle safety purposes. It has since been incorporated into the Code of
Federal Regulations under Title 49, Part 572 subpart E, and is the required dummy in NHTSAsmotor vehicle safety standards. The Hybrid III 50th male features a neck design that simulates
the human dynamic moment / rotation, flexion, and extension response characteristics of an
average size adult male. The upper torso has 6 high strength steel ribs with polymer baseddamping material to simulate human chest force-deflection characteristics. The lower torso has a
curved cylindrical rubber lumbar spine that provide human-like slouch of a seated person. The
-
8/8/2019 Hunter Bldg Test 2008
16/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
8
pelvis is vinyl skin/urethane foam molded over an aluminum casting in the seated position. Theball-jointed femur attachments carry bump stops to reproduce the human leg to hip
moment/rotation characteristics.
The Hybrid III was instrumented with three piezo-resistive accelerometers in the head with one
in the vertical axis and two placed orthogonally in the horizontal plane, front to back and ear toear.
Figure 9. HYBRID III 50th
Percentile Male Crash Test Dummy
Instrumentation measurements were measured utilizing a Yokogawa DL750 Oscilloscope,
shown in Figure 10. The Oscilloscope is capable of recording up to sixteen channels at high data
sampling rates (i.e., > 1 MHz). Testing experience indicates that a sampling rate of at least 500KHz or 500 samples per millisecond for shock pressure histories and 300 kHz (or 300 samples
per millisecond) for acceleration time histories provides adequate fidelity for a structural
response. This ensures that very short duration peaks in shock pressure and accelerationmeasurements are not missed by the data recording process. In general, a sample rate of 500
KHz was used to record the test data when the Hybrid III was utilized and 1 MHz otherwise.The Yokogawa scope was placed within a bunker on the side of the building away from the
charge as shown in Figure 11.
-
8/8/2019 Hunter Bldg Test 2008
17/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
9
Figure 10. Yokogawa DL750 Oscilloscope
Figure 11. Instrumentation Bunker
The building was placed on concrete pads in order to more accurately assess the sliding response.
In addition to utilizing accelerometers to measure sliding, the building position was marked
using spray paint at each footing location as shown in Figure 12 so that the sliding distance could
be observed directly.
-
8/8/2019 Hunter Bldg Test 2008
18/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
10
Figure 12. Concrete Footing and Spray Paint Marker
3.3.Test I ConfigurationThe purpose of Test I was to test the building at the upper limit of Medium Response in order to
validate modeling methods and building response mechanisms. In order to achieve those goals
the explosive charge and instrumentation were arranged to produce the desired level of walldamage, to measure the applied loads to the building and the level of structural response.
3.3.1. Range and Explosive Charge
The test arena was arranged with two free-field pressure gauges and three high speed cameras as
shown in Figure 13. Free-field gauge #1 was placed in the shadow of the building from the
explosive charge and free-field gauge #2 was placed at an identical range to the charge as thebuilding to measure the free-field pressures associated with the applied building loads. The
explosive charge, Figure 15, was placed at a range of 100 ft from the center of the blastward wall
of the building. The three high speed cameras were placed further from the explosive chargethan the building so that the structural response could be recorded by the cameras before the
shockwave arrived at the camera locations.
For the first test, the building was skirted with 2x12 wood joists along the reflected wall to
prevent shock from traveling underneath the building. A photo of the skirted building is
provided in Test I - Skirted Building. By preventing shock from traveling under the building the
effects of the dynamic roof load on the friction force could be evaluated.
-
8/8/2019 Hunter Bldg Test 2008
19/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
11
Figure 13. Test I - Range Layout
Figure 14. Test I - Skirted Building
-
8/8/2019 Hunter Bldg Test 2008
20/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
12
Figure 15. Test I - Explosive Charge
3.3.2. Building Instrumentation Placement
The building was oriented such that the building elevation holding the two blast doors was facing
the charge as shown in Figure 16. Figure 16 also shows the numbering of the concrete footingsthe building was placed on for reference to passive sliding measurements. The reflected wall
was instrumented with two pressure gauges for measuring the applied reflected load, and three
accelerometers for measuring the wall panel response as well as the sliding and tipping response
of the building. The reflected wall instrumentation plan is provided below in Figure 17.
-
8/8/2019 Hunter Bldg Test 2008
21/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
13
100 ft
2
3
1
4
100 ft
22
33
11
44
Figure 16. Test I - Building Layout Relative to Explosive Charge
Pressure
Gauge
Pressure
Gauge
Wall Panel
Accelerometer
Sliding and TippingAccelerometers
Pressure
Gauge
Pressure
Gauge
Wall Panel
Accelerometer
Sliding and TippingAccelerometers
Figure 17. Test I - Reflected Wall Instrumentation (Elevation 2)
The leeward wall of the building was instrumented with a single pressure gauge to measure theapplied load to the backside of the building. An elevation of the back wall detailing the location
of the pressure gauge is provided in Figure 18.
-
8/8/2019 Hunter Bldg Test 2008
22/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
14
Pressure
Gauge
Pressure
Gauge
Figure 18. Test I - Rear Wall Instrumentation (Elevation 1)
The sidewall of the building opposite of the HVAC equipment was instrumented with a pressuregauge, as shown in Figure 19, in order to measure the applied pressure to the enwall of the
building.
Pressure
Gauge
Pressure
Gauge
Figure 19. Test I - Sidewall Instrumentation (Elevation 3)
The roof of the building was instrumented with a pressure gauge to measure the applied pressure
at the center of the roof. An accelerometer was placed at the mid-span of a roof joist so that the
response of the roof joist to the measured roof load could be evaluated. A detail of the roofinstrumentation plan is provided below in Figure 20.
-
8/8/2019 Hunter Bldg Test 2008
23/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
15
Pressure
Gauge
Accelerometer Pressure
Gauge
Accelerometer
Figure 20. Test I - Roof Instrumentation
Cameras and instruments were also placed within the building to assess the occupant
environment during structural response to the explosion. Three closed circuit cameras wereplaced inside the building along with an instrumented Hybrid III dummy (see Figure 21), amannequin and two pressure gauges. The Hybrid III was placed in a chair with the back of the
dummy and chair resting against the reflected wall. A plan showing the location of the cameras
and instruments is provided in Figure 22. As can be seen in Figure 22, the Hybrid III was placedaway from a column so that it could be impacted by the responding wall panel. One pressure
gauge was placed in the occupied volume of the building and a second was placed within the
plenum between the roof and drop ceiling so that any disparity of pressure between these twovolumes within the building could be evaluated.
-
8/8/2019 Hunter Bldg Test 2008
24/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
16
Figure 21. Test I - Instrumented Hybrid III Placement
Figure 22. Test I - Interior Cameras and Instrumentation
-
8/8/2019 Hunter Bldg Test 2008
25/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
17
3.4.Test II ConfigurationThe purpose of Test II was to test potential building failure mechanisms and damage at the upper
limits of High Response. In order to achieve those goals the explosive charge and
instrumentation were arranged to produce the desired level of wall damage, to measure theapplied loads to the building and the level of structural response.
3.4.1. Range and Explosive Charge
The test arena was arranged with two free-field pressure gauges and three high speed cameras as
shown in Figure 25. Free-field gauge #1 was placed in the shadow of the building from the
explosive charge and free-field gauge #2 was placed at an identical range to the charge as thebuilding to measure the free-field pressures associated with the applied building loads. The
explosive charge, Figure 23, was placed at a range of 75 ft from the center of the blastward wall
of the building. The three high speed cameras were placed further from the explosive chargethan the building so that the structural response could be recorded by the cameras before the
shockwave arrived at the camera locations.
For the first test, the building was skirted with 2x12 wood joists along the reflected wall to
prevent shock from traveling underneath the building. By preventing shock from traveling under
the building the effects of the dynamic roof load on the friction force could be evaluated.
Figure 23. Test II - Explosive Charge
-
8/8/2019 Hunter Bldg Test 2008
26/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
18
Figure 24. Test II - Unskirted Building
Figure 25. Test II - Range Layout
3.4.2. Building Instrumentation Placement
The building was oriented such that the building elevation holding the two blast doors was facingaway from the charge as shown in Figure 26. Figure 26 also shows the numbering of the
concrete footings the building was placed on for reference to passive sliding measurements. The
reflected wall was instrumented with two pressure gauges for measuring the applied reflectedload, and three accelerometers. One accelerometer was placed for measuring the wall panel
-
8/8/2019 Hunter Bldg Test 2008
27/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
19
response and two accelerometers for the sliding and tipping response of the building. Thereflected wall instrumentation plan is provided below in Figure 27.
75 ft
2
3
1
4
75 ft75 ft
22
33
11
44
Figure 26. Test II - Building Layout Relative to Explosive Charge
Pressure
Gauge
Wall Panel
Accelerometer
Sliding and Tipping
Accelerometers
Pressure
Gauge
Pressure
Gauge
Wall Panel
Accelerometer
Sliding and Tipping
Accelerometers
Pressure
Gauge
Figure 27. Test II - Reflected Wall Instrumentation (Elevation 1)
-
8/8/2019 Hunter Bldg Test 2008
28/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
20
The leeward wall of the building was instrumented with a single pressure gauge to measure theapplied load to the backside of the building. An elevation of the back wall detailing the location
of the pressure gauge is provided in Figure 28.
Pressure
Gauge
Pressure
Gauge
Figure 28. Test II - Rear Wall Instrumentation (Elevation 2)
The sidewall of the building opposite of the HVAC equipment was instrumented with a pressure
gauge and accelerometer, as shown in Figure 28. The pressure gauge measured the applied loadto the side wall and the accelerometer measured the flexural response of the eave strut.
Pressure
Gauge
Accelerometer
Pressure
Gauge
Pressure
Gauge
Accelerometer
Figure 29. Test II - Sidewall Instrumentation (Elevation 3)
The roof of the building was instrumented with a pressure gauge to measure the applied pressure
at the center of the roof as shown in the detail of the roof instrumentation plan provided below in
Figure 30.
-
8/8/2019 Hunter Bldg Test 2008
29/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
21
Pressure
Gauge
Pressure
Gauge
Figure 30. Test II - Roof Instrumentation
Cameras and instruments were also placed within the building to assess the occupant
environment during structural response to the explosion. Three closed circuit cameras wereplaced inside the building along with a mannequin and two pressure gauges. The Hybrid III was
not utilized for Test II due to the potential to damage the Hybrid III and instrumentation. A plan
showing the location of the cameras and instruments is provided in Figure 31. One pressure
gauge was placed in the occupied volume of the building and a second was placed within theplenum between the roof and drop ceiling so that any disparity of pressure between these two
volumes within the building could be evaluated. The mannequin was situated against the desk
along the reflected wall.
Figure 31. Test II - Interior Cameras and Instrumentation
-
8/8/2019 Hunter Bldg Test 2008
30/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
22
4. Test I Results
The first explosive test produced the crater shown below in Figure 32. The crater had an inner
diameter of 7 feet, an outer diameter of 15 feet and a depth of 38 inches. A summary of the blast
loading, observed pressure and structural response are provided in the following sections.
Figure 32. Test I Crater
4.1.Free Field and Applied PressuresThe measured free-field and applied pressures are summarized below in Table 5 with the
associated time histories in Figure 33 through Figure 39. The free-field and reflected peakpressures compared well to the theoretical values for 1,250 lbsANFO at 100 feet. The endwallpressure gauge failed and did not record a good trace. Of interest are the interior pressure
histories in Figure 38 and Figure 39. Peak pressures in the occupied volume peaked at 4 psi and
the plenum pressures were on the order of 1 psi. The interior pressures are not the result ofshock infiltrating the structure through openings. Instead they are a result of pressure waves
transmitted into the structure from deformation of the buildings surfaces (walls and roof).
-
8/8/2019 Hunter Bldg Test 2008
31/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
23
Table 5. Test I - Measured and Applied Load Summary
Peak Positive PhaseGauge
Pressure
(psi)
Impulse
(psi*msec)
PressureTime History
Free Field 9.6 51 Figure 33
Reflected Wall #1 24.0 154 Figure 34Reflected Wall #2 25.5 153 Figure 35
Roof 7.0 30 Figure 36
Rear Wall 3.0 59 Figure 37
Side Wall Gauge Failure
Interior Pressure
(Occupied Volume)
3.7 22 Figure 38
Interior Pressure(Plenum)
0.8 71 Figure 39
Time (msec)
Pressure(psi)
Im
pulse(psi-msec)
-40 -20 0 20 40 60 80 100 120-5 -20
0 0
5 20
10 40
15 60Raw DataFiltered Data (3.5-250hz)Impulse
Figure 33. Test I - Free-Field Pressure Time History
-
8/8/2019 Hunter Bldg Test 2008
32/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
24
Time (msec)
Pressure(psi)
Impulse(psi-msec)
-60 -40 -20 0 20 40 60 80 100 120 140-15 -60
-5 -20
5 20
15 60
25 100
35 140Raw DataFiltered Data (2.7-1000hz)Impulse
Figure 34. Test I - Reflected Wall Pressure Time History #1
Time (msec)
Pressure(psi)
Impulse(psi-mse
c)
-75 -50 -25 0 25 50 75 100 125 150 175-30 -120
-20 -80
-10 -40
0 0
10 40
20 80
30 120
40 160Raw DataFiltered Data (4-500hz)Impulse
Figure 35. Test I - Reflected Wall Pressure Time History #2
-
8/8/2019 Hunter Bldg Test 2008
33/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
25
Time (msec)
Pressure(psi)
Impulse(psi-msec
)
-100 -75 -50 -25 0 25 50 75 100 125 150-4 -30
-2 -15
0 0
2 15
4 30
6 45
8 60Raw DataFiltered Data (1500hz)Impulse
Figure 36. Test I- Applied Roof Pressure Time History
Time (msec)
Pressure(ps
i)
Impulse(psi-m
sec)
-75 -50 -25 0 25 50 75 100 125 150 175
-15 -45
-10 -30
-5 -15
0 0
5 15
10 30
15 45
20 60
Raw DataFiltered Data (1.1-1000hz)Impulse
Figure 37. Test I - Applied Rear Wall Pressure History
-
8/8/2019 Hunter Bldg Test 2008
34/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
26
Time (msec)
Pressure(psi)
Impulse(psi-msec)
-25 0 25 50 75 100 125 150 175 200 225-7.5 -24
-5 -16
-2.5 -8
0 0
2.5 8
5 16
7.5 24
10 32
Raw DataFiltered Data (5.5-500hz)Impulse
Figure 38. Test I - Interior Pressure Time History (Occupied Volume)
Time (msec)
Pressure(ps
i)
Impulse(psi-msec)
-75 -50 -25 0 25 50 75 100 125 150 175
-2 -10
-1 -5
0 0
1 5
2 10
3 15
4 20
5 25Raw DataFiltered Data (1200hz)Impulse
Figure 39. Test I - Interior Pressure Time History (Plenum)
-
8/8/2019 Hunter Bldg Test 2008
35/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
27
4.2.Observed DamageDamage to the Hunter Standard Building is characterized by the permanent deformation of
structural components such as wall panels and roof joists, sliding and tipping of the building, and
displacement of internal fixtures.
After Test I a permanent deflection of the reflected wall was measured to be between 3 and 4inches depending upon the location of the measurement. Reflected wall damage is shown in
Figure 40. Cracking of the wall panel supporting overhead welds along the top of the panel wereobserved and are highlighted by magenta paint in Figure 40. A total of five cracks, all on the
tension face of the panel, were observed with lengths of 1 inch, 13 inches, and 3.5 inches. The
total length of cracking was measured to be 34 inches. It is suspected, but not confirmed, thatthe cause of the cracking was improper fit up of the panel prior to welding. The suspected fit-up
issue would be caused by the panel sitting on the bottom tube and too large of a gap existing
between the top of the panel and the top tube. In this condition, the toe of the weld on the panelwould be insufficient. It is important to note that the weld cracks did not lead to any structural
failure or increased wall panel response when subjected to the test blast loading.
No permanent deformations of the side-wall or rear wall panels was visible and fieldmeasurements showed no permanent damage to these building surfaces. Figure 41 shows the
lack of damage to the rear wall after Test I.
-
8/8/2019 Hunter Bldg Test 2008
36/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
28
Figure 40. Test I - Reflected Wall Damage (Weld Cracks Spray Painted Magenta)
Figure 41. Test I - Rear Wall Damage
-
8/8/2019 Hunter Bldg Test 2008
37/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
29
The roof of the building sustained little damage as shown in Figure 42. There was no visible or
measurable permanent deformation to the roof joists. Roof panel deformations were measured
between 3/8 and 5/8 inches.
Figure 42. Test I - Roof Damage
Sliding of the building was measured actively utilizing an accelerometer and passively by spraypainting around the building base plates. After the first test the building slid between two and
three inches as shown in Figure 43.
-
8/8/2019 Hunter Bldg Test 2008
38/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
30
Figure 43. Test I - Passive Building Sliding Measurements
1
2
3
4
1
2
3
4
-
8/8/2019 Hunter Bldg Test 2008
39/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
31
The HVAC unit on the end wall of the building was damaged by the test and is shown in its posttest condition in Figure 44. The interior view of the HVAC shows that the air intake filter is still
in place. In addition no blowout of any of the ducts inside the building was observed.
Figure 44. Test I - Damage to HVAC: (a) Exterior and (b) Interior
The test building was fitted with doors provided by Booth Industries. Both doors were Intact butInoperable after the test as show in Figure 45. The doors were inoperable due to damage to the
latch plate on the door as shown in Figure 46. The rightmost door into the work room was blownopen during the negative phase of the explosion. The leftmost door in Figure 45 could not be
opened manually or with the application of force by sledge hammer. No permanent bending of
the door leaf was observed nor measured.
(a) (b)
-
8/8/2019 Hunter Bldg Test 2008
40/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
32
Figure 45. Test I - Booth Blast Door Response: (a) Leftmost Door and (b) Rightmost Door
Figure 46. Test I - Booth Door Latch Damage: (a) Pre-Test and (b) Post-Test
(a) (b)
-
8/8/2019 Hunter Bldg Test 2008
41/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
33
Simulated occupants, the Hybrid III and Mannequin, were moved by the explosion but were still
in their places. The Hybrid III, which was situated against the reflected wall, had obviously been
rotated slightly forward about the hips as shown in Figure 47. In the post test condition theHybrid IIIs feet are no longer pressed against the bathroom wall but are placed firmly to the
floor. In addition, the right arm of the Hybrid III was found to be resting against the chair andthe Hybrid IIIs torso had been rotated forward. Measurements from the Hybrid IIIaccelerometers are presented in Figure 48. The peak acceleration was from front to back on the
Hybrid III and measured approximately 8 g. For comparison, the peak acceleration of the
building from sliding was measured to be approximately 25 g. Although the Hybrid III was
situated directly against the reflected wall only of the peak kinematic building accelerationwas transmitted to the Hybrid III. Peak vertical acceleration measured in the Hybrid III was
approximately 2 g.
Figure 47. Test I - HYBRID III: (a) Pre-Test and (b) Post-Test
(a) (b)
-
8/8/2019 Hunter Bldg Test 2008
42/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
34
Time (msec)
Acceleration(g)
0 5 10 15 20 25 30 35 40 45 50 55 60 65-12.5
-10
-7.5
-5
-2.5
0
2.5
5
7.5
10Raw Data_Dummy 01 (Front and Back)Raw Data_Dummy 02 (Left and Right)Raw Data_Dummy 03 (Up and Down)
Figure 48. Test I - HYBRID III Measured Accelerations
The mannequin was placed at the desk situated along the rear wall of the building as shown in
Figure 49. The mannequin was held in place by a bungee cord around the waist of themannequin and fastened to the chair. The bungee cord is visible in Figure 49. After the test, the
mannequin was still in place in the chair. The mannequin was impacted by folders and books
that were placed along the shelf above the desk as wall as some of the framing for the acoustic
ceiling.
-
8/8/2019 Hunter Bldg Test 2008
43/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
35
Figure 49. Test I - Mannequin: (a) Pre-Test and (b) Post-Test
The damage to the interior of the building is summarized in Figure 50 through Figure 54. The
main work room is shown in Figure 50. Ceiling tiles and framing for the ceiling tiles were found
on the floor. All overhead fluorescent light fixtures were still in place as was the overhead
drywall insulation above the acoustic ceiling. The books placed on the shelf along the back wall
were thrown to the floor. The cabinet on the blastward wall was moved approximately 6 inchesaway from the reflected wall as highlighted in Figure 51.
Figure 50. Test I - Building Interior: (a) Pre-Test and (b) Post-Test Damage
(a) (b)
(a) (b)
-
8/8/2019 Hunter Bldg Test 2008
44/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
36
Figure 51. Test I - Cabinet Movement on Reflected Wall
The porcelain bathroom fixtures were shattered by the shock to the building, see Figure 52. The
sink had fallen to the floor from its mount and shattered as had the toilet. Several large shards of
porcelain from the sink and toilet were observed.
Figure 52. Test I - Lavatory Fixtures: (a) Pre-Test and (b) Post-Test Damage
The interior metal stud wall was impacted by the responding reflected wall and the steel studs
were bent inward permanently. Evidence of this damage, see Figure 53, could be seen aroundlight switches and plugs. A section of the interior wall panel was removed to reveal the damage
to the interior metal studs.
(a) (b)
-
8/8/2019 Hunter Bldg Test 2008
45/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
37
Figure 53. Test I - Interior Wall Damage: (a) Drywall Pulling Away and (b) Metal Stud
Damage
Two fire extinguishers were mounted to the blastward wall and both were thrown across the
building to the opposite wall. One fire extinguisher which was located in the end work room is
shown in Figure 54.
(a) (b)
-
8/8/2019 Hunter Bldg Test 2008
46/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
38
Figure 54. Test I - Fire Extinguisher Throw
4.3.Structural Response MeasurementsAs discussed in Section 3.3.2, the building was instrument to active record structuralaccelerations of sliding and tipping, the reflected wall panel and roof joist. The acceleration data
was filtered and integrated twice to produce displacement time histories. The wall panelaccelerometers recorded the kinematic sliding of the building in addition to the flexural responseof the wall panel. Therefore, the sliding response had to be subtracted from the wall panel
response in order to obtain the wall panel relative displacement time history. A summary of the
active response measurements are provided below in Table 6. The wall panel and building
response compared well to pretest predictions as evidenced by the 6 degree rotation of thereflected wall panel. The roof joist response was low, about 1 degree of support rotation. The
sliding response was recorded in building corner 1, see Figure 16. The recorded sliding response
of 1.7 inches compared well with the passive measurement at this corner of 2 inches.
-
8/8/2019 Hunter Bldg Test 2008
47/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
39
Table 6. Test I - Measured Response Summary
Measured ResponseComponent
max (in) (deg)Wall Panel
6.3 in 6.0
Roof Joist 1.2 in 1.0
Sliding* 1.7 in -
Tipping**
-* Sliding passive response measurements presented in Figure 43.** Tipping data is incomplete due to loss of signal during the test.
4.3.1. Sliding and Tipping
The sliding and tipping measurements experienced some drift of the signal at later times and the
tipping accelerometer measurements experienced a loss of signal for about 20 msec. The
acceleration and integrated sliding data are presented below in Figure 55. This data compared
well to the passive sliding measurement of the same building corner as was instrumented. Peak
sliding accelerations were on the order of 100 gs. The active tipping acceleration measurementscould not be evaluated due to loss of the signal as shown in Figure 56.
Time (msec)
Acc
eleration(in/msec^2)andVelocity(in/msec)
Displacement(in)
-12 -4 4 12 20 28 36 44-0.3 -10
-0.24 -8
-0.18 -6
-0.12 -4
-0.06 -2
0 0
0.06 2
0.12 4
0.18 6
0.24 8
0.3 10Raw Acceleration DataFiltered Acceleration DataVelocityDisplacement
Figure 55. Test I Measured Sliding Time History
-
8/8/2019 Hunter Bldg Test 2008
48/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
40
Time (msec)
Acceleration(in/msec^2)andVelocity(in/msec)
Displacement(in)
-12 -4 4 12 20 28 36 44-0.25 -60
-0.2 -30
-0.15 0
-0.1 30
-0.05 60
0 90
0.05 120
0.1 150
0.15 180
0.2 210Raw Data_1st halfRaw Data_2nd halfFiltered Data (1000hz)velocity
displacement
Figure 56. Test I - Measured Tipping Time History
4.3.2. Wall Panel
The wall panel acceleration time history and integrated data is presented below in Figure 57.
The peak acceleration of the wall panel including sliding was recorded to be approximately 400gs, which compares well to the theoretical peak acceleration. The accelerometer recorded boththe wall panel response and kinematic sliding. Therefore, in order to properly assess the panel
displacement time history, the sliding response must be subtracted. The relative wall panel
displacement time history is presented in Figure 58. The peak recorded wall displacement
relative to the supporting structural members was 6.3 inches. This displacement corresponds to asupport rotation of 6 degrees. The design limit for medium response was 6 degrees; therefore,
the response correlated well to the pre-test prediction.
-
8/8/2019 Hunter Bldg Test 2008
49/70
-
8/8/2019 Hunter Bldg Test 2008
50/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
42
4.3.3. Roof Joists
The roof joist measured response time history is presented below in Figure 59. The peak roof
joist acceleration was approximately 160 gs. The peak displacement as integrated from the
acceleration time history was 1.2 inches which corresponds to a support rotation of 1 degree.
Time (msec)
Acceleration(in/msec
^2)andVelocity(in/msec)
Displacement(in)
-7.5 -2.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5-0.48 -15
-0.32 -10
-0.16 -5
0 0
0.16 5
0.32 10
0.48 15
0.64 20Raw Acceleration DataFiltered Acceleration DataVelocityDisplacement
Figure 59. Test I - Roof Joist Response Time History
-
8/8/2019 Hunter Bldg Test 2008
51/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
43
5. Test II Results
The second explosive test produced the crater shown below in Figure 60. The crater had an innerdiameter of 7 feet, an outer diameter of 15 feet and a depth of 41 inches. A summary of the blast
loading, observed pressure and structural response are provided in the following sections.
Figure 60. Test II Crater
5.1.Free Field and Applied PressuresThe measured free-field and applied pressures are summarized below in Table 7 with the
associated time histories in Figure 61 through Figure 67. The free-field and reflected peakpressures were higher than the theoretical values for 1,250 lbsANFO at 75 feet but not
unreasonably so. The endwall pressure gauge failed and did not record a good trace. Of interest
are the interior pressure histories in Figure 66 and Figure 67. Peak pressures in the occupiedvolume peaked at 4.5 psi and the plenum pressures were on the order of 1.5 psi. The interior
pressures are not the result of shock infiltrating the structure through openings. Instead they are
a result of pressure waves transmitted into the structure from deformation of the buildings
surfaces (walls and roof).
-
8/8/2019 Hunter Bldg Test 2008
52/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
44
Table 7. Test II - Measured and Applied Load Summary
Peak Positive PhaseGauge
Pressure
(psi)
Impulse
(psi*msec)
PressureTime History
Free Field 23.5 62 Figure 61
Reflected Wall #1 77.9 248 Figure 62Reflected Wall #2 67.1 313 Figure 63
Roof 8.8 32 Figure 64
Rear Wall 5.5 70 Figure 65
Side Wall Gauge Failure
Interior Pressure
(Occupied Volume)
4.5 39 Figure 66
Interior Pressure(Occupied Volume)
1.4 24 Figure 67
Time (msec)
Pressure(psi)
Im
pulse(psi-msec)
-40 -20 0 20 40 60 80 100-10 -20
0 0
10 20
20 40
30 60
40 80Raw DataFiltered Data (6-2500hz)Impulse
Figure 61. Test II - Free-Field Pressure Time History
-
8/8/2019 Hunter Bldg Test 2008
53/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
45
Time (msec)
Pressure(psi)
Impulse(psi-msec
)
-4 -2 0 2 4 6 8 10 12 14-100 -0.8
-50 -0.4
0 0
50 0.4
100 0.8
150 1.2
200 1.6
250 2
300 2.4Raw DataImpulse
Figure 62. Test II - Reflected Wall Pressure Time History #1
Time (msec)
Pressure(psi)
Impulse(psi-msec
)
-10 -5 0 5 10 15 20-50 -400
0 0
50 400
100 800
150 1200Raw DataImpulse
Figure 63. Test II - Reflected Wall Pressure Time History #2
-
8/8/2019 Hunter Bldg Test 2008
54/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
46
Time (msec)
Pressure(psi)
Impulse(psi-msec
)
-40 -20 0 20 40 60 80 100 120-10 -30
-5 -15
0 0
5 15
10 30
15 45Raw DataFiltered Data (500hz)Impulse
Figure 64. Test II - Applied Roof Pressure Time History
Time (msec)
Pressure(ps
i)
Impulse(psi-msec)
-50 -25 0 25 50 75 100 125 150 175 200
-10 -80
-7.5 -60
-5 -40
-2.5 -20
0 0
2.5 20
5 40
7.5 60
10 80Raw DataFiltered Data (2.7-900hz)Impulse
Figure 65. Test II - Applied Rear Wall Applied Pressure Time History
-
8/8/2019 Hunter Bldg Test 2008
55/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
47
Time (msec)
Pressure(psi)
Impulse(psi-mse
c)
-20 0 20 40 60 80 100 120 140 160 180-15 -120
-10 -80
-5 -40
0 0
5 40
10 80
Raw DataFiltered Data (4-1000hz)Impulse
Figure 66. Test II - Interior Pressure Time History (Occupied Volume)
Time (msec)
Pressure(psi)
Impulse(psi-msec
)
-50 -25 0 25 50 75 100 125 150 175 200 225 250
-2 -20
-1.5 -15
-1 -10
-0.5 -5
0 0
0.5 5
1 10
1.5 15
2 20
2.5 25
3 30Raw DataFiltered Data (2.5-750hz)Impulse
Figure 67. Test II - Interior Pressure Time History (Plenum)
-
8/8/2019 Hunter Bldg Test 2008
56/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
48
5.2.Observed DamageDuring the second test the wall panels were pressed inward and developed in-plane tensile
membrane forces. This is evidenced in the high speed video image in Figure 68. The supportingHSS Eave Strut is bent between the columns from the panel tensile reaction. Unfolding and
flattening of the corrugations can also be seen. The post test condition of the reflected wall panelis shown in Figure 69. The panels were found to be pulled outward approximately 5 inches in
the middle with permanent inward deflections of approximately 8 inches to either side of theoutward panel bulge. No cracking of the reflected wall panel welds was observed after the
second test. Although significant demand was placed on the HSS eave strut at the peak wall
panel response as shown in Figure 68, no permanent downward deflection of the eave strut waspresent after the test.
The side wall panel was buckled and had a permanent inward deformation of 5/16 inches asshown in Figure 70.
Figure 68. Test II - High Speed Video Capture of Peak Wall Panel Response
-
8/8/2019 Hunter Bldg Test 2008
57/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
49
Figure 69. Test II - Reflected Wall Damage
Figure 70. Test II - End Wall Damage
Damage to the roof deck and roof joists after Test II, shown in Figure 71, was not measurablydifferent that that which was observed after Test I. Photographs of the underside of the buildingwere taken during the load out of the building and floor deck damage was observed as shown in
Figure 72. This is not unexpected since the building was not skirted for the second test and a gap
varying between 6 and 10 inches was present between the building and the ground thus allowingshock to get underneath the building during the second test.
-
8/8/2019 Hunter Bldg Test 2008
58/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
50
Figure 71. Test II - Roof Deck Damage
Figure 72. Test II - Floor Deck Damage
Sliding of the building was measured actively utilizing an accelerometer and passively by spraypainting around the building base plates. After the second test the building slid between thirteen
and twenty inches as shown in Figure 73.
-
8/8/2019 Hunter Bldg Test 2008
59/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
51
Figure 73. Test II - Passive Building Sliding Measurements
1
2
3
4
1
2
3
4
-
8/8/2019 Hunter Bldg Test 2008
60/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
52
The HVAC unit was heavily damaged by the second test as evidenced in Figure 74. The airreturn intake was blown into the work room at the end of the structure; the exterior unit was
heavily bent with the blower cover no longer attached to the unit. There was also evidence of
HVAC duct bulging inside the building, as shown in Figure 75. However, it is not clear whetherthe damage was caused by shock inside the duct or blast response of the roof.
Figure 74. Test II - Damage to HVAC: (a) Exterior and (b) Interior
Figure 75. Test II - Damage to HVAC Duct
Although there was no failure of the reflected wall the damage to the interior of the building was
heavy and a significant amount of interior debris was generated from the High Response of the
reflected wall. Figure 76 through Figure 80 detail the level, energy and hazardous nature of the
interior debris. In Figure 76 the damage to the end office is highlighted by the severedisplacement of the interior metal stud wall, throw of the gypsum wall sheathing and
fragmentation and throw of the book shelf and desk. The desk edging was thrown at a high force
-
8/8/2019 Hunter Bldg Test 2008
61/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
53
impacting the office hallway door and penetrating the door as shown in Figure 77. Furtherevidence of debris impacts on the back wall surfaces was also evident.
Figure 76. Test II - Office Room: (a) Pre-Test and (b) Post- Test
Figure 77. Test II - Desk Debris Impacts: (a) Door Scarring and (b) With Impacting
Debris
-
8/8/2019 Hunter Bldg Test 2008
62/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
54
The bathroom of the building was moved between 2 and 3 feet towards the back of the structureand into the hallway as shown in Figure 78. In Figure 79 debris from the reflected wall and
ceiling can be seen on the sink and cabinet located in the rear of the work room. Part of the
reflected wall desk top is also visible in Figure 79 having been thrown to the rear of the building.
Figure 78. Test II - Central Work Room: (a) Pre-Test and (b) Post Test
Figure 79. Test II - Interior Debris
-
8/8/2019 Hunter Bldg Test 2008
63/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
55
Overhead light fixtures were found to be mostly intact with just a few fixtures dangling but still
at the level of the drop ceiling as shown in Figure 80.
Figure 80. Test II - Light Fixture Damage
5.3.Structural Response MeasurementsAs discussed in Section 3.4.2, the building was instrumented to actively record structuralaccelerations of sliding and tipping, the reflected wall panel and end wall eave strut. The
acceleration data was filtered and integrated twice to produce displacement time histories. The
wall panel accelerometers recorded the kinematic sliding of the building as well as the flexuralresponse of the wall panel. Therefore, the sliding response had to be subtracted from the wall
panel response in order to obtain the wall panel relative displacement time history. A summary
of the active response measurements are provided below in Table 8. The wall panel response
exceeded the pretest prediction of 12.75 inches by 40%. The eave strut response was moderate,about 3 degrees of support rotation. The sliding response was recorded in building corner 4, see
Figure 26. The recorded sliding response, using the passive marking of the supporting concrete
pad, was 14 inches. A direct comparison to the active sliding accelerometer measurements couldnot be made due to the signal drift of the accelerometer data at the time scale necessary to
produce the peak sliding response.
Table 8. Test II - Measured Response Summary
Measured ResponseComponent
max (in) (deg)Wall Panel
17.5 in 16.2
Eave Strut 3.9 in 3.4Sliding
*-
Tipping* -
*Accelerometer data drifted therefore data was not reliable at time
necessary to integrate peak response for sliding or tipping. See
Section 5.2 Figure 73 for passive sliding measurements.
-
8/8/2019 Hunter Bldg Test 2008
64/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
56
5.3.1. Sliding and Tipping Response
The sliding and tipping measurements experienced some drift of the signal at later times
preventing the active measurement of sliding and tipping at time scales necessary for peak
kinematic building movement. However, the data was sufficient in the time scale of peak wallpanel response, about 20 msec. The acceleration and integrated sliding data is presented below
in Figure 55. Peak sliding accelerations were on the order of 25 gs. The active tippingacceleration measurements could not be evaluated due to loss of the signal as shown in Figure
56.
Time (msec)
Accele
ration(in/msec^2)andVelo
city(in/msec)
Displacement(in)
-5 0 5 10 15 20 25 30 35 40-0.3 -6
-0.25 -5
-0.2 -4
-0.15 -3
-0.1 -2
-0.05 -1
0 0
0.05 1
0.1 2
0.15 3
0.2 4
0.25 5
0.3 6Raw Acceleration DataFiltered Acceleration DataVelocityDisplacement
Figure 81. Test II - Measured Sliding Time History
-
8/8/2019 Hunter Bldg Test 2008
65/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
57
Time (msec)
Acceleration(in/msec^2)andVelocity(in/msec)
Displacement(in)
-3 0 3 6 9 12 15 18-0.4 -4
-0.3 -3
-0.2 -2
-0.1 -1
0 0
0.1 1
0.2 2
0.3 3
0.4 4
0.5 5Raw Acceleration DataFiltered Acceleration DataVelocityDisplacement
Figure 82. Test II - Measured Tipping Time History
5.3.2. Wall Panel Response
The wall panel acceleration time history and integrated data is presented below in Figure 83.
The peak acceleration of the wall panel including sliding was recorded to be approximately
2,000 gs. The accelerometer recorded both the wall panel response and kinematic sliding.Therefore, in order to properly assess the panel displacement time history, the sliding response
must be subtracted. The relative wall panel displacement time history is presented in Figure 84.
The peak recorded wall displacement relative to the supporting structural members was 17.5inches. The wall panel response exceeded the pretest prediction due to eave strut deformation
that was more pronounced in the test. The structural model was revised to incorporate this
flexibility and better matched the test. This revised model was used to predict strains occurringin the wall panels during the tests and to revise the blast capacity calculation for strain and for
support rotation.
-
8/8/2019 Hunter Bldg Test 2008
66/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
58
Time (msec)
Acceleration(in/msec^2)andVelocity(in/msec)
Displacement(in)
-5 0 5 10 15 20 25 30 35 40 45-2 -20
-1.5 -15
-1 -10
-0.5 -5
0 0
0.5 5
1 10
1.5 15
2 20
Raw Acceleration DataFiltered Acceleration DataVelocityDisplacement
Figure 83. Test II - Total Wall Panel Response Time History (Includes Sliding)
-40
-30
-20
-10
0
10
20
30
0 5 10 15 20 25 30 35
Time (msec)
Displacement(in)
Wall Panel Displacement
Figure 84. Test II - Relative Wall Panel Response Time History
-
8/8/2019 Hunter Bldg Test 2008
67/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
59
5.3.3. End Wall Eave Strut Response
The end wall eave strut measured response time history is presented below in Figure 85. The
peak eave strut acceleration was approximately 1,500 gs. The peak displacement as integrated
from the acceleration time history was 3.9 inches which corresponds to a support rotation of 3degrees.
Time (msec)
Acceleration(in/msec^2
)andVelocity(in/msec)
Displacement(in)
0 2 4 6 8 10 12 14 16 18 20-5.6 -5.6
-4.8 -4.8
-4 -4
-3.2 -3.2
-2.4 -2.4
-1.6 -1.6-0.8 -0.8
0 0
0.8 0.8
1.6 1.6
2.4 2.4
3.2 3.2
4 4Raw Acceleration DataFiltered Acceleration DataVelocityDisplacement
Figure 85. Test II - End Wall Eave Strut Response Time History
-
8/8/2019 Hunter Bldg Test 2008
68/70
Standard Building Full Scale Explosive Testing, Final Report July 9, 2008
Hunter Buildings and Manufacturing Project No. 174999
60
6. Summary
ABS Consulting conducted two full scale field tests utilizing 1,250 pounds of ANFO explosiveon a standard 8 psi, 200 msec Heavy Response Hunter blast resistant modular building. The
purpose of the explosive testing was to determine performance of the building at the upper limit
of Medium Response (Test I) and the upper limit of High Response (Test II). Testing consistedof the detonation of a 1,250 lbANFO charge at a range of 100 feet for Test I and 75 feet for Test II.
The ANFO charge was placed on the door side of the building for Test I and the opposite wall
for Test II. Peak side-on pressures were 9.7 psi for Test I and 17.4 psi for Test II.
Test I - Medium Response
Performance of the structure in Test I was consistent with ASCE Medium Response. Whileprimary components exhibited some plastic deformation, structural integrity was not
compromised