AZF FERTILIZER PLANT EXPLOSION

A CASE WHICH WILL

NEVER BE SOLVED BUT

CLEARLY SHOWS THE

DANGEROSITY OF

COMPOUNDS SUCH AS

AMMONIUM FERTILIZER

RECENTLY, IN WEST TEXAS, IT HAS ONCE MORE BEEN DEMONSTRATED.

Draft to be corrected and completed if of interest to anyone

AZF INDEPENDANT INVESTIGATION

A HUGE EXPLOSION OCCURRED IN A CHEMICAL PLANT IN TOULOUSE , FRANCE

ON SEPTEMBER 21, 2001,WITHOUT ANY OBSERVED PRECURSOR SIGN.• OCCURRED 10 DAYS AFTER SEPTEMBER 11,• SAME DATE BUT 80 YEARS AFTER OPPAU,• KILLED 31 AND INJURED THOUSANDS,

13 YEARS LATER, NO CLUES WHAT EXACTLY HAPPENED AND MORE IMPORTANT, WHY.

PURPOSE OF THE DOCUMENT• THE PURPOSE OF THIS DOCUMENT IS NOT TO

CRITISIZE THE HUGE WORK DONE BY THE COURT EXPERTS OR BY THEIR DELEGATED EXPERTS OR BY INDEPENDANT SPECIALISTS,

• IT IS ALSO TO SUM UP, IN A PEDAGOGIC WAY WHAT I FOUND RELEVANT TO THIS CASE AND SHOULD HAVE HELPED TO SOLVE IT.

THE MAIN INVESTIGATION FAILURES ARE: THE DEBRIS PROJECTION HAS NOT BEEN STUDIED, IMPORTANT WITNESSES HAVE BEEN HEARD, BUT

NOT BELIEVED.

ABOUT THE AUTOR• I AM A RETIRED ELECTRONIC DIPLOM ENGINEER,• I WORKED OVER 25 YEARS FOR MATRA / AEROSPATIALE

FRANCE AS HEAD OF TECHNICAL ASSISTANCE AND SAFETY FOR OUR CUSTOMERS IN FRANCE AND ABROAD.

• I WAS SPECIFICALLY IN CHARGE OF OUR MISSILES DEDICATED INFRASTUCTURE AND EVIDENTLY THE TM 5 -1300 WAS MY BIBLE, EVEN IF I CAME TO HATE THOSE UK UNITS.

• I PARTICIPATED TO DDESB SEMINARS.• I MUST CONFESS THAT THE AZF TOPIC INTERESTED ME

WHEN, IN 2009, I HEARD THAT THE TRIAL WAS TO BEGIN BUT THE MAIN QUESTIONS WHERE STILL UNANSWERED.

• AS FREE AND INDEPENDENT INVESTIGATOR, THE TRUTH , AND EXCLUSIVELY THE TRUTH, IS MY GUIDE.

• I TAKE THE OPPORTUNITY TO THANK THE US EXPLOSIVE SAFETY COMMUNITY FOR PROVIDING FOR FREE , MANY IMPORTANT DOCUMENTS AND TOOLS .

REFERENCE DOCUMENTS / SOFTWARE

• THE REFERENCE DOCUMENTS ARE EVIDENTLY THE REPORTS AND ALL OTHER AZF TRIAL DOCUMENTS,

• THE TECHNICAL REFERENCE DOCUMENTS WOULD BE TOO LONG TO BE LISTED, BUT ARE MAINLY US DEFENSE SAFETY DOCUMENTS.

• SOFTWARE USED IS MAINLY CONWEP, BEC V.4 FOR SCALED METRIC DISTANCES < 40 , A PERSONNEL EXCEL SHEET FOR DISTANCES ABOVE (BASED ON EMPIRICAL SCALING LAWS FOR TRUCK BOMB EXPLOSIONS) AND OTHER SUCH USEFULL EXCEL PERSONNEL TOOLS.

• I ALWAYS USE TRADITIONAL CHARTS (TM 5-1300 WITH DPLOT AMONGST OTHERS) TO MAKE SURE MY COMPUTATIONS ARE SOUND.

AZF INVESTIGATION AND TRIAL DOCUMENTS

TWO MAIN ACTIONS HAD TO BE TAKEN IMMEDIATELYAFTER THE ACCIDENT :

QUICKLY SECURE THE AZF SITE (CLASSIFIED SEVESO II ) TO AVOID A FURTHER ACCIDENT, SECURE ALL EVIDENCE FOR THE INVESTIGATION. CLEARLY,SOME IMMEDIATE SAFETY ACTIONS HAD NEGATIVE EFFECTS ON THE INVESTIGATION. I HAVE THE FEELING THAT SAFETY TOPICS ARE WELL PROCESSED, BUT POST ACCIDENT INVESTIGATION SEEMS IMPROVISED. EVIDENTLY, 10 DAYS AFTER WTC, THE INVESTIGATION FOCUSED ON A POSSIBLE TERRORIST ACTION. TO PREPARE THE 2009 TRIAL OVER 50000 PAGES OF REPORTS AND DOCUMENTS ARE PILED UP. THIS HUGE AMOUNT IS LINKED TO THE EFFORT OF FINDING SOMETHING, BUT ALMOST EVERYTHING IN THIS INVESTIGATION IS DISPUTED.

AZF TRIAL• THE AZF TRIAL HELD IN 2009 WAS HUGE, SINCE MANY

ASSOCIATIONS TOOK PART (SIMILARLY TO A CLASS ACTION).

• THIS CASE IS EXEPTIONALLY COMPLICATED, NO CLUES BUT THOUSANDS OF DOCUMENTS / REPORTS, 800 WITNESSES.

• THE COURT EXPERTS, PAID TO FIND SOMETHING, HAD TO MANIPULATE THE FACTS SO THAT THE CHLORE THEORY COULD WORK AS INITIATOR.

• THE JUDGE DECIDED THAT NO PENALITY COULD BE GIVEN, BASED ON SUPPOSITIONS AND PROBABILITIES.

• THIS DECISION LED TO AN APPEAL HELD IN 2011, SINCE MANY SAFETY RULES WERE NEGLECTED BY AZF, EVEN, IF NOT PROVEN TO BE DIRECTLY RELATED TO THE ACCIDENT.

AZF CHLORE THEORY

WITHOUT ANY OTHER IDENTIFIED AGRESSOR, THE EXPERTS WERE SUMMONED TO FIND SOMETHING, AFTER SUCH LONG TIME AND SO MUCH MONEY SPENT.

THE THEORY IS AS FOLLOWS:

• SOME UNDEFINED KILOS OF A CHLORE PRODUCT CALLED DCCNa HAVE BEEN, SOME 15 MINUTES EARLIER, ACCIDENTLY SKIPPED ON THE “AN” IN THE “BOX”, WHICH ACTS AS A TEMPORARY STORAGE.• THE CHLORE AND “AN” MIX, LED RAPIDLY TO THE PRODUCTION OF NCl3 AND HEAT, INDUCING A GENERAL DETONATION IN THE “BOX”,• THE MAIN “AN” STOCKPILE BEEING VERY CLOSE, IT ALSO DETONATED, TRIGGERED BY THE “BOX” BLAST.• THE EXPERTS JUST TOOK THE DISTANCE RELATION FOR SYMPATHETIC DETONATION, FORGETTING ONLY THAT “AN “ AS SUCH, IS NOT AN EXPLOSIVE!

AZF DESCRIPTION

AZF PLANT

• AZF PLANT IS LOCATED FEW Km SOUTH OF TOULOUSE (FRANCE), ON A 0.7Km2 LAND,

• AZF IS PART OF AN IMPORTANT INDUSTRIAL COMPLEX DEDICATED TO CHEMICAL PRODUCTS, SOME MILITARY ORIENTED,

• THE PLANT PRODUCES MAINLY AMMONIAC, UREA , NITRIC ACID AND AMMONIUM NITRATE.• AN AVERAGE OF 30000T DANGEROUS CHEMICALS

ARE TO BE FOUND ON THE SITE, LINKED TO THE PRODUCTION PROCESS OR FINAL PRODUCT.

• AZF IS CLASSIFIED SEVESO II

AZF PLANT

BLDG 221

AZF PLANT, SOME DAYS LATER !!

AZF BUILDING 221 STORE

• BLDG 221 IS PART OF A BUILDING COMPLEX (221 TO 225).

• BLDG 221 IS DEDICATED TO THE STORAGE OF OUT OF SPECIFICATION « AN » PRODUCED ON THE PLANT.

TWO TYPES OF « AN » ARE STORED IN 221 :• « AN » FOR AGRICULTURAL USE, NAA WITH

33,5% NITROGEN, • « AN » FOR INDUSTRIAL USE, NAI WITH 34.5%N,

FOR EXPLOSIVE OR OTHER INDUSTRIAL USE.• HYDROFUGE ADDED PRODUCT, 0.2% IN MASS (CARBON ADDED 0.1% IN MASS).

BUILDINGS 221 TO 225 PERSPECTIVE VIEW BLDG 221- 225

221 -222 SEPARATIN

G COLUMNS

BUILDINGS 221 / 222

JC TIRAT

ALUMINIUM ROOF

STOCKPILEBOX

LOADINGPLATFORM

STOCKPILES IN BOX AND MAIN PILE

35m10m

2.7m

BOX

“AN” STORED IN BUILDING 221

MAIN STOCKPILE IS ESTIMATED AT 400 TONS:• 380T, OF WHICH 75% NAA , 25% NAI, ρ = 800Kg / m3

• 20 T AS A CRUST LAYER , ρ = 1200Kg / m3. (THE CRUST LAYER, NOT UNDER THE STOCKPILE

IS IGNORED ≈ 50T ).IN THE « BOX » 20T:• 11.5 T, 10 T NAA AND 3 PILES NAI, 500Kg EACH,• 8.5 T AS A CRUST LAYER.MOST PROBABLY 50% OF THE « AN » IN THE BOX

PARTICIPATED TO THE DETONATION BUT CAN BE IGNORED (ONLY ≈ 4T EQUIVALENT TNT).

TOTAL MASS, USED FOR FURTHER COMPUTATION : 400T

“AN” STOCKPILE ESTIMATION

• M , UNDETONATED “AN”, SMALL CONFINEMENT

• C , DETONATED “AN”, => M + C = 400Tons, • ФB *( C – M / 3) = 40T ( TNT BASED ON BLAST EFFECT),• ФB IS THE AN =>TNT BLAST EQUIVALENCY FACTOR,• M / 3 , FOR THE « AIR » ENERGY LOST BY EJECTING

« M » AT ≈ 800m/s , (SIMILAR GURNEY).

M

C

STOCKPILE BASED ON CRATERIF USING CONWEP OR OTHER CHARTS,THE CRATER IS COHERENT WITH A BARE TNT CHARGE OF 100T ON CONCRETE (SEE NOTE), THEREFORE WE CAN WRITE: ФC *( 1.2*C + M / 5 ) = 100T,ФC IS THE AN => TNT FACTOR FOR CRATERING,1.2 IS THE COEFFICIENT FOR THE HIGHER GROUND ENERGY, AIR / GROUND SURFACE RATIO FOR SUCH PILE 0.55/ 0.45 (COMPARED TO HEMISPHERIC 0.67 / 0.33), M / 5 FOR THE LIGHT CONFINEMENT EFFICIENCY NOTE : AN AVERAGE 0.5*(ASPHALT + CONCRETE) OVER SOIL HAS BEEN USED INSTEAD OF THE CONCRETE, SINCE THE 0.15m THICK, LIGHT REINFORCED CONCRETE SLAB, IS DAMAGED, EATEN AND WEAKENED BY THE « AN » PILE ABOVE.

STOCKPILE BEST FITDIFFERENT Ф SOLUTIONS:M = 100T , C = 300T WITH ФC = 0.15 ФB = 0,26M = 150T , C = 250T WITH ФC = 0.20 ФB = 0,30M = 175T , C = 225T WITH ФC = 0.24 ФB = 0,33 M = 200T , C = 200T WITH ФC = 0.30 ФB = 0,36 M = 225T , C = 175T WITH ФC = 0.40 ФB = 0,39 M = 250T , C = 150T WITH ФC = 0.59 ФB = 0,43)

CONSIDERING THAT ФC AND ФB SHOULD BE CLOSE, THE BEST SOLUTION IS,

M = 225T AND C = 175T, ± 20% WITH Ф ≈ 0.4

THE 175T DETONATED AND SIMPLIFIED STOCKPILE COULD THEREFORE BE AS FOLLOWS:

• CRUST AVERAGED 25m x 6m x 0.1m x 1.2T/m3 ≈ 20T,

• PILE AVERAGED 25m x 6m x 1.3m x 0,8T/m3 ≈ 155T.

THE EQUIVALENT TNT IS 0.4 * 175T = 70T, WITH EFFECTIVE BLAST EFFECT ► 40T, WITH EFFECTIVE GROUND EFFECT ► 100T.

IF WE CONSIDER THIS PILE TO BE INITIATED EAST, THE INITIATION POINT IS SOME 6m FROM THE BOX SEPARATING WALL AND ON PILE LONGITUDINAL AXIS.

DETONATED STOCKPILE

DETONATED STOCKPILE

INITIATION

6m

5m

1,3m 25m

“AN” DETONATION COMPARED TO TNT

• THE SIMPLE « AN » DETONATION FORMULA IS :

NH4NO3 = N2 + 2H2O + ½ O2

• THE DETONATION ENERGY IS 1400 kJ / kg COMPARED WITH 4200kJ / kg FOR TNT THE ENERGY RATIO « AN » / TNT = 0.33• THE « AN »REACTION RELEASES 3.5moles / 0.08Kg

≈ 43 moles OF GAZ PER Kg OF « AN » AT ≈ 1700K .

• THE MUCH HIGHER ANFO ENERGY IS LINKED TO THE EFFICIENT USE OF THE LOST OXYGEN.

METEOROLOGICAL DATAS 1

AT 10H 17: 55 , PRESUMED LOCAL TIME OF DETONATION, THE CONDITIONS ARE:

• TEMPERATURE 17.2°C,• PRESSURE 997 mbar, (ALTITUDE 158m),• HUMIDITY 88%,• TEMPERATURE INVERSION 770m TO 970m, (SEE GRAPH HEREAFTER) ΔT = 1.5°C, BUT

MEASURED 3 HOURS LATER,• CLOUDY, AVERAGE SOLAR IRRADIATION

700W / m2

METEOROLOGICAL DATAS 2

• WIND ≈ 6,7 m / s DIRECTION ≈ 145°, COMING FROM SOUTH EAST,

• MAXIMUM WIND PRESSURE ( WITH GUST SPEED ) FOR 10m/s => Pa = ρ*V2/ 2 = 1.2*100 / 2 = 60Pa = 0.6mbar.

BLAST EFFECT

• OUTSIDE• INSIDE BUILDING

TEMPERATURE INVERSION AND WIND EFFECT ON BLAST

ESTIMATED TEMPERATURE PROFILE AT To

THE TEMPERATURE INVERSION DOES NOT SEEMRESPONSIBLE FOR UNEXPECTED BLAST DAMAGES.

CALCULATED BLAST PRESSURES, FOR 70T TNT

WIND 6.7m/s

100mbar 550m 50mbar 950m 20mbar 1800m 10mbar 3000m 5 mbar 5000m

BLAST ESTIMATION FROM DAMAGES

CHARGE20mbar average distance 1.8Km

50mbar average distance 1Km

NORTH

EAST

OUTLINES FROM ORANGE

TO BLUE REPRESENT :

200,140,100,70, 50, 20 mbar

MA

IN F

AR

FIE

LD

BL

AST

AX

IS

ZOOM ON GZO VICINITY

THIS BLAST STRENGTH REMINDS THE ROCKET EFFECT ON THE EAST

SIDE OF THE CRATER

CHARGEHEMISPHERICAL 200mbar

EAST

50

EAST SIDE DAMAGES, OPPOSITE PLANT

50m HIGH CLIFF,1200m FROM GZO,REFLECTED WAVE OF APPROX 2 KPa. RESPONSIBLE FOR ENHANCED DAMAGES ONOPPOSITE PLANT?

70mbar 20mbar REFLECTED

3s

Time

P

AZF

P

BLAST EFFECT, DAMAGED ROOFS

THE EXTENSIVE ROOF DAMAGES

ARE PROBABLY LINKED

TO THE PILE DETONATION DURATION

AND THE FINAL STRONG

NEGATIVE PHASE (UNDERPRESSURE).

SCHOOLS CLOSED FOR REPAIR

NORTH 5 mbarDefinitivelyMany monthsOver 4 weeksOver 2 weeksOver 1 weekLess 1 weekFew days

7 mbar10 mbar18 mbar

47 mbar

113 mbar

OVERPRESSURES

FOR 70T TNT

WIND 6.7m/s

BLAST EFFECT EAST

DETONATION GAS PATH

EAST

BLAST EFFECT

• WE HAVE TO CONSIDER A LONG ALMOST RECTANGULAR CHARGE, WITH A 4 / 1 RATIO, IN THE NEAR FIELD,THE SHAPE OF THE CHARGE PLAYS AN IMPORTANT ROLE,

• OBVIOUSLY IT HAS ALSO PLAYED A ROLE IN THE FAR FIELD SINCE THE HIGHEST OVERPRESSURES ARE ON AN ALMOST NORTH SOUTH AXIS,

• THE WIND DOES NOT SEEM TO PLAY A SIGNIFICANT ROLE , • THE DETONATING PROCESS LASTS 25m / (3500m/s) => 7ms,

(3500m/s IS THE THEORETICAL “AN” DETONATION SPEED), AND REINFORCES THE POSITIVE / NEGATIVE BLAST IMPULSE.

• WINDOW BREAKAGE OR NOT, DEPENDS ON DISTANCE BUT ALSO ON WIND AND WINDOW BLAST ORIENTATION (FULL REFLECTED WAVE PRESSURE IS TWICE THE DIRECT WAVE).

• 5 mbars INCIDENT , IS CONSIDERED AS THE LOWER GLASS BREAKAGE LIMIT FOR CORRECTLY INSTALLED WINDOWS.

• THE NEAR FIELD EAST SIDE BLAST REMINDS A ROCKET GAS PLUME SHAPING THE CRATER END.

THE EQUIVALENT TNT IS 60T< W >80T CONSIDERING THE DAMAGE / DISTANCE CHARTS.

GAS PRESSURE

GAS PRESSURE ESTIMATION THE GAS OVERPRESSURE HAS FOLLOWING PROFILE:

KNOWING THE GAS TEMPERATURE OF THE DETONATION , COMBINED WITH THE GAS MOLES IN THE ROOM IT ALLOWS TO EASILY COMPUTE THE PEAK GAS OVERPRESSURE P over WITHOUT HAVING TO GUESS AN EQUIVALENT TNT.P over ≈ (Tdet / Tamb) -1 (GAS MOLES RATIO NEGLECTED)

MISSILES / FRAGMENTS

BLDG 221 § 222 FRAGMENTS • UNFORTUNATELY, IN THE FRAME OF THE ACCIDENT

INVESTIGATION, THIS TOPIC HAS NOT BEEN STUDIED ,• IT WOULD CERTAINLY HAVE HELPED TO UNDERSTAND A LITTLE BETTER THIS DETONATION,• APPROXIMATELY 18 MAJOR IMPACTS HAVE BEEN REPORTED ON AZF SITE, SOME PERFORATING BUILDING ROOFS AND OTHERS LEAVING SIGNIFICANT CRATERS.• FOR MOST IMPACTS THE BROKEN CONCRETE AND STEEL DEBRIS HAVE BEEN PHOTOGRAPHED AND COLLECTED BUT NOT ANALYZED,• ALMOST ALL DISTANT AND SIGNIFICANT FRAGMENTS ARE FROM THE 221 CONCRETE SLAB AND THE 221-222 SEPARATING COLUMNS,• THESE COLUMN PARTS ARE EASY TO RECOGNIZE DUE TO THE RECENT CONCRETE AND SPECIFIC REBAR.

FRAGMENT GENERALITIES• FRAGMENT DISTANCE IS MAINLY FUNCTION OF INITIAL

SPEED, MASS, DRAG AND EJECTION ANGLE.• FRAGMENTS AT VERY LOW EJECTION ANGLES ARE

DANGEROUS ALONG MOST OF THE FLIGHT PATH, • FOR THE HIGH PARABOLIC TRAJECTOGRAPHIES , THE RISK

IS MUCH LOWER DUE TO ARRIVING IMPACT ANGLES > 70° ,• SECONDARY FRAGMENTS QUANTITY REPARTITION f(MASS)

IS USUALLY APPROXIMATED AS FOLLOWS: M < 0.1Kg , 55% , 0.1 < M > 5Kg, 42% AND M > 5Kg , 3%

ABSTRACT FROM BOMB FRAGMENT, RISK STUDY

Number of fragments

Increasing Weight

BLDG 221 § 222 FRAGMENTS • FOR A BOMB,THE CASING IS IN DIRECT CONTACT WITH

THE HUGE EXPANDING GAS PRESSURE,• THEREFORE THE CASING FRAGMENTS ARE EJECTED AT TREMENDOUS SPEED (see Gurney / Mott for distribution),• THOSE FRAGMENTS ARE DURING SOME 100m IN ADVANCE OF THE SHOCKWAVE, BUT THEN, DUE TO THEIR DRAG, ARE OVERTAKEN BY THE SHOCKWAVE.• HERE THE SITUATION IS DIFFERENT, A MUCH SMALLER IMPULSE IS GIVEN TO THE BUILDING FRAGMENTS,• THE IMPULSES WILL LEAD TO FRAGMENTS / MISSILES WITH VELOCITIES RANGING FROM 50 UP TO 800m/s DEPENDING ON FRAGMENT WEIGHT / DIMENSIONS / SURFACE PERPENDICULAR TO BLAST.• IN THIS CASE,THE SHOCKWAVE IS WELL IN ADVANCE OF SUCH FRAGMENTS DUE TO MODERATE SPEED / INERTIA.

BLDG 221 § 222 FRAGMENTS • THE CONCRETE AND BRICKS OF THIS 80 YEARS OLD BUIDING ,

WEAKENED BY THE « AN » HAVE BEEN PULVERIZED IN CLOSE CHARGE VICINITY,• THE STEEL PARTS FROM THE ROOF, ALSO WEAKENED AND HIGHLY CORRODED HAVE BEEN EJECTED AT GREAT DISTANCES,• THE ROOF COVER, ALUMINIUM SHEETS , CRUSHED BY THE BLAST, HAVE BEEN FOUND IN QUANTITIES, NORTH WEST, FOLLOWING THE WIND DIRECTION.• THE BLAST IMPULSE DECREASES WITH INCREASING, STRUCTURE HEIGHT , THEREFORE THE HIGHEST VELOCITIES ARE THOSE UNDER LOWER EJECTION ANGLES.• THE WALL FRAGMENTS ARE EJECTED FROM 0° TO APPROX 40° ELEVATION, HIGHER EJECTION ANGLES ARE MAINLY FOR ROOF STRUCTURE FRAGMENTS.• IN THIS RANGE OF PARAMETERS, FRAGMENT SPEED IS APPROXIMATED BY SPEED m/s = IMPULSE IN Pa*s / FRAGMENT AREA MASS IN Kg /m2.

AZF , IMPORTANT FRAGMENT IMPACTS

THE MOST IMPORTANT FRAGMENTS ARE:• 221 CONCRETE SLAB• 221 - 222 COLUMNS.MANY FRAGMENTSARE EJECTED UNDERRELATIVE AZIMUT + 15°,THIS ANGLE REFLECTS A CORRESPONDING CHARGE (PART) ORIENTATION.

UNDER -40° A BIG COLUMN PART IS EJECTED, FALLS ON A CAR (R5) AND FINALLY LEAVES A SIGNIFICANT CRATER (SEE HEREAFTER)

FRAGMENT TRAJECTOGRAPHY 80000Pa*s, 32°, Cx 2

AVERAGE SMALL BUILDING FRAGMENTS

COLUMNS 221 - 222 FRAGMENTS • THESE FRAGMENTS CAN EASILY BE IDENTIFIED BY THE STEEL

REINFORCEMENT OF THE CONCRETE PILLAR AND FOR SOME BIG PIECES BY THE ROOF SUPPORTING STEEL LATTICE .• THEY HAVE BEEN MADE (YEAR 98) AROUND THE STEEL LATTICE TO REPAIR THEIR DAMAGED BASE.

FLOORCONCRETE SLAB

STEEL LATTICE COLUMNSUPPORTING THE ROOF

1.80

m

0.8m

MASS ≈ 2200KgAREA DENSITY 1670 Kg / m2

COLUMNS FOUND IN CRATER VICINITY

COLUMNS 221 - 222 FRAGMENTS

• BLACK DOTS ARE THE 11 COLUMNS FOUND IN CRATER VICINITY,• COLUMN 19 (MARKED VIII ) WAS STILL STANDING UPRIGHT ,• COLUMN 14 RECEIVES AN ESTIMATED 20000Pa*s IMPULSE, SO WE TAKE THIS VALUE AS THE POWER NEEDED TO BREAK AWAY AND INITIATE MOVEMENT,• COLUMNS 2 TO 8 RECEIVE AN ESTIMATED IMPULSE OF 220000Pa*s,• TO EJECT THESE COLUMNS WE HAVE 0.65*(220000 - 20000)Pa*s =130000Pa*s , (0.65 FOR CIRCULAR COLUMN / EFFICIENCY FACTOR) .

Ba

t 22

1

EAST

Car Az - 40°

34

5

6

8

10

7

9

15

1112

13

14

4.000m

16

17

18

19

Columns found near crater, total 11

0°

20m

Ba

t 22

2

1

2

* 8 Columns (12 to 19) barely moved* 3 Columns close to bdg 224

10m

a

d

b

e

c

Roof supports only a => e

Crater outline

COLUMN OR PART, PERHAPS Nr 8, FALLEN ON CAR

CRATERDiam. 0.8m Depth 0.2m

ONE CAN ASSUME THAT AT LEAST, THE HALF UPPER COLUMN HAS HIT THE CAR AT ≈ 50m/s, BEFORE IMPACTING THE GROUND AT ≈ 30m/s, DISTANCE 420m, Az – 40° , SOUTH- WEST, ELEVATION IMPACT ANGLE ≈ 40°, CRATER DEPTH COHERENT WITH A FINAL SPEED OF 30m/s.

COLUMN STEEL LATTICE

SCATTERED DEBRIS

CAR FRONT DETAIL

40°

DETAIL

HEAVY PROJECTIONS TRAJECTOGRAPHY 130000Pa*s, 32°, Cx 2

CALCULATED FOR THE COLUMNS PARTS, BLDG 221-222 SEPARATION

POSSIBLE CAR IMPACT

HEAVY PROJECTION, EMPALOT BLOCK

THIS REINFORCED CONCRETE BLOCK FELL IN A SUBURB CALLED EMPALOT, 1600m FROM AZF CRATER!

REBAR

HEAVY PROJECTION, EMPALOT CONCRETE BLOCK

THIS FRAGMENT HAS A MASS APPROX 300KG , PROBABLY VERY COMPACT, LOW Cx , AND DIMENSIONS ESTIMATED 0.7x0.5x0.4m,

1600m ! SUCH DISTANCE FOR A CONCRETE BLOCK SEEMS EXEPTIONNAL .

THIS INCREDIBLE FRAGMENT HAS NOT BEEN ANALYSED AND WE HAVE NO CLUE OF ITS ORIGIN!!

AS IS KNOWN, THE USUAL MAXIMUMTHROW DISTANCE FOR SECONDARY FRAGMENTS IS IN THE PERPENDICULARBUILDING AXIS.

Ba

t 22

1

Ba

t 22

2

EAST

a

b

cde

1

234

5

6

7

89

Empalot

20m

Box

3T, 2nd det

40T first det

1bars*s

1,9bar*s

2,1bar*s

17°

600m

Impact bdg I8 ? or Y1?45°26°

Detonated pile

Crater outline

SOUNDS

EXPLOSION SOUNDS• IN MANY PLACES, AROUND THE TOWN, RECORDED

CONFERENCES WERE HELD SO AS ONE RADIO STATION EQUIPPED WITH PROFESSIONAL SOUND EQUIPMENT,

• BASICALLY THE TAPE RECORDERS ARE LIMITED IN THE LOW FREQUENCY BAND AND HAVE NO TIME BASE.

• THESE RECORDINGS HAVE BEEN STUDIED BY NOT LESS THAN THREE DIFFERENT EXPERTS !!

• TWO MAIN NOISES, SIMILAR TO EXPLOSIONS ARE HEARD,• THE RECORDS, CORRECTED FOR TAPE SPEED VARIATIONS

REVEAL THE TIME DIFFERENCE OF E1 AND E2 AT THE DIFFERENT LOCATIONS ,

• E2 IS OBVIOUSLY THE AZF BLAST ARRIVAL AND E1 IS BELIEVED TO BE THE SEISMIC WAVE ARRIVAL ON THE BUILDING, INDUCING THE E1 RECORDED SOUNDS,

• INDEED, EVEN IF SUCH DATA IS NOT WELL DOCUMENTED THE TIME DIFFERENCE BETWEEN EVENTS E1 AND E2 IS TOO CLOSE AT THE DIFFERENT LOCATIONS TO BE ORIGINATED BY A LOW SPEED WAVE SUCH AS SOUND.

SOUND RECORDING PLACES

WIND

URSSAF

POUVOURVILLE

H DR P

OMP

E D

BLAGNAC

A F

ABREUVOIR

TELEPHONE CONVERSATION

H P

AZF

GOOGLE MAPS

SOUND SEISMIC ARRIVALS

• IF SOUND E1 IS THE ACOUSTIC INDUCED SEISMIC PERTURBATION BY AZF, WE HAVE A VERY GOOD CORRELATION (<0.02s) BETWEEN THE TIME DIFFERENCES THEORETICAL , AND MEASURED ARRIVALS (EXEPT FOR « HP » , PURPAN HOSPITAL).• FOR THE SEISMIC SITES WE HAVE A VERY GOOD CORRELATION BETWEEN THE THEORETICAL TIME DIFFERENCE BETWEEN P WAVE AND AIR SLAP.• IS THERE A REASONABLE DOUBT WHEN THESE MEASURED PARAMETERS POINT ALL TOWARD AZF DETONATING AT To, EVEN IF ITS SEISMIC SIGNATURE SEEMS FAR TOO LARGE AND NOT ALL EVENTS CAN BE EXPLAINED?

SOUNDS ACOUSTIC / SEISMIC NORMAL SPEECH (SEE GRAPH 1)30Hz => 10KHz BANWIDTHMICRO PRESSURE ≈ 0,4Pa SEISMIC ARRIVALS CONVERTED INTO SOUNDAT THE SOUND RECORDINGPLACES Pa ≈ 0.420 * Vmm/s,420 = AIR IMPEDANCE,THE SEISMIC (GRAPH 2) INDUCEDPRESSURES ≈ SPEECH PRESSURE,THE SEISMIC FREQUENCIESARE USUALLY MUCH LOWER, BUT SPECTRAL MODULATION FROM AN8ms DURATION, LINE DETONATION, FURNITURE SHAKING, MICROPHONE VIBRATIONS, HARMONICS, CAN EXPLAIN MUCH HIGHER FREQUENCIES,NOT PICKED UP BY GEOPHONE BUT BY MICROPHONE.

SEISMIC / SOUND CORRELATION

SOUND LEVEL RECORDER POUVOURVILLE

• THIS SONOMETER IS DEDICATED TO MONITOR AIRCRAFT NOISE, SOUTH EAST AND 3840m FROM AZF,• THIS RECORDER WOULD HAVE DEFINITIVELY NAILED DOWN THE TIME OF AZF DETONATION BUT NO LUCK , THE EQUIPMENT, RECENTLY INSTALLED WAS NOT YET LINKED TO AN OFFICIAL TIME BASE, IT HAD ONLY THE COMPUTER TIME, SET FEW MONTHS BEFORE.• THE AZF BLAST, GOING UPWIND NEEDS 11s TO ARRIVE AT THE SOUND MONITORING STATION,• OBVIOUSLY THERE IS A BIG TIMING PROBLEM ,SINCE THE BLAST ARRIVAL IS 10H18:18 , MINUS 11s , WHICH PLACES THE To AT 10H18:07 , UNREALISTIC.• A TIME CORRECTION BASED ON RADAR FLIGHT PATHS (SEE HEREAFTER) GIVES AT BEST A ± 3s ACCURACY.

SOUND LEVEL RECORDING POUVOURVILLE

SATURATED LEVEL ?

OVERFLYING AIRCRAFTS

45dBA NOISE LEVEL

ESTIMATED SENSITIVITY 1Pa,NO PRIOR EXPLOSION TO BE SEEN

BEFORE AZF, ON THIS RECORD

SOUND LEVEL RECORDING POUVOURVILLE

SONOMETER

SONOMETER

LBT 3317FLIGHT PATH

AF - ELFLIGHT PATH

THE FLIGHT PATH TIMINGS, ARE SHOWN HERE AT LOCAL TIME BUT THEY DO NOT ALLOW A PRECISE TIME CORRECTION.

BLAGNAC,RUNWAYS

AZF

AZF

4400 feet10h10:10

3500 feet10h09:30

5000 feet10h13:25

5800 feet10h11:07

6600 feet10h14:01

2000 feet10h11:54

4100 feet10h12:57

CRATER

AZF CRATER AND VICINITY

PRILLING

TOWER

EAST

GARONNE RIVER

NORTH

CRATER PROFILE WITH BUILDING

MAIN STOCKPILE

“BOX” PILES

MAX DEPTH 7,0m

VOLUME 8700M3

45m

65m

BLDG OUTLINE

NORTH

CRATER PROFILE / CHARGE

CRATER BOTTOM

Box

CHARGE ESTIMATION

CENTRAL PEAK

CRATER RIDGE

CRATER EAST END BLAST PROFILED

http://www.esic-sn.fr/PDF/ESIC-XYZ-AZF.pdf ISIG

CRATER PROFILE• AZF CRATER IS ELLIPTIC ≈ 65 x 45 x 8m , FINAL

VOLUME 8700m3 , • THE AZF CRATER DIMENSIONS MATCHES AN

EQUIVALENT TNT CHARGE OF ≈ 100Tons.• THE CRATER PROFILE IS SYMETRIC ACROSS EAST/

WEST AXIS BUT NOT SYMETRIC NORTH / SOUTH AXIS, LOW SLOPE EAST 11° AND 30° IN THE 3 OTHER DIRECTIONS.

• THE WATER BED LEVEL IS ≈ - 3m• DETONATION INITIATION IS PROBABLY ON THE

EAST SIDE.• CONWEP IS OF NO HELP FOR CYLINDRICAL

CHARGES PLACED HORIZONTALLY (THE BOMB CRATERING COMPUTATION, CONSIDERS THE BOMB IN VERTICAL POSITION).

CRATER CONSIDERATIONS

• THE CRATER PROFILE IS FUNCTION OF THE VERTICAL CHARGE DENSITY,THAT MEANS, IN THE CASE OF AN EXPLOSIVE STOCKPILE ,THE CRATER IS DUG IN THE GROUND AS A MIRROR OF THE EFFECTIVE DETONATING PILE ABOVE.

• THIS MIRROR CAVITY HAS AN AMPLIFICATION FACTOR FUNCTION OF CHARGE / SOIL TYPE,

• THE CAVITY, IS ALSO MODELLED BY THE CHARGE INITIATION POINT (Ki = 1 center, 1.15 top, 0.85 bottom)

• FOR A STOCKPILE , THE CRATER DIMENSIONS ESTIMATION (TO BE VERIFIED):

▫ DEPTH Dc = 1.2*Ki *(TK /ρs )1/2 * Hp1/2 *( Lp*Wp)1/4,

▫ LENGTH Lc = 1.2 * Ki *(TK /ρs)1/2 *{ Lp + 2.5 *(Wp*Hp)1/2 }

▫ WIDTH Wc = 1.3 * Ki *(TK /ρs)1/2 *{ Wp + 2.5 *(Lp*Hp)1/2 } Hp PILE HEIGHT, Lp PILE LENGTH ,Wp PILE WIDTH IN METERS TK DETONATION GAS TEMPERATURE °K, ρs SOIL DENSITY Kg / m3.

CRATER PROFILE FOR RECTANGULAR CHARGE

• IT IS MY UNDERSTANDING THAT AN END INITIATION WOULD HAVE THE LONGITUDINAL RED PROFILE, COMPARED TO THE BLUE PROFILE FOR A CENTER INITIATION, BOTH CRATER VOLUMES BEEING SIMILAR.

• THE AZF CRATER HAS THE RED PROFILE IN TERMS OF DEPTH AND LONGITUDINAL POSITION VERSUS CHARGE POSITION.

CRATER LENGTH

METERS

CRATER DEPTH METERS

CHARGE

CRATER EAST PROFILE

EAST

• THE CRATER PROFILE ON THE EAST SIDE SEEMS SHAPED BY A GAS PLUME SIMILAR TO A ROCKET ,• IN LESS THAN 1ms, 20T OF GAS AT 1700K ARE EJECTED TO THE REAR AT TREMENDOUS SPEED > 1000m/s , IT COULD WELL EXPLAIN THE EAST SIDE CRATER GROUND SHAPING.• THEREFORE, THE DIFFERENT ASPECTS OF THE CRATER PROFILES ARE CONSISTANT WITH AN EAST SIDE START OF THE DETONATION (THIS, AS EVERYTHING ELSE IS DISPUTED).

EXPLOSIVE GASES

SHOCK FRONT

SEISMIC

MY SEISMIC (IN)COMPETENCE

• I CANNOT GO ANY FURTHER WITHOUT INFORMING THE READER THAT MY SEISMIC KNOWLEDGE HAS ONLY BEEN GATHERED SINCE AZF STUDY, THAT MEANS BEGIN 2009.

• PRIOR THAT DATE I ONLY KNEW SOME BASICS ABOUT THE RICHTER SCALE.

• THEREFORE MY TECHNICAL APPROACH ON THIS SUBJECT MUST BE READ WITH CARE.

• BY ENTERING THIS FIELD, LITTERED WITH LOG FORMULAS, ONE MUST ALSO BE AWARE THAT SMALL APPROXIMATIONS LEAD TO IMPORTANT CHANGES OF THE FINAL RESULT.

AZF SEISMIC ANALYSIS• THE AZF DETONATION HAS BEEN WELL RECORDED AT

LARGE DISTANCES (A DOZEN RéNaSS STATIONS AND AS MANY CEA - DASE STATIONS SEE MAP HEREAFTER).

• THE AVERAGE MAGNITUDE GIVEN BY THOSE SEISMIC STATIONS IS ML = 3.3.

• ONE NAMED OMP IS VERY INTERESTING SINCE THE LOCATION IS 4190m FROM GZO.

• IT HAD A REJECTED SEISMOMETER FOR RECORDING TESTS , NOT INSTALLED PROPERLY,THE SENSOR JUST SET ON THE FLOOR OF A GROUND FLOOR OFFICE.

• IT PROVIDED EXELLENT SIGNALS.• UNLUCKYLY, THE PERSONNEL IN CHARGE WAS TOO

INCOMPETENT TO PROVIDE ACCURATE CALIBRATION OF THIS EQUIPMENT (EVEN THE SENSOR ORIENTATION NEEDED TO BE CORRECTED TWICE)!

PYRENEEN SEISMIC STATIONS

AZF SEISMIC ARRIVAL AT STATIONS :

OMP VERTICAL SEISMIC SIGNAL

DETAIL OF FIRST P WAVE ARRIVAL,

VP = 4190m / 1.42s = 2950 m / s

AIR SLAP

V = 4190m/ (10.57+1.42)s =

349.5 m/s

ΔT = 10.57s

To

ΔT = 1.42s

OMP AIR BLAST SPEED INVESTIGATION

• WE HAVE THE MEASURED AVERAGE BLAST SPEED ARRIVING AT OMP AS 4190m / 11.99s = 349.5m/s,

• THIS BLAST SPEED MUST BE WIND CORRECTED, 6,7m/s*COS (150°- 98°) = + 4.1m/s => 349.5m/s + 4.1m/s = 353,6m/s, (98° GZO => OMP), • SO THE THEORETICAL BLAST SPEED IS IN FACT 353,6m/s. • THE SOUND SPEED AT 17.2°C AND 88% HYGRO IS 342.7 m/s,• THE DIFFERENCE OF THE AVERAGE BLAST SPEED TO SOUND

SPEED IS THEREFORE 353,6m/s - 342.7m/s = 10.9m/s, • THIS OVERSPEED ΔV IS RELATED TO THE SCALED DISTANCE Dr AS ΔV m/s = 1100/ Dr for Dr > 30, => W = (ΔV * D / 1100)3

SO W = (10.9 m/s * 4190m / 1100)3 ≈ 71600Kg TNT ( FACTOR 1100 FOR THE GIVEN ATMOSPHERIC CONDITIONS). THIS CALCULATED CHARGE CONFIRMS THAT THE 70T TNT

FOR THE BLAST ESTIMATION IS REASONABLE. THE EMPIRICAL SCALING LAW AND WIND, DOES NOT ALLOW A

PRECISION BETTER THAN ± 20% .

OMP SEISMIC VERTICAL SPEED• OMP GEOPHONE USED TO RECORD THIS SIGNAL IS A MARK PRODUCTS SENSOR, TYPE L- 4C3D HAVING A SENSITIVITY OF 171V/ m / s,• IT IS ASSOCIATED TO A HARRIS DECODER 24BITS, DYNAMIC RANGE FROM – 4V TO + 6V => LSB = 6V-(- 4V )/ 224 = 600nV => ONE THEORETICAL COUNT => 600*10-9V / 171V/m/s = 3.51*10-9m/s.• OMP HAS PROVIDED THREE DIFFERENT CALIBRATIONS

FOR THE VERTICAL CHANNEL: (1.78 , 2.67, AND FINALLY 0.55)*10-9 m/s / Count,• THE P WAVE AT MAX 280KCounts / s IS THEN, BASED ON

THESE CALIBRATION DATAS, SOMEWHERE BETWEEN 0.15 AND 0.74 mm/s.

• THESE FIGURES SHOULD BE MULTIPLIED BY AN UNKNOWN LOSS FACTOR FOR INSIDE BUILDING MEASUREMENTS.

OMP SIGNAL ESTIMATION• THE SEISMIC PARTICULE VELOCITY INDUCED BY THE

BLAST AT SUCH DISTANCE IS MAINLY FUNCTION OF THE BLAST PRESSURE AND THE SOIL IMPEDANCE,

• THE FORMULA IS V ≈ P / Z , V THE VERTICAL SPEED, P IS THE OVERPRESSURE AT OMP AND Z THE SOIL IMPEDANCE.

• IF WE CONSIDER THE MAXIMUM AIR SLAP SPEED RECORDED AT 50KCounts / s, P ≈ 550Pa FOR 70T AT 4190m, Z ≈ 3*106 Pa*s / m, V = 550Pa / 3*106 m / s => 0,18mm/s

• THAT MEANS THAT P WAVE SIGNAL RECORDED AT 280KCounts SHOULD BE APPROX. 280*0.18/50 ≈ 1mm/s.

• USING CONWEP , WITH 80T TNT FOR GROUND SHOCK ATTENUATION 1.7 , GROUND COUPLING FACTOR 0.2, AT DISTANCE 4190m WE OBTAIN ≈ 0.7mm/s.

• THE USE OF THIS FORMULA AND THE FACT THAT THE SEISMIC SENSOR WAS INSIDE AN OFFICE BUILDING GIVES ONLY AN APPROXIMATED FIGURE.

OMP FINAL CONSIDERATIONS• AT 4190m FROM GZO,THE GEOPHONE, POSITIONED ON

THE OFFICE CONCRETE FLOOR, HAS WELL RECORDED THE SEISMIC SIGNALS, BUT THE PHASES AND AMPLITUDES ARE MOST PROBABLY BIASED.

• THE RELATIVE TIMINGS PROVIDE ACCURATE INFORMATION (BUT NO ABSOLUTE TIME REFERENCE).

• THE TIME OF ARRIVAL FOR THE BLAST IS NOT A GOOD PARAMETER FOR CHARGE ESTIMATION,

• AT OMP, A 10% CHARGE VARIATION MAKES ONLY ≈ 0.1% DIFFERENCE OF BLAST TIME ARRIVAL.

• THE REAL PARTICULE VELOCITY OF THE P WAVE IS PROBABLY IN THE RANGE 0.5 TO 1 mm/s.

• THE UNKNOWN BUILDING ATTENUATION MODIFIES THE SIGNAL AMPLITUDES AND PHASES.

SEISMIC MAGNITUDE

• THE AVERAGE SEISMIC MAGNITUDE RECORDED , ML = 3.3 ,• ASSUMING THIS MAGNITUDE IS AZF DETONATION, HOW DO WE ESTIMATE THE CHARGE W ?• IN FACT SOME STUDIES BASED ON NUCLEAR OR

CHEMICAL DETONATIONS RELATE THE MAGNITUDE TO THE CHARGE,

• THE FORMULAS ARE IN THE FORM M = K*log(W) + G WITH “K” A COEFFICIENT RANGING FROM 0.70 TO 0.85, “W” THE CHARGE AND “G” A CORRECTION FACTOR FOR

SOIL / PROPAGATION SPECIFICITIES,• THE NUCLEAR TESTS HAD AN AVERAGE MAGNITUDE OF

mb = 0.85*log(W KT) + 4.2 , (+ 3.8 FOR NEVADA TESTS, DUE TO EARTH PROPAGATION PARTICULARITY).

MAGNITUDE RELATED TO CHARGE

• A DERIVED FORMULA IS M = 0.75*log (f*WKg) + G, WE INCLUDE THE DEFICIT LINKED TO THE GROUND COUPLING FACTOR “f “, (f = 0.14 FOR SURFACE DETONATION) , AND USE G = - 0,2 AS MAGNITUDE DEFICIT FOR ALLUVIUM SOIL,

• USING THOSE ASSUMPTIONS WE OBTAIN : M = 0.75*log( 0,14*100000) - 0,2 ≈ 2.9 , 10% LOWER THAN THE AZF MEASURED AVERAGE OF 3.3.

TO EXPLAIN THIS 10% CALCULATED MAGNITUDE DEFICIT ONE COULD ASSUME A DOWNWARD DETONATION, IMPROVING BY SUCH FACTOR THE GROUND COUPLING.

EAST

INVESTIGATION MAIN TESTS /

TRIALSAUDITIONS

DCCNa CHLORE INVESTIGATION

• A REASONABLE DOUBT WAS ABOUT SOME CHLORE PRODUCT, DCCNa, SKIPPED BY ERROR IN THE BLDG 221 BOX,

• THIS PRODUCT, FORMULA C3N3O3Cl2Na, HAS A VERY STRONG CHLORE SMELL,

• THE JUDGE ORDERED THE REENACTING OF THE SHOVELING OF SUCH PRODUCT,

• IT WAS FUNNY TO WITNESS HOW FAST THE ASSISTANCE MOVED FROM THE SCENE, SUFFOCATING,

• SO THE THEORY CHANGED FROM IMPORTANT QUANTITIES SHOVELED BY INADVERTANCE ,TO A FEW KILOS OF THIS PRODUCT,

• NEVERTHELESS,THE EXPERTS CONSIDERING SUCH EVENT COULD HAVE HAPPENED, LAUNCHED A HUGE AND COSTLY INVESTIGATION BASED ON THIS REMOTE POSSIBILITY.

DCCNa CHLORE INVESTIGATION

• THEORETICALLY IT WAS PROVEN THAT DCCNa, MIXED WITH AMMONIUM NITRATES AND SOME WATER, COULD PRODUCE NCl3 , WHICH INDEED IS A PRIMARY EXPLOSIVE,

• WELL ENGINEERED TRIALS PROVED THAT SUCH PRIMARY DETONATION CAN HAPPEN, EVEN IF ONLY ONE OUT OF 20 TRIALS WAS POSITIVE!!

• IN CASE THE MAIN STOCKPILE IS VERY CLOSE TO THE “BOX “ THE SOIL CRUST CONNECTING BOTH PILES, SYMPATHETIC DETONATION COULD OCCUR,

• BUT THIS THEORY IS VERY FAR FROM THE REAL FIELD CONDITIONS , AND EVEN MORE IMPORTANT , IT IS BASED ON THE UNPROVEN FACT OF DCCNA PRESENCE IN THE BOX.

DCCNa INVESTIGATION, EXPERT VERSION

INITIATOR

EAST

RELAY 2RELAY 1

MAIN STOCKPILE

WALL

10T NAA PILE

2 NAI PILES

NAI + DCCNa

WET « AN » CRUST

WE REPRODUCE THIS NICE DRAWING FROM THE FINAL EXPERT REPORT

FORGOTTEN WALL?

DCCNa SOLUTION

• FIRST, THE PRESENCE OF CHLORE, IN SUFFICIENT QUANTITIES IN THE “BOX “ IS FAR FROM PROVEN,

• SECOND, AFTER MANY COMPLICATED CHEMICAL TRANSFORMATIONS, THE PRODUCTION OF NCL3 IN REAL CONDITIONS, COMPARED TO THE WELL ENGINEERED TRIALS, IS RATHER DOUBTFUL,

• THIRD, THE DISTANCE LAW FOR SYMPATHETIC DETONATION APPLIES BETWEEN TWO EXPLOSIVES AND NOT FOR AN EXPLOSIBE (BOX) AND A FERTILIZER STOCKPILE ,

• FOURTH THE REAL DISTANCE BETWEEN THE PILES, HAS BEEN MANIPULATED,

• FIFTH THE “BOX”SEPARATING WALL IS IGNORED.• FINALLY THIS SOLUTION HAS THE MERIT TO BE THE ONLY

EXPLANATION OF THE STOCKPILE INITIATION , UNFORTUNATELY IT HAS ONLY A TINY PROBABILITY TO BE TRUE,

TESTS AND TRIALS , ELECTRICAL 1

EVIDENTLY, IN SUCH INDUSTRIAL ENVIRONMENT MANY HV TRANSFORMERS ARE INSTALLED,

• MAIN POWER AT 225KV , DOWN TO 63KV, 20KV AND 6.2KV,• EVEN IF NO ELECTRICAL CABLING IS IN BLDG 221 A

HIGH GROUND POTENTIAL COULD BE A SUSPECT,• MANY TRIALS HAVE BEEN MADE, ALL NEGATIVE,• SINCE ALL ELECTRICAL CABLES, GROUNDINGS ARE

DESTROYED AT CRATER VICINITY ,THESE TESTS CAN GIVE AT BEST AN INDICATION BUT NO PROOF.

• ELECTRICAL DISTURBANCES HAVE BEEN REPORTED PRIOR To , BUT THEY COULD NOT BE TRACED,

• DUE TO THE DETONATION, NUMEROUS ELECTRICAL ANOMALIES HAVE BEEN AUTOMATICALLY RECORDED,

• BUT PRIOR To, NOTHING CONSISTANT.

TESTS AND TRIALS , ELECTRICAL 2

EVIDENTLY, HUGE ELECTRICAL POWER WAS AVAILABLE ON THE SITE,THE DIFFERENT LINES WERE INTERCONNECTED FOR BACK UP REASONS AND THE RESULTING NET WAS RATHER COMPLEX,• THE EXPERTS CONCLUDED THAT ELECTRICAL DISTURBANCES COULD NOT BE RESPONSIBLE FOR THE DETONATION.• CURIOUSLY, ON THE 63KV LINE CLOSE TO AZF, THE MAST TOP GROUNDING CABLE HAS BEEN REPAIRED MANY TIMES, AT SHORT DISTANCES, • THIS COULD INDICATE THAT THE ELECTRICAL ENVIRONMENT / GROUNDING AT AZF AND VICINITY, WAS NOT REALLY UNDER CONTROL.

63KV LINE, ELECTRICAL 3

• ON THE 63KV LINE (SEE HEREAFTER) THE CABLE OFPHASE 7 HAS BEEN FOUND CUT, BOTH ENDS LYINGON THE GROUND, MIDDLE OF THE SUPPORTING TOWERS,• A SHORT CIRCUIT BETWEEN PHASE 7 AND PHASE 3(SOME 2.5m ABOVE LINE 7) IS RECORDED AT 10H18:07.39s.• THE EXPERTS EXPLANATION IS THAT THE FAILURE OCCURED DUE TO A ≈ 70Kg METALIC FRAGMENT, WHICH AFTER A 11s PARABOLIC FLIGHT , HITS AT HIGH ANGLE LINE 7 AND THE UP-REBOUND LINKS PHASES 7 AND 3,• THE SHORT CIRCUIT FINALLY RUPTURE THE CABLE WHICH HAD ALREADY BEEN WEAKENED BY THE BLAST AND FRAGMENT HITS .• PROBLEM, NO SUCH HEAVY FRAGMENT HAS BEEN FOUND AND THIS THEORY SEEMS RATHER UNBELIEVIBLE,• 15 PAGES OF THE FINAL REPORT GIVE DETAILED CALCULATIONS FOR SUCH REMOTE PROBABILITY!!

ELECTRICAL LINES, TRANSFORMERS

T36

T0,T10

T24

T53

T23

220KV6,2KV

T xx 6,2 KV

380V, 3Φ

63KV

20KV

LA FOURGUETTE

63 KV LINE

LINE CUT

P9

P10

SEISMIC TRIALS YEAR 2004 PART 1

THE PURPOSE OF THESE TRIALS WERE:• PROVIDE THE SOIL SEISMIC CHARACTERISTICS,• DEFINE PRECISELY THE ARRIVAL TIMES FROM AZF

CRATER TO THE PLACES OF INTEREST ,• TRY TO COMPARE THE WAVES AND AMPLITUDES AT

THE SEISMIC STATIONS BETWEEN THESE TRIALS AND AZF EVENT.

FOR THESE TRIALS CHARGES OF YIELD BETWEEN 1 AND 35Kg HAVE BEEN FIRED, CYLINDRICAL SHAPE, PLACED VERTICALLY, AT A DEPTH AROUND 30m.

FOR SUCH CAREFULL ENGINEERED TRIALS THE COUPLING FACTOR CAN BE CONSIDERED AS OPTIMAL.

SEISMIC TRIALS 2004 PART 2

DEPTH m SOIL ρ SOIL Kg / m3 VP m/s VS m/s

0 - 5 DRY ALLUVIUM

1460 500 200

5 - 10 WET ALLUVIUM

1930 1500 500

> 10 MOLLASSES ≈ 2000

1000 3800 2200 est.

4000 5000 3000 est.

THE ACCURATE WAVE SPEED MEASUREMENTS ARE PROVIDED IN THE SOUND CHAPTER WITH THE PURPOSE TO COMPARE THE ARRIVAL TIMES SOUND / SEISMIC.THE VERTICAL SOIL SPEED MEASUREMENTS HAS AN OVERALL GOOD MATCH IN THE RANGE UP TO 4.2Km,WITH PPV mm / s = 5000 * WKg0,75 / Dm1.7

SEISMIC TRIALS 2004 PART 3

ADDITIONAL TRIALS HAVE BEEN MADE WITH A

FALLING WEIGHT IN THE VICINITY OF AZF CRATER:

• WEIGHT 20T, HEIGHT 20m,

• ENERGY E = mgh = 3.9*106J, CLOSE TO THE ENERGY OF

1 Kg TNT (4.2*106J/Kg ).

• IN FACT SUCH SEISMIC SIGNATURE WAS, AT CLOSE RANGE, SIMILAR TO A 1 KG TNT COUPLED DETONATION: THE FALLING WEIGHT HAS A GOOD SEISMIC EFFICIENCY, THE ALLUVIUM SOIL CAN BE CONSIDERED AS A GOOD SEISMIC PROPAGATING MEDIA.

WITNESS VERSIONS

WITNESS LOCATION FUNCTION OF DEPOSITION

A curious geometrical pattern, centered on BLDG 221

63 KV line

WITNESS LOCATION / NUMBER OF EXPLOSIONS

0 DETONATION12

DISTANCE FROM CRATER METERS

NUMBER OF WITNESS, BLACK POINTS

64000 DOLLAR QUESTION , HOW MANY EXPLOSIONS?

SEISMIC RUMBLING , SHAKING

DETONATION TIME THE DETONATION TIME To, BASED ON SEISMIC Pg

WAVE ARRIVAL, ML = 3.3 , To = 10H17: 55.45s ± 0.02s. THE To BASED ON OTHER EFFECTS COULD NOT

BEEN DETERMINED WITH IDENTICAL PRECISION:• TRANSFORMER T 24 SOME 100m FROM BLDG 221 ,

REGISTERED A FAILURE AT 10H17:55.52s ,THIS TIME HAS BEEN CORRECTED BY CORRELATION WITH AN OTHER RECORDER HAVING A REFERENCE TIME, AND ASSUMING A BLAST ARRIVAL TIME OF 100ms WE OBTAIN To 10H17:55.42s ± 0.05s,

• AIR SLAP ARRIVAL AT MTLF STATION IS 10H21:19 THE THEORETICAL SOUND TRAVEL TIME IS 203.8s (SEE EXCEL SHEET IN SOUND CHAPTER) SO WE CAN ESTIMATE To AT 10H17:55s.

DISCOVERED ANOMALIES 1THE INVESTIGATION FOUND OUT THAT : BLDG 221 WAS NOT CONSIDERED AS A SAFETY HAZARD, NEGLECTING COMPLETELY THAT “OUT OF SPECIFICATION AN” WAS STORED THERE ! NO FIRE, SMOKE OR NOx DETECTOR WERE INSTALLED, THE FLUORESCENT LIGHTING WAS NOT ANTI DEFLAGRANT THE RECOMMENDATION OF STORING SEVERAL PILES, 50T EACH WITH A 2 m SEPARATION WERE NOT FOLLOWED, THE 60 YEARS OLD CONCRETE SLAB, WAS HEAVILY DAMAGED, THE CONCRETE EATEN AND PROGRESSIVELY REPLACED BY THE AN CRUST EMBEDED IN THE REBAR, THIS SLAB HAS NEVER BEEN REPLACED AND THE OLD POLLUTED “AN “ CRUST NEVER BEEN REMOVED, WITH THE DOORS ALWAYS OPEN, DEPENDING ON AIR HYGROMETRY, SOME WATER FORMED ON THIS CRUST SEEPING UNDERGROUND THROUGH THE DAMAGED SLAB.

DISCOVERED ANOMALIES 2 UP TO 25 SUB CONTRACTORS WERE WORKING PERMANENTLY ON THE SITE, THE SAFETY MANAGEMENT WAS THEREFORE VERY VULNERABLE ON THIS SEVESO CLASSIFIED SITE, THE MANAGEMENT LOST PROGRESSIVELY KNOWLEDGE OF THE HANDLING, STORAGE AND TRANSPORT PROCESSES. IT HAS BEEN PROVEN THAT PRODUCT FLOW WAS NOT WELL MONITORED, BIG BAGS SUCH AS DCCNa OR Cyanuric acid WERE FOUND AT THE WRONG PLACES => DCCNa ACCIDENT THEORY, ONLY SUB CONTRACTORS WERE WORKING IN BLDG 221, WITHOUT PROOF, HEAVY CRITIC FELL RAPIDLY ON THESE SUB CONTRACTORS ,THIS, AND THE FACT THAT THE COMPANY BARELY KNEW BLDG 221 EXISTENCE, LEAD TO ACCIDENT INVESTIGATION DIFFICULTIES.

DISCOVERED ANOMALIES 3

TO MAKE THINGS A LITTLE BIT MORE COMPLICATED FOLLOWING ANOMALIES ARE WORTH MENTIONING:• 18Kg OF HEXAVALENT CHROME, DELIVERED IN AUGUST 2001, HAVE, AT AN UNKNOWN MOMENT, DISAPPEARED FROM THE AZF STORE,• AN ELECTRIC DETONATOR, TYPE DAVEY BICKFORD, HAS BEEN FOUND UNDER A METAL SHEET, AMONGST BLAST PROJECTIONS, IT BELONGS TO AZF , IT WAS IN PERFECT CONDITIONS, OBVIOUSLY DEPOSITED THERE,• AN ELECTRICAL HV POWER TRANSFORMER CLOSE TO BLDG 221 HAS BEEN REMOVED WITH CUTTING TORCHES AND CRANE , THIS UNAUTHORIZED HEAVY OPERATION WENT COMPLETELY UNNOTICED !

EXPLOSION INITIATION PROBLEM

• NOBODY WAS INSIDE THIS BLDG,• 15 MINUTES PRIOR “To”, BLDG 221, SEEN FROM OUTSIDE

SEEMED NORMAL,• NO ELECTRICAL LINES IN THE BLDG, LIGHT FROM 222. HERE BELOW WHAT HAS (ALMOST) BEEN EXCLUDED:• TERRORIST ACTION,• FIRE, LIGHTNING,• METEORITE AND OTHER FALLING OBJECT,• BOMB FROM LAST WAR UNDER THE PILE,• GUIDED WEAPON IMPACT,• MAGNETIC, ELECTROMAGNETIC IMPULSE,• HIGH ELECTRICAL DISTURBANCE,• BACTERIOLOGICAL , CHEMICAL DECOMPOSITION.

INVESTIGATION ANOMALIES

AND LESSONS

INVESTIGATION MAIN ANOMALIES 1OMP , SEISMIC SIGNALS , A MAJOR WITNESS IS STILL HULLED IN HEAVY FOG:• 3 DIFFERENT CALIBRATION VALUES HAVE BEEN OFFICIALLY PROVIDED SO AS 2 DIFFERENT SENSOR ORIENTATIONS, WHAT CONFIDENCE REMAINS ?• TWO SETS OF DIFFERENT DIGITAL RECORDINGS OF THESE SIGNALS WERE RELEASED, EVEN IF NOT BOTH OFFICIALLY.• THE SENSOR WAS INSIDE OMP BUILDING, ON THE FLOOR, THE TRIALS WERE SUPPOSED TO CLARIFY, THE INSIDE / OUTSIDE SEISMIC / ACOUSTIC DATAS. • THE OMP SEISMIC EQUIPMENT WAS A REJECTED GEOPHONE JUST USED TO TEST THE RECORDERS, BUT THIS REJECTED EQUIPMENT , IT SEEMS, WENT LATER IN OPERATION , NO REPAIR INFORMATION PROVIDED.• THE REJECTED EQUIPMENT WORKED CURIOUSLY WELL, NO CLUE WHY IT WAS REJECTED.• THE JUDGE CONSIDERED THESE ANOMALIES AS NORMAL, (FOR FRANCE PROBABLY).

INVESTIGATION MAIN ANOMALIES 2

THE CRATER, ALSO A MAJOR WITNESS HAS NOT BEEN MODELLED IN DETAILS WITH THE STOCKPILE ABOVE.

• A MODELLING (DYNA2D) ORDERED BY TOTAL HAS BEEN MADE BY QinetiQ ,

• THE WORK IS CORRECT BUT OBVIOUSLY IT LACKS OF DETAILED SIMULATIONS UNDER THE GUIDANCE OF A FRENCH EXPERT OF THE CASE.

• CURIOUSLY THE FINAL REPORT OF THE COURT EXPERTS DOES NOT USE THIS STUDY.

• IN FACT THE COURT EXPERTS USED EXCLUSIVELY THE FACTS SUITABLE TO THEIR DEMONSTRATION AND SIMPLY IGNORED THE REST OR DISCARDED IT AS NOT RELEVANT.

• UNDOUBTLY THIS CASE IS INCREDIBLY COMPLICATED AND THE EXPERTS, IN GENERAL , WERE NO MATCH FOR SUCH A CHALLENGE.

INVESTIGATION MAIN ANOMALIES 3

THE FRAGMENTS, ANOTHER MAJOR WITNESS OF THE DETONATION HAVE NOT BEEN STUDIED AT ALL.

• BASED ON BUILDING CHARACTERISTICS IT WOULD HAVE BEEN EASY TO LOCATE THE ORIGINAL LOCATION OF MOST OF THE BIG FRAGMENTS,

• BASED ON FRAGMENT DISTANCE AND EJECTION ANGLE THE DETONATED STOCKPILE COULD HAVE BEEN MODELLED AND COMPARED TO THE CRATER MODEL.

• MANY HEAVY FRAGMENTS, IN THE MASS RANGE OF 500Kg WOULD HAVE PROVIDED THE IMPULSE ESTIMATION OF THEIR EJECTION,

• THE IMPACT CRATER OF THOSE FRAGMENTS INDICATED THEIR ARRIVAL ANGLE.

• THE FINDING OF ALL ROOF SUPPORTING COLUMNS SHOULD HAVE BEEN A PRIORITY.

POST ACCIDENT INVESTIGATION 1

• THIS CASE HAS PROVEN THE UTMOST IMPORTANCE OF RELIABLE AND PRECISE TIME BASE FOR ALL TYPE OF RECORDING EQUIPMENT,

• WITHOUT SUCH PRECISE INFORMATION IT IS QUITE IMPOSSIBLE TO HAVE AN UNCHALLENGED CHRONOLOGY OF THE DIFFERENT EVENTS,

• WITHOUT SUCH CHRONOLOGY, IT BECOMES IMPOSSIBLE TO RELATE THE EVENTS, WHICH, FOR EXPLOSIONS, OCCUR IN A VERY SMALL TIME GAP.

• USE RECORDERS WHICH DO NOT ERASE PRE ACCIDENT DATA DUE TO POST ACCIDENT DATA SATURATION, ELECTRICAL PRE - DATAS ARE LOST FOR AZF.

• IMMEDIATELY FIND AND SECURE ALL RECORDED DATAS OF THE EVENT ,

• IN AZF CASE, TWO IMPORTANT RECORDS HAVE BEEN DISCOVERED IN 2004 AND 2005 RESPECTIVELY.

POST ACCIDENT INVESTIGATION 2

• THE PRELIMINARY INVESTIGATION MUST QUICKLY ESTABLISH THE MOST CREDIBLE EVENT LIST AND ANALYSE IMMEDIATELY ALL DISCREPENCIES,

• AS TIME GOES, SUCH LATE ANALYSE BECOMES IMPOSSIBLE OR TOO UNRELIABLE.

• EVEN IF DIFFICULT TO ENFORCE IN SUCH CHAOTIC CONDITIONS, THE AUTHORIZED ACCESS OF THE SITE MUST BE DRASTICALLY MONITORED,

• AN OTHER LESSON, IS THE ABSOLUTE NEED OF AT LEAST ONE HIGH LEVEL PROFESSIONAL IN THE MAIN FIELD OF INVESTIGATION.

POST ACCIDENT INVESTIGATION 3

• THE FINAL REPORT OF THE COURT EXPERTS MUST BE CLEAR, CONCISE, DETAILING IN TERMS OF CERTAINITY OR PROBABILITY THE DIFFERENT EVENTS ANALYZED.

• NO NEED TO GIVE A SOLUTION BASED ON GUESSES UNLESS CLEARLY STATED SO.

• AZF FINAL REPORT IS FULL OF MISTAKES AND APPROXIMATIONS, BUT THE FINAL RESULT IS GIVEN WITH A PRECISION OF 3 DECIMALS !!

• AS USUAL, THE FACTS ARE DISTORTED TO FIT THE UNIQUE FOUND SOLUTION.

• EVIDENTLY, MISTAKES IN SUCH IMPORTANT REPORT TRIGGERS IMMEDIATE MISTRUST FOR EVEN THE BEST ANALYSED TOPIC.

• IN FACT, IN ALL SUCH CASES,THE TENDANCY IS TO SEE A CONSPIRATION INSTEAD OF SOLID INCOMPETENCE.

AZF ACCIDENT SCENARIO

BASIC FACTS

THE HUGE DIFFICULTY OF THE CASE IS TO PICK UP THE FEW DIRECTLY RELEVANT FACTS AMONG THE HUNDREDS LISTED. BASED ON MANY WITNESS ACCOUNTS IT SEEMS PROVEN THAT A RELATIVE SMALL DETONATION OR DEFLAGRATION OCCURRED SOME SECONDS PRIOR MAIN DETONATION, A HUGE GROUND POTENTIAL, ELECTRICAL SHOCKS ARE REPORTED PRIOR To AT BLDG 221 VICINITY. THIS FIRST EVENT DID NOT HAVE ENOUGH POWER TO BE RECORDED BY ACOUSTIC OR SEISMIC EQUIPMENT. THE INVISIBLE AGRESSION OCCURED PROBABLY UNDERGROUND TRIGGERED BY SOME GAS POCKETS (POLLUTED UNDERGROUNG ) INITIATED BY THE ELECTRICAL DEFECT.

INITIATION THEORY A DANGEROUS GAS MIX IS JUST WAITING TO BE TRIGGERED BY SOME ELECTRICAL GROUND FAILURE, WHICH SOON OCCURS.THE CONFINED VAPOR EXPLODESBREAKS EASILY A HOLE IN THE CONCRETE SLAB, AND PUSHS UPWARD THE « AN » PRILLS.THE ROOF IS EJECTED AND THE COLUMN IS SUSTAINED BY MORE COMBUSTION GASES FROM THE AGRESSED PRILLS ON COLUMN EDGE.A STRONG HISSING NOISE, HEARD IN AZF VICINITY, COULD BE LINKED TO SUCH HIGH PRESSURE ESCAPING GAS.

STEP 1

STEP 2

STEP 3

AZF DETONATION

IT IS WELL KNOWN THAT IN SUCH COLUMNS WITH PARTICLES RUBBING AGAINST EACH OTHER IMPORTANT STATIC ELECTRICITY BUILDS UP,THE ELECTRICAL DISCHARGES HEAT THE COLUMN EVEN MORE AND WITHIN 2 TO 3 SECONDS THE COLUMN DETONATES AND TRIGGERS THE STOCKPILE WHICH WAS ALREADY HEAVILY AGRESSEDFROM BOTTOM TO TOP.

STEP 4

STEP 5

ANNEXES

SOME TOPICS DETAILED HERE :

• CHARGE CONSIDERATIONS,

• GROUND COUPLING FACTOR,

• SEISMIC ENERGY,

• PEAK PARTICULE VELOCITY

• MAGNITUDE <= > CHARGE RELATION,

• TERRORIST ATTACKS / ACCIDENTS

CHARGE CONSIDERATIONS 1WE COMPARE HERE THE STANDARD REFERENCE SPHERICAL / HEMISPHERICAL CHARGE USED FOR ALL SOFTWARES / CHARTS WITH OUR SUPPOSED PARALLELIPEDIC OR CYLINDRICAL CHARGE:

• FOR BLAST EFFECT,

• FOR GROUND SHOCK,FOR COMPARISON WE REPRODUCE THE NEAR FIELD BLAST EFFECTS OF AN ALMOST EQUIVALENT CYLINDRICAL CHARGE.

CHARGE CONSIDERATIONS 2

FOR BLAST EFFECT, A CYLINDRICAL / PARALLELIPEDIC CHARGE GEOMETRY GIVES A DIRECTIONAL BLAST DIAGRAM ( SEE HEREAFTER).

75T TNT EQUIVALENT

CG 1.0m

R ≈ 2.8m

R = 2.2m

CG 2.2m

CG 0.7m

CYLINDRICAL CHARGE, NEAR FIELD PRESSURES

• FIGURES FOR THEORETICAL NEAR FIELD OVERPRESSURES VERSUS AZIMUT, FOR A CYLINDRICAL CHARGE 70T TNT WITH L / D ≈ 5 ,

END INITIATED, GIVEN AT DIFFERENT DISTANCES.

• TOP FIGURE CANNOT APPLY EXACTLY TO OUR STOCKPILE, DUE TO ITS IMPORTANT DIMENSIONS.

• CYLINDRICAL (OR PARALELLIPEDIC) CHARGES GENERATE SECONDARY SHOCK WAVES SOMETIMES GREATER THAN THE INITIAL SHOCK (OFTEN IN THE LONGITUDINAL AXIS )

• FOR D > 300m PRESSURES ARE CLOSE TO HEMISPHERICAL CHARGE

Pressures in bar

Pressures in mbar

BASED ON NWC TP 6382

AZF CHARGE, PRESSURE FOCUSING NORTH

150m

• THE GROUND COUPLING FACTOR “ f ” AS DEFINED BY CONWEP IS A FACTOR TAKING INTO ACCOUNT: THE CHARGE ENERGY PARTITIONING AIR / GROUND , THE CHARGE / GROUND EFFICIENCY FOR RADIATED SEISMIC EFFECTS,• THIS FACTOR DOES NOT TAKE INTO ACCOUNT THE CHARGE INITIATION POINT AND THE SOIL SPECIFICITY.• THIS FACTOR VARIES FROM 0.14 FOR SURFACE DETONATION TO 1 FOR FULLY BURIED AND EARTH/ROCK INTIMATE CONTACT.• FOR CONWEP, ALL SEISMIC EFFECTS ARE PROPORTIONAL TO THIS FACTOR.• FOR PARTIALLY BURIED CHARGES f = (0.14*W1 + 0.4* W2) W WWITH W1 AND W2 THE CHARGE PARTS RESPECTIVELY ABOVE AND BELOW SURFACE AND W THE TOTAL CHARGE.

• WE COMPARE ALSO CONWEP TO LAMPSON COUPLING FACTOR, HIS ESTIMATION TAKES INTO ACCOUNT THE EFFECTIVENESS LOSS AT GREATER DEPTH DUE TO

SOIL DENSITY INCREASE.

GROUND COUPLING FACTOR 1

• CONWEP IS THE RED FUNCTION, WE HAVE ADDED THE ESTIMATED FACTOR CURVES FOR UPWARD / DOWNWARD CHARGE INITIATION,• WE COMPARE ALSO CONWEP TO LAMPSON COUPLING FACTOR, HIS ESTIMATION TAKES INTO ACCOUNT THE LOSS OF CHARGE EFFECTIVENESS AT GREATER DEPTH

DUE TO SOIL DENSITY INCREASE.

GROUND COUPLING FACTOR 2

FOR SURFACE CHARGES GROUND EFFECTS, WE HAVE TO CONSIDER FOLLOWING FACTORS:• CHARGE SURFACE S IN CONTACT OR PROJECTED ON THE GROUND / TOTAL CHARGE SURFACE,• HEIGHT OF CHARGE GRAVITY CENTER, HG

• INITIATION POINT, Init

• AZF CHARGE HAS AN ESTIMATED IMPROVED GROUND IMPACT OF 40% COMPARED TO HEMISPHERICAL , • THAT MEANS THAT THE BASIC COUPLING FACTOR OF 0.14 COULD BE 0.20 FOR AZF CHARGE.

GROUND COUPLING FACTOR 3

CHARGE S HG Init

AZF 150 / 400 = 0.375 1.4 / 2 = 0.7 ?

HEMISPHERICAL πR2/3πR2 = 0.33 0.35*2.8 = 1 Center

SPHERICAL πR2/4πR2 = 0.25 2.2 Center

PEAK PARTICULE VELOCITY FORMULA

• FOLLOWING CHART IS AN EXTRACT OF SOME FORMULAS,

• THE RANGE OF VALIDITY OF THE FORMULAS IS NOT KNOWN,

• ALL FORMULAS HAVE BEEN AFFECTED BY A COUPLING FACTOR 0.14 TO REMAIN COMPARABLE,

• A PPV CLOSE TO 1mm/s IS EXPECTED AT 4190m FOR 80T.

• CONWEP IS THE LOWEST FOR CHARGES >10000Kg

DUE TO THE 1.7/ 3 = 0.57 => SMALLEST CHARGE EXPONENT.

SEISMIC INDUCED SOUNDS

• WHEN THE SOIL VIBRATES, IT COMMUNICATES THE VIBRATIONS TO THE AIR, SIMILARLY AS DOES A LOUDSPEAKER,

• THE INDUCED PRESSURE Pa = Vm/s* ρKg/m3 * c m/s, V THE SOIL PARTICULE VELOCITY, ρ THE AIR DENSITY AND c THE SONIC SPEED, SO WE OBTAIN 1Pa FOR ≈ 2.5mm/s .

FOR BURIED DETONATIONS IN ALLUVIUM SOIL, Vm/s ≈ 5*(DOB/W1/3)-2.3, W THE TNT CHARGE IN Kg AND DOB ( DEPTH OF BURST) IN METERS.

Example : FOR W = 35 Kg, DOB = 30m, Vm/s = 0,03 OR 30mm/s => P = 1Pa* 30mm/s / 2.5mm/s = 12Pa.

Note: THE SOIL VIBRATION SPEED INDUCED BY SOUND PRESSURE IS MUCH LOWER, ONLY ≈ 1μm/s FOR 1Pa, DUE TO SOIL AND AIR, STRONG IMPEDANCE DIFFERENCE.

MAGNITUDE TO CHARGE FOR NUCLEAR TESTS

33,5

44,5

55,5

66,5

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mb

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mb

ex URSSmb = 0,85logYKT+4,2

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KT

mb

Essaisatmosphériques

USA NEVADA mb = 0.85*log(WKT) + 3.8

EX URSS mb = 0.85*log( WKT) + 4.2

FRANCE PACIFIC mb = 0.85*log(WKT) + 4.17 THE YELLOW TREND LINES

CHECK THE 0.75 (INSTEAD 0.85) LOG COEFFICIENT, ( IN FACT W EXPONENT ), COEFFICIENT 0.75 SEEMS A BETTER OVERALL FITFOR SMALLER CHARGES.

3 ATMOSPHERIC TESTS

SEISMIC EFFICIENCY IN FACT, PREVIOUS FORMULA CAN ALSO HELP AS SEISMIC EFFICIENCY INDICATOR BY COMPUTING {Measured Magnitude} / {0.85*log (W KT) + 4.2 },

EXAMPLE BELOW FOR NEVADA TESTS (WITH + 3.8 INSTEAD + 4.2) FUNCTION OF SCALED DEPTH OF BURST IN m / KT 0.33

EFFICIENCYCONTAINMENTLIMIT

MAGNITUDE TO CRATER RELATION

THE APPROXIMATION BETWEEN MAGNITUDE AND CRATER VOLUME Vm3 FOR SURFACE OR NEAR SURFACE DETONATION IS Mcrat ≈ 0.75*log(Vm3)

ACCIDENTS / TERRORIST ACTIONS

• OKLAHOMA BOMBING , April 19 1995

• NAIROBI, US EMBASSY, August 7 1998

• ROMANIA TRUCK , May 24 2004,

• SIERRA CHEMICAL, January 7 1998,

OKLAHOMA BOMBING

• Estimated 2000KG TNT,

• Crater 8.4m diameter, 2m deep, soil covered by 0.3m asphalt and 0.2m concrete,

• HOB of the charge estimated 1.5m

• Surprising crater depth with such HOB,

• Surprising blast strength,

• Magnitude 1,6 ?

OKLAHOMA BUILDING DAMAGES

FEMA SLIDE

Approx 1000m

10 mbars for 2000Kg TNT

TERRORIST ATTACK NAIROBI

• Facts based on seismic recording, 2940m from Gzo,• Air blast arrival time To + 8.46s, positive duration 0.2s,

Vertical speed 0.08mm/s• Nairobi elevation 1700m,temperature 25°C,wind 0• Estimation 3000Kg TNT for such datas .

ROMANIA TRUCK ACCIDENT

• ROAD ACCIDENT INVOLVING A TRUCK LOADED WITH 20 TONS AMMONITRATES,

• FIRE AND LATER HUGE DETONATION,

• ALL 20 PEOPLE NEAR BY DIED, FIRE CREW, TV CREW PASSER BY WANTING TO ASSIST,

• CRATER 15m DIAMETER AND 5m DEEP, ≈ 600m3

• TRUCK MOTOR AXIS EJECTED 1 Km,

• RICHTER MAGNITUDE ML = 1.9

ISRF Z 27KM FROM GZO AIR SLAP

SIERRA CHEMICAL ACCIDENT 1

• PRODUCTION ACCIDENT,

• FIRST EXPLOSION “A” = 3400KG TNT, BAD GROUND COUPLING, NO CRATER,

• SECOND EXPLOSION “B” = 7000KG TNT, 3.5s LATER IN A STORAGE LOCATION, 73m APART, TRIGGERED BY MISSILE (S) FROM EXPLOSION “A”.

• FOR “B” , CRATER 18m x 12m x 1.8m, ≈ 180m3

• HOB FOR BOTH EXPLOSIONS APPROX + 1.5m,

• RICHTER MAGNITUDE ML ≈ 1.6

PAH Z 28.3Km AIR SLAPS

See zoom next slide A B