EARTHQUAKES LIKE THE 6.8 NISQUALLY QUAKE.
NISQUALLY QUAKE. >> Reporter: THINK OF IT LIKE
WEATHER FORECASTING.
WEATHER FORECASTING. ONLY WEATHER FORECASTING LOOKS
OUT A FEW DAYS.
EARTHQUAKE FORECASTING LOOKS
OUT A FEW DECADES.
THE FORECAST IS THIS.
THERE IS AN 84% CHANCE WE WILL
SEE ANOTHER NISQUALLY TYPE
EARTHQUAKE IN THE NEXT 50
YEARS.
YEARS.
YEARS. THEN THERE IS A MAGNITUDE 9
SUBDUCTION ZONE EARTHQUAKE
ALONG OUR COAST AND THE RISK
OF A SHALLOW CRUST FAULT ON
THE SEATTLE FAULT IN THE SOUTH
WHIDBEY ISLAND.
WHIDBEY ISLAND. EACH OF THOSE, ABOUT A 15%
CHANCE EACH IN 15 YEARS.
THE TUNNEL DESIGNED TO TAKE
ALL OF THOSE RIPS INTO
CONSIDERATION.
CONSIDERATION. >> EARTHQUAKE.
>> EARTHQUAKE. >> EARTHQUAKE.
>> EARTHQUAKE. >> THAT'S A SERIOUS
EARTHQUAKE.
EARTHQUAKE. >> Reporter: THE NISQUALLY
EARTHQUAKE, FEBRUARY 28, 2001.
A DEEP MAGNITUDE 6.8, 30 MILES
DOWN.
DOWN.
DOWN. IT
DOWN. IT RATTLED THE REGION.
>> IT WAS FELT STRONGLY AT THE
LAB.
LAB.
LAB. WE
LAB. WE SUFFERED MINOR DAMAGE TO
CEILING AND PIPING.
>> Reporter: WHAT THEY TEST
HERE INCLUDES THE ABILITY OF
DIRT TO HOLD UP THE STATE'S
INFRASTRUCTURE.
INFRASTRUCTURE. THE ROADS AND BRIDGES.
>> IT IS CURRENTLY DOING A
TEST WHERE IT IS BEING
CALIBRATED?
CALIBRATED? >> THERE IS A SAMPLE IN THERE.
WE'RE IN THE SATURATION PHASE.
THIS WILL CONTINUE TO SATURATE
ABOUT A FOUR HOUR PERIOD.
>> Reporter: JIM STRUTHERS IS
THE CHIEF ENGINEERING
GEOLOGIST.
GEOLOGIST. THEY ARE LOOKING AT
LIQUIFACTION.
LIQUIFACTION. WHAT HAPPENS TO WET SOGGY
SOIL.
SOIL.
SOIL. IT
SOIL. IT GOES FROM A SOLID TO A
LIQUID WHEN SHAKEN AND WILL NO
LONGER HOLD THINGS UP.
IT'S THAT RISK THAT LED WSDOT
TO PRODUCE THIS ANIMATION BACK
IN 2009.
IN 2009.
IN 2009. INTENDED TO BE A CLOSE
APPROXIMATION OF THE VIADUCT'S
VULNERABILITY SITTING IN THE
WET SOIL WHICH WOULD ALSO
SLIDE INTO PUGET SOUND THROUGH
THE OLD VULNERABLE SEAWALL
DESIGNED TO KEEP IT IN PLACE.
THAT SEAWALL HAS NOW BEEN
FIXED.
FIXED.
FIXED. THE VIADUCT HASN'T.
>> THE ANIMATION WAS OUR
ATTEMPT TO AS ACCURATELY AS
POSSIBLE USING SCIENCE PORTRAY
THE EFFECTS OF THE EARTHQUAKE.
>> Reporter: IF WE CAN GET
THROUGH THE NEXT FEW WEEKS, WE
MAY NEVER HAVE TO WATCH THIS
SCENARIO PLAY OUT FOR REAL
WITH TRAFFIC ROLLING OVER IT.
THAT'S THE VIADUCT.
WHAT ABOUT THE TUNNEL
REPLACING IT?
REPLACING IT? WHY WILL THE TUNNEL WILL DO
BETTER?
BETTER?
BETTER? >> WHEN YOU LOOK AT AN
INDIVIDUAL SEGMENT, IT'S A
FAIRLY MASSIVE PIECE OF
CONCRETE.
CONCRETE.
CONCRETE. AT THE SCALE OF THE DIAMETER
OF THE TUNNEL, THERE IS FLEX
IN THERE.
IN THERE.
IN THERE. THE APPROACH THAT WAS TAKEN
FOR THE TUNNEL WAS TO ACTUALLY
SIMULATE REAL EARTHQUAKE
GROUND MOTIONS COMING INTO
THAT STRETCH.
THAT STRETCH. AND ACTUALLY CHECK ITS
FLEXIBILITY DURING THE TYPE OF
EARTHQUAKE YOU WOULD EXPECT.
>> Reporter: THE TUNNEL IS
DESIGNED TO BE FLEXIBLE.
BUT UNDERGROUND, THE SAME
EARTHQUAKE WOULD NOT CAUSE THE
SAME KIND OF SHAKING YOU WOULD
SEE AT THE SURFACE.
FIRST, THE SOIL, MOST OF THE
TUNNEL RUNS THROUGH, IS
TOUGHER STUFF.
TOUGHER STUFF. COMPRESSED BY HEAVY GLACIERS
DURING THE ICE AGE.
NOT THE LOOSE FILL THAT
SURROUNDS THE SUPPORTS HOLDING
UP THE VIADUCT.
SECOND, THE TUNNEL WOULD MOVE
WITH THE SHAKING WHERE THE
VIADUCT WOULD SWAY, BREAKING
ITS JOINTS AND FALLING APART.
THE VIADUCT, IT'S ALSO A
HEIGHT PROBLEM.
HEIGHT PROBLEM. >> IF YOU'RE UP ON THE UPPER
DECK OF THE VIADUCT, YOU ARE
SEEING A LOT MORE THAN YOU
WOULD BE SEEING INSIDE THE
TUNNEL ITSELF.
TUNNEL ITSELF. >> Reporter: THEN THERE'S
THIS.
THIS.
THIS. WHEN DRIVING THROUGH IT, THINK
OF IT AS ONE TUNNEL.
BUT THERE ARE ACTUALLY TWO.
THERE'S THE BORE, THE PART DUG
BY BERTHA THE TUNNELING
MACHINE, THE PART WITH THE
RINGS, THEN, THERE'S THE CUT
AND COVER TUNNEL.
ALSO KNOWN AS THE PORTALS.
CONSTRUCTED MORE LIKE A
BUILDING.
BUILDING.
BUILDING. AND THIS BIG RUBBER JOINT
INSULATES ONE FROM THE OTHER
WHEN THE SHAKING ROLLS
THROUGH.
THROUGH.
THROUGH. >> RIGHT AT THE JOINT BETWEEN
THOSE, WHERE YOU HAVE THE
BOARD TUNNEL AND THE PORTAL,
THERE IS ACTUALLY A JOINT THAT
ACCOMMODATES ANY MOTION THAT
WOULD BE EXPECTED BY THE
EARTHQUAKE.
EARTHQUAKE. THAT WAS SOMETHING THE
DESIGNERS PUT A LOT OF TIME
AND EFFORT INTO.
I THINK IT IS ONE OF THE MORE
CRITICAL ELEMENTS OF THE
DESIGN.
DESIGN.
DESIGN. >> Reporter: BUT NOT EVERYONE
ASSOCIATED WITH EARTHQUAKE
RESISTANCE IS UNDERGROUND.
ONE OF THE LONG BRIDGES THAT
SUPPORTS A MAJOR RAMP LEADING
INTO DOWNTOWN IS ACTUALLY A
TEST, A FIRST OF ITS KIND
FLEXIBLE BRIDGE.
FLEXIBLE BRIDGE. IT'S BUILT WITH SPECIAL METAL
PINS MADE FROM A NICKEL
TITANIUM ALLOY THAT CAN
REMEMBER THEIR SHAPE BEFORE
THE QUAKE.
THE QUAKE. >> ONCE YOU UNLOAD IT, YOU LET
THE LOAD GO.
IT GOES BACK TO ITS ORIGINAL
PLACE.
PLACE.
PLACE. AS
PLACE. AS THOUGH NOTHING HAS
HAPPENED.
HAPPENED.
HAPPENED. >> Reporter: THERE IS A
SPECIAL CONCRETE THAT ACTS
LIKE FLEXIBLE RUBBER.
SCIENCE IS OFFICE EVOLVING.
FOR NOW, THE TUNNEL IS STATE
OF THE ART.
>> DOES THAT MAKE THE TUNNEL
QUAKE PROOF?
QUAKE PROOF? >> IT'S QUAKE PROOF IS AN
INTERESTING TERM.
INTERESTING TERM. I DON'T THINK ANYTHING IS
QUAKE PROOF.
QUAKE PROOF. >> ONE QUESTION I HAVE IS THE
TUNNEL'S VULNERABILITY TO
TSUNAMI.
TSUNAMI.
TSUNAMI. COULD THE TUNNEL FLOOD?
WASH DOT TOOK THAT INTO
CONSIDERATION AS WELL AND THE
LOWER ENTRANCE SHOULD STILL BE
BELOW THE LEVEL OF THE TSUNAMI
AND THE PORTAL HIGH ENOUGH TO
STAY OUT OF REACH.
WE DON'T EXPECT A TSUNAMI FROM
A COASTAL EARTHQUAKE TO GET
ALL THE WAY IN HERE, BUT WE
KNOW THAT THE SEATTLE FAULT,
THE SOUTH WHIDBEY FAULT COULD
POTENTIALLY GENERATE A LOCAL
TSUNAMI.
TSUNAMI.
TSUNAMI. >> A LOT OF THE EARTHQUAKE
RISK HAS BEEN TAKEN INTO
CONSIDERATION.
CONSIDERATION. HAVE WE TOUCHED EVERY POSSIBLE
RISK HERE?
RISK HERE? >> WE HAVE TOUCHED EVERY
POSSIBLE RISK.
POSSIBLE RISK. THEY HAVE EXAMINED ALL OF THAT
FOR THE STATE.
THE STATE OF THE ART NOW.
>> YEAH.
>> YEAH.
>> YEAH. >> BUT, REMEMBER, WHEN THEY
DESIGNED THE VIADUCT, THEY
WEREN'T REALLY PAYING
ATTENTION TO EARTHQUAKES.
NOW WE ARE PAYING ATTENTION TO
EARTHQUAKES BUT THE SCIENCE IS
STILL OUT THERE.
THEY ARE LOOKING FOR MORE
FAULTS.
FAULTS.
FAULTS. THEY ARE FINDING OLDER FAULTS.
ARE THEY STILL ACTIVE, THE
SEATTLE FAULT WHILE CONSIDERED
VERY DANGEROUS, LAST ONE ABOUT
1100 YEARS AGO, THEY DON'T
KNOW HOW OFTEN IT OCCURS.
AND THAT'S A PROBLEM.
IS IT DONE?
IS IT NOT DONE?
WE DON'T KNOW.
BUT WE WANT TO OPEN UP THE
FLOOR WHEN IT COMES TO
QUESTIONS FROM YOU.
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