Orange, California – July 23, 2009 – VanDorpe Chou Associates, Inc. (VCA) has participated in an unprecedented full-scale earthquake test of a wood-framed 6 over 1 residential building. Last week this 7 story structure successfully withstood the tremor from a severe earthquake in a full-scale test that occurred on the world’s largest shake table located at the Hyogo Earthquake Engineering Research Center near Kobe, Japan. This $100 million facility was constructed in the wake of the 1995 Kobe earthquake that claimed over 6,400 lives, displaced over 10,000 residents and caused over $100 billion in damage.
Tom VanDorpe, SE returned this week from Japan where he witnessed the testing and spoke with the many engineers, manufacturers and international developers gathered for the event. Prior to the test, Mr. VanDorpe reviewed the plans and worked on a committee that provided ideas that researchers incorporated into the construction. Mr. VanDorpe indicated that the Commercial Affairs divisions of the US Consulate and Embassy are actively promoting the expertice of US based businesses.
The finished structure consisted of 23 finished multi-family units over a one level steel-framed podium, weighed almost a million pounds and rose more than 70 feet over the shake table. The building was finished with drywall on the interior, but funds ran out for the stucco exterior that was originally envisioned. The researchers provided an upgraded shear wall system to see how well a 6 story wood structure would perform when subjected to the ground motion recorded in Canoga Park, California during the 1994 Northridge Earthquake – scaled up to 180% of the actual groundmotions!
The test revealed that the construction was able to withstand ground motions exceeding those that damaged buildings during the 1994 Northridge Earthquake. Mr. VanDorpe stated “when the test data becomes available, we plan to make the case for taller wood-framed buildings.” The primary objective of the researchers was to better understand the behavior of wood structures so that different levels of damage potential could be selected by the building owner prior to the structural design. This concept is called “Performance Based Design” and differs from the current code level design which focuses on collapse prevention rather than damage control. According to Mr. VanDorpe, “the real significance of this testing is that a 6 story wood frame building can work.” In Kobe, narrow “pencil” buildings are common and are known to be particularly susceptible to earthquake damage. VanDorpe added “many lives could be spared internationally if future midrise buildings use this system in high seismic areas.” Currently, wood-frame buildings are limited to 4 stories in Japan and 5 stories in the United States.
Further information including videos of the testing and setup can be obtained from the e-links below. For any questions please contact us.