susano
12-08-2013, 04:26 AM
“If the rods go,” Chung said in an interview, “the whole bridge would come down.”
Yun Chung, a retired engineer and metallurgist, read the official report explaining why massive, high-strength steel rods on the new San Francisco-Oakland Bay Bridge broke last March and was stunned – then alarmed.
At first glance, Chung said about the July report, he saw obvious errors – some typographical, others that confused basic terminology. Digging deeper, he discovered more important problems. He concluded that the analysis defied metallurgical science and common sense.
“I think it’s very shameful that in this public document, this important (oversight) report, there are so many errors. (I have) a sense of outrage,” Chung said in an interview last week.
Diverting attention from caring for his disabled wife, Chung, 81, said he spent hundreds of hours reviewing the report, consulting the technical literature and writing – with another engineer – a 105-page rebuttal. Chung, who had worked for Bechtel Corp., and Lisa K. Thomas, a materials engineer at Berkeley Research Company, a consulting and test lab, recently prepared an 18-page supplement to the report after a request from The Sacramento Bee to further detail their concerns.
Their unsolicited peer-reviewed report, which the two engineers completed in October, has gained traction among eminent engineers and a key elected official, and has begun to garner attention from bridge authorities.
The often-scathing critique disputes official assurances about the reliability of hundreds of high-strength steel rods that support the new San Francisco-Oakland Bay Bridge.
The two engineers challenged basic assumptions about why 32 rods that secured seismic gear on the eastern pier of the new suspension span broke in March.
Chung and Thomas wrote that hundreds of rods that attach the main suspension cable to its eastern anchorage and affix the tower to its foundation appear vulnerable – not just the ones that broke. They called those rods “fracture critical.”
“It means that their failures can bring down the entire (suspension) bridge,” they said.
Cont., http://www.sacbee.com/2013/12/08/5981376/experts-raise-new-doubts-about.html#storylink=cpy
Yun Chung, a retired engineer and metallurgist, read the official report explaining why massive, high-strength steel rods on the new San Francisco-Oakland Bay Bridge broke last March and was stunned – then alarmed.
At first glance, Chung said about the July report, he saw obvious errors – some typographical, others that confused basic terminology. Digging deeper, he discovered more important problems. He concluded that the analysis defied metallurgical science and common sense.
“I think it’s very shameful that in this public document, this important (oversight) report, there are so many errors. (I have) a sense of outrage,” Chung said in an interview last week.
Diverting attention from caring for his disabled wife, Chung, 81, said he spent hundreds of hours reviewing the report, consulting the technical literature and writing – with another engineer – a 105-page rebuttal. Chung, who had worked for Bechtel Corp., and Lisa K. Thomas, a materials engineer at Berkeley Research Company, a consulting and test lab, recently prepared an 18-page supplement to the report after a request from The Sacramento Bee to further detail their concerns.
Their unsolicited peer-reviewed report, which the two engineers completed in October, has gained traction among eminent engineers and a key elected official, and has begun to garner attention from bridge authorities.
The often-scathing critique disputes official assurances about the reliability of hundreds of high-strength steel rods that support the new San Francisco-Oakland Bay Bridge.
The two engineers challenged basic assumptions about why 32 rods that secured seismic gear on the eastern pier of the new suspension span broke in March.
Chung and Thomas wrote that hundreds of rods that attach the main suspension cable to its eastern anchorage and affix the tower to its foundation appear vulnerable – not just the ones that broke. They called those rods “fracture critical.”
“It means that their failures can bring down the entire (suspension) bridge,” they said.
Cont., http://www.sacbee.com/2013/12/08/5981376/experts-raise-new-doubts-about.html#storylink=cpy