Big Dig firm warns tests might do damage

The former project manager for the Big Dig's main contractor has cautioned state officials that safety tests on the epoxy bolts upholding concrete ceiling panels in the Ted Williams Tunnel may have damaged their long-term integrity.

In a memo sent on Aug. 2, Keith S. Sibley of Bechtel/Parsons Brinckerhoff said recent tests by state inspectors have used 8,500 pounds of pressure to check the strength of the panels, much more than the load they were designed to support.

``We have some concern that this load, approximately five times the dead load and in excess of the vender's published allowable tension load, may cause damage to the epoxy adhesive that is not readily apparent, but might impact its long-term integrity," wrote Sibley, who remains a senior official at Bechtel/Parsons Brinckerhoff.

The memo, sent to Massachusetts Turnpike Authority project director Michael Lewis, added that the state should ``consider whether such high-load tests should be categorized as destructive testing, potentially requiring replacement of the anchor."

Sibley said the Turnpike Authority should review the load with the manufacturer of the epoxy to ``determine its impacts on long-term performance."

After the Globe obtained the memo yesterday, Jon Carlisle, spokesman for the Massachusetts Highway Department, called the tests ``appropriate." He said the state has tested 16 bolts on the tunnel's eastbound section and two on the westbound side.

``The testing was necessary and safe," said Carlisle, adding that the tests were done with loads of 8,400 pounds, not the 8,500 cited in Sibley's memo.

No defects were found in the testing; all the bolts held firm, he said. Carlisle said state officials felt that the 16 tests conducted on the eastbound side were a sufficient sample group. No other tests are planned there, but he said officials planned additional tests on the west side.

A spokesman for Governor Mitt Romney did not return calls last night.

The memo, which has a stamp indicating it was received Aug. 4, was drafted nearly a month after the July 10 ceiling collapse that killed Milena Del Valle.

Whether the letter was intended to limit Bechtel/Parsons Brinckerhoff's potential liability was uncertain. Asked about the memo, spokesman Andy Paven would only say, ``Our sole intent in sending the letter was to make sure [the epoxy] anchors were not inadvertently damaged."

Globe correspondent Elizabeth A. Ratto contributed to this report.