STATNAMIC Case History

STATNAMIC CASE HISTORY

S9513: Toronto, Ontario. On November 13, 1995, three STATNAMIC load tests were conducted using the latest in foundation load testing equipment—the hydraulic catch mechanism. The tests were conducted at Crescent Town School in Toronto, Ontario for McClymont and Rak Engineers Inc, of Toronto. The piling contractor, Pietz W. C. Ltd., supplied the crane and the necessary welding. The 0.6 MN Statnamic device, fitted with an hydraulic catch mechanism to arrest the reaction mass, had been previously used at the First International Statnamic Seminar in Vancouver where 4 tests to 400 kN had been conducted in two hours.

At the Crescent Town School site, two piles were tested; both 150 mm diameter pipe piles with 9.5 mm walls. Pile A1 was 11.5 metres long and pile C/5 16 metres. Pile A1 was test loaded to 550 kN and pile C/5 was test loaded twice to 310 kN and 540 kN.The site soil consisted of a very hard layer of till.

The hydraulic catch mechanism greatly reduces preparing and testing time. Berminghammer personnel arrived on site with equipment at 8:00 a.m. The two test piles were cut off at an elevation of about 1 foot above the site grade. A circular, 0.5 m diameter, 25 mm thick plate was welded to the top of each pile to support the Statnamic device. At 10:00, the piles were surveyed to determine their pre-test elevations for physical verification of the displacement measuring systems (laser sensor and accelerometer). At 11:36, pile A1 was tested. By noon, the device was moved to pile C/5. At 1:28 p.m., the first test on pile C/5 was completed and at 1:41 the pile was reloaded. At 2:00, the two piles were surveyed to determine their final elevations. The Statnamic equipment was loaded on a flat-bed and at 3:20 p.m., the Statnamic equipment and personnel left the site.

For pile A1, the load-displacement behaviour exactly followed the theoretical elastic stiffness of the pile, correlating well with the soil borings which indicated a primarily end-bearing pile. For pile C/5, both tests showed linear behaviour, however, the pile was stiffer than theoretically expected, suggesting that there may have been a high degree of skin friction. All results were available immediately on site.

For more information on STATNAMIC tests, please contact Berminghammer.