CONCRETE COLUMN TEST

At the request of JF Shea company in Redding, California C. H. Bull Company supplied a pair of calibrated 100 ton jacks to test the clamp mechanism JF Shea wanted to use on a upcoming project.

Caltrans required they have test data supporting load capability of the clamps they wanted to use. They cast test columns in their Redding yard and Stan Sheppard went up and supervised the tests. The clamps were successfully tested.

JF Shea, a company who has been involved with many high profile jobs including the Hoover Dam the Golden Gate Bridge and many interstate highway jobs companies, called on C. H. Bull Company to help them with a job for Caltrans.

JF Shea designed a clamp mechanism to be used on a job in Redding, CA. Caltrans required they have test data supporting load capability of the clamps they wanted to use. They cast some test columns in the yard of their Redding, CA facility.

Test column with a clamp in place being tested with 2 – 100 ton jacks.

column1

100 ton 6” stoke hydraulic jack with an acme threaded piston
and a locking collar

column2

In many applications, Caltrans and other inspectors on a job like this or a pile testing application, require the load test to be held for a sustained period, in some cases up to 24 hours. C. H. Bull uses locking collar jacks for this and other applications requiring a load to be held for long periods of time.

Stan Sheppard, our high tonnage jacking specialist, brought to the test site a jacking system consisting of 2 – 100 ton calibrated locking collar jacks, a pump, a manifold with a calibrated gauge, and hoses. The system was put in place and the required load, per Caltrans, was put on the system and held for a 24 hour period. The clamps successfully passed the test and were then used by JF Shea for the Caltrans job.