Bi Directional Static Load Testing (BDSLT)

Pile Integrity Testing of Bridge The Bi Directional Static Load Test is truly an innovative static load testing technique. It is the only load test that provides separate measurement of a pile's end bearing and skin friction. The reaction system in Bi Directional Static Load Test is derived from the soil and/or rock along and below the drilled shaft, hence the system is not restricted by the limits of overhead structural beams, large kentledge, tie-down reaction piles and deep cut of level as in the conventional top loaded static load test system.

Advantages of Bi Directional Static Load Testing

Eliminates the need for overhead beams or reaction piles
It only takes hours to prepare a shaft for the installation of the pre-manufactured
Bi-Directional pressure cell
Simple to conduct, the Bi-Directional method provides engineers with separate
data on the end-bearing and frictional resistance of the shaft.
Bi-Directional Static Load Testing has been proven to be much more cost-effective than traditional load testing methods
The Bi-Directional Static Load Test is useful on battered piles and sloping or
belled shafts. Each shaft can be reused to carry working loads after the test is completed. This is easily done by grouting the test system.

Hydraulically-drive, high capacity, sacrificial bi directional hydraulic jacks are pre-installed
in the test pile. Loading is applied in equal and opposite directions - upwards against Bi Directional Static Load Testing upper skin friction and downwards against lower skin friction and/or end bearing. By using multiple bi directional jacks on a single horizontal plane, the available test capacity can be more than 100MN, and by utlising multiple bi directional jacks on different planes, distict elements with a shaft can be isloation for testing.

The addition of strain gauges within the shaft can help to determine the distribution of the load throughout the shaft length. The speed and accuracy of testing have made the Bi-Directional Static Load Test a valuable tool during value engineering and the redesign of projects.