A hydraulically-driven, high capacity, sacrificial pressure cell is pre-installed in a test pile. Loading is applied in two equal opposite directions: upwards against side shear of the upper section and downward against soil resistance on the lower portion.

The effectiveness and wealth of information yielded by the bi-directional static load test are the reasons why more engineers and contractors are turning to the method. Since the end-bearing and upward shear resistance are measured independently, there is no guesswork in how much load was carried by each component. Testing is typically performed until the ultimate capacity in either shear of end-bearing is reached to determine the maximum pile capacity. 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 in foundation engineering.

Advantages:

Mobility and space efficiency – eliminates the need for overhead beams or reaction piles.

Time efficiency – it only takes a few hours to prepare a shaft for the installation of the pre-manufactured bi-directional pressure cell.

Precision testing – simple to conduct, the bi-directional method provides engineers with separate data on the end bearing and frictional resistance of the shaft.

Cost efficiency – Bi-directional static load has proven to be much more cost-effective than traditional load testing methods

Versatility – 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 done easily by grouting the test system.