Secant pile wall systems are constructed using the auger cast pile method or cased drilled shaft technique so that there is an overlap between one pile to the adjacent piles. Usually the piles are installed in an alternative fashion along the line of the wall leaving a clear space of a little under the diameter of the required intermediate piles. The intermediate piles are then installed after their adjacent piles have had some time to set-up. Condon-Johnson & Associates is experience in building hard/soft, hard/firm, and hard/hard secant pile walls over 150 feet deep.
In a tangent pile wall, there is no overlap as the piles are constructed flush to each other. Both types of piles are reinforced with either steel rebar or with steel beams. Where the bottom of excavation is below the ground water table and water permeability is a requirement, secant walls systems can be combined with jet grouting at the base of excavation “bottom plug” so that the excavation remains watertight.
Secant pile walls offer an increased stiffness compared to sheet pile walls, decreased noise during installation, and are installed with minimized vibrations using an oscillator for sensitive areas where settlement and/or noise is an issue. Due to Condon-Johnson and Associate’s innovative construction methods and modern drill equipment, we are able to install secant or tangent pile walls in the most challenging urban environments with minimal impact to adjacent structures, utilities, and/or roadways.
For more information on CJA’s expertise, design/build options, and services for secant and tangent pile walls please contact our nearest office location.