Wenzel Engineering, Inc. - Structural Engineers

Empire Township Wastewater Treatment Plant Cofferdam

• For the construction of the Empire Township wastewater treatment plant the contractor wanted to use a circular cofferdam. Circular cofferdams eliminate the need for internal bracing of the wales or the need to use anchors. This cofferdam is 150' in diameter and 45' below grade at the deepest point.
• The use of a circular cofferdam eliminated internal bracing or external anchors.
• Usually circular cofferdams don't have ramps. The ring beam needs constant pressure to function efficiently and the ramp space is an area of no pressure. This made for a very complicated analysis. Below is a close up of the ring beams. They are 2.5' tall and 5.5' wide concrete, and spaced 13' apart. The contactor has wrapped the sides and bottom of the ring beam to allow for the removal of the sheets.