A South Florida Solution to a Central Florida Problem - A 44 Feet Deep Bottom Seal Excavation-PPT Presentation

PPT Presentation

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The D.L. Tippin Water Treatment Facility project in Central Florida required two challenging excavations: a 44-foot-deep High Service Pump Station (HSPS) excavation and a 26-foot-deep Chlorine Contact Basin (CCB) excavation. Both involved high groundwater recharge, karstic limestone, nearby utilities and structures, and the need to keep construction areas dry.<br /><br />For the HSPS, the excavation extended more than 35 feet below the groundwater table and had to be built beside an operating 5-million-gallon water tank. The solution combined a twin soil-mix wall with a deep soil-mix bottom-seal plug, stabilized by tiedown piles. Jet grouting underpinned the tank. Tieback anchors and internal bracing supported the wall while limiting movement and accommodating site constraints, including existing utilities and a basement.<br /><br />The CCB excavation also required groundwater control and support around existing and proposed utilities, including two 60-inch-diameter pipes. Its support system used drilled W18 soldier beams, primarily anchored into Florida limestone, with some internal and external bracing.<br /><br />Three-dimensional modeling helped resolve complicated anchor layouts. Karst-related voids and drilling challenges were addressed through grout placement and grout socks, which reduced the need for anchor redrilling. Together, the engineered systems enabled deep, dry excavations in difficult ground conditions while protecting adjacent infrastructure and maintaining the facility’s operations.

Keywords

D.L. Tippin Water Treatment Facility

Central Florida

deep excavation

high groundwater

soil-mix wall

chlorine contact basin

high service pump station

karstic limestone

tieback anchors

jet grouting