Permanently Fixing a Settling Pool Part IV | Ask a Registered Engineer
The Final Step To Permanently Fixing A Settling Pool: The Installation and Repair Process
Once a proper helical screw pile configuration has been designed to support your pool at the optimum depth below the surface, and the layout in the bottom of the pool shell where each pile will be installed is determined; the repair process can finally begin.
In order to access the ground beneath the pool, the pool is drained. Access holes are core drilled through the bottom of the pool at precise locations determined by the engineering plan. These access holes must be of sufficient diameter to pass the helical plates on the pile shaft.
The Next Step In The Process
Once all access holes are drilled, the Helical Screw Pile is driven into the ground. A hydraulic gear motor is used to advance the helical screw pile into the soil quietly, fast and vibration free. Throughout installation the pile shaft torsion is monitored in order to verify the pile capacity was achieved at the target depth. Monitoring the shaft torsion of the pile during installation ensures that the helical screw pile will provide long term support with a factor of safety against future settlement.
After all the helical screw piles have been installed and capacity verified, the pool restoration process begins. An adjustable steel pier cap is installed on top of each pile shaft. The areas where the steel pile cap bears against the pool shell are grouted to level the pile cap, secure the connection to the pool shell, and allow even load transfer from the pool shell to the pile cap.
Hydraulic jacks are positioned on all of the pier caps. All of the jacks are carefully pressurized equally at each location, and the pool shell is gently lifted to recover lost elevation. As the pool shell restoration progresses, various jack valves are closed, which allows for continued lifting of only the heavier parts of the pool shell. When the shell is restored to level, the pile loads are mechanically transferred from the hydraulic jacks, to the pool shell using threaded bars and nuts.
The Final Process To Permanently Fix A Settling Pool
After all plumbing connections are water-tight and functioning properly, the void created between the soil below the pool and the raised pool shell is filled with low-strength concrete slurry. The purpose of the void filling is to provide uniform contact between the pool shell and the underlying soil.
Once the void filling operation is completed, moisture sealant is applied at the cold joints of the access holes, rebar splices are made, and the access holes are filled with high strength, non-shrink concrete grout.
Once all repaired concrete is sufficiently cured and all cracks and leaks repaired, the pool can be filled and put to good use for years to come. If one follows these processes, permanently fixing a settling pool should be a swift one.
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