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<br /> 3 3/1/2021 <br /> <br />allowed to initially set, the entire manhole structure was filled but for the last foot. The <br />remaining roughly one-foot depth from the top of the CDF fill to the surface of the manholes <br />was left unfilled to allow for final grading of the site by KC’s contractor and to avoid impacting <br />and damaging the structure and CDF. <br />Specific Details <br />On Thursday February 27, 2020, all connections including inlet and outlet pipes from each of <br />the nine manholes across the site were filled with the specified CDF mix. At each location, the <br />manhole was prepared by city crews prior to being abandoned. Manholes and their connecting <br />pipes were previously cleaned by city crews and were void of debris . At each location, a crew <br />member made entry to and inspected the manhole and connecting lines to verify the lines were <br />still clean. <br />Once a manhole was ready, a cement mixer with a pumper delivered the CDF directly to each <br />manhole and their connecting pipes. The pumper hose was inserted by the crew member into <br />each pipe for the CDF volume needed to meet the five times the diameter length requirement. <br />For example, the first upstream manhole had a 10-inch pipe for its inlet and outlet and <br />therefore required a length of 50 inches of each pipe to be filled. The hose was inserted 50 <br />inches resulting in the CDF being pumped into and filling the pipe beyond the required 50 <br />inches. This allowed the full lay length of CDF required to fully fill the circumference. This was <br />repeated at each of the manhole and connecting pipe locations for all inlets and the outlet <br />segments of pipe. Once the pumping was completed at each manhole the pipe was visually <br />checked to ensure that it was filled. <br />On Friday February 28th, 2020, after the previous day’s applied CDF could initially cure, each of <br />the nine manholes had additional CDF added to within one foot of the surface. This eliminated <br />air gaps and prevented ground water inflow. <br />Some of the manholes were smaller due to their last section being a cone rather than a cylinder <br />shape. Manhole No. 9, the last structure discharge was smaller than was estimated. <br />See photos below for typical installation examples. Photo 1 shows how a pump line was <br />typically processed with the entrant entering the manhole to push the line up the pipe. Photo 2 <br />shows a manhole after both upstream and downstream pipes had been filled.