Harlan Diversion Project Construction Foundation Report

摘要

The southeastern Kentucky community of Harlan is located in a flood prone areanear the confluence of three major forks of the Cumberland River. The project consists of four parallel tunnels which divert Clover Fork through Ivy Hill and away from the Harlan central business district. Each tunnel is 32 feet high, 34 feet wide, and approximately 2,000 feet long. The tunnels are reinforced by rock bolts and lined with shotcrete. Near the upstream portals a diversion structure diverts Clover Fork into the tunnels. The diversion embankment is approximately 30 feet high, with a maximum height of 50 feet. It is 200 feet wide at the base and 600 feet long. A slurry trench and sheet pile cutoff prevents seepage beneath the embankment. A floodwall and a closure structure across a single track railroad line are incorporated into the left abutment of the diversion embankment. Changes in the flow of Clover Fork required two highway relocations, one at either end of the diversion tunnels. Upstream, Kentucky Highway 38 was relocated away from the existing Clover Fork channel through road cuts and over a 316 feet long, two span, post-tensioned, I-beam bridge which spans the diverted channel as it enters the tunnels. On the downstream side Kentucky Highway 72 was re-built over a 450 feet long, four span, pre-tensioned, I-beam bridge which spans Clover Fork as it exits the tunnels.