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Show Second Stretch of 1-70 In Grand Gets New Top An additional nine-mile section of 1-70, from the Colorado state line toward a Westwater in Grand County, is '' scheduled for final surfacing ; during the next two constructs construc-ts tion seasons, v ' The Utah Transportation Commission opened bids last week on a contract that provides for a final eight-inch ' layer of "black top" for the t, four-lane interstate section, ., and includes some excavation J1 and reconstruction work to repair damage to the existing V pavement caused by the movements of underlying "i Mancos Shale along some portions of the highway. 'r W.W. Clyde and Co., of Springville, Utah, submitted M the apparent low bid of $3,336,675. The official engi-i engi-i neer's estimate was N $3,396,292. This project adjoins ad-joins a similar project which " runs from Westwater east to Whitehouse. Both projects are scheduled for completion by September 15, 1977. 1-70 has experienced heavy increases in traffic volumes and the present surface, applied about six years ago, shows signs of premature aging. The new surface will protect the roadbed and provide a smother driving surface for the traveler. Some portions of this interstate section, where it crosses Mancos Shale formations, forma-tions, will have to be excavated excavat-ed and reconstructed before the final surface can be applied. A total of about two miles of road within this project show damage from the "heaving" of the underlying shale. "Heaving" is caused by seasonal contraction and expansion ex-pansion of the shale, and causes buckling and ridging of the road surface. To avoid future damage, the contractor will excavate the road bed to a depth of about five feet and replace the shale with granular backfill. Previously Previ-ously used methods of counteracting coun-teracting the effects of the shale, such as adding lime to change the shale's chemical structure, or placing water proof membrane under the pavement to keep the shale dry, have not been satisfactory. |