A contracting company has been awarded a contract for reshaping and leveling 10 miles of a gravel road. For a 2-mile portion of this road, the geotechnical data shows the natural soil to have high clay content. Therefore, soil stabilization for a 12-inch layer of soil is required. Answer the following questions:
Which ground modification methods may be used to address this problem, and which methods are appropriate for stabilizing this type of soil?
The contractor is considering using a physiochemical method to stabilize the soil. However, the project schedule allows for a maximum of forty-eight hours between the start of the stabilization operation and the start of the grading operation. If the blending of the chemical admixture can be done in about twenty-four hours at best, what admixtures may the contractor use and what precautions might the contractor need to take during the stabilization operation?
A motor grader requires two passes at 2 miles per hour, two passes at 3 miles per hour, and one pass at 4 miles per hour to accomplish the work; job efficiency is 0.80. How many hours will it take to complete the grading operation for the 2-mile portion of the road? Provide a rationale for your answer