Areas of land must be leveled and prepared before construction can begin on them. Quality soils can sometimes result in strong foundations. Engineers need to prepare the cost estimate that the soil excavation would entail. The image below shows what land area will be used in this lab.
Experimental procedures:
1. Set up the automatic level somewhere where you can see the benchmark and the grid points. 2. Take a backsight of the benchmark. 3. Use the equation below to establish the height of the instrument:
4. Take the foresight of each grid point. It’s okay if your measuring rod is not on the point exactly. 5. Find the elevation of each point using this equation:
6. Once the elevations have been found, determine the grade elevation by taking the minimum observed elevation and subtracting 2 feet from it. 7. Use this grade elevation to find the difference between each elevation in relationship to the grade elevation. 8. Now, use the trapezoidal rule to find the total cut area at each cross section:
9. Use the average end area method to find the total cut volume between cross sections:
10. Sum the total volume for excavation and apply the soil swell factor of 1.1 (used to account for the amount that soil will expand after excavation). 11. Use this new swell volume to calculate the cost estimate. 12. Calculate the cost estimate (where the unit cost is $12.00 / yd3).
Experimental Data and Discussion:
Below is the table of data that was obtained and calculated.
Table 1 (earthwork data and calculations)
The minimum elevation that was chosen for the grade elevation was at point 100 + 0N with an elevation of [516.42 ft]. Grade elevation was [514.42 ft]. Backsight to the Benchmark was [5.68 ft]. The Height of benchmark was [532.97 ft].
