# Methods of Estimation in Civil Engineering

**1. Types of Estimates**

**2. Approximate or Rough Estimates**

**3. Detailed Estimates**

**4. Material Component of Estimation**

**5. Determining Unit Costs**

**6. Allowances**

**7. Non-Material Components**

**8. Earthwork**

**Average Method:**In the average method, one would first determine the average level of existing conditions, then the average level of the final proposed conditions, and finally multiply this difference by the area of the work. This would roughly determine the overall amount of fill or excavated soil that would be necessary to transport to or from the site. It would be most appropriate to use this method as either a preliminary estimation method or on a smaller scale project.**Block or Grid Method:**In the block (or grid) method, one would divide an area up into smaller areas and determine the amount of difference between the existing and finish grade in each of those areas. One would then multiply the area of each of these blocks by the difference determined from each of these blocks and the sum of these numbers to determine the total amount of cutting or filling. The difference between the two totals would indicate the total soil either required to be brought in or removed. This method would result in more accuracy than the average method.**Section Method:**The section method is most appropriate for infrastructural projects, such as new highways where there is a linear area under consideration. Sections are taken at regular intervals along a path through the project area, such as at the centerline of a roadway. The existing terrain and the proposed terrain shown within these sections allow for the area difference between the two to be calculated using calculation techniques such as the trapezoidal method, wherein complex shaped sectional areas are determined by first breaking them down into simpler areas. These areas would then be multiplied by the distance between the sections taken along the path to determine the volumes of cutting or filling. Computer software is often used to generate these sections once survey data of the terrain is imported into the software.**Soil Swell:**It should also be noted that a given volume of soil, once excavated, typically expands to a larger volume, and this should be taken into consideration when determining the number of vehicle trips required for transporting the soil. This is sometimes referred to as "swell." When soil is brought into a site and then compacted, it occupies a smaller volume of space. This is sometimes referred to as "shrinkage."

**Conclusion**

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