Surveying ME - BMEEOAFM201

Introduction

Accuracy of volume computation depends on many factors, like

• the accuracy of surveying
• the accuracy of modelling
• the accuracy of the excavation.

Always keep in mind that computed volume regards compact soil, in fact, the soil is loosened during earthworks. Their rate depends on many factors and this is taught not in surveying but in soil mechanics.

Volume computation should be done as thoroughly as possible since earthwork is quite an expensive job. Even minor mistakes in the calculation can cause a significant increase in costs. Having computers and appropriate software, the computation is rather a simple job for those who have the necessary skills and knowledge. 

There are a few typical issues in the practice as regards volume computation works.

1. there is no documentation of the computation. Please note that just the final result, the total volume is not enough. Major steps and details of computation need to be documented in a way that other engineers would be able to follow them.
2. there is no check-up of the result. Due to the enhanced responsibility, the final result needs to be checked by applying an independent calculation.
3. lack of survey before excavation works. Sometimes the demand for volume computation arises well after the works have started. Without having surveyed the original terrain, there is no reference state hence the differences cannot be derived.