Analysis of Change Orders in Geotechnical Engineering Work at INDOT

Change orders represent a cost to the state and to taxpayers that is real and often extremely high because contractors tend to charge very large amounts for any additional work that deviates from the work that was originally planned. Therefore, efforts must be made to reduce significantly the occurrence of change orders. The proposed research developed a set of guidelines that will allow the Indiana Department of Transportation’s geotechnical office to minimize the probability of...
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Change orders represent a cost to the state and to taxpayers that is real and often extremely high because contractors tend to charge very large amounts for any additional work that deviates from the work that was originally planned. Therefore, efforts must be made to reduce significantly the occurrence of change orders. The proposed research developed a set of guidelines that will allow the Indiana Department of Transportation’s geotechnical office to minimize the probability of having change orders in those projects in which they are truly preventable. These guidelines include not only recommendations on how to manage change orders when they are unavoidable but also general recommendations for adequate site investigation, design procedures, and quality assurance and quality control (QA/QC) processes that could help minimize the need for change orders. Based on the analysis conducted on the data collected from 300 INDOT contracts, it was found that the average geotechnical change order amount per district per year was 1.34% of the total estimated construction cost per district per year. The average geotechnical change order amount per district per year was 10.25% of the average amount of total change orders per district per year. The average net overrun due to geotechnical change orders was $707,000 per district per year. About 28% of the contracts that were considered in this study experienced geotechnical change orders. In total, 158 geotechnical change orders were recorded in all the contracts. About 41% of the total road contracts and 37% of the total bridge contracts experienced geotechnical change orders. INDOT personnel who were interviewed acknowledged the fact that the variability of soil is so great that it would be literally impossible to eliminate geotechnical change orders. However, they did recognize the need to address the following issues that lead to geotechnical change orders: (1) failure to identify areas of poor subgrade soil, (2) mismatch in piling quantities, and (3) omissions and constructability issues associated with erosion control work.