Methods to Include the Impact of Factors in Postearthquake Cost Estimations for Earthquake Damage Repair Work

Abstract

Earthquakes are catastrophic natural disasters, and the built environment requires a quick recovery after such events. Estimating the loss from an earthquake can be complex as unique factors, in addition to conventional repair work, that need to be considered during the postperiod stage. Previous research has been able to identify 11 factors that impact the postearthquake cost estimation for the earthquake damage repair work (CEEDRW) process. Current loss estimation methods such as PACT, SLAT, and SP3 do not incorporate the impact of all these factors. This paper identifies the factors that impact different stages of traditional CEEDRW: precontract estimates, estimates during repair work, and cost calculations after construction. Discussion around methods to adopt these modeling factors into CEEDRW is also presented. A two-stage data collection method was adopted for this paper. Data were collected through semistructured interviews using 19 participants and a questionnaire survey using 92 participants who have experience in the CEEDRW process. The interview data analysis emphasized the usage of 11 factors at the three stages of estimation. Furthermore, survey results identified the most suitable methods of incorporating each factor in CEEDRW. Existing estimation tools used for CEEDRW do not consider a number of factors. This paper suggests the most suitable methods of considering these into an estimation tool that aims to enhance the accuracy and reliability of the CEEDRW process. The methods identified in this paper can be used in developing more reliable future cost estimation models used to determine postearthquake damage repair work. The data were collected from professionals who are experienced in housing repair work in New Zealand. The results vary for other types of geographic regions and construction methods. Currently used postearthquake cost estimation processes for earthquake damage repair work have a lot of drawbacks. To achieve the final aim of developing a standard postearthquake cost estimation model for earthquake damage repair work that is more accurate and faster than current ones, this research achieved one of the objectives of identifying methods that can be used to mitigate problems of the current cost estimation process. The research identifies methods that can be used to include factors that were not fully considered in current postearthquake cost estimation processes. The results of the research will help with increasing the accuracy of the upgraded model. The next step in this process is the develop the upgraded standard postearthquake cost estimation model for earthquake damage repair work. Even with the current findings, cost estimators, builders, and insurance agencies can improve their cost estimation process by including the impact of the factors through the suggested methods. Governments can implement changes to standard construction contracts and policies so that the construction industry can positively manage the cost-varying dynamics of earthquake damage repair work.