Fuzzy-stochastic model to assess defects in low-rise residential buildings

Understanding the severity level of defects in buildings can help project managers to take appropriate corrective actions. The objective of this study is to assess the severity of defects in low-rise residential buildings and develop a stochastic model for predicting the likelihood of occurrence of various categories of defects. The defects data for ground floor slabs and walls were extracted from engineering inspection reports of 252 residential buildings in Melbourne, Australia. The analyses were then carried out using Fuzzy Synthetic Evaluation (FSE) and Monte Carlo Simulation (MS) techniques. The outputs of the FSE showed that the severity index of the floor cracks was found to be 3.05 with the equivalent linguistic term of ‘slight’ or 1- 2.0mm in size. Similarly, the severity index of wall cracks was found to be 3.01 with the equivalent linguistic term of ‘slight’ or 1 - 5.0mm in size. This indicates that the severity level of defects in floor and wall is low. Likewise, the findings of the simulation analysis revealed that the probability of occurrence of floor cracks with width ranging from 2 to 4mm is 40.9%, and the chance of occurrence of wall cracks having widths ranging from 5 to 15mm is 73.6%. The proposed models can assist the regulatory bodies and construction supervisors to assess the probability of occurrence and severity of the building defects in the ground floor slabs and walls of low-rise residential buildings. Further, this study contributes to the body of knowledge by proposing methods to assess defects in buildings.