Evaluation of Utility Cut Patching on Pavement Structure

Utility Cut Patching (UCP) typically involves cutting road pavement, often with subsurface excavation, and patching works related to utility pipeline maintenance. UCPs disrupt the static behavior of pavements, causing cracking and altering their impermeability and adherence. Generally, there is poor quality control of UCPs, leading to rapid degradation of pavements within a few years, which has severe impacts on traffic quality and safety. This paper presents a case study of a bidirectional urban road where a water pipeline has been constructed in one of the two lanes. The rapid deterioration of the lane was investigated using in-situ nondestructive FWD deflectometric testing, comparing its structural quality with the adjacent pavement not affected by the works. A total of 312 tests were conducted at 80 locations, 40 for each lane, with a 20.0 m pitch by repeating the measurements for 3 stress levels. The analysis results show how the pavement subjected to UCP increases its deformability by about 25%, with less homogeneous and highly variable values. The coefficient of variation is 40% for all layers of the pavement without UCP, while in the one with UCP it is increased by 116% in the HMA, 73% in the foundation, and 58% in the subbase. Further analysis was performed using FE simulations to investigate the effect of the load position with respect to the UCP. Similar maximum deflection values occur in a large range of position while highest horizontal tensile stress peaks occur in the granular foundation when the load is located outside the UCP.