Forensic analysis of a pile foundation failure

Abstract

Abstract This paper presents the results of the forensic analysis carried out on a set of buildings located on the same block in the center of Gijon (NW of Spain). The foundations of these buildings were laid between the years 1944 and 1945, using wooden piles. These wooden piles may have been affected by a subsequent reduction in the groundwater table, caused by the depletion of water that occurred during the construction of the basement of a building located on the adjacent block. Evidence of the first major damage to the building appeared upon initiating construction of the aforementioned basement. The situation was worsened by debris falling from one of the damaged buildings onto a public street below. Within a week, after the city authorities had reviewed the technical reports, they decided to proceed with the eviction of more than forty families in the affected buildings, thus triggering considerable social alarm throughout the region. This article provides a detailed description of the problem, analyzes the damage caused to the buildings, and based on such analysis and description, this article seeks to establish the different hypotheses in an effort to reveal what caused the problem. The focus of this analysis is to present the rotting of the head of the wooden piles of the foundation as the main cause responsible for the ruin of the affected buildings. The rotting was caused as a result of artificially lowering the groundwater table, which occurred during the construction of a building located in the vicinity. This study also analyzes the land subsidence and negative friction experienced by the piles as a result of artificially lowering the groundwater table.