Analysis of Structural Failure of Cerucuk Galam Foundation (Galam Wood Pile Foundation) in Banjarmasin Swamp Land in Indonesia

The cerucuk (pile) galam foundation made from local wood is the most widely used foundation for houses in Banjarmasin which is a swamp land. The cerucuk galam foundation consists of 4 main elements, namely: columns, sunduk, lapak and galam pile. However, in recent years there have been problems that are strongly indicated to be related to this type of foundation, namely the collapse of 47 house buildings from 2018 to 2023, and many more cases of damage that did not cause a collapse. There fore it is necessary to analyze the causes of structural failure of this type of foundation, as a preliminary to a series of studies to obtain a safer type of foundation. To find out the cause, this is done through direct observations in the field, interviews with experienced carpenters, mainstream and online media, as well as calculations of the loads and stresses that occur in the model house compared to the maximum load and stress. The results of the analysis show 2 main causes of the failure of the foundation structure. First, the broken sunduk on some of the columns with the heaviest loads, which is indicated by the high bending and shear stresses exceeding the maximum stress. Second, the weathering of the galam head which causes a decrease in the maximum bearing capacity, which causes a shift or detachment of lapak from the galam head. Weathering occurs because the galam head is not completely submerged.