Pullout capacity of single pile in gypseous soil

Abstract

This study investigated the behavior of steel pile in gypseous soil with 30%, and 60% gypsum content in both dry and soaking cases when subjected to pure tension load. The comparison was made between the pullout capacities of that pile when embedded in both types of gypseous soils. All pile tests were conducted via used manufactured laboratory model. The gypseous soil used was brought from Salah Al-Deen governorate in Iraq, with 30%, and 60% gypsum content. The pile used is solid steel with L/D equal to 10. The model was examined in a dry case and after soaking with water for 24 hours to show the effect of the presence of water on the pile capacity. Based on the result of the present study it can be recognized a substantial decrease in the pullout capacity of the pile of about 64%, and 68% after soaking of the soil-pile model for 24 hours with water for both gypseous soils of 30%, and 60% gypsum content respectively due to the dissolution of the gypsum content which related between the soil particles. The results showed also that the pullout capacity of steel pile in the gypseous soil of 60% gypsum content is more than that in the gypseous soil of 30% gypsum content in both dry and soaking cases due to the high amount of gypsum which strengthen the soil structure.