Laboratory evaluation of pullout capacity of reinforced silty sands in drained and undrained conditions

This paper presents results of laboratory pullout tests performed to determine the drained and undrained pullout capacity of reinforced silty sands. The pullout tests were conducted for different soil types: clean sand and silty sand with 5, 10, 15, and 35% silt, and overburden pressures: 30, 100, and 200 kPa. Pullout experiments were performed on a large Pullout box with dimension 1.5 m long, 0.5 m high, and 0.4 m wide, where a single steel inclusion was placed inside a mass of homogeneous soil. Both drained and undrained Pullout capacities depended on the silt content and increased with internal friction angle of the soil and with overburden pressure. Undrained conditions could significantly reduce the pullout capacity. The reduction was caused by the generation of excess pore pressures in the soil under rapid loading. which in turn decreased the effective normal stress at the soil-reinforcement interface.