Effects of corrosion on bearing capacity of steel pile foundation in acidic soil

Soil acidity is one of the reasons for corrosion of steel piles. The material deterioration of steel pile foundation served in the acidic soil will affect the safety and durability of pile foundation. In order to understand the bearing capacity of corroded piles, the indoor model tests are carried out under two kinds of neutral and simulated acidic soil environments. The pile cap settlement and the pile tip resistance changing with the loading and unloading of pile top are tested. The changes of the soil layer settlement, pile tip resistance, pile axial stress and friction resistance in the process of ground load-consolidation are also measured. The results show that because the steel pile surface produces a lot of loose rust, the adhesion of pile-soil interface is greatly reduced. So the settlement of corroded pile cap is larger than that of non-corroded pile, and the end resistance of the corroded pile is also larger than that of the non-corroded pile. But under the load-consolidation conditions, because the loading accelerates the consolidation of soil between piles, the pile-soil interface is re-compacted, and the pile end resistances of both single pile and pile groups decrease. The neutral point location of corroded piles descends. The more the corrosion rate of piles, the more the lateral negative friction resistance of piles, and the more the changes of axial force at the neutral point position. The results may provide references for the studies on the loading performance of all kinds of pile foundations under corrosion condition.