Experimental Study on Reinforcement of Existing Bridge Pile Foundations Subjected to Lowering of Riverbed Soil Using Sheet Pile Wall

抄録

Development of an effective countermeasure for the existing bridge foundations subjected to the influence of riverbed excavation in Thailand is the main objective of this study. Due to the riverbed soil excavation for the utilization in construction works for many years, the levels of riverbed have been considerably decreased, resulting in reduction of embedded lengths of piles for bridge foundations. The reductions of pile embedment lengths, in other words, reductions of bearing capacity due to the lowering of riverbed soil is the main cause of bridge pile foundation settlements or collapses at present. In order to prevent the damages of existing bridge pile foundations caused by riverbed soil excavation, a reinforcement method using sheet piles called “Sheet Pile Wall (SPW) reinforcement” is proposed in this paper. The proposed SPW reinforcement method consists of 2 simple steps without new additional piles or any modifications of existing structures. Firstly, sheet piles are constructed surrounding the existing problematic bridge pile foundation. Secondly, the empty space inside the SPW is filled with sand or other porous materials such as crushed concrete. In order to investigate the performance of the proposed SPW reinforcement method, series of load tests on the small sized model single pile and model 4-pile pile foundation were carried out. The experimental results show that the proposed SPW reinforcement method is very efficient and promising.