Renmin Zhujiang (Jan 2021)
Study on Weakening Model of Bearing Capacity of Rock-socketed Pile under Periodic Saturated Water and Drainage in Three Gorges Reservoir Area
Abstract
In view of the problem that there is a large difference in the performance degradation test results of sand and mudstone and the lack of an analytical model for the weakening of bearing capacity of rock-socketed piles under the periodic saturated water and drainage in reservoir area, based on the experimental data of sand and mudstone under the action of saturated water and drainage, the strength weakening law of sand and mudstone under the action of saturated water and drainage is analyzed, and it’s found that the strength of sand and mudstone decreased logarithmically with the action of saturated water and drainage, which is obvious in the initial stage, especially for the first 10 times, and unobvious in the later stage. In addition, the compressive strength deterioration of sand and mudstone is related to its initial compressive strength. The strength deterioration rate of rocks with high initial compressive strength is slower, but the total deterioration degree is higher. A normalized model of sand and mudstone with periodic saturated water and drainage is established, which indicates that rock with different strength has consistent attenuation law under the action of saturated water and drainage. Considering the weakening of rock and soil strength under the action of saturated water and drainage, and combining the established weakening model of sand and mudstone under the action of periodic saturation and drainage, the calculation formula for the bearing capacity of rock-socketed pile in the pile foundation is adjusted and optimized, and a model for calculating the weakening of rock-socketed pile bearing capacity is established, which provide a theoretical basis for weakening and durability prediction of the bearing capacity of rock-socketed pile foundation in the Three Gorges reservoir area.
