Model Test and Numerical Simulation Study on Bearing Characteristics of Pervious Concrete Pile Composite Foundation

When pervious concrete is used as pile material, both high strength and water permeability will be available. By comparing the strength and permeability of pervious concrete with different aggregate size (3–5 mm and 4–6 mm) and porosity (20%, 25%, 30% and 35%), the recommended aggregate size (3–5 mm) and porosity (30%) can be achieved. To investigate the installation effect and bearing characteristics of the pervious concrete pile composite foundation, the excess pore water pressure, settlement, pile-soil stress ratio and skin friction were recorded in the model test. Results show that, compared with the impervious pile, the pervious pile can significantly accelerate the dissipation of excess pore water pressure after pile installation, and in the loading test can shorten the consolidation time by 30.3%, increase the skin friction 0.12 kPa averagely, reduce the peak value of excess pore water pressure by 30.2%, and increase the characteristic value of bearing capacity by 43.2%. When the linear penalty method is applied, and the friction coefficient is 0.6, compared with the test, the deviation of simulated skin friction is the largest, being about 15%, so in general the model test results are reliable.