Approximate Experimental Simulation of Clogging of Pervious Concrete Pile Induced by Soil Liquefaction during Earthquake

摘要

It has been reported by previous studies that the pervious concrete pile (PCP) has the advantagesof high permeability and strength as a novel ground-improvement technology. However,during an earthquake, the liquefied soil particle is bound to migrate into the PCP under theexcess pore water pressure because of dynamic stress. This leads to the clogging of PCP. In thisstudy, a permeability test system for an approximate simulation of this clogging is presented.The experimental results obtained by employing this system were reported and validated. Inorder to gain insight into the clogging caused by earthquake, the effects of the porosity onpervious concrete were evaluated. Clogging that accounted for the acceleration peak, the frequency,and the duration of vibration were characterized. The thickness of the impervious layerof ground surface and the pile spacing on the clogging were studied as well. Results show thatwithin the scope of this study, the clogging of PCP is significantly related to the aforementionedfactors. In addition to the thickness of the impervious soil layer, the clogging becomesmore obviously with the increase of the other five factors. However, the overlarge values ofsome factors, such as the porosity of pervious concrete, the acceleration peak, and thefrequency/duration of vibration, cannot obviously aggravate the clogging of pervious concrete.Based on the experimental evidence, a preliminary dynamic clogging model is proposed,which is helpful for the design of PCP composite foundation.