Visualization Investigation of the Plugging Effect on Open-Ended Pipe Pile Jacked in Transparent Sand

Abstract

This paper describes the findings of a study of the soil plugging progressive formation process during pipe pile penetration using a transparent soil model test. The objective of this study is to visually investigate the factors affecting the plugging effect such as the pile diameter, penetration speed, relative density, and wall thickness. To measure the plugging development, an image measurement system was utilized. It found that pile diameter, relative density, and wall thickness were more sensitively influencing factors and that changing penetration speed had a minor influence on the degree of soil plug. The visualization analysis results show that the formation of plugging is not continuous, but intermittent and progressive. The soil plug was an alternate process from formation to destruction repeatedly. In addition, it revealed that the mobilization of internal frictional resistance depends on the height of the formed plugging and that the degree of soil plug only affects the magnitude of unit internal friction resistance. The underlying dynamic evolutionary mechanism of plugging formation was further discussed. In addition, a linear empirical formula between the incremental filling ratio and plug length ratio value was proposed.