Soil Plug Effect Of Jacked Open Pile In Layered Foundation

In the southeast of our country,silt soft soil,cohesive soil and other formations are widely distributed and the climate has high annual precipitation of wetting and precipitation,while the acidity of rainwater has a corrosive effect on the pile foundation.Compared with the characteristics of closed-end pipe piles,open pipe piles are more suitable for these areas.In addition,the static pressure open pipe pile is also widely used in the construction field with many advantages such as saving materials,construction environmental protection,strong earthquake resistance and good economic benefits.However,the plug effect of the open pipe pile will inevitably exert some influence on the terminal resistance and destructive traits and the bearing capacity of the pile.At present,the theoretical research on the plug effect of open pipe piles is not perfect,and the current research object is mostly homogeneous soil with different soil types,However,there are few researches on the plug effect of static pressure open pipe piles in layered soils.In this paper,the indoor model test was used to study the pile-sinking process of static pressure open piles in different types of soil layers.The main contents of this study include the comparison of the soil plug growth,the structure of soil plug,the filling rate of soil plug in different soil layers,the variation of soil plug in different soil layers is revealed,put forward the empirical formula between soil plugging rate and soil plug rate.In addition,based on the indoor model test,the engineering example is compared with the test results.The results show that the larger the inner diameter of the open pile,the higher the height of the soil plug,and the development pattern of the soil plug of open piles under the layered foundation is obviously different from that in the homogeneous foundation.In addition,the numerical development trend between test and engineering is basically similar,which verifies the reliability of empirical formula.The research results have guiding significance for further clarifying the internal mechanism and development of open pile plug effect.