Abstract: Due to the advantages of the low cost and construction convenience, the geo-tubes are widely used in reclamation projects to build dikes on thick soft soil foundation. As the bearing capacity of soft foundation soil isn’t high enough,and usually the soil is in plastic flow state, the geo-tubes will penetrate into the foundation soils by squeezing out soft soil when geo-tubes dike is built on soft soils. With increasing penetration, the bilateral load applied on geo-tube dike become bigger. When the basal of geo-tube dike lands on the deep soil layers with higher bearing capacity, the weight of the dike approaches the bearing capacity of foundation soil, the penetration will stop, at this time, the soil attains limiting equilibrium condition. In the actual project, it is crucial to estimate the specified penetration at the design stage of constructing a geo-tube dike, and determine the quantity of the geo-tubes. Based on the limit equilibrium concept, in which the weight of dike and the bearing capacity of the foundation soil are balanced, a formula for caculating penetration depth of geo-tubes is deduced by considering the effect of the soil upheaval on the bearing capacity. The rationality and applicability of the formula is validated by model test results and the observed data from practical construction projects. The results can provide reference for the design of penetration of geo-tubes dike.

Key words: geo-tubes dike, penetration , bearing capacity, integral sliding failure, model test