关键词: 筒型基础, 数值分析, 挤土效应, 挤土机理, 沉放阻力

Abstract: In view of the fact that the conventional formula or numerical method of penetration resistance for bucket foundation do not take the soil squeezing effect into account, large errors may occur for some bucket foundations with small diameter or large diameter with bulkheads in it as the restriction effect from the cylinder wall or bulkheads induced higher soil squeezing effect inside the cylinder than outside. In order to reveal the difference of soil squeezing effect between interior and exterior, an arbitrary Lagrangian– Eulerian method is used to simulate the dynamic continuous sinking process for real simulation of the soil squeezing effect during sinking by overcoming the problems which involve large deformation and nonlinear contact. The numerical analysis results show that the earth pressure of the internal cylinder wall is almost 10 times higher than that of the external wall when the ratio of the embedded depth to the diameter is about 1.6. The mechanism of the soil squeezing effect is elucidated by analyzing the soil squeezing displacement and stress distribution. At last, a penetration resistance formula for bucket foundation considering the effect of soil squeezing is proposed which obviously improves the stability of penetration resistance calculation since the calculation results are in good agreement with the test results.

Key words: bucket foundation, numerical analysis, soil squeezing effect, soil squeezing mechanism, penetration resistance