关键词: 灌注桩套管, 振动贯入, 地面振动, 有限元, 隔振沟

Abstract: With the development of the construction technique of cast-in-place piles with vibratory sleeves driving, the cast-in-place piles have been widely used in construction engineering. But the researches on the penetration mechanism of sleeve for cast-in-place piles installed by vibratory driving are still not complete, especially the ground vibration due to sleeve driving. The paper presents a finite element and infinite element coupling model for full penetration process of sleeve installed by vibratory driving, and investigates in detail the rule and construction safety distance of ground vibration. The orthogonal finite element method is used to evaluate the influence of each factor on the construction safety distance by orthogonal test and numerical simulation. The results indicate that the ground vibrates horizontally in sleeve penetration. The horizontal peak velocity at the ground surface does not occur until the sleeve toe is on the ground surface. As the sleeve penetrates into the ground, the horizontal peak velocity occurs at a critical depth of vibration. And the horizontal peak velocity at the ground surface exponentially decays with the increasing of radial distances. Construction safety distance increases with the increase of dynamical load amplitude, soil–sleeve friction, and decreases with the increase of vibration frequency, soil elastic modulus. Furthermore, the influence of isolation trench’s filling material, depth and width on the damping effect are investigated. The results show that damping effect of open isolation trench is the best. The depth of the isolation trench has vital effect on the damping effect while the width has little effect.

Key words: sleeve of cast-in-place pile, vibratory driving, ground vibration, finite elements, isolation trench