中文摘要：

随着全套管振动取土灌注桩施工工艺的发展,灌注桩在工程中的应用越来越广泛,但关于灌注桩套管振动贯入机制,特别是套管贯入引起的地面振动研究还不全面。在全面介绍了套管振动贯入全过程的有限元-无限元耦合模型的建立过程后,对套管振动贯入引起的地面振动规律及施工安全距离进行了详细研究。采用正交试验与数值模拟相结合的正交有限元法评价了各因素对施工安全距离的影响程度。研究结果表明：套管贯入过程中,地面振动主要沿水平向;在套管贯入初期,地面不会产生水平向峰值速度,当套管贯入到振动临界深度时,地面产生水平向峰值速度;地面水平向峰值速度随径向距离增大呈指数型衰减;施工安全距离随动力荷载幅值、接触面摩擦系数增大而增大,随振动频率、土体模量增大而减小。研究了隔振沟的填充材料、深度和宽度对隔振效果的影响,结果表明,无填充料的隔振沟隔振效果最好;隔振沟的宽度对隔振效果影响不大,其深度对隔振效果影响显著。

英文摘要：

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.