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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,但是关于灌注桩套管高频振动贯入机理,特别是套管贯入引起的超孔隙水压力的研究还不全面。在全面介绍了套管高频振动贯入有限元分析模型的建立过程后,对套管高频振动贯入引起的超孔隙水压力分布规律、变化趋势进行了详细研究。同时,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孔压性状的影响程度。研究结果表明:套管振动贯入过程中,超孔隙水压力随距套管端部垂直距离、水平距离的增大而减小,且超孔隙水压力幅值随时间逐渐增大,随振动频率增大而减小;套管振动贯入结束后,超孔隙水压力随时间大致呈指数型衰退,且主要沿套管内侧路径消散;影响孔压性状的主要因素为贯入深度和渗透系数。研究结果对套管高频振动贯入砂土中的孔压性状分析具有理论和实际意义。
With the development of full-pipe vibro-earth bored piles construction technology, the application of bored piles in engineering is more and more widely. However, the mechanism of high frequency vibration penetration of bored pile bushing, especially the excess pore water The study of stress is not comprehensive. After comprehensively introducing the establishment process of bushing penetrating into the finite element analysis model, the distribution law and trend of excess pore water pressure caused by high-frequency casing penetration are studied in detail. At the same time, orthogonal experiment and numerical simulation were used to evaluate the influence of various factors on the pore pressure. The results show that during the process of casing penetration, the excess pore water pressure decreases with the vertical distance and horizontal distance from the end of casing, and the amplitude of excess pore water pressure increases with time. With the increase of vibration frequency The pore water pressure decreases roughly exponentially with time, and dissipates mainly along the inner diameter of the casing. The main factors affecting the pore pressure behavior are penetration depth and permeability coefficient. The research results have theoretical and practical significance for analyzing the pore pressure characteristics of casing casing penetrated into sand.