基于Gudehus-Bauer模型的砂土中灌注桩护壁套管高频振动贯入速率

随着全套管护壁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，但是关于灌注桩护壁套管高频振动贯入速率的研究较少。通过假定套管为刚体，将套管周围土体划分为同心轴的圆环柱体，利用Gudehus-Bauer亚塑性本构模型计算套管外侧各土体单元接触面间的剪应力和套管端部土体竖向应力，并考虑套管振动贯入过程中土塞效应，建立灌注桩套管高频振动贯入砂土中贯入速率的计算模型。将所提出的贯入速率计算结果和物理模型试验结果与有限元结果进行对比分析，验证了计算模型的合理性。通过参数分析，得到地基土体孔隙比、振动频率和套管直径对贯入速率的影响规律，为实际工程中快速、准确地预测套管振动贯入速率提供了可靠方法。

Penetration speed of sleeve for cast-in-place pile installed in sand by high frequency vibratory hammers using Gudehus-Bauer hypoplastic model

With the development of the construction technique of pile sleeves driven by high frequency vibratory hammers, the cast-in-place piles have been widely used in construction engineering. However, the studies on the penetration speed of sleeves for cast-in-place piles driven by high frequency vibratory hammers are still not complete. Assuming rigid body for the sleeve, the soils around the sleeve were divided into several concentric circular cylinders. Considering the soil plugging effect during vibratory sleeve driving, the shear between the soil elements outside the sleeve and the vertical stress at the sleeve bottom were calculated by using the Gudehus-Bauer hypoplasticity constitutive model. The penetration speed was obtained by modelling of the high-frequency vibratory driving of the cast-in-place pile sleeve into sand. To validate the calculation model, the penetration speed obtained by the calculation model was compared with those by the experiment and the finite element simulation. The influence of the void ratio of foundation soil, the vibration frequency and sleeve diameter on the penetration speed of sleeve is analyzed through parametric analysis. The calculation model provides a reliable way for practical engineering to quickly and accurately predict the penetration speed of sleeve.