《Journal of Geotechnical and Geoenvironmental Engineering》杂志刊登“打桩过程中长桩的侧向移动”

作者：L. M. Zhang; K. H. Chu

刊物：《Journal of Geotechnical and Geoenvironmental Engineering》，2012年10月，138卷第10期，1222-1236页

关键词：打入桩；单桩承载力；打桩；桩基；侧向位移；载荷试验

摘要：打桩过程中较大的侧向位移能够引起周边土体的屈服，此时土与桩壁之间的有效应力降低，并且桩的侧阻力降低。在香港的一个大理岩区进行了一个桩基工程，该地区基岩面高低起伏，其中构造洼地由软土沉积充填。许多钢制H型桩的打入深度要超过100 m，对于如此长的桩，其垂直度引起广泛关注。为此进行了一个试桩项目，试验采用4个长度达164.5m的钢制H型打入桩，在不同的贯入深度进行了垂直度监测及动桩测试。本文旨在阐释四个长桩的垂直度，并研究桩的垂直度与沿程地质特征的关系以及桩的垂直度对桩承载力的影响。打桩过程中，在深度为100 m时桩的最大侧向位移达8.7m， 并且桩的最大倾斜度达到了0.139。打桩过程中桩的侧向位移与基岩倾斜度和土体条件密切相关。试验中既观测到了桩的单向倾斜，也观测到了双向环形倾斜，并且环形倾斜引起的桩侧阻力的降低比单向倾斜严重。

Lateral Movements of Long-Driven Piles during Pile Driving

Authors: L. M. Zhang; K. H. Chu

Journal: Journal of Geotechnical and Geoenvironmental Engineering, Volume 138, Issue 10 (October 2012), 1222–1236

Key words: Driven piles, Pile capacity, Pile driving, Pile foundations, Lateral displacement, Load tests

Abstract: Large lateral movements of a pile during impact driving can cause yielding of the surrounding soil. When this happens, the effective stresses between the soil and the pile wall diminish, and the pile shaft resistance decreases. A piling project was carried out in a marble area in Hong Kong, where highly variable rockhead contours and deep depressions filled with weak soil deposits were found. Many steel H-piles were driven to depths of more than 100 m, and the verticality of such long piles was a concern. A pile test program consisting of four driven steel H-piles with pile lengths up to 164.5 m was conducted. Verticality monitoring and dynamic pile tests at several penetration depths were performed. This paper aims at interpreting the verticality of the four long piles, studying the relevance of pile verticality to the encountered geological features, and studying the effect of pile verticality on the pile capacity. The maximum lateral pile movement during driving was up to 8.7 m at a depth of 100 m, and the maximum local pile inclination reached 0.139. The lateral movements of the piles during driving well matched the rockhead inclination and soil conditions. Both one-way sway and two-way cyclic sway of the test piles were observed. Cyclic sway was shown to cause more severe reduction of the pile shaft resistance than one-way sway.

原文链接：http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29GT.1943-5606.0000707

翻译：孙庆雷；审核：邓刚