大直径桩桩身压缩量和侧摩阻力综合分析  

The Comprehensive Analysis of Large Diameter Pile Compression and Side Friction

作　　者：焦雷[1] 郭忠贤[1] 马亮[1] 

机构地区：[1]石家庄铁道学院土木工程分院,河北石家庄050043

出　　处：《岩土工程技术》2010年第2期94-97,共4页Geotechnical Engineering Technique

摘　　要：为了分析桩身压缩量和侧摩阻力对大直径桩承载力的影响,通过桩基现场静载试验,获得各级荷载作用下各土层交接面处的桩身应力应变值,计算出不同土层间每1m桩身段的压缩量和侧摩阻力值。实验结果表明:各土层间桩侧摩阻力实测最大值与勘察报告值之比差别较大,其中上部土层间的摩阻力比值较小,下部比值较大。上部土层桩侧摩阻力在各级荷载作用下变化不大,而下部土层桩侧摩阻力随荷载逐级递增。由于压缩量是反映材料受力变形的物理量,虽然下部土层的摩阻力实测值与报告值比值较大,但其桩身压缩量较小,因而可以判断侧摩阻力发挥程度并估算其极限值。大直径桩的承载力主要是由侧摩阻力来提供的,因此可以通过桩身压缩量和侧摩阻力的综合分析为石家庄乃至河北地区的大直径桩承载力确定提供有价值的参考。In order to analyze the pile compression and lateral friction impact on the bearing capacity of large-diameter pile and obtain the stress-strain values of the pile which are situated at the interface of soil layers under all levels of the loads, a great in-site static pile test is carried. We can calculate per meter of the pile compression and side friction between different layers. The test results show that between different layers the pile side frictions ratios of measured value to surveyed value are radically different, the ratios of upper parts are smaller and the lower parts are larger. There are few changes of the pile side friction on the upper parts but the lower parts increase by stages. The compression is a physical quantity which reflects the working characters of the material. Although the pile side friction＇s ratios of upper parts are larger, the pile compression is small. As a result the pile side friction still has the development potential and its limit value can be estimated. The bearing ca- pacity of the large diameter pile are mainly produced by side friction, therefore, based on a comprehensive analysis of pile compression and side friction, this paper hopes to supply the valuable reference for determining the bearing capacity of the large diameter pile in Shijiazhuang Region and even in Hebei Province.

关 键 词：大直径桩承载力 桩身压缩量 桩侧摩阻力 静载试验 

分 类 号：TU473.1[建筑科学—结构工程]