南沙地区钉形水泥土搅拌桩荷载传递规律的试验研究  

Load transfer mechanism of T-shaped soil-cement deep mixing pile in Nansha area, Guangzhou

作　　者：罗大生[1] 肖超[1] 张可能[1] 何杰[1] 陈星光[1] 

机构地区：[1]中南大学地球科学与信息物理学院,有色金属成矿预测教育部重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2012年第9期3575-3581,共7页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51078140;51108176);湖南省博士生科研创新项目(CX2010B050)

摘　　要：以广州南沙某城市干道地基加固的钉形水泥土搅拌桩为研究对象,通过在桩体中埋设应变片,结合现场载荷试验,对钉形水泥土搅拌桩桩身应力、轴力和侧摩阻力的变化规律进行研究。研究结果表明:由于钉形水泥搅拌桩变截面的作用,在变截面上下两端桩体的应力和轴力产生较大衰减,形成1个明显的凸峰;桩身的应力和轴力主要集中在变截面之上,它们分别占全部应力和全部轴力的58.79%和78.82%,而变截面下部12.0 m长桩身的应力和轴力分别只占42.21%和21.17%;桩体的桩身侧摩阻力与深度曲线具有明显的分段性,呈S型;在距桩体上部4.5 m范围内,桩体侧摩阻力占总侧摩阻力的88.89%,而桩身下部10.5 m长桩体的侧摩阻力仅占总侧摩阻力的11.11%。T-shaped soil-cement deep mixing column was used in the soft foundation reinforcement of one urban road in Nansha area of Guangzhou.Axial force and stress and shaft resistance of two T-shaped soil-cement deep mixing piles,in which equipped strain gages,were studied in the process of pile’s load test.The result shows that because of effects of the variable section of T-shaped piles,its axial force and stress vary greatly on both sides of pile’s variable section,and curves of axial force-depth and stress-depth are convex forms obviously.The area above pile’s variable section concentrates the main axial force and stress,which accounts for 58.79% and 78.82% respectively,but the area below the variable section,where the length of pile body is 12.0 m,only accounts for 42.21% and 21.17%,respectively.The curve of pile’s shaft resistance-depth has obvious segmentation and presents a ＂S＂ type.The shaft resistance of the upper 4.5 m length of piles accounts for 88.89%,but shaft resistance of the lower piles of 10.5 m length just accounts for 11.11%.

关 键 词：钉形水泥土搅拌桩 载荷 变截面 桩身应力 桩身侧摩阻力 

分 类 号：TU473[建筑科学—结构工程]