南沙地区钉形水泥土搅拌桩荷载传递规律的试验研究
来源期刊：中南大学学报(自然科学版)2012年第9期
论文作者：罗大生 肖超 张可能 何杰 陈星光
文章页码：3575 - 3581
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
Key words：T-shaped soil-cement deep mixing column; load tests; variable section; column body stress; column lateral friction resistance
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%。
Abstract: 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%.
罗大生，肖超，张可能，何杰，陈星光
(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)
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%。
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
LUO Da-sheng, XIAO Chao, ZHANG Ke-neng, HE Jie, CHEN Xing-guang
(Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
School of Geosciences and Info-Physics, Central South University, Changsha 410083, China)
Abstract: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%.
Key words:T-shaped soil-cement deep mixing column; load tests; variable section; column body stress; column lateral friction resistance
