抗拔支盘桩桩周土体位移场模型试验

Anti-tension model test on soil displacement field around squeezed branch anti-uplift pile

利用数字图像技术,结合支盘桩室内模型试验,对支盘桩在上拔荷载作用下的工作机制进行研究,得到等直径桩和单支盘桩在上拔荷载作用下的荷载变形特性、桩周土体位移场的分布规律.研究表明:单支盘桩抗拔承载能力高于等直径桩;等直径桩桩周土体位移沿深度减小,桩周土体影响区域呈V形,极限状态时桩顶处土体的影响范围约为4倍桩径;单支盘桩桩周土体位移受支盘影响,桩周土体的影响范围较大,影响区域近似呈U形,极限状态时桩顶处土体的影响范围达到6倍桩径左右.

A anti-uplift mechanism of squeezed branch pile was studied and the images captured by digital camera were analyzed by the digital image correlation procedure.Through the analysis,the bearing capacities of equal-diameter pile and squeezed branch pile,as well as the full-field gradual displacement of the soil were obtained.Test results show that the bearing capacity of squeezed branch pile under the uplifting load is higher than that of the equal-diameter pile.The range of the soil influenced by equal-diameter pile decreases along depth direction,and in ultimate state it reaches four times of the pile diameter at the pile top.The area influenced by equal-diameter nomal pile is V shape.The soil range influenced by squeezed branch pile is greater than that of the equal-diameter nomal pile,and at the pile top it reaches about six times of the pile diameter in ultimate state.The area influenced by squeezed branch pile is similar to U shape.