砂土中圆形板式基础板周土体抗拔破坏机理影响因素分析

圆形板式基础是架空送电线路常用的基础形式之一,在送电线路基础设计中,板式基础的抗拔承载力往往是基础设计的控制性因素,对板式基础板周土体破坏机理的正确识别是板式基础可靠计算的基础。本文采用PIV变形测量技术(PIV技术),对板式基础在不同埋深下,不同密度砂土中板周土体的变形场进行了分析,结果表明对于埋置于松砂中的板式基础,在不同埋置深度下的破坏模式都为冲切式破坏,而对于密砂中的板式基础不同埋置深度下出现不同的破坏模式,浅埋板式基础出现扩展到地面的梯形剪切面,深埋基础则为土体内部的局部破坏。

Circular plate foundation is one of the common foundations for transmission towers. The uplifting capacity of plate foundation is a control factor for foundation design. The reliable design of plate foundations depend on the identification of true failure mechanism.The PIV technology is used to analyze the the deformation fields around the plate foundations in sand at different depth and density. The results show that the failure mode of plate foundations in loose sand is punching shear failure at different depth. For plate foundations in dense sand, there are different failue mods at different depth. The shallow plate foundations shows a trapzoid failure plane which expanded to the ground surface. The deep plate foundations shows a local failure mode under the groundsurface.