碎石土-基岩斜坡桩基参数m值影响因素研究

Study of Infl uential Factors of Pile Foundation Parameters m Value for Gravel Soil^bedrock Slope

四川输电线路经过的山区斜坡场地中,碎石与破碎基岩分布普遍,斜坡桩基碎石土与破碎基岩水平抗力系数的比例系数m值取值是陡峻边坡输电线铁塔桩基设计中亟待解决的问题。根据输电线路实际走线中常见的地形地貌和碎石土-破碎基岩等场地条件,应用FLAC3D数值分析软件建立斜坡桩基概化模型,探讨斜坡坡度、桩径、嵌岩深度对桩基抗力系数比例系数m值的影响,并对斜坡地基m值取值方法进行了建议。研究表明:桩顶位移较小时地基岩土m值随坡度增大而减小,随桩径、嵌岩深度增大而增大。故对位于斜坡输电线路铁塔进行桩基设计时,m值取值应考虑上述因素的影响,适当折减或不折减。

Sichuan transmission rock and broken rock ,evaluatin lines through the mountain slope area with a wide distribution rubble and broken g the proportional coefficient m of ground horizontal resistance coefficient is value of slope foundation. The researches show that, the m value decreases with the increase of slope gradient when displacement of the pile head is small, and increases with the increase of pile diameter, rock-socketed depth. Sotaken into account the above factors, m value should be appropriate reduce or no reduce when design pile foundation of transmission line tower that located the slope.