斜坡桩基水平承载变形特性试验研究

Preliminary Experimental Study on Development of Horizontal Bearing Capacity of Pile Adjacent to Slope

利用自行研制的地基基础模型试验装置,通过埋置不同临坡距的模型桩,采用单桩水平加卸载试验方法,研究了临坡距对桩身变形及承载力的影响。研究成果表明:在水平推力较小时,每级荷载下的循环加卸载具有很好的重复性,说明桩身及其周围土体变形为弹性变形。在水平推力较大时,每级荷载下的单循环加卸载重复性较差,存在残余变形,说明桩身周围土体存在塑性变形;同时桩身应变随着临坡距的增加而减小。临坡距对斜坡输电塔桩基础的水平承载性能有较大影响,临坡距离较大时,水平临界荷载和极限承载力均较大;在桩径和桩长不变的情况下,通过加大临坡距离,可有效提高水平承载能力。

Through laying model pile at different distance from slope in model test device,the single pile loading and unloading tests in horizontal force to research the deformation and bearing capacity of pile in different distance from slope are used.Research shows that each stage of loading under cyclic loading and unloading has a good reproducibility when the horizontal force is small,thus it indicates that deformation is elastic in pile and its surrounding soil.However,each stage of loading under cyclic loading and unloading has a bad reproducibility and exist residual deformation when the horizontal force is large,thus it indicates that deformation is plasticity in pile and its surrounding soil.Meanwhile,pile strain increase with distance from slope decreases.Distance from slope has a great influence in horizontal bearing capacity of pile,critical load and bearing capacity in horizon increase with distance from slope increase.It can obvious improve horizontal bearing capacity through increasing distance from slope when pile diameter and pile length is constant.