索连板球基础竖向抗拔承载特性及其影响因素

Vertical uplift resistance of the foundation of plate and ball connected by anchor cable and its influencing factors

针对沙漠地区砂土地基的工程特性及现有输电塔基础存在的不足,研发出索连板球基础。将室内相似模型上拔试验与数值模拟计算相结合,对不同上拔荷载作用下的基础位移进行分析,并研究了埋深比、球径及柱径对基础极限抗拔承载力系数及土体表面主破裂面半径的影响及其规律。研究结果表明:数值模拟计算结果与模型试验结果吻合较好,与土体变形演化的三阶段相对应,荷载位移曲线呈三段式变化;埋深比对基础极限抗拔力影响最大,且它们之间呈正相关关系;极限抗拔承载力系数随埋深比增大呈先增大后减小的变化趋势,与球体直径呈负相关关系,与水泥土柱直径呈正相关关系;土体表面主破裂面半径与埋深比、球径及柱径均呈负相关关系。

According to the engineering properties of sandy soil foundation in desert area and the shortcomings of the existing transmission tower foundation,a foundation of plate and ball connected by an anchor cable is developed.By combining the similar model uplift tests and numerical simulations,the displacement of the foundation under different uplift loads is analyzed.Besides,the influence and its rule of buried depth ratio,spherical diameter and column diameter on the ultimate uplift bearing capacity coefficient of the foundation and the radius of main rupture surface of soil surface are studied.The results show that the numerical simulation results are in good agreement with the experimental results.The loaddisplacement curve presents a three-stage form,which corresponds to the three stages of soil deformation evolution.The ratio of buried depth is of the greatest influence on the ultimate uplift resistance of foundation,and there is a positive correlation between them.The ultimate uplift bearing capacity coefficient increases first and then decreases with increase of burial depth ratio.It is negatively correlated with the sphere diameter and positively correlated with the cement-soil column diameter.The radius of the main rupture surface of soil is negatively correlated with the buried depth ratio,spherical diameter and column diameter.