嵌岩桩竖向承载力预测方法

Prediction methods for vertical bearing capacity of socketed piles

现行规范计算方法不同、参数取值不一,导致各类设计方案差异较大。基于收集的193组嵌岩桩静载试验数据,对各类极限侧阻力、端阻力预测方法的适用性进行研究,分别建立了不同岩石类型极限侧阻力、端阻力与岩体无侧限抗压强度的关系。在此基础上,给出了嵌岩桩竖向承载力的建议计算方法。结合试验实测资料验证了推荐方法的可行性,并与现行规范方法进行比较。结果表明,对于硬质岩层嵌岩桩竖向承载力的确定,现行规范方法计算结果偏大,用于工程设计时偏于危险,建议采用推荐的计算方法。

With the advantages of high bearing capacity and small settlement,the socketed piles are widely used in basic structures.However,due to the complexity of geological conditions,the diversity of construction process and the difference of industry requirements,the vertical bearing capacity of different calculation methods is very different.Based on the collected 193 groups of socketed piles static load test data,the applicability of the existing prediction method of ultimate lateral resistance and ultimate end resistance is analyzed,respectively,different types of rock ultimate lateral resistance,ultimate end resistance and the relationship between unconfined compressive strength of rock mass is set up.Based on this,the proposed calculation method of vertical bearing capacity of socketed piles is given,and the feasibility of the proposed method is verified with the measured data,and the results are compared with the current standard method.The results show that the ultimate bearing capacity is overestimated by general standard methods for hard rock,which is dangerous for engineering design.The calculation method in this paper is recommended.