沙漠风积沙地基扩展基础抗拔现场试验研究

通过在新疆、宁夏和内蒙古典型沙漠地区完成的现浇混凝土和装配式2种扩展基础在上拔、上拔与水平力组合工况下的25个现场试验,获得了风积沙扩展基础抗拔荷载-位移曲线,并确定了各试验基础的抗拔极限承载力。按照"土重法"计算原理,得到了反映沙漠风积沙地基抗拔承载性能的极限"上拔角"。经统计分析,得到沙漠风积沙极限"上拔角"标准值为16.8°,该值考虑了沙漠风积沙的区域特征、基础型式与尺寸、荷载工况等因素,可为沙漠地区输电线路杆塔基础的工程设计提供依据。

Uplift Field Load Tests on Spread Foundations in Aeolian Sand Area

In this study ,the uplift performance of spread foundations were investigated in aeolian sand at typical deserts in Xinjiang ,Ninxia ,and Neimeng .Twenty-five full-scale spread foundations were installed at the aforementioned test sites ,including the cast-in-place concrete spread foundations and the assembly foundations .The field load testing was conducted for each spread foundation under uplift loading or under the combination of uplift and lateral loadings ,and the load-displacement curves for all tested foundations were obtained .Based on the characteristics of the load-displacement curve ,the ultimate uplift capacity of each spread foundation was determined .The slope angle for the earth cone method was suggested ,which is the parameter to determine the uplift capacity of spread foundations .Based on the statistic analy-sis ,the standard value of the slope angle for earth cone method was suggested as 16 .8° .The results in this study could be served as the support for foundation designs in aeolian sand because of the comprehensive considerations of the desert differences ,the spread foundation structures ,and the loading cases .