特高压直流输电线路岩石锚杆群锚基础试验

Field Full-scale Tests on Group Anchorage Rock Foundations of DC UHV Transmission Line Project

针对山区特高压直流输电线路荷载大、杆塔基础全方位铁塔长短腿和高低主柱基础配合方案的工程实际需求,提出了一种新型的山区特高压直流输电线路承台嵌岩式岩石锚杆群锚基础型式,并在现场完成了不同锚杆埋深和承台嵌岩深度的3个2×2承台式群锚基础的抗拔试验、3个3×3承台式(8根锚杆布置)群锚基础的上拔与水平力组合荷载工况试验。试验结果表明:水平力明显降低了承台嵌岩式岩石锚杆群锚基础的抗拔承载性能,适当增加锚杆长度及承台嵌岩深度可有效提高承台嵌岩式岩石锚杆群锚基础的抗拔承载性能。

A new type of group anchorage rock foundation is presented according to the fact that the load of UHV DC transmission tower foundations are large and the scheme of unequal tower leg length with unequal height of foundation is widely used in the UHV DC transmission project. In addition, three uplift load tests were carried out on 2×2 bearing platforms with four bolts of different anchor length and rock-socked depth, and three load tests were also carried out on 3×3 bearing platforms with eight bolts of different anchor length and rock-socked depth under uplift combined with lateral loading. It is indicated that the lateral loading could reduce the uplift capacity of the group anchorage rock foundation obviously. Increseaing the bolt anchorage length or the rock-socked depth can effectively enhance the uplift and lateral bearing capacties of the group anchorage rock foundation. This work is supported Science and Technology by State Grid Corporation of China （GCB17201200123）.