750kV钢构架节点试验研究

Test & Research on Joints of 750kV Substation Steel Lattice Frames

钢管格构式构架中出(母)线梁弦杆与构架柱主材的连接,无论从构造还是受力上都很复杂,同时这种节点又是构架结构的关键部位之一,目前关于这种节点的受力性能尚未有研究报道。结合渭南东750 kV输变电工程,针对这种节点的受力性能进行了6个足尺实型节点在拉(压)、剪复合作用下的试验研究。试验节点承受荷载均大干其设计承载力,并具有较大的安全裕度,说明所设计的节点是安全可靠的。试验还表明,在节点板及与之相连的附近钢管截面存在较大的应力集中现象。虽然钢管截面个别点上应力达到了屈服应力,但对整个节点的受力性能未有影响;试验进一步表明,所采用的6.8级镀锌螺栓即使在荷载远大于设计承载力时,也未有较大的滑移和松动。

In steel tubular lattice structural frames, joints between beam chords and column chords are rather complex, either for their details or the stresses, and such structural joints are key parts of the structures. At present, there is no study on such structural joints. To understand the behavior of such joints, six full-scale specimens based on the East Weinan 750 kV substation project are tested under combined loading. It is shown that the tested joints possess higher load bearing capacity than their design capacity, and the designed joints are safe and reliable. The tests also show that there exists obvious stress concentration on the tube cross-section near the connections between the gusset plate and tube. Although some stresses on the tube section reach the yielding stress, the load bearing behavior of the joints has not been affected. Furthermore, even if the loads are greater than their design load bearing capacity, the galvanized bolts of class 6.8 show little slip.