Experimental Study On Shear Capacity Of Q460 High-Strength Angle Bolt

With the rapid economic and social development, the demand for electricity is growing in China, power industry is entering a new development track, high-capacity, long distance, high voltage transmission line caused transmission towers increasingly upsizing, the load-carrying capacities are growing too, Q235 and Q345 angle steels which are commonly used are difficult to meet the use requirements of large load towers in strength and specification. If the design loads are big, the cross-section method is accepted to meet the bearing capacity requirements; as a result, the quantity of transmission tower members and the difficulty of the joint splicing are both increased, which wastes the material and the power. In order to solve this issue effectively, the use of high-strength steel has become a necessity, not only to meet strength design requirements of the tower, avoiding the use of cross-section method, but also reduce the weight and construction difficulty of the tower.This paper studies the ultimate strength of Q460 high-strength angle bolt and joint strength systematically based on the theoretical analysis and experiment of the Q460 high-strength angle bolt and joint,(In the bolt test, the type of angles is L125×8. And there are three types of experiment members, SK101, SK102, SK103 respectively, one group of test pieces for each type, each leg of the piece has 6 test holes, there are 12 test holes altogether, and conduct the test with the 8.8 bolt for one leg and 6.8 bolt for another; in the joint experiment,4 groups of test specimens are designed,3 specimens in each group, two groups of pressure test and two groups of tensile test, specimen cross-sections are L125×10 and L160×12 bolts are 6.8 and 8.8) then compared the results with the existing standards, and discusses and analyses the applicability of the Q460 high-strength angle steel in the existing standards. The conclusions reached by the research are as following:Q460 high strength steel has the same bearing failure characteristics in the hole wall with Q235 steel, but the destruction is sudden because the yield ratio of high strength steel is smaller than ordinary steel. Keep increasing the end distance to enhance the hole wall extrusion capacity which plays a part in controlling is limited when the end distance of the high-strength steel bolt reaches 2.0d,easily leads to waste of materials. In the tower provisions of our country, there are greater remaining for 6.8 and 8.8 high-strength bolt in the design value of the shear bearing capacity.The results are safer when calculate the Q460 high-strength angle bolts and joints using GB50017-2003,L/T5154-2002 and ASCE10-97, in which the value calculated by ASCE10-97is closer to the experimental value than GB50017-2003 and L/T5154-2002.