| With the development of society and economy,the span of bridge is increasing.It is the trend of the development of long-span suspension Bridges to use higher strength steel wire to reduce the dead weight of main cables.For the moment,the research and application of1960MPa suspension bridge main cable strands in the world has just started.China Nan Sha bridge has successfully developed the domestic 1960MPa super-high strength main cable strands and realized the real bridge large-scale application of more than 30,000 tons for the first time,which not only has significant economic and social benefits.This thesis is based on"The key technology research topic of 1960MPa super-high strength main cable steel wires and strands"of Nan Sha bridge,in view of the new product development of quality reliability and real bridge application security,1960MPa super-high strength of the main cable strands performance experiment was carried out analysis and study,which show that the results of new product performance test meet the technology indexes of 1960MPa main cable strands and reached the international leading level.The main work and achievements of the thesis include:(1)The tensile strength and torsion indexes of 1960MPa super-high strength zn-al alloy coated wires were researched on uniformity,by a large number of experimental data statistical analysis,the tensile strength of domestic 1960MPa super-high strength zn-al alloy coated wires reached more than 1960 MPa,the number of torsion reached more than 14,and has good uniformity.It meets the production requirements of 1960MPa super-high strength main cable strands.(2)The static load and dynamic load tests of the domestic 1960MPa super-high strength main cables were carried out,and a number of comparative tests were set up.By calculating and analyzing the test data,it was concluded that the static load breaking force of the domestic 1960MPa ultra-high strength main cables reached more than 95%of the nominal breaking load;the fatigue performance meets the requirements of dynamic load test with the stress limit of 0.4P_b、the stress range of 200MPa and the test number of 2 million times,the static load breaking force is still more than 95%after fatigue effected;there was no broken wires in the cable strand and no abnormality in the casting and anchor cup after the test.The results show that the performance of the domestic 1960MPa super-high strength main cables is safe and reliable,and it has a certain reserve capacity.(3)The slip resistance of main cable(cable clip)of 1960MPa zn-al alloy coated wire cables were tested and researched,and 1960MPa zinc coated wire cables were set up.The test results show that domestic 1960MPa zn-al alloy coated main cables(cable clip)slip resistance value is greater than the design specification,smaller than 1960MPa zinc coated main cables,but the difference is little.(4)The structural size of the 1960MPa super-high strength main funicular anchor are checked and calculated.The results show that the designed structure size of anchor meets the breaking requirements of the 1960MPa main cable strands;the finite element analysis of anchor and the stress test of anchor structure of 1960MPa super high strength main cable strands were studied,the results show that under normal loading condition,the stress of steel wire and anchor of 1960MPa main cable strands are uniform,and the maximum stress of anchor cup of main cable is less than the yield strength of anchor material,which meets the design load requirement and has plenty of allowance.It is shown that the mechanical performance of the domestic 1960MPa super-high strength main cable-strands anchorage structure is safe and reliable,and the anchorage performance is good. |
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