The sub-channel bridge of Maanshan Changjiang River Rail-cum-Road Bridge carrying a section of Chaohu-Maanshan Intercity Railway is a steel truss girder cable-stayed bridge with two pylons creating a main span of 392 m,two side spans of 168 m and two end spans of 58 m.Arranged in three cable planes,the stay cables are composed of low-relaxation PE-sheathed galvanized steel strands of 15.2 mm diameter,featuring the tensile strength and stress range of 2 100 MPa and 280 MPa,respectively.The 2 100 MPa stress strands are developed on the basis of the fellow 1 860 MPa steel strands,which have improved pull-out bond strength due to the increase of the amounts of C,Si and Mn elements in the raw material.The 14 mm-diameter steel wire rods of PQS92Si-HT was finally selected as the raw material of the 2 100 MPa steel strands.To improve the anchoring performance of the steel strands,the sandwitch plates are made of 20CrMnTi steel,which measure 52 mm long,with teeth depth of 0.45 mm,taper angle of 6°10′,surface roughness above Ra3.2,and surface hardness equal to or more than 56 HRC.To accommodate the load bearing performance of the 2 100 MPa steel strands and the material properties of the currently-used anchor plates,the selected anchor plates are made of 40Cr steel,subjected to quenching and tempering treatment.Fatigue tests and post-fatigue static load tests were conducted for the single-hole anchorage and anchorage constituents.The results show that 2 100 MPa steel strands and the anchorages meet the code requirements and feasible for the case bridge.
关键词
公路铁路两用桥/斜拉桥/斜拉索/钢绞线/锚具/夹片/疲劳试验/静载试验
Key words
rail-cum-road bridge/cable-stayed bridge/stay cable/steel strand/anchorage/sandwitch plate/fatigue test/static load test
万方数据