The Calculation Analysis On Static Performance Of Super-tonnage Strand Stay Cable

Chongqing Liangjiang Bridge is referred to Dongshuimen Bridge and QiansimenBridge, both of which are extradossed cable-stayed bridges with single cable plane. Thesize of stay cable is139Φ15.2mm, namely meaning that the ultimate bearing capacityof single cable comes to36140kN. While a problem is encountered: existing testequipment can not meet such a large tonnage of cable-stayed in the static load test.The31-hole anchorage、73-hole anchorage and139-hole anchorage are selected asthe research target because of the same anchor hole’s topology in this paper. On thebasis of searching and learning relevant literature and the finite element method,considering some necessary simplification and certain assumption,1/12three-dimensional models of31-hole anchorage、73-hole anchorage and139-holeanchorage are established by ANSYS, in which the frictional contact between the jawsand the anchor head、elastic-plastic nature of anchor head and geometric nonlinearityare taken account.After tanking the load mode as the same as static test, the mechanicalbehaviors of anchor head are analyzed. By contrasting some parameters (such as stressand strain) of the the31-hole anchorage、73-hole anchorage and139-hole anchorage, anevaluation method of static loading performance using small tonnage strand stay cableinstead of large tonnage strand stay cable is pursued.Firstly, the mechanical behavior of cable-stayed anchor hole139in the loadingprocess is simulated. By analyzing the draw-in value of strand and stress、strain、deformation of anchor head, distribution and development law in the loading process isobtained.Secondly, comparison and analysis of three models are conducted, some results areconcluded:①In the contrast in draw-in value of strand, difference rate of strand of73-holemodel and139-hole model is7%, that of31-hole model and139-hole model is10.61%.②In the overall analysis and comparison of the anchor head, comparison on threeaspects is conducted, which contain the max stress and plastic strain、the stress andplastic strain on the top of anchor head、axial deformation on bottom. The resultsdemonstrated that31-hole model、73-hole model and139-hole model have similarmechanical behavior in the loading process, however the value of73-hole is closer to 139-hole.③In the local analysis and comparison of the anchor head, center hole、secondaryside hole、the weakest area between the side hole、the edge of anchor head are selectedas study target. By comparing stress and plastic strain in every loading process, theresults are demonstrated that the73-hole model and139-hole model coincide with ahigh degree, while there is a certain degree of difference between31-hole model and139-hole model.As above analysis results show, the method of using73-hole strand stay cablesinstead of139-holes strand stay cables in the static load performance test is feasible.Finally, by comparing the calculation results with the experimental results of73-hole strand stay cables,the validity of the numerical model is verified.