Research On Design And Details Of Key Joints In Cable Structure Buildings

In cable structure buildings,the cable is one of the main load-bearing components of the structure,and the cable joint plays the role of the force-transfer station between the cable and the components connected with it.And its destruction is more likely to cause the progressive collapse.The design of joints and construction details have a decisive effect on the structure safety,integrity and economy.The key connection joints in cable structure include cable clamps,saddle and cable-end joints.However,the design specifications of domestic cable structure joints(mainly cable-end joints and cable clamps)are still not perfect,and the designers still need to use the relevant regulations of other industries and personal experience to complete the design.In this paper,two joints about the design and details were mainly studied,including pin-connected plate of cable-end joint and the clamp.(1)pin-connected plate of cable-end jointThis paper summarized the specifications and research literature on the bearing capacity calculation of pin-connected plate,and compared the differences of domestic and foreign regulations for the bearing capacity calculation and detailing requirements,and pointed out the parts that the specification needs to be improved.Furthermore,different pin-connected plates were designed respectively using domestic and European specifications,and the size and bearing capacity were compared and analyzed.And the three-dimensional solid finite element analysis was performed considering the contact nonlinearity and taking the bare plate without the reinforcing plates as an example.The basic rules of the stress distribution were obtained.The bare plate were compared with the pin-connected plate with the reinforcing plates,and the rules were found that the reinforcing plates that connected with the main plate only by circumference welding,could be co-stressed with the main board,and the stress distribution of the main plate near the soldering feet were changed by the reinforcing plates.which the parametric experiment and study of the bearing capacity of the pull-tab plate provide the necessary theoretical basis.Through the material performance experiment and parametric experiments on the pin-connected plates,the influence of the size and details of the plates on the tensile strength of the pin-connected plates were studied.According to the load-displacement curves obtained by the experiments,the yield capacity of each pin-connected plate was obtained using the adjusted CEN bilinear method.Based on the experimental results,the calculation formula of tensile bearing capacity across the pin-hole section and the calculation formula for splitting bearing capacity at the front end of the pin hole of the bare plate in the national standard were adjusted.And the calculation formula of tensile bearing capacity across the pin-hole section of the plate with reinforcing plates was proposed.Using the material model obtained from the material performance experiment,taking the material nonlinearity and contact nonlinearity into account,a three-dimensional solid finite element analysis of the parametric experimental plates was performed to obtain the load-displacement curve.Comparing it with the experimentally obtained curve,the accuracy of the finite element analysis was verified.By comparing the bearing capacity calculated by the proposed formula with that obtained from the experiments,and that from the finite element analysis,the rationality and reliability of the the proposed formula was verified.In addition,suggested design methods of pin-connected joints were given systematically including the calculation method of the bearing capacity of the pin,the calculation method of the bearing capacity of pin-connected plates and detailing requirements,which provides the engineering designers with certain reference.(2)clampThe paper summarized the existing research results of the anti-slipping performance of cable clamps and pointed out its limitations that the domestic and foreign regulations about clamp design are imperfect and inconsistent with each other,especially the calculation of anti-sliding bearing capacity and anti-sliding experiment.The anti-sliding experiment of five clamps was designed and conducted in the background of stadium and natatorium in Zhengzhou Olympic Sports Center.The rules of sliding displacement of the cable clamps and changement of tightening force of the high-strength bolts,the ultimate anti-sliding bearing capacity and the comprehensive friction coefficient were obtained.It was also found that the comprehensive friction coefficient of the clamps clamped with the Galfan steel strand were higher than that of the Galfan full lock coil strand cable.According to the result of the anti-sliding experiment,the calculation formula of the slip ultimate bearing capacity of the cable clip,which was given by Li Jinfei,considering the loss of the pre-tightening force of high-strength bolts,was verified and adjusted.The rationality and reliability of the calculation system was verified under the current cable clamp experiment,and the proposed design methods of the cable clamp and operational requirements of the anti-sliding experiment in the structural cable buildings were summarized.At last,the research contents and main achievements of this paper were summarized.The shortcomings of this paper were pointed out,and the future research on the design methods and detailing requirements of key joints in cable structure buildings were also prospected.