Research On Key Technologies Of Cable Clamp Design And Installation For Long-Span Suspension Bridge

At present,the main concerns for the design and fastening construction of cable clamps of suspension bridges are the strength of the design of cable clamps and the anti-sliding bearing capacity of the design of cable clamps under tension by the design of cable clamps and bolts.It is required that the cable clamps have sufficient safety reserve for anti-sliding bearing capacity,while less attention is paid to the nature of the phenomenon that may cause cable clamps to slip.This phenomenon is caused by many reasons.The main reason is that the stress state between the wire strands of the main cable under the action of the cable clamp is very complex and the deformation of the main cable under the cable clamp is irregular.Therefore,this paper hopes to study the interaction between the internal wires of the main cable under the action of the cable clamp and the state of the contact stress on the surface of the main cable under the cable clamp and put forward the energy.Suggestions for effectively improving the anti-sliding bearing capacity of cable clips.Based on the pin-connected cable clamp of the Second Humen Bridge,this paper studies the distribution of radial and tangential stresses on the surface of the main cable under the cable clamp and the influence of the ratio on the internal stresses in the section of the main cable by establishing a fine contact friction model of the main cable system of the cable clamp,and choosing different design parameters such as the wall thickness of the cable clamp,the bolt spacing between the cable clamps and the contact friction coefficient.The influence of number and bolt tension on the ultimate anti-sliding bearing capacity of the cable clamp is discussed.Finally,the calculation method of the position of the cable clamp under the condition of empty cable is studied.The influence of temperature and span parameters on the installation position of the cable clamp is analyzed.The anti-sliding ability of the final state formed under different tightening sequence and times of tightening of the cable clamp bolt is analyzed.The analysis and calculation results show that the stress distribution on the surface of the main cable under the long cable clamp is not uniform.Under the action of the cable clamp,the stress in the cross section of the main cable presents a layered distribution.The stress in the inner layer is large and the stress in the outer layer is small.The contact stress near the zenith line of the main cable is the largest,followed by the stress near the opening of the cable clamp,while the stress on the surface of the main cable at the variable cross section is the smallest,and the arc section from the opening of the cable clamp to Surface stress is large at both ends and small in the middle along the clamp axis.The surface stress of the main cable from the variable cross section of the clamp to the arc section of the zenith line of the main cable is small at both ends and large in the middle along the clamp axis.The thickness of the clamp wall mainly affects the surface stress of the main cable at the opening of the clamp and the variable section of the clamp.The bigger the thickness of the clamp wall,the smaller the anti-sliding safety factor;the bigger the friction coefficient of the contact surface,the greater the tangential stress near the opening position of the clamp,and the smaller the radial stress of the contact surface as a whole,and the bigger the maximum axial friction resistance of the clamp,the change of the bolt spacing.There is no influence on the overall distribution of stress on the contact surface of main cable.The spacing of cable clips only affects the overall stress of main cable.The larger the spacing of cable clips,the greater the anti-sliding friction resistance of cable clips.Increasing the spacing of bolts is conducive to improving the anti-sliding bearing capacity of cable clips.The fastening order of bolts has little effect on the ultimate ultimate bearing capacity,but the ultimate anti-sliding bearing capacity of cable clips after third-order tension.The ability is obviously higher than the result of second-order tension,and multi-order tension can make the cable clamp achieve better fastening effect.