Experimental Research on Anti-Slip Performance of Closed Cable Clamp Joints in Dalian Suoyuwan Football Stadium

Due to the advantages of reasonable stress performance， light weight， high strength， and beautiful structural form， long-span space structures have been widely used in many stadiums， exhibition halls， assembly halls， and other buildings. As a large-scale civil building， Dalian Suoyuwan Football Stadium features a cable-truss structure with a four-center circle in plan. Its upper chords are obliquely crossed， while the lower chords follow a radial layout. Compared with conventional spoke-type cable-truss structures， the football stadium system demonstrates improved in-plane stiffness and overall torsional resistance. Because of its complex structure， the lower loop cable needs to fix 8 cables and other lower-chord radial cable members. To meet the requirements， a 125-mm-diameter plate press-fit cable clamp joint with six high-strength bolts was designed. Two experimental studies were carried out on the designed cable clamp joint. The paper investigated the tightening force loss of high-strength bolts during cable tensioning and the ultimate anti-slip capacity of the joint under cable clamp jacking conditions. Firstly， the cable clamp joint was assembled and left undisturbed for 24 hours. Then， the cable was tensioned in three stages up to 50% of its breaking load， followed by the cable clamp jacking until significant sliding occurred. The entire process was monitored in real time for high-strength bolt tightening force changes， cable diameter changes， and cable clamp displacement changes. The results showed that the tightening force of high-strength bolts was lost by 11% due to the time effect. The high-strength bolts experienced a 17.8% tightening force loss due to the reduction of the diameter of the tension cable when the cable was tensioned in the second step. During the third-step cable clamp jacking， the first inflection point of the displacement-jacking force curve was taken as the limit value of anti-slip capacity， and the anti-slip capacity value of the cable clamp joint was determined as 500 kN. The friction coefficient between the cable clamp channel and the cable body was 0.165 by introduing the anti-slip capacity formula. The tightening torque value and anti-slip capacity value of high-strength bolts obtained by the test can be used as the design basis for plate press-fit cable clamp joints， providing a solid theoretical basis for on-site installation monitoring and construction.