Mechanical performance of precast pile cap-to-pile connection under cyclic loading
Li Guoping1 Qin Zhongyu1 Cao Sugong1,2 Tang Xiaolin1
1. Tongji University, Shanghai 200092, China；2. Zhejiang Provincial Key Lab for Detection and
Maintenance Technology of Road and Bridge, Hangzhou 311305, China
Abstract： In the construction of mountainous highway viaduct bridges with inconvenient traffic, scarce land resources and high environmental protection requirements, in order to make full use of the advantages of integrated bridge erecting machines and maximally realize fully precast bridge construction, an alternative method of inverting cast-in-situ pile cap to precast pile cap was proposed. To investigate the safety and reliability of the connection between precast pile cap and pile, two 1/3-scale precast cap-to-pile connection specimens and one 1/3-scale cast-in-situ cap-to-pile connection specimen were designed and manufactured. The analysis of the specimens was conducted using cyclic loading test and nonlinear numerical analysis methods. The test results show that the yield points and bearing capacities of precast cap specimens are basically the same as those of cast-in-situ cap specimen, as well as the crack resistance and crack distribution of piles. The crack load of cast-in-situ cap is smaller than those of precast pile caps, but the number of cracks and the maximum crack width of the precast caps are larger. The initial stiffness of the pile-precast cap specimen is slightly smaller, but the post-cracking stiffness is the same as the cast-in-place cap specimen. Both two kinds of caps can work together with piles, so the integrity of structures can be guaranteed. The hysteresis curves and inclination-displacement curves obtained by numerical analysis are in good agreement with the test results, indicating that the numerical models well predict the deformations, bearing capacities and pinch characteristics of the specimens. Both test and numerical analysis results verified the reliability of the mechanical performance of the proposed precast pile cap-to-pile connection construction.
