Study On Static Behavior And Vibration Serviceability Of Prestressed Cable RC Truss Floor System

A comprehensive study on static behavior and vibration serviceability of prestressed cable RC truss(PCT)floor system was conducted.And the details could be summarized below:Three PCT girders(span 16.0 m,16.0m and 9.2 m)were tested and the load-displacement curve,the strain distribution along the height of the girder,and the failure mode of the PCT based on crack growth,were captured.Comprehensive comparison of the results from the static tests against codes such as EC 2,ACI 318 and GB50010 was carried out.The ratio for the shear capacity of the upper chord and the lower one was simulated by Abaqus.Different flexural modals were recommended basced on the failure mode.The juming teats were employed and the acceleration traces were captured.The fundamental frequencies of three PCT gieders were obtained through the Fast Fourier Transformation technology.The relationship between the frequency of a single PCT girder and the frequency of the PCT floor was researched using Abaqus.The model whose flange width was equal to the PCT spacing could be reasonable for understanding the fundamental frequency of PCT floor.Three on-site PCT floors(span 39.0 m,36.0m and 28.2 m)due to heel-drop,jumping,and dropping-into-seats were tested.The time domain files were got from the floor vibration test.The analytical solution obtained from the weighted residual method agrees well with the experimental results and thus validates the proposed analytical expression.The dynamic loading factors for heel-drop,jumping,and dropping-into-seats were modified based on the test results.Three on-site PCT floors(span 39.0 m,36.0m and 28.2 m)due to walking,running,and hopping were tested.The distribution of RMS and MTVV were compared.Based on the single-degree-freedom-system,the analytical expression for peak acceration was proposed.The dynamic loading factors for running and hopping were recommended.Based on the classic plate theory,a derived accurate formula for PCT floor system is proposed.Extensive sensitivity studies using Abaqus were conducted with the variation of(a)live load;(b)number of web members;(c)opening ratio;(d)span;(e)rise-span ratio;(f)span to spacing ratio.Lastly,a simplified method is suggested,which uses the constant moment of inertia for the cross-section of PCT girder.The innovation points of this thesis are listed below:1.The ratio for the shear capacity of the upper chord and the lower has been proposed.The shear capability can be calculated by the sum of the chords once the ratio for the shear capacity of the upper chord and the lower one ranges from 3.5 to 4.0.2.The fluxual capacity model for different PCT has been proposed.The classic fluxual formula could be used for the fluxual capacity of PCT with lower chord while the effect of catenary had been considered in this paper for PCT without lower chord.3.The solution for transient impact of PCT floor has been proposed.The analytical solution for transient impact obtained from the weighted residual method agrees well with the experimental results and thus validates the proposed analytical expression.4.A unified formula has been proposed for calculating the peak acceleration due to continuous impact,i.e.,walking,running,and hopping.5.Based on the classic plate theory,a derived accurate formula for PCT floor system is proposed.