Experimental Research And Technical Application Of Joint Mechanical Behavoir Of Disk Lock And Cuplok Steel Tubular Falsework

With the development of economy and construction technology,many new types of formwork systems which includes socket-type have been more and more widely used in the field of construction because of their advantages of simple structure,convenient erection,large carrying capacity,etc. However,the research on the mechanical behavior of the socket-type falsework is not very comprehensive at present. There are mainly two kinds of socket-type falsework which includes disk lock and cuplock steel tubular falsework.The research of mechanical properties of the joints is fundamental and vital.The mechanical properties of the joints of disk lock and cuplock steel tubular falsework was studied and the characteristics of semi-rigid connection was paid significant attention in this paper.The main contents and conclusions of this paper are as follows:(1)Experimental studies were inplemented on the disk lock and cuplock steel tubular falsework,including bending resistance of joint, shear resistance of connecting plate, tensile of connecting plate,bearing tests on adjustable seats and brackets. The bending performance of joint, ultimate shear carrying capacity of connecting plate, ultimate tensile bearing capacity of connecting plate, ultimate bearing capacity on adjustable seats and brackets were obtained.(2)To analyze the relationship of semi-rigid joint moment-rotation numerical model between various angle,a three line model was selected to simulate the moment-rotation characteristics of joints. The joint stiffness characteristics of different specifications of falsework joints were acquired.And calculation formula for the disk lock steel tubular scaffold calculating length coefficient of single bar stability considering the semi-rigid joints was acquired. Rapid scaffold joint rotational stiffness decreases as the rotation increases and diameter of upright tube decreases. The average rotational stiffness of rapid scaffold is about 26kNm/rad. Cuplock scaffold joint rotational stiffness increases as the length of upright tube increases, its rotational stiffness is about 79kNm/rad. Rotational stiffness of Cuplock scaffold reaches its maximum when certain rotation occurs on account of initial loose. Effective length coefficient which joint smi-rigidity connection is considered is more reasonable but still conservative.(3) The force analysis and calculation theory of all kinds of falsework was introduced. By using the finite element software ANSYS to establish a disk lock steel tubular falsework models,including rigid model, articulated model, semi-rigid model were bulit,and the stable bearing capacity analysis was implemented. The results showed that the stable bearing capacity of rigid model is largest;the stable bearing capacity of articulated model is least;the stable bearing capacity of semi-rigid model is in between. Joint semi-rigid model is a best modle to consider joint smi-rigidity connection, and its analysis results are more fit for practical situation.(4)Relying on the project of rectifier cone bearing support system of Liyang pumped storage power station,the characteristics of semi-rigid connection was applied in practical projects. The semi-rigid connection and rigid connection of joints were taken into account separately in the analysis on mechanics performance of the disk lock steel tubular formwork by using the software ANSYS. The analysis results were compared with the measurement data, it was concluded that the finite element analysis results are more accord with the actual situation when the semi-rigid joints are considered. The semi-rigid joints worth being considered in pursuit of a better analysis results in the process of the finite element analysis.