Performance Analysis Of High-rise Building Construction Protection System And New Node Development

Due to the acceleration of urbanization and the shortage of land resources,high-rise buildings are becoming more and more common in daily life,and traditional scaffolding has been unable to suit the needs of construction activities in high-altitude environments.And in many emerging high-altitude protective equipment,attached climbing scaffolding and steel cantilever scaffolding not only with its efficient,safe,material-saving,reusable and their respective characteristics have been vigorously promoted,but also made major breakthroughs in various technical details.This article takes the attached climbing scaffold and the steel cantilever scaffold as the starting point.Based on the existing theory,and uses the research methods of limiting element simulation and field test to analyze these new features.Through analysis,some practical and effective data such as the force distribution,technical characteristics and the most unfavorable situation of these two types of high-altitude protection equipment are obtained.At the same time,the key factors affecting the performance of the scaffolding system were found.The work done in this paper and the main conclusions obtained are as follows:(1)This paper starts with the basic mechanics theory,comparing the differences between steel structures and the attachment characteristics of existing concrete joints,four forms of attachment nodes have been designed for the effective connection of such climbing frames and steel structures.At the same time,the finite element simulation and field test method are used to analyze the stress characteristics of four new types of nodes under multiple working conditions,and the most unfavorable load position and ultimate bearing capacity of the four types of nodes are obtained.By analyzing the nodes attached to different positions of the steel beam,different sections and other working conditions.Analysis of different situations such as different positions and different sections of steel beams acting on nodes.The general rule of node work is found,such as the most unfavorable position in the middle of the span,and the working performance of the node decreases rapidly as the height of the attached steel beam decreases.(2)In cooperation with the local construction equipment company,a steel frame was designed as a building structure for field test according to the specifications of the currently used LZC10 type attached scaffolding.The scaffolding node and the steel frame were processed according to the actual size.According to the results of finite element analysis,the strains of the key parts of the scaffold and the steel frame were dynamically monitored.Through the whole process test of loading,construction,lifting and falling prevention,the strain curves of the joints and the steel frame were obtained.The stress and deformation characteristics of the joint.In addition,the deformation and failure state of the smallest steel beam before and after the reinforcement of the section is compared by the failure test.It is found that the section properties of the steel beam,especially the torsion resistance,have a decisive influence on the failure of the joint.(3)The new protective steel outer net used in the steel cantilever scaffolding is more efficient and safer than the previous safe green net,but its self-weight and sensitivity to wind loads are also significantly enhanced.Through the comparative analysis of stress and displacement of a single protection unit,one side scaffolding and surrounding scaffolding system,the maximum stress appears on the steel frame of the protective plate,and the surface of the plate is greatly deformed due to wind load.By analyzing the force characteristics of the frame under different wind loads,the ultimate height of the frame is about 115 m.According to the local deformation caused by the wind load on the protective plate during actual use,a variety of angular displacements are applied near the maximum stress,and the influence of the deformation of the plate support on the stress distribution and horizontal displacement of the scaffolding system is obtained.