Research On The Comprehensive Monitoring Technology Of The High Formwork System Of The Buckle Type Steel Pipe

With the increasing application of tall formwork support systems,the buckle-type steel tube formwork has been popularized and used in many places due to its advantages of high bearing capacity,quick installation and disassembly,easy management and transportation,but in the process of concrete pouring,The high-support formwork body is complex and has many uncertain factors.At present,the monitoring indicators in the relevant regulations on the monitoring of high-support formwork in my country are independent of each other,and there is no relatively complete real-time safety assessment method.This paper takes the structure of the high-support formwork of the disc buckle as the research object,and focuses on the comprehensive monitoring method of the high-support formwork,mainly from three aspects:finite element analysis,theoretical analysis,and engineering measurement.The main research contents and results are as follows:(1)The stable bearing capacity of the high-support formwork is greatly affected by the connection method of the nodes and is easily affected by unfavorable conditions.Firstly,according to the finite element analysis method,the stress mechanism and buckling bearing capacity of the high-support formwork with different connection modes of nodes under eigenvalue buckling and nonlinear buckling are compared,and the relative weak parts of the buckle-type high-support formwork are found out.Provide a basis for the layout of comprehensive monitoring and measuring points;then,the key points of the simulated on-site monitoring are determined,and the axial force-displacement relationship of the semi-rigid model is obtained.The unfavorable conditions of defects,adjustable base void,and uneven settlement of the frame are analyzed by parameter analysis,and the sensitivity index of the comprehensive monitoring of the high-supporting formwork frame is obtained.(2)In order to improve the accuracy of high support formwork monitoring and safety warning,a comprehensive monitoring method of high support formwork system based on multi-source data fusion is proposed.Firstly,the standard calculation method of the steel pipe formwork support is analyzed and compared with the finite element analysis to verify the reference of the numerical model.Then,based on the finite element analysis results of the high support formwork and related specifications,the key technologies,sensor selection and layout and the overall process of the comprehensive monitoring of the high support formwork system are designed.Finally,through the comparative analysis of multi-source information fusion level and algorithm,the D-S evidence theory fusion algorithm suitable for the comprehensive monitoring of high formwork system is obtained.(3)The feasibility and superiority of comprehensive monitoring technology for high formwork system are verified by engineering examples.Firstly,the theoretical calculation is carried out for the high formwork support system of the actual engineering to verify its safety and reliability.Then,the variation laws of the vertical bar axial force,the support settlement and the stability of the frame of the disc-button high-support formwork system during the concrete pouring process are analyzed,and the axial force-settlement curve is fitted,and the results show that there is a correlation between each index.Finally,the adaptive weighted fusion algorithm and D-S evidence theory are used to fuse the data of three monitoring indexes.Compared with the single monitoring index judgment,the data fusion method can judge the working state of the frame more accurately.With the increase in the volume,scale and complexity of construction projects,the construction support system also shows higher and more complex characteristics.The comprehensive monitoring method of high-support formwork system proposed in this paper aims to monitor the complex high-support formwork structure with a small number of sensors,and use multi-source data fusion technology to perform correlation analysis on monitoring indicators,which can efficiently and economically realize high-support formwork structure.The safety assessment and early warning of the system provide a strong guarantee for the project quality and construction safety.