Key measurement points and early warning system for scaffolding under different working conditions

LIU Shengjie; ZHAO Zhizhong; CHEN Xu; SUI Mingyan; ZHAO Yulong

doi:10.3969/j.issn.1672-0032.2023.04.019

Abstract：In order to effectively prevent scaffold collapse accidents during construction and address the problem of untimely warnings,a plug-in type scaffold calculation model is established,which uses angular deformation as the representation index.The stress and deformation of the scaffold structure under different construction conditions are analyzed,and the failure process of the scaffold is simulated,to determine key measurement points and warning criteria,and to establish the corresponding relationship between critical measurement points and angular thresholds.The on-site bridge in-situ test method is used,and 9-axis attitude angle sensors are deployed to collect data.The angular threshold of each measurement point is used as a monitoring indicator and compared with the on-site data.The results show that the maximum deformation and maximum stress of the scaffold are located at the mid-span position.Under normal serviceability limit state,the load response of the transverse measurement points at the ends of the mid-span in the x-direction is good,with a maximum angular threshold of 0.0222°.The measurement point at the edge of the mid-span in the y-direction can be considered as a key measurement point,with a minimum angular threshold of 0.0065°.Under the ultimate limit state,the angular threshold in the x-direction decreases by approximately 50%compared to the normal serviceability limit state,while the angular thresholds in the y-direction and z-direction increase by 6%and 24%respectively.The simulation results are consistent with the actual monitoring data,demonstrating the practicality of using angular thresholds as monitoring indicators.