Study On Collapse Analysis And Inclination Monitoring Method Of Gan-type Transmission Tower Under Uneven Settlement

In recent years,with the extensive and in-depth promotion of various types of infrastructure construction,as well as the impact of climate and environmental factors,landslides,foundation settlement problems occur fro m time to time,and its adverse impact on the surrounding transmission tower cases are becoming more and more common.Correctly analyzing the influence of uneven settlement on the safety of transmission tower,studying the collapse mode of transmission tower under the condition of uneven settlement of foundation,and discussing the monitoring method of transmission tower collapse are necessary conditions for correctly monitoring and evaluating the safety of transmission tower under the condition of uneven settlement of foundation.In this paper,a 500 kV double-circuit transmission tower is taken as the research object,and a finite element model of the coupling system of one tower and two towers is established.The dynamic characteristics of the transmissio n tower model are obtained by numerical simulation.The calculated results of the empirical formula given by the model frequency and the code are analyzed and compared,and the validity of the model is verified.The multi-scale dynamic finite element analysis of the tower-line coupling system was carried out under the settlement modes of single support,double support and three support.On the whole scale,the collapse modes of transmission towers are summarized,and the distribution of damaged poles,displacement of tower body,tilt of tower top,and overall stress during the collapse of transmission towers are analyzed.The types and failure sequence of failure poles,damage distribution and weak parts of transmission towers are summarized.On the component scale,the overall stress of typical sections is analyzed.Change process and characteristic stress change process.The results show that during the collapse of the transmission tower,the displacement and tilt of the top of the tower are linearly related to the uneven settlement of the foundation.On this basis,the sensitivity and robustness of the change of the overall tilt of the tower to the uneven settlement of the foundation are analyzed,and the feasibility of the tilt monitoring of the transmissi on tower is clarified.Five diaphragms and eight main material assemblies are selected as measuring units in the tower body of transmission tower.The optimal monitoring points in the main material assemblies are obtained by comparing the tilt changes of f our main materials at different positions in the main material assemblies.By comparing the tilt changes of the optimal points in 5th diaphragms and 8th main material assemblies,the overall tilt of the tower body is obtained.Excellent monitoring area.Then,by analyzing the tilt of transmission towers under different conditions,the monitoring and early warning threshold of the tilt of transmission towers is proposed.Combining with the measured data of several transmission tower tilt monitoring systems,the regularity of tilt variation and the correctness of tilt warning threshold are verified.Further,according to the measured results and numerical simulation results of the tilt of transmission tower,the installation position of tilt meter in the current Technical Specification for Tilt Monitoring Devices of Transmission Line Towers is pointed out.There are some unreasonableness in setting up regulations and the regulation of early warning level,and then some suggestions are put forward.