The Monitoring System And Data Predicting Of Foundation Pit Engineering Based On LoRa Wireless Transmission

The construction of cities reflects the country’s rapid development.In recent years,urban land has become increasingly tense.In order to seek development space for urban construction,it has to extend to the air or underground,which promotes the rapid development of foundation pit engineering.On the one hand,the rise of foundation pit engineering has accelerated the construction of cities;on the other hand,safety accidents caused by foundation pits have occurred frequently.Therefore,it is necessary and significant to study the monitoring and predictiing foundation pit engineering.Based on the foundation pit project of Hangzhou Metro Line 9 Yu Dao Station,this paper conducts data collection and regular analysis on the top horizontal displacement,vertical displacement and steel support axial force of the maintenance structure of the foundation pit.First,the methods of subway foundation pit monitoring is summarized.Through the analysis of sensor systems and data transmission problems,it is found that the existing foundation pit monitoring terminals adopt wireless communication technologies such as Zig Bee and WIFI,which have high power consumption,high cost,and short communication distance.Therefore,this paper studies and designs a LoRa-based low-power and long-distance communication foundation pit monitoring system.Secondly,this paper proposes a method of combining gray prediction with a large amount of data under a small amount of data and using exponential smoothing under a large amount of data to perform data fitting and prediction on the horizontal displacement,vertical displacement and supporting axial force of the maintenance structure collected through the LoRa node.The lithium battery-powered LoRa node can transmit stably,upload the collected data to the server without packet loss,and use a combination of gray prediction and exponential smoothing to fit the horizontal and vertical displacements of the maintenance structure and the supporting axial force.And forecast,analyze the it can forecast results,and the results show that the model can predict the project well.The LoRa wireless monitoring system with low power consumption,long transmission distance and self-organizing network proposed in this paper,as well as the combination of gray prediction and exponential smoothing method,can not only be used in foundation pit projects,but can also be extended to tunnel projects with weak cellular signals and other Large-scale projects have great market prospects and social value.