The Synchronous Monitoring Method of Axial Pressure and Horizontal Displacement of Pile Foundation

The axial force and horizontal deformation of super-long pile foundation were vital to service and safety of construction projects in deep soft soil layer, however, the synchronous monitoring of axial force and horizontal deformation was not available. In this paper, a synchronous monitoring method of axial pressure and horizontal displacement of pile foundation was proposed based on strain measurement. The Strain gauge was used to reflect the axial pressure and horizontal displacement, which was verified by vibrating wire reinforcement meter. The wireless intelligent monitoring system was established for super-long pile foundation in deep soft soil in the overpass project. The sensor data was acquired using wireless intelligent acquisition instrument. The local area network was formed by Lora modules, thus the monitoring data of each sensor was collected. Furthermore, the collected data was uploaded to the cloud platform using 4G wireless communication technology. By comparing the intelligent monitoring data with the traditional collector data, it was found that the error was negligible(within 0.3Hz), which indicated that the accuracy and stability of wireless intelligent monitoring system was reliable. The error between the strain measured by the traditional vibrating wire reinforcement meter and the intelligent inclinometer was -11.32%~6.03%, which indicated that the intelligent inclinometer has high accuracy and stability. It is feasible to use the intelligent inclinometer to monitor the mechanical performance of Pile foundation. The research could provide a new method for monitoring the axial pressure and horizontal displacement of Pile foundation.