On-site monitoring of expansive soil slope protected by soilbags based on the universal Beidou monitoring system

Abstract

To explore an effective method for deformation monitoring and behavior prediction of expansive soil slope, field tests are conducted for a flexible slope protection scheme with soilbags that has been implemented in an expansive highway soil slope. A new monitoring system, i.e., the universal Beidou deformation monitoring system, is developed to overcome the limitations of traditional Global Navigation Satellite System (GNSS) software and hardware, simplify the hardware structure and realize the power sharing mode; furthermore, this system can create and upload a large amount of monitored data to a cloud platform to enable real-time calculation. Compared with traditional GNSS, the volume of equipment required is reduced by approximately 75%, and the cost is reduced by approximately 80%. Secondly, a multilevel safety early-warning evaluation system is constructed by integrating the monitoring results of the universal Beidou deformation monitoring system, bag damage states, rainfall conditions, and slope fissure development; additionally, a deformation early-warning mechanism of flexible support of soilbags was established. Finally, the deformation and collapse of flexible supports of soilbags can be successfully predicted in the field. This research on flexible support of soilbags provides new ideas and methods of deformation monitoring, safety evaluation, and early warning for expansive soil slopes.