Automation of water drainage and dewatering management systems at construction sites in complex hydrogeological conditions to reduce the risks of flooding and erosion

Abstract

Automation of drainage and dewatering control systems at construction sites in complex hydrogeological conditions ensures operational and predictive regulation of pumping equipment to prevent inundation, foundation erosion, deformation of excavation slopes, and loss of stability in soil masses. The hydrogeological setting in areas with high groundwater tables, waterlogged territories, and proximity to water bodies is characterized by high variability under the influence of precipitation intensity, seasonal fluctuations in aquifer levels, and technogenic impacts during earthworks. This leads to sharp increases in water inflow and requires continuous monitoring to maintain safety and continuity of the construction process. Identification of water sources reveals the predominance of subsurface filtration through the excavation walls and bottom, constituting 58 to 79% of the total volume, along with surface runoff from adjacent areas and technogenic leaks, while the ratio between sources varies substantially depending on the season and stage of operations. In-situ observations document seasonal dynamics with two maxima – a spring maximum associated with snowmelt and groundwater rise, and an autumn maximum caused by prolonged rains – with daily water inflow amplitude ranging from 12,3 to 47,8 cubic meters per hour and a coefficient of variation from 0.31 to 0.47, indicating moderate process instability and significant autocorrelation of time series with a lag of 1-3 days. Automated systems based on hydrostatic level sensors with an error of no more than 0,1%, electromagnetic flowmeters, submersible pumps with frequency regulation, programmable logic controllers, and SCADA platforms implement a hierarchical architecture with field, controller, and supervisory levels, ensuring communication via Modbus RTU, Ethernet TCP/IP, and a backup LoRa radio channel. Control algorithms utilize water level thresholds, moving averages of recent measurements, first-order derivatives, and integration of meteorological forecasts to transition to a proactive mode, enabling preemptive increases in equipment performance and creation of reserve capacity in the excavation. Comparative indicators confirm a 75,35 reduction in the number of emergency level exceedances, a decrease in average response time to increased water inflow from 42,6 to 4,3 minutes, a 26,4% reduction in specific electricity consumption, an 82,2% decrease in forced work stoppages, and an 85,2% reduction in construction equipment downtime. Numerical modeling of filtration processes calibrated against results of pumping tests and laboratory determinations of filtration coefficients demonstrates acceptable accuracy with a normalized root-mean-square deviation ranging from 8,7 to 11,3%. Expert ranking of inundation risk factors assigns the greatest weight to unforeseen penetration of a confined aquifer, equipment failure, and exceedance of precipitation intensity – factors on which automation exerts direct influence by reducing the overall probability of events. Economic assessment indicates a payback period for additional equipment costs ranging from 2,1 to 4,7 months due to reduced energy consumption, damage prevention, and minimized downtime. The obtained data substantiate the advisability of scaling such systems to sites with greater excavation depths, adaptation to confined filtration conditions, and expansion of the forecasting horizon by incorporating long-term climate models to optimize construction scheduling in a variable hydrogeological environment, thereby enhancing overall reliability, safety, and resource efficiency of work performance.