Enhancing the Efficiency of Geotechnical Piling Operations: A Comparative Analysis of Polymer and Bentonite Slurries

Deep foundation engineering relies on stabilizing fluids to ensure borehole integrity during the construction of cast-insitu piles, particularly in unstable soil conditions. For over six decades, bentonite slurry has been the industry-standard stabilizing agent. However, its application is increasingly constrained by significant operational inefficiencies, high logistical costs, and adverse environmental impacts, including the generation of large volumes of contaminated waste. This paper presents a detailed, field-based comparative analysis of synthetic polymer-based fluids as a high-efficiency alternative to traditional bentonite slurry in bored piling operations. The study was conducted on the Mumbai–Ahmedabad High Speed Rail (MAHSR) project, providing a direct comparison of the two methods under identical geotechnical conditions for 1.5-meter diameter, 55- meter deep piles. Key performance indicators—including project duration, direct and indirect costs, manpower deployment, fuel consumption, muck disposal logistics, and overall productivity—were systematically quantified. The outcome demonstrate that the adoption of polymer slurry leads to a profound enhancement in operational efficiency, doubling the daily output from one to two piles cast per day. A granular cost analysis of 20 pile borings reveals a net cost saving of 46.7%, driven by substantial reductions in fuel (44.1%), manpower (40.7%), and muck disposal (85.3%). Beyond economic benefits, polymer fluids offer superior environmental performance due to their biodegradability and the elimination of complex slurry disposal protocols. This research provides conclusive, data-driven evidence that replacing bentonite with advanced polymer fluids is a strategically sound decision that significantly improves the technical, economic, and environmental sustainability of modern piling works.