Experimental Study of Biopolymer Soil Stabilization of a Peruvian Coastal Sand

Erosion susceptibility of cohesionless soils drives failures in coastal and river settings. This paper presents a Phase 1 study to investigate whether biopolymers can enhance erosion resistance of coastal sands. Two sustainable stabilizers, Xanthan gum and Gellan gum, were applied at multiple dosages to a coastal Peruvian sand. Water-induced erosion was assessed using drip erosion tests; treated specimens were compared with untreated controls. Strength was also measured to evaluate mechanical benefits. Both biopolymers improved strength and erosion resistance overall. However, low dosage samples still had substantial erosional damage. Erosion susceptibility decreased with higher dosages and longer curing, with most gains achieved within the first 30 days and minimal change thereafter. Findings from this Phase 1 program identify the more promising biopolymers for the tested sand and outline application and curing practices likely to achieve adequate ground improvement. Results highlight dosage and curing time as key design variables for sustainable biopolymer stabilization of coastal sands.