Field Test Study on Treatment of Dredged Soil with Cotton Straw

Abstract

A new method for treatment of dredger fill was proposed to address its low bearing capacity, high consolidation cost, and long treatment duration. In this method, cotton straw is used as both the draining and reinforcement material. Specifically, cotton straw bundles are driven into the dredged soil and vacuum preloading is then performed. Subsequently, environmentally friendly grout is poured into the cotton straw bundles, and solidified vertical reinforcements are thus formed, allowing dredged soil to be treated. Design parameters for the cotton straw draining were obtained from previous laboratory test. Based on a real-world project, a field test was performed to study treatment of dredged soil through cotton straw drainage and reinforcement, and a comparison was drawn with the traditional cement mixing vertical reinforcement method. The vacuum degree, settlement, and water content of reinforced soil suggested a good ability of cotton straw drainage to solidify dredged soil. The static load test indicated that vertical reinforcement after grouting demonstrated better strength than cement reinforcements. This study provides new insights into the treatment of dredger fill and can broaden the application of cotton straw and also reduce environmental pollution caused by cotton straw burning.