Results of Load Tests on DMM Piles Set in Lateritic Soil-Paper

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The study evaluates the feasibility of using Deep Mixing Method (DMM) piles in lateritic soil in Primavera do Leste, Mato Grosso, Brazil. The site has a deep, weathered tropical soil profile with low SPT resistance. Laboratory tests found that particle-size classification differed depending on whether a dispersant was used, reflecting lateritic soil aggregation.<br /><br />Researchers installed 14 wet-mixed piles, each 0.6 m in diameter and 3.5 m deep, using 120 kg of cement per cubic metre of soil. Three fast static load tests were conducted on two piles. Using a settlement limit of 5 mm, pile E11 carried 203.7 kN at 75 days and 217.2 kN at 16 months. Pile E13 carried 162.9 kN at 75 days. The authors attribute E11’s higher resistance to its two mixing cycles, which may have produced a more uniform soil-cement mixture; E13 received one cycle. Van der Veen analysis gave higher estimated failure loads, ranging from 200 to 232 kN.<br /><br />These preliminary results suggest that DMM piles in lateritic soil can function as individual foundation elements, unlike applications focused on improving soft-soil masses. The authors consider the method promising for foundations in agriculture-related infrastructure and other projects, while emphasizing that further research is needed.

Keywords

Deep Mixing Method

DMM piles

lateritic soil

wet-mixed piles

static load test

soil-cement mixture

Brazil geotechnical engineering

pile settlement

Van der Veen analysis

foundation feasibility