Soil stabilization improves weak soils to increase bearing capacity or reduce settlement. Methods include chemical stabilization (Portland cement, lime, or other additives mixed with soil), grouting (injection of cementitious or chemical grouts), and mechanical stabilization (compaction or installation of soil nails). Portland cement stabilization mixes cement into the top 12 inches of soil, improving strength and durability. This method is common for improving road bases and preparing poor soils for building construction. Lime stabilization uses hydrated lime to treat clay soils, improving workability and reducing plasticity. Lime treatment is effective for clay-heavy soils. Grouting involves injecting liquid materials into voids and fractures to improve soil strength and reduce permeability. Cementitious grouts consist of Portland cement, water, and sometimes sand. Chemical grouts provide more flowable systems suitable for fine soils. Soil nails are closely spaced passive anchors installed in soil slopes to provide tensile strength and resist slope movement. Nails are typically small-diameter bars driven into the slope at angles. Grouting of the nail-soil interface provides bond. Soil nail walls are effective for steep slopes and retaining wall applications. Jet grouting uses high-pressure jets to break down soil and inject grout, creating columns or panels of stable soil. This method is useful in confined spaces where conventional equipment cannot operate. Vibroflotation uses vibration to compact loose granular soils, increasing bearing capacity. This method is limited to granular soils and is not effective in clays.