Open Trial Pit Method for assessment of safe bearing capacity

Soil investigation by open trial pit is a direct and visual method of exploring subsurface conditions, typically used for shallow-depth assessments. This technique involves excavating a pit—usually 1 to 3 meters deep—at the project site to expose soil layers for manual inspection, sampling, and field testing. Engineers can observe soil texture, colour, moisture content, and stratification firsthand, allowing for accurate classification and identification of potential issues like organic matter, fill material, or groundwater presence. Open trial pits are especially useful for small-scale projects, foundation evaluations, and verifying borehole data. Their simplicity, cost-effectiveness, and ability to provide immediate insights make them a valuable tool in preliminary geotechnical investigations.