Which test determines soil bearing capacity before foundation construction?

• A. Standard Proctor test
• B. Penetration test
• C. Soil surveys
• D. Soil borings

Answer: (D)

When you need to know how much load the ground can safely carry before building, you want concrete, site-specific information about the soil layers and their strength. That comes from drilling into the ground and taking soil samples at various depths to identify the types and thicknesses of soils, the presence of groundwater, and other conditions. With those samples and measurements, engineers can perform tests to determine bearing capacity and design an appropriate foundation.

The Standard Proctor test looks at how compactable the soil is and the moisture content for achieving maximum density, which is about subgrade or fill performance rather than in-situ bearing capacity. A penetration test provides in-situ resistance data that can help classify soils and give rough strength indicators, but it doesn’t directly establish the site’s bearing capacity. Soil surveys map and describe soils over an area, offering general information rather than the precise, representative data needed for designing a foundation.

Soil borings are the method that yields the direct, site-specific information required to determine bearing capacity before construction.