What Does Bearing Strength Mean?
Bearing strength is a measure of the maximum stress that soil can withstand before it deforms and fails. It can be measured in terms of:
- Tensile strength.
- Compressive strength.
- Flexural strength.
To prevent problems such as subsidence or heaving during a trenchless construction project, it is important to understand the physical properties, chemical composition and bearing capacity of the soil through which the bore will pass.
Bearing strength is also referred to as bearing capacity.
Trenchlesspedia Explains Bearing Strength
The bearing capacity and type of soil at a site must be determined by a geotechnical survey before beginning work, according to OSHA regulations.
It is important to know how much stress due to loading soil can withstand before it deforms. Resistance to deformation depends on different factors such as:
- Bulk density.
- Moisture content.
- Shear strength.
- Loading condition.
To test the bearing capacity of the soil and its resistance to penetration the static cone penetration test, also known as the cone penetration test (CPT) is used. This test is best performed in soft clay, silt, medium, and fine sands and is unsuitable for gravelly soil or soil with standard density test value > 50.
The standard penetration test (SPT) provides an indication of the relative density of the granular deposit and its approximate shear strength. Moist granular soil with small amounts of cohesive material can be remolded to simulate in-situ conditions for shear strength testing. The SPT results can be used to determine the relative density, settlement and bearing capacity of granular soils.