Which type of foundation is preferable on soil of poor bearing capacity?
Answers
Types of Soil Investigations for Foundation Selection
Subsurface Soil Investigations
Subsoil conditions are examined using test borings, provided by soil engineer (geotechnical). Number of borings and location of borings depends on building type and site conditions.
Typically for uniform soil conditions borings are spaced 100-150′ apart, for more detailed work, where soil footings are closely spaced and soil conditions are not even borings are spaced 50′ apart.
Larger open warehouse type spaces, where fewer columns are present (long span) required less boring samples. Borings must extend to firm Strata (go through unsuitable foundation soil) and then extend at least 20 feet more into bearable soil.
Location of borings samples are indicated on engineer plan. These are not taken directly