1810.3.1 Determination of allowable individual axial compressive loads.
BC § 1810.3.1
The allowable individual axial compressive loads on deep foundations shall be the lesser of the allowable structural capacity of the element or the allowable geotechnical capacity of the element. This allowable load shall be determined by an engineer experienced in geotechnical engineering and shall be approved by the commissioner as described below: 1. The allowable structural capacity of the deep foundation shall be determined in accordance with Sections 1810 through 1816.
2.The allowable geotechnical capacity of the deep foundation shall be calculated using a recognized method of analysis and a minimum factor of safety of 2 with respect to failure.
3.The allowable geotechnical capacity shall be demonstrated by load tests. Exceptions: 1. Allowable loads for deep foundations installed by jacking shall be determined in accordance with Section 1810.3.2.
4.Micropiles with allowable loads less than or equal to 20 tons (196.1 kN), provided all of the following criteria are satisfied: 4.1. The maximum allowable bond stress between the soil and the grout is less than or equal to 4 psi (27.6 kPa). 4.2. The minimum bond zone diameter is greater than or equal to 9 inches (228.6 mm). 4.3. The bond zone is formed entirely in Class 3b or better soils.
