The provisions of Section 1803 of IBC are adopted by reference with the following modifications:
1. Revise Section 1803.1 by replacing "registered design professional" with "registered geotechnical engineer."
2. Add new exceptions following Section 1803.1 to read:
"Exceptions:
1. Geotechnical investigations are not required for single-story storage structures without basements and detached private garages not exceeding 2,000 square feet (185.8 m2).
2. Geotechnical investigations are not required for alterations and additions that do not require new foundations and do not result in an increase in loads exceeding 5 percent of the existing foundation design capacity.
3. Full geotechnical investigations by a registered geotechnical engineer are not required where excavation more than 8 feet (2438 mm) below existing grade is not required, a test pit is used for soil classification and to locate the ground-water table, and the values used as the basis for design do not exceed the presumptive values in Table 1806.2(1)."
3. Revise Section 1803.3.1 by replacing "registered design professional" with "registered geotechnical engineer."
4. Revise Section 1803.4 by replacing "registered design professional" with "registered geotechnical engineer."
5. Revise Section 1803.5.2 to read:
"1803.5.2 Questionable soil or fill.
Where the classification, strength or compressibility of the soil or fill is in doubt or where a load-bearing value superior to that specified in this code is claimed, the building official shall require that a geotechnical investigation be conducted."
6. Revise Section 1803.5.3 to read:
"1803.5.3 Expansive soil or fill.
In areas likely to have expansive soil or fill, the registered geotechnical engineer shall perform soil tests to determine where such soils or fills do exist.
Soils or fills meeting all four of the following provisions shall be considered to be expansive, except that tests to show compliance with Items 1, 2 and 3 shall not be required if the test prescribed in Item 4 is conducted:
1. Plasticity index (PI) of 15 or greater, determined in accordance with ASTM D4318.
2. More than 10 percent of the soil particles pass a No. 200 sieve (75 µm), determined in accordance with ASTM D422.
3. More than 10 percent of the soil particles are less than 5 micrometers in size, determined in accordance with ASTM D422.
4. Expansion index greater than 20, determined in accordance with ASTM D4829.
Steel slag shall be tested for expansive properties in accordance with ASTM D4792 prior to use as a fill material."
7. Delete the exception to Section 1803.5.4.
8. Revise Section 1803.5.5 to read:
"1803.5.5 Deep foundations.
Where deep foundations will be used, a geotechnical investigation shall be conducted and shall include all of the following, as applicable:
1. Recommended deep foundation types and installed capacities.
2. Recommended center-to-center spacing of deep foundation elements.
3. Recommended driving installation acceptance criteria.
4. Recommended installation procedures.
5. Field inspection and reporting procedures (to include procedures for verification of the installed bearing capacity where required).
6. Load test requirements.
7. Suitability of deep foundation materials for the intended environment.
8. Designation of bearing stratum or strata.
9. Reductions for group action, where necessary."
9. Revise items 1 and 2 in Section 1803.5.8 to read:
"1. Recommended specifications for the preparation of the site prior to placement of compacted fill material.
2. Recommended specifications for material to be used as compacted fill."
10. Revise items 1 and 2 in Section 1803.5.9 to read:
"1. Recommended specifications for the preparation of the site prior to placement of the CLSM.
2. Recommended specifications for the CLSM."
11. Delete Section 1803.5.10.
12. Revise the title and first sentence of Section 1803.5.11 to read:
"1803.5.11 Seismic Design Category C or D.
For structures assigned to Seismic Design Category C or D a geotechnical investigation shall be conducted, and shall include an evaluation of all of the following potential geologic and seismic hazards:"
13. Revise the title and first sentence of Section 1803.5.12 to read:
"1803.5.12 Seismic Design Category D.
For structures assigned to Seismic Design Category D, the geotechnical investigation required by Section 1803.5.11 shall include all of the following as applicable:"
14. Revise item 5 in Section 1803.6 to replace "expansive" with "questionable."
15. Revise Section 1803.6 to add new items to read:
"11. Construction considerations: earth retention systems, underpinning, excavation slopes, effects on adjacent structures, utilities and improvements, corrosivity, drainage systems and dewatering, as necessary.
12. Site class in accordance with Chapter 20 of ASCE 7 and the horizontal seismic forces to be considered in slope stability analysis."
16. Add a new exception following Section 1803.6 to read:
"Exception: For construction not exceeding four stories above grade plane, not requiring excavation more than 8 feet (2438 mm) below existing grade, and not covering more than 16,000 square feet (1486.4 m2) of ground area, a written report of geotechnical investigations shall not be required at the time of permit application but shall be completed prior to the actual start of construction to confirm presumed conditions used as the basis for design. The report shall be made available to the building official upon request. Where the written report of geotechnical investigations, completed after permit application, does not confirm presumed conditions used as the basis for design, a revised permit application and revised construction documents shall be submitted to the building official and construction shall not commence until the revised permit has been issued."