International Building Code 1803.1
Excavations near footings or foundations. Excavations
for any purpose shall not remove lateral support from any
footing or foundation without first underpinning or protecting
the footing or foundation against settlement or lateral translation.
International Building Code 1803.2
Placement of backfill. The excavation outside the
foundation shall be backfilled with soil that is free of organic
material, construction debris, cobbles and boulders or a controlled
low-strength material (CLSM). The backfill shall be
placed in lifts and compacted, in a manner that does not damage
the foundation or thewaterproofing or dampproofing material.
Exception: Controlled low-strength material need not be
compacted.
International Building Code 1803.3
Site grading. The ground immediately adjacent to the
foundation shall be sloped away from the building at a slope of
not less than one unit vertical in 20 units horizontal (5-percent
slope) for a minimum distance of 10 feet (3048 mm) measured
perpendicular to the face of thewall. If physical obstructions or
lot lines prohibit 10 feet (3048 mm) of horizontal distance, a
5-percent slope shall be provided to an approved alternative
method of diverting water away from the foundation. Swales
used for this purpose shall be sloped a minimum of 2 percent
where located within 10 feet (3048 mm) of the building foundation.
Impervious surfaces within 10 feet (3048 mm) of the
building foundation shall be sloped a minimum of 2 percent
away from the building.
Exception: Where climatic or soil conditions warrant, the
slope of the ground away from the building foundation is
permitted to be reduced to not less than one unit vertical in
48 units horizontal (2-percent slope).
The procedure used to establish the final ground level adjacent
to the foundation shall account for additional settlement of
the backfill.
International Building Code 1803.4
Grading and fill in flood hazard areas. In flood hazard
areas established in Section 1612.3, grading and/or fill shall
not be approved:
1. Unless such fill is placed, compacted and sloped to minimize
shifting, slumping and erosion during the rise and
fall of flood water and, as applicable, wave action.
2. In floodways, unless it has been demonstrated through
hydrologic and hydraulic analyses performed by a registered
design professional in accordance with standard
344 2006 INTERNATIONAL BUILDING CODE
SOILS AND FOUNDATIONS
engineering practice that the proposed grading or fill, or
both, will not result in any increase in flood levels during
the occurrence of the design flood.
3. In flood hazard areas subject to high-velocity wave
action, unless such fill is conducted and/or placed to
avoid diversion of water and waves toward any building
or structure.
4. Where design flood elevations are specified but
floodways have not been designated, unless it has been
demonstrated that the cumulative effect of the proposed
flood hazard area encroachment, when combined with
all other existing and anticipated flood hazard area
encroachment, will not increase the design flood elevation
more than 1 foot (305 mm) at any point.
International Building Code 1803.5
Compacted fill material. Where footings will bear on
compacted fill material, the compacted fill shall comply with
the provisions of an approved report, which shall contain the
following:
1. Specifications for the preparation of the site prior to
placement of compacted fill material.
2. Specifications for material to be used as compacted fill.
3. Test method to be used to determine the maximum dry
density and optimum moisture content of the material to
be used as compacted fill.
4. Maximum allowable thickness of each lift of compacted
fill material.
5. Field test method for determining the in-place dry density
of the compacted fill.
6. Minimum acceptable in-place dry density expressed as a
percentage of the maximum dry density determined in
accordance with Item 3.
7. Number and frequency of field tests required to determine
compliance with Item 6.
Exception: Compacted fill material less than 12 inches
(305 mm) in depth need not comply with an approved
report, provided it has been compacted to a minimum of 90
percent Modified Proctor in accordance with ASTM D
1557. The compaction shall be verified by a qualified
inspector approved by the building official.
International Building Code 1803.6
Controlled low-strength material (CLSM). Where
footings will bear on controlled low-strength material
(CLSM), the CLSM shall comply with the provisions of an
approved report, which shall contain the following:
1. Specifications for the preparation of the site prior to
placement of the CLSM.
2. Specifications for the CLSM.
3. Laboratory or field test method(s) to be used to determine
the compressive strength or bearing capacity of the
CLSM.
4. Test methods for determining the acceptance of the
CLSM in the field.
5. Number and frequency of field tests required to determine
compliance with Item 4.