The provisions of this chapter shall apply to building and foundation systems in those areas not subject to scour or water pressure by wind and wave action. Buildings and foundations subject to such scour or water pressure loads shall be designed in accordance with Chapter 16 and Appendix G. (Note: Where the text in this Code refers to ASCE 7, the 2005 edition shall be used; and where the text in this Code refers to ASCE 7-10, the 2010 edition shall be used.)
Allowable bearing pressures, allowable stresses and design formulas provided in this chapter shall be used with the allowable stress design load combinations specified in Section 1605.3. The quality and design of materials used structurally in excavations and foundations shall conform to the requirements specified in Chapters 16, 19, 21, 22 and 23. Excavations and fills shall also comply with Chapter 33.
The following terms shall, for the purposes of this chapter, have the meanings shown herein.
AUGERED-CAST-IN-PLACE PILES. Augered-cast-in-place piles are constructed by pumping grout into an augered hole during the withdrawal of the auger. The pile is reinforced with a single reinforcing bar, a reinforcing steel cage or a structural steel section.
CAISSON PILES. Steel cased piles constructed by advancing a steel shell seated into rock and drilling of an uncased socket within the rock. The shell and socket are filled with a steel core section or steel reinforcing, and concrete or grout.
COMPACTED CONCRETE PILES. Compacted concrete piles are constructed by filling a driven casing with low-strength concrete and compacting the concrete as the casing is withdrawn.
COMPOSITE PILES. Composite piles consist of two or more approved pile types joined together.
CONCRETE-FILLED STEEL PIPE AND TUBE PILES. Concrete-filled steel pipe and tube piles are constructed by driving a steel pipe or tube section into the soil and filling the pipe or tube section with concrete. The steel pipe or tube section is left in place during and after the deposition of the concrete. For the purposes of this code these piles shall be considered driven piles.
DAMPPROOFING. Dampproofing is a protective measure applied to building foundation walls and slabs to prevent moisture from passing into interior spaces.
DEEP FOUNDATIONS. Deep foundations are comprised of concrete, grout, wood or steel structural elements either driven, drilled or jacked into the ground or cast in place. Deep foundations are relatively slender in comparison to their length, with lengths exceeding 12 times the least horizontal dimension. Deep foundations derive their load-carrying capacity through skin friction, end bearing, or a combination thereof.
DRIVEN UNCASED PILES. Driven uncased piles are constructed by driving a steel shell into the soil to shore an unexcavated hole that is later filled with concrete. The steel casing is lifted out of the hole during the deposition of the concrete. Driven uncased piles are not permitted under the provisions of this code.
ENLARGED BASE PILES. Enlarged base piles are cast-in-place concrete piles constructed with a base that is larger than the diameter of the remainder of the pile. The enlarged base is designed to increase the load-bearing area of the pile in end bearing. Enlarged base piles include piles installed by driving a precast concrete tip or by compacting concrete into the base of the pile to form an enlarged base.
HELICAL PILES. Helical piles are manufactured deep foundation steel elements consisting of a shaft and one or more helical bearing plates (helices) screwed into the ground by application of torque on the shaft. The various products marketed as screw piles, torque anchors, and helical piers are considered helical piles.
H-PILES. Steel H-piles are constructed by driving a steel H-shaped section into the ground.
FIXED HEADED PILE (DEEP FOUNDATION). A pile connected to a pile cap in a manner that prevents rotation of the pile head.
FREE HEADED PILE. A pile with a head that is free to rotate.
GEOTECHNICAL CAPACITY OF DEEP FOUNDATIONS. The load that can be supported by the soil or rock surrounding deep foundation as determined using a recognized method of analysis or as established by load tests. The geotechnical capacity can be developed through skin friction, end bearing, or a combination thereof.
LIQUEFACTION. For granular soils, liquefaction is defined as the loss of shear strength in soils resulting from increased pore-water pressure and reduced effective stress that may develop as a result of cyclic loading during earthquakes. For cohesive soils with a plasticity index of less than 20, liquefaction is defined as any transient softening and increased cyclic shear strains that may occur during earthquakes.
MICROPILE. A micropile is a drilled and grouted deep foundation element with a diameter that measures 5-inches (127 mm) to 14-inches (356 mm) that develops its load-carrying capacity by means of a bond zone in soil (also commonly known as a minipile).
PIER FOUNDATION. A pier foundation is a shallow foundation element of masonry or cast-in-place concrete construction. Piers are relatively short in comparison to their width, with lengths less than or equal to 12 times the least horizontal dimension of the pier. Piers derive their load-carrying capacity from end bearing on soil or rock.
RETAINING WALL. A wall that resists lateral or other forces caused by soil, rock, water or other materials, thereby limiting lateral displacement and the movement of the supported materials. Basement walls and vault walls that are parts of buildings and underground structures, including but not limited to utility vault structures, tunnels and transit stations, are not considered retaining walls.
SHALLOW FOUNDATION. A shallow foundation is an individual or strip footing, a mat foundation, a slab-on-grade foundation or a similar foundation element.
UNDERPINNING. The alteration of an existing foundation to transfer loads to a lower bearing stratum using new piers, piles, or other structural support elements installed below the existing foundation.
WATERPROOFING. Waterproofing is a protective measure applied to building foundation walls and slabs to prevent moisture and liquid water from passing into interior spaces.
AUGERED-CAST-IN-PLACE PILES. Augered-cast-in-place piles are constructed by pumping grout into an augered hole during the withdrawal of the auger. The pile is reinforced with a single reinforcing bar, a reinforcing steel cage or a structural steel section.
CAISSON PILES. Steel cased piles constructed by advancing a steel shell seated into rock and drilling of an uncased socket within the rock. The shell and socket are filled with a steel core section or steel reinforcing, and concrete or grout.
COMPACTED CONCRETE PILES. Compacted concrete piles are constructed by filling a driven casing with low-strength concrete and compacting the concrete as the casing is withdrawn.
COMPOSITE PILES. Composite piles consist of two or more approved pile types joined together.
CONCRETE-FILLED STEEL PIPE AND TUBE PILES. Concrete-filled steel pipe and tube piles are constructed by driving a steel pipe or tube section into the soil and filling the pipe or tube section with concrete. The steel pipe or tube section is left in place during and after the deposition of the concrete. For the purposes of this code these piles shall be considered driven piles.
DAMPPROOFING. Dampproofing is a protective measure applied to building foundation walls and slabs to prevent moisture from passing into interior spaces.
DEEP FOUNDATIONS. Deep foundations are comprised of concrete, grout, wood or steel structural elements either driven, drilled or jacked into the ground or cast in place. Deep foundations are relatively slender in comparison to their length, with lengths exceeding 12 times the least horizontal dimension. Deep foundations derive their load-carrying capacity through skin friction, end bearing, or a combination thereof.
DRIVEN UNCASED PILES. Driven uncased piles are constructed by driving a steel shell into the soil to shore an unexcavated hole that is later filled with concrete. The steel casing is lifted out of the hole during the deposition of the concrete. Driven uncased piles are not permitted under the provisions of this code.
ENLARGED BASE PILES. Enlarged base piles are cast-in-place concrete piles constructed with a base that is larger than the diameter of the remainder of the pile. The enlarged base is designed to increase the load-bearing area of the pile in end bearing. Enlarged base piles include piles installed by driving a precast concrete tip or by compacting concrete into the base of the pile to form an enlarged base.
HELICAL PILES. Helical piles are manufactured deep foundation steel elements consisting of a shaft and one or more helical bearing plates (helices) screwed into the ground by application of torque on the shaft. The various products marketed as screw piles, torque anchors, and helical piers are considered helical piles.
H-PILES. Steel H-piles are constructed by driving a steel H-shaped section into the ground.
FIXED HEADED PILE (DEEP FOUNDATION). A pile connected to a pile cap in a manner that prevents rotation of the pile head.
FREE HEADED PILE. A pile with a head that is free to rotate.
GEOTECHNICAL CAPACITY OF DEEP FOUNDATIONS. The load that can be supported by the soil or rock surrounding deep foundation as determined using a recognized method of analysis or as established by load tests. The geotechnical capacity can be developed through skin friction, end bearing, or a combination thereof.
LIQUEFACTION. For granular soils, liquefaction is defined as the loss of shear strength in soils resulting from increased pore-water pressure and reduced effective stress that may develop as a result of cyclic loading during earthquakes. For cohesive soils with a plasticity index of less than 20, liquefaction is defined as any transient softening and increased cyclic shear strains that may occur during earthquakes.
MICROPILE. A micropile is a drilled and grouted deep foundation element with a diameter that measures 5-inches (127 mm) to 14-inches (356 mm) that develops its load-carrying capacity by means of a bond zone in soil (also commonly known as a minipile).
PIER FOUNDATION. A pier foundation is a shallow foundation element of masonry or cast-in-place concrete construction. Piers are relatively short in comparison to their width, with lengths less than or equal to 12 times the least horizontal dimension of the pier. Piers derive their load-carrying capacity from end bearing on soil or rock.
RETAINING WALL. A wall that resists lateral or other forces caused by soil, rock, water or other materials, thereby limiting lateral displacement and the movement of the supported materials. Basement walls and vault walls that are parts of buildings and underground structures, including but not limited to utility vault structures, tunnels and transit stations, are not considered retaining walls.
SHALLOW FOUNDATION. A shallow foundation is an individual or strip footing, a mat foundation, a slab-on-grade foundation or a similar foundation element.
UNDERPINNING. The alteration of an existing foundation to transfer loads to a lower bearing stratum using new piers, piles, or other structural support elements installed below the existing foundation.
WATERPROOFING. Waterproofing is a protective measure applied to building foundation walls and slabs to prevent moisture and liquid water from passing into interior spaces.