AN OVERVIEW OF SHALLOW AND DEEP FOUNDATION SYSTEMS PAUL F. MARANO, P.E.

INTRODUCTION Shallow Foundations: Footings Mats Deep Foundations: Quality Control Issues INTRODUCTION Shallow Foundations: Footings Mats Deep Foundations: Driven piles Augered, cast-in-place piles Helical piles Rammed aggregate piers Drilled piers (caissons) Quality control issues

Introduction Shallow Foundations Column/Wall Footings Mat Foundations Deep Foundations Quality Control Issues COLUMN/WALL FOOTINGS Appropriate for stable, near-surface soils with no underlying shallow compressible layers Low to moderate loads (typ. 2,000-8,000 psf) Load spread over localized soil contact area Typically 3 feet deep for frost protection Practical limiting depth: 7 feet

COLUMN/WALL FOOTINGS Introduction Shallow Foundations Mat Foundations Deep Foundations Quality Control Issues COLUMN/WALL FOOTINGS

COLUMN/WALL FOOTINGS Advantages: Economical, easy to construct Introduction Shallow Foundations Column/Wall Footings Mat Foundations Deep Foundations Quality Control Issues COLUMN/WALL FOOTINGS Advantages: Economical, easy to construct Disadvantages: Susceptible to differential settlements Cost: $300/c.y.

Introduction Shallow Foundations Column/Wall Footings Mat Foundations Deep Foundations Quality Control Issues MAT FOUNDATIONS Appropriate for stable, near surface soils with no underlying compressible layers Moderate to high column loads Load spread over entire building footprint Depth usually dictated by required mat thickness

MAT FOUNDATIONS Introduction Shallow Foundations Column/Wall Footings Deep Foundations Quality Control Issues MAT FOUNDATIONS

MAT FOUNDATIONS Advantages: Economical, easy to construct Introduction Shallow Foundations Column/Wall Footings Mat Foundations Deep Foundations Quality Control Issues MAT FOUNDATIONS Advantages: Economical, easy to construct Useful where property line restrictions are present Disadvantages: Requires continuous pour Capacity limited by soil conditions Longer exposure of bearing surface Cost: $360/c.y.

DEEP FOUNDATIONS PILE CLASSIFICATION Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DEEP FOUNDATIONS PILE CLASSIFICATION FHWA Publication HI-97-013

DEEP FOUNDATIONS Will Focus On: Driven piles: Timber piles Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DEEP FOUNDATIONS Will Focus On: Driven piles: Timber piles Steel H piles Pipe piles Pre-cast concrete Augered, cast-in-place piles Helical piles Rammed aggregate piers Drilled piers (caissons)

DEEP FOUNDATIONS Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DEEP FOUNDATIONS

DRIVEN PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRIVEN PILES Drawing courtesy of FHWA Publication HI 97-014

DRIVEN PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRIVEN PILES Photo courtesy of University of California at Davis - Civil and Environmental Engineering Department

Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues TIMBER PILES Appropriate for support when poor, near-surface soils and/or compressible layers are present Support via end bearing and/or skin friction For low to medium column loads Short to medium lengths Typical load range: 10 to 40 tons per pile

TIMBER PILES Introduction Shallow Foundations Deep Foundations Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues TIMBER PILES Drawing courtesy of NAVFAC DM-7.2

TIMBER PILES Advantages: Economical Readily available Easy to handle Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues TIMBER PILES Advantages: Economical Readily available Easy to handle Disadvantages: Difficult to splice Potential head/tip damage during hard driving Cannot penetrate very dense layers or small obstructions Vulnerable to deterioration in wet/dry condition Susceptible to degradation from insects Cost: $25/ft.

Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues STEEL H PILES Appropriate for support when thick layers of poor soils and/or compressible materials are present Best suited for end-bearing support on rock For moderate to high column loads Short to long lengths Typical load range: 60 to 220 tons per pile

STEEL H PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues STEEL H PILES Drawing courtesy of NAVFAC DM-7.2

STEEL H PILES Advantages: Small displacement Easy to splice Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues STEEL H PILES Advantages: Small displacement Easy to splice Available in various lengths and sizes Can penetrate most obstructions/soft rock Disadvantages: Minimal skin friction Web joint is vulnerable during hard driving Vulnerable to corrosion Cost: $50/ft.

Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues PIPE PILES Appropriate for support when moderate to thick layers of poor soils and/or compressible materials are present Support via end bearing and skin friction For moderate to high column loads Medium to long lengths Hollow or concrete filled (with or without reinforcement) Typical load range: 70 to 200 tons per pile

PIPE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues PIPE PILES Drawing courtesy of NAVFAC DM-7.2

PIPE PILES Advantages: Easy to splice Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues PIPE PILES Advantages: Easy to splice Internal inspection (prior to concrete placement) Available in various lengths, diameters, and wall thicknesses Disadvantages:a High initial cost Susceptible to damage during driving Cannot penetrate very dense layers or smaller obstructions Cost: $40/ft. (pipe only) $55/ft. (w/concrete)

PRE-CAST CONCRETE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues PRE-CAST CONCRETE PILES Appropriate for support when moderate layers of poor soils and/or compressible layers are present Support via end bearing and skin friction For moderate to high column loads or large lateral loads Can be pre-stressed for higher capacity Medium lengths Typical load range: 50 to 100+ tons per pile (higher if pre-stressed)

PRE-CAST CONCRETE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues PRE-CAST CONCRETE PILES Drawing courtesy of NAVFAC DM-7.2

PRE-CAST CONCRETE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues PRE-CAST CONCRETE PILES Photo courtesy of University of California at Davis - Civil and Environmental Engineering Department

PRE-CAST CONCRETE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues PRE-CAST CONCRETE PILES Photo courtesy of University of California at Davis - Civil and Environmental Engineering Department

AUGERED, CAST-IN-PLACE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues AUGERED, CAST-IN-PLACE PILES Appropriate for support when moderate to thick layers of poor soils and/or compressible materials are present No vibration, minimal installation noise Support via end bearing and skin friction For low to high column loads Short to long lengths Typical load range: 30 to 100 tons per pile

AUGERED, CAST-IN-PLACE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues AUGERED, CAST-IN-PLACE PILES Drawing courtesy of L.G. Barcus and Sons

AUGERED, CAST-IN-PLACE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues AUGERED, CAST-IN-PLACE PILES Photo courtesy of L.G. Barcus and Sons

AUGERED, CAST-IN-PLACE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues AUGERED, CAST-IN-PLACE PILES Photo courtesy of L.G. Barcus and Sons

AUGERED, CAST-IN-PLACE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues AUGERED, CAST-IN-PLACE PILES Photo courtesy of L.G. Barcus and Sons

AUGERED, CAST-IN-PLACE PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues AUGERED, CAST-IN-PLACE PILES Advantages: Relatively quiet installation No driving vibrations No splicing required Can be reinforced Can be installed in low headroom locations Disadvantages: Highly dependent on proper installation technique Thorough knowledge of subsurface conditions required Possible “necking” in very soft soils Susceptible to degradation from sulfates, chlorides, or acidic conditions Cost: $35/ft.

Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues HELICAL PILES Appropriate for support when near-surface soils and/or moderate compressible layers are present No vibration, minimal installation noise Support via end bearing For low to moderate column loads Short to medium lengths Typical load range: 7.5 to 50 tons per pile

HELICAL PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues HELICAL PILES

HELICAL PILES Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues HELICAL PILES

HELICAL PILES Advantages: Relatively quiet installation Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues HELICAL PILES Advantages: Relatively quiet installation No special installation equipment Shaft can be grouted to provide skin friction Provides significant uplift resistance Can be installed in low headroom locations Can be used to supplement existing foundations Disadvantages: Cannot penetrate very dense layers or smaller obstructions Minimal skin friction Possible buckling under compression in very soft soils Cost: $20-$30/ft. (equivalent)

RAMMED AGGREGATE PIERS Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues RAMMED AGGREGATE PIERS Appropriate for support when poor near-surface soils and/or moderate compressible layers are present Support via end bearing/densification Install by drilling or via driven mandrel Can increase stiffness by adding grout to the aggregate Short to medium lengths Typical load range: 30 to 100+ tons per pier*

RAMMED AGGREGATE PIERS Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues RAMMED AGGREGATE PIERS

RAMMED AGGREGATE PIERS Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues RAMMED AGGREGATE PIERS Advantages: Densifies/stiffens surrounding poor soils Materials (aggregate) readily available Can increase stiffness by adding grout Disadvantages: Highly dependent on proper installation Difficulty penetrating dense materials or small obstacles Proprietary technique Need aggregate mat at surface Cost: $30-$60/ft.*

DRILLED PIERS (CAISSONS) Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRILLED PIERS (CAISSONS) Appropriate for support when near-surface soils and/or compressible layers are present Low vibration, low noise installation Support via end bearing For high column loads Short to medium lengths Typical load range: 150 to 2,000+ tons per pier

DRILLED PIERS (CAISSONS) Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRILLED PIERS (CAISSONS)

DRILLED PIERS (CAISSONS) Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRILLED PIERS (CAISSONS)

DRILLED PIERS (CAISSONS) Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRILLED PIERS (CAISSONS) Photo courtesy of University of California at Davis - Civil and Environmental Engineering Department

DRILLED PIERS (CAISSONS) Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRILLED PIERS (CAISSONS) Photo courtesy of University of California at Davis - Civil and Environmental Engineering Department

DRILLED PIERS (CAISSONS) Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRILLED PIERS (CAISSONS)

DRILLED PIERS (CAISSONS) Introduction Shallow Foundations Deep Foundations Timber Piles Steel H Piles Pipe Piles Pre-Cast Concrete Piles Augered, Cast-In-Place Piles Helical Piles Rammed Aggregate Piers Drilled Piers Quality Control Issues DRILLED PIERS (CAISSONS) Advantages: Can increase capacity by belling or with socket in competent material or rock Bearing surface can be evaluated* No vibration Can be readily modified based on field conditions No pile cap needed Disadvantages: Highly dependent on proper installation technique and clean out Large amounts of drilling spoils Obstructions (boulder) removal difficult Cost: $60/c.y.

QUALITY CONTROL ISSUES Introduction Shallow Foundations Deep Foundations Quality Control Issues Load Testing Driven Piles Drilled Piers QUALITY CONTROL ISSUES Why Perform a Load Test? Local regulations Design loads are significantly higher than local practice Potential for substantial cost savings Existing piles are reused for heavier design loads Safe design loads are in doubt Static load test (ASTM D 1143) Dynamic load test (ASTM D 4945)

QUALITY CONTROL ISSUES Introduction Shallow Foundations Deep Foundations Quality Control Issues Load Testing Driven Piles Drilled Piers QUALITY CONTROL ISSUES

QUALITY CONTROL ISSUES Introduction Shallow Foundations Deep Foundations Quality Control Issues Load Testing Driven Piles Drilled Piers QUALITY CONTROL ISSUES

QUALITY CONTROL ISSUES Introduction Shallow Foundations Deep Foundations Quality Control Issues Load Testing Driven Piles Drilled Piers QUALITY CONTROL ISSUES Driven Pile Specifications: Site/Project Conditions - include geotechnical report (for information purposes) Fabrication (Pile Markings) - every 6 inches, with distances marked every foot Concrete Mixes - is air entrainment necessary? Driving Equipment - hammer should be approved by geotechnical design engineer

QUALITY CONTROL ISSUES Introduction Shallow Foundations Deep Foundations Quality Control Issues Load Testing Driven Piles Drilled Piers QUALITY CONTROL ISSUES Driven Pile Specifications (Continued): Static Pile Tests - Test pile refusal defined by geotechnical engineer, geotechnical design engineer to oversee load test and review records Quality Assurance and Field Quality Control - performed by geotechnical design engineer

QUALITY CONTROL ISSUES Introduction Shallow Foundations Deep Foundations Quality Control Issues Load Testing Driven Piles Drilled Piers QUALITY CONTROL ISSUES Drilled Pier Specifications: Site/Project Conditions - include geotechnical report (for information purposes) Excavation - assure that contracts are consistent with specifications (rock) Test drilling - test drilling is only necessary in highly variable subsurface materials Concrete Placement - chutes or tremies may not be necessary Field Quality Control - performed by geotechnical design engineer

SUMMARY To Minimize Cost Overruns: Quality geotechnical information Introduction Shallow Foundations Deep Foundations Quality Control Issues SUMMARY To Minimize Cost Overruns: Quality geotechnical information Appropriate pile type and capacity Pertinent specifications Appropriate installation equipment Quality control by geotechnical design engineer

SUMMARY Acknowledgements: Introduction Shallow Foundations Deep Foundations Quality Control Issues SUMMARY Acknowledgements: Robert MacIntosh, P.E. – MacIntosh Engineering William Burger, Jr., P.E. - L.G. Barcus & Sons