A Contractor’s Perspective on Geotechnical Education

1. A Contractor’s Perspective on Geotechnical Education 2009 Professors’ Driven Pile Institute Utah State University Logan, Utah 2009 Professors' Driven Pile Institute

2. Starting Point • “Virtually everything I know about piles I learned after graduation.” • “It’s true that you never have to learn something so well as when you have to teach it.” • “There’s always more to learn. I tell clients, if a geotechnical engineer tells you that they know everything there is to know about piles, show them the door. The one who says it seems there’s always more to know is the one to hire.” Van Komurka 2009 Professors' Driven Pile Institute

3. Education - Issues • Contractor Comments • West Coast contractor noted they had interns and a recent fulltime new hire not understand how to use a tape measure or any basics of layout.  They lacked knowledge of drafting & how to read a set of drawings. • The new generation can run a computer, but they don’t want to get dirty, which to me means they aren’t being exposed to practical applications of the subjects that they are required to take.  2009 Professors' Driven Pile Institute

4. Education - Issues • Contractor Comments • It seems disturbing that some engineering schools have dropped surveying all together (i.e., UC Berkeley).  Contractor (also PE) was required to take 2 semesters of surveying.  How can you build or design something if you don’t where to put it or tell someone where it goes? • Some universities are training engineers to be graduate students and then professors. 2009 Professors' Driven Pile Institute

5. Education - Observations • Lack of practical knowledge • Not unusual • Mitigation Methods • Internships • Invite industry professionals to visit classes • Contact industry professionals to arrange for site visits • Develop working relationships with local engineering and construction firms to provide additional resources and mentors for students 2009 Professors' Driven Pile Institute

6. Practice - Observations • Young engineers need mentors within the profession • Need to stay at one place long enough to really learn their profession • It takes time and effort to learn the peculiarities of a particular aspects of a profession. • It takes time and effort to learn the peculiarities of a given region. 2009 Professors' Driven Pile Institute

7. Practice • Be informed. Engineers need to visit the site prior to design to ensure what they are designing is practical and can be constructed. • Know your options. • Select and appropriate pile for a particular site . • Know what materials are available. • Beware the catalog engineer! 2009 Professors' Driven Pile Institute

8. Frog Pond Apartments 2009 Professors' Driven Pile Institute

9. Frog Pond Apartments 2009 Professors' Driven Pile Institute

10. Frog Pond Apartments 2009 Professors' Driven Pile Institute

11. Practice • Be realistic. We are driving piles to their maximum capacity (with at least a 2:1 safety factor) then only using a portion of that capacity, particularly when setup is not factored into the design. • Design for what is needed, don’t overdesign unnecessarily. • Don’t compound safety factors • Be reasonable. Don’t make the pile hammer the weak link in the system. Why are we driving to 20 bl/in? 2009 Professors' Driven Pile Institute

12. Practice • The motto is “A driven pile is a tested pile” not “Every driven pile is a test pile”. • Establish a driving criteria and let the contractor do his job. • Changing the rules after the contract is signed costs money. 2009 Professors' Driven Pile Institute

13. Cape Canaveral Hospital Cape Canaveral Hospital 2009 Professors' Driven Pile Institute

14. Cape Canaveral Hospital • Had previously driven hundreds of piles at this same site with the same geotechnical engineering firm. The soils are highly dependent upon setup. • Structural design predicated on geotechnical report that recommended a design allowable capacity of 50-tons for HP14x89 piles, 110’ to 115’ in length. This was based on static analyses using SPT-97. • Conducted three PDA’s, a 7-day re-strike with PDA and a successful, 100-ton static load test to 2x design capacity . 2009 Professors' Driven Pile Institute

15. Cape Canaveral Hospital • Engineer could provide neither definitive answer nor immediate reviews of driving information . He still wanted to prove setup on each pile using re-strikes. • Suspect lack of experience/knowledge led to overly cautious approach and slowed responses to questions, which delayed completion and increased costs. 2009 Professors' Driven Pile Institute

16. Practice • What are the design objectives? • What are we trying to accomplish? • To drive each pile to the bearing capacity required by the structure? • To maximize the capacity of each pile based on the geotechnical report? • To drive to refusal? 2009 Professors' Driven Pile Institute

17. Practice • General lack of understanding of geotechnical work and the unknowns with which we work among owners and general contractors • Most GC’s and Owners do not differentiate between trades – everything is a commodity • To an Owner or General Contractor the number of piles driven in a day is similar to the number of bricks laid in a day. 2009 Professors' Driven Pile Institute

18. Practice • Push for adequate testing to determine reasonable expectations. • Uncertainty leads to higher cost. • Driven piles compensate for uncertainty of subsurface conditions. You pay for what is needed to meet job requirements. 2009 Professors' Driven Pile Institute

19. Practice • Often deal with limited information • Owners might not want to pay for full design. • Owners might only want to pay for minimal subsurface exploration. • No consideration given by Owners beyond the immediate objective. 2009 Professors' Driven Pile Institute

20. Glynn County, GA Outfall 2009 Professors' Driven Pile Institute

21. Glynn County, GA Outfall 2009 Professors' Driven Pile Institute

22. Practice • Many construction claims pertain to subsurface conditions. • Owners need to understand that the more that is known about site and subsurface conditions, the more the report can be used to accomplish and the more reasonable the construction cost estimate will be. An incremental investment in exploration can pay big dividends. 2009 Professors' Driven Pile Institute

23. Practice • Design-Build contracts are becoming more prevalent • Engineers need to improve their relationships and familiarity with contractors • Improve the relationships between professional associations. • Dual memberships • Programs of mutual interest 2009 Professors' Driven Pile Institute

24. Practice • Acknowledge the potential for pile setup. • Educate owners and structural engineers regarding the potential cost and time savings derived from pile setup. • An early investment in testing can provide benefits • Once a project starts, time and cost pressure do not allow for full exploration. 2009 Professors' Driven Pile Institute

25. Practice • Are engineers doing the best job for their clients? • Engineers cannot be all things to all people. • Have found that there are a number of structural engineers that do not have a good understanding of soils and geotechnical design. They tend to select a pile from a geotechnical report like they would a column from a steel manual - by column and row based on bearing capacity, which is usually determined by static analysis methods. 2009 Professors' Driven Pile Institute

26. Practice • Geotechnical engineers are concerned about the commoditization and marginalization of their profession. They explore and analyze soils and are paid to make recommendations. They provide information to structural engineers who design the foundation or retaining wall. • Not enough communication between geotechnical engineers and structural engineers. • Some geotechnical engineers prepare a report for an owner and never hear from the structural engineer. 2009 Professors' Driven Pile Institute

27. Practice • Poor or expensive designs resulting from lack of experience or limited information increase costs and/or lend themselves to contractor innovation • Good for the contractors in that we can use our knowledge and experience to get work • Not conducive for good, long-term between engineering firms and their clients 2009 Professors' Driven Pile Institute

28. Practice • Retaining Wall Contractor Comment regarding H-pile and lagging systems: In the 70’s he used 3” lagging. Lagging has steadily progressed to 4”, 6” and in some cases, 8” thick. Either the soil has become worse or the designs have changed. 2009 Professors' Driven Pile Institute

29. Practice • It is not uncommon for a structural engineer to rely on a geotechnical report to provide the “specifications” for pile installation. This practice highlights the gap between the recommendations in the geotechnical report and the decisions/non-decisions on specifications made by the structural engineer. • Contractors need to know the specific requirements of the project and we are to get paid. 2009 Professors' Driven Pile Institute

30. Orange Avenue Apartments 2009 Professors' Driven Pile Institute

31. Orange Avenue Apartments • 02350 DEEP FOUNDATION SYSTEMS • Install deep foundation units or systems only under the direct supervision of the owner’s Geotechnical Engineer . • Load Test Report shall verify assumed capacities or foundation may be subject to redesign. • Contractor shall review the Geotechnical Engineer’s Report and follow its recommendations. • The Geotechnical Engineer will report on the conformance of the installation to the specifications and the capacity based on in-situ conditions encountered during the installation. Structural Engineer will review the reports and, at contractor expense, will recommend remedial action if necessary. 2009 Professors' Driven Pile Institute

32. Orange Avenue Apartments • Foundation Plan Notes: Steel “H” – piles shall be installed per Geotechnical Report. All piles shall be HP12x84 with design capacities of 58 tons compression & 19 tons uplift. Provide load test to confirm design capacities. Pile splices shall be fully welded. 2009 Professors' Driven Pile Institute

33. Orange Avenue Apartments • 10.2 H-Pile Recommendations • In order to provide the necessary load carrying capacity, we recommend that the steel H-piles be embedded to a tip elevation of -35 feet NDVD, roughly 110 to 115 feet below existing grades. Below is a table showing the estimated allowable compressional and tensional capacities for single H-piles with a tip elevation of -35 feet NGVD. Table X Estimated Pile Capacities for H-Piles • Capacities are based on a factor of safety of 2.0 for compression and 3.0 for uplift 2009 Professors' Driven Pile Institute

34. Orange Avenue Apartments • 10.5 PILE DRIVING ANALYER (PDA) AND OBSERVATION • We recommend that all piles be driven under the full-time observation of a representative of [the geotechnical engineering firm]. Further, we recommend the use of dynamic pile testing, commonly referred to as PDA (Pile Driving Analyzer) testing. The recommended factors of safety of 2.0 (compression) and 3.0 (uplift) included in the allowable capacities provided in Table X are based on the use of PDA testing. Where the pile testing program consists solely of selected static pile load tests we recommend applying a factor of safety of 2.5 against the ultimate capacity in compression. 2009 Professors' Driven Pile Institute

35. Orange Avenue Apartments • 10.8 QUALITY CONTROL • For H-piles and pipe pile, several test piles should be initially driven at various locations over the site. Their driving should be carefully inspected by a geotechnical engineer and the driving log recorded. A Pile Driving Analyzer (PDA) should be utilized on each pile to monitor and record pile capacity during driving. Afterwards, at least two (2) piles should be selected for a full scale load test in accordance with ASTM D – 1143 to confirm the driving criteria ten (10) days or longer, after installation in order to negate the effects of pore pressure build-up during pile driving. The load test should be taken to at least three (3) times the pile design capacity, or failure, whichever occurs first. By taking the test to 300% of design, it may be possible to increase the allowable pile capacity and save a great deal of money by reducing the number of piles required on the project. We recommend that a PDA device be utilized for all of the production piles. Further, driving should be inspected and driving record maintained. 2009 Professors' Driven Pile Institute

36. Practice • ASFE – Marginalization and commoditization have surpassed loss prevention as the most critical business issues challenging the welfare and survival of the geoprofessions. 2009 Professors' Driven Pile Institute

37. Practice • Discussion topic at the recent Geo-Council Meeting regarding retaining walls: • According to the SEI, Structural Engineers believe any wall design should be done by a certified Structural Engineer registered separately from Civil Engineers. Since they are not likely to spend years studying the ground and observing the performance of the walls, they wish to use code-driven design methods, particularly LRFD. All they require from other engineers, such as geotechnical engineers, are design values, preferably design values taken from standardized tests. 2009 Professors' Driven Pile Institute

38. Practice • This has the potential to reduce other civil engineers, such as geotechnical engineers or foundation engineers, to technicians serving the Structural Engineer, instead of a team of civil engineers with different specialties working together. The party that knows the least about the ground, which is the controlling factor, will assume legislated dominance over other civil engineers. Why should Structural Engineers assume that given a few design values they should be the only area of civil engineering that can act as the lead professional in a deep excavation, a landslide prevention wall or the underpinning of a building. 2009 Professors' Driven Pile Institute

39. Practice • Geotechnical engineers need to engage now and demand greater input into foundation design and retaining wall design. • Consider a greater partnership between geotechnical and structural engineers in foundation design or consider Foundation Engineering as a distinct discipline within civil engineering. 2009 Professors' Driven Pile Institute