1. Engineering Presentation

2. Basic Soil Mechanics Soil type classification Gravel, sand, silt, clay Soil strength classification Granular soils (sand and gravel) Loose Dense Cohesive soils (silt and clay) Soft - toothpaste Hard – difficult to mark with your fingernail

3. Investigations Soil borings Drill holes, take samples Types of samples Undisturbed – Driven Tubes Disturbed - Bags Logs Soil tests N-Values – Drive Blow Counts Shear Strength – Direct Shear Test Moisture/density Compressibility – Consolidation Test Expansion Index Chemical Tests - Corrosion

4. Standard Penetration Test Standard Test Penetration Test Video

5. Bucket Auger Drill Rig Bucket Auger Drill Rig Video

6. Typical Soil Problems Fill Settlement Expansive Soil Movement Slope Creep Land Slides Liquefaction

7. Fill Settlement Thickness Age Soil type

8. Expansive Soil Shrinks when dry – summer Swells when wet – winter Plumbing leaks Timing of movement Maintenance

9. Examples of Poor Site Maintenance Lift and Separation Separation Between Sidewalk and Wal l

10. Examples of Poor Site Maintenance Separation Between Landing and HousePavement Damage

11. Examples of Poor Site Maintenance Pavement Damage

12. Examples of Poor Site Maintenance Pavement Damage Wall Damage

13. Examples of Poor Site Maintenance Wall DamageWall Tilt

14. Examples of Poor Site Maintenance Wall Damage Slope Between Building and Wall

15. Slope Creep Upper 5 to 10 feet – 3:1 (horizontal: vertical) or steeper slopes Usually expansive soils Slope maintenance

16. Slope Creep

17. Effect of Poor Slope Maintenance Wall is Tilted Crack in Seam Between Ceiling and Wall

18. Effect of Poor Slope Maintenance Wall is Tilted Cracks in Foundation

19. Effect of Poor Slope Maintenance Crack in Wall Crack Radiating From Window

20. Landslides Deep (typically more than 5 feet) Large, affecting more than one property Different types mud flows – very fast Circular – slow – 1inch per year or less

21. Landslides Landslide Video

22. Signs of Movement

23. Slope Movement

25. Foundation Clearances From Slope

26. Examples of Lateral Movement

31. Liquefaction Loose sand below water table during earthquake. Liquefaction Potential Maps Definition of Water Table

32. Pier Spacing Pier spacing is usually 5 feet to 7 feet, depending on foundation loads. Some buildings are heavier than others (masonry v. wood frame, multi-story vs. single-story). Some buildings have interior and exterior spread footings that support heavy loads. Most footings are designed to support 1500 psf – 2500 psf. 5’ x 5’ footing could support 62,500 lbs. 2’ wide perimeter footing could support up to 5,000 lbs/ft.

33. Typical Residential Building Loads

34. Types of Building Loads Line Loads – Along exterior walls 1000 lbs/ft./floor (typical) Concentrated Loads – Below columns 2000 lbs/sq. ft. (typical) 5 ft. square footing = 50,000 lbs

35. Pier Spacing Pier Design Capacity 75 kips to 87 kips ultimate 37 kips to 43 kips allowable Helical Piers – tension or compression 52 to 249 kips ultimate 23 to 131 kips allowable

36. Pier Spacing Foundation Strength During Lift Depends on concrete strength Steel placement Dimensions 7 ft. Typical for single story – spacing usually dependent on concrete strength 6 ft. Typical for two-story – spacing usually dependent on concrete strength

37. Test Piers Test piers provide very useful information. Sometimes better than borings.

38. Push Pier Graph

39. Helical Pier Graph

40. Push Pier Graph

41. Compaction Grouting Injecting grout into loose soils will densify the soils Denser soils are stronger, less likely to settle 10% - 20% increase in density is usually the goal.

42. Compaction Grouting

43. Soil Densification Using Foam Similar to grouting – install material in the ground to displace and densify soils. Works best in loose fills, with voids Need to do DCP or other testing to estimate foam quantities.

44. Typical Example Foam Injection

45. Corrosion Electro-chemical attack on buried metal Some soils are more corrosive than others Usually not an issue if galvanized piers are used Some jurisdictions require a study

46. Battered Helical Anchors To resist lateral loads Different angles –different combination of lateral and vertical loads

47. Lateral Loads

48. When Should You Always Call An Engineer? Buildings less than 10 years old Hillsides affecting structure More than 2-story buildings Buildings with irregular footprints Buildings with more than 3 inches differential Buildings with a history of plumbing leaks Properties with post construction engineering reports Buildings that have been part of litigation

49. Is the recommended scope of repair appropriate? Are there risks that EagleLIFT and the owner would like to know about? Are you “over-selling” the job? “We won’t cause any cracks”. “There will be no further movement”. “Our system is guaranteed”. “All the existing cracks will close up or disappear”. All estimates should be subject to results of engineering. An engineer can help you be more clear about potential risks with the client.

50. Industry Standards Foundation and Slab Tilt Construction Tolerance¼”/20 ft. = 1/960 Human Perception2”/20 ft. = 1/125 Structural Damage1”/20 ft. = 1/240

51. Any Questions? Contact Helfrich-Associates at: steve@helfrich-associaties.com 909-389-7316 steve@helfrich-associaties.com