Transcript Overheads - Hydraulics and Geotechnical

Bridge Hydraulics
and
Geotechnical
BRIDGE HYDRAULICS AND GEOTECHNICAL
The Hydrological Cycle
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 2
BRIDGE HYDRAULICS AND GEOTECHNICAL
North Saskatchewan River at Edmonton
Maximum Discharge
5000
4000
Q
3000
(m3/sec)
2000
1981
1971
1961
1951
1941
1931
1911
0
1921
1000
Year
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 3
BRIDGE HYDRAULICS AND GEOTECHNICAL
Flood Frequency Plot
(Max Mean Daily Data)
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 4
BRIDGE HYDRAULICS AND GEOTECHNICAL
Design Flood Frequency
•
•
•
•
Local roads
Secondary Highways
Primary Highways
High Water Marks
- 25 year return
- 50 year return
- 100 year return
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 5
BRIDGE HYDRAULICS AND GEOTECHNICAL
Streambed Profile of Typical
Watercourse
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 6
BRIDGE HYDRAULICS AND GEOTECHNICAL
Channel Types
Meandering Channel
Braided Channel
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 7
BRIDGE HYDRAULICS AND GEOTECHNICAL
Continuity: Q = AV
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 8
BRIDGE HYDRAULICS AND GEOTECHNICAL
Typical River Channel Before
Constriction
RIVER BANK
10 m3
10 m3
10 m3
10 m3
10 m3
10 m3
10 m3
10 m3
FLOW
3
10 m
3
10 m
RIVER BANK
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 9
BRIDGE HYDRAULICS AND GEOTECHNICAL
Continuity: V = Q/A
• Area can be reduced by:
- Ice
- Collapsed pipe
- Drift
- Struts
- Liners
- Insufficient Inlet
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 10
BRIDGE HYDRAULICS AND GEOTECHNICAL
Typical River Channel After
Constriction
MAX BACKWATER
10 m3
10 m3
FLOW
10 m3
10 m3
10 m3
10 m3
10 m3
10 m3
10 m3
10 m3
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 11
BRIDGE HYDRAULICS AND GEOTECHNICAL
General Scour
Top of road embankment
Flood peak
L.W.
17 ft depth of scour
Scoured bed at flood peak
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 12
BRIDGE HYDRAULICS AND GEOTECHNICAL
Local Scour
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 13
BRIDGE HYDRAULICS AND GEOTECHNICAL
Slope Protection
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 14
BRIDGE HYDRAULICS AND GEOTECHNICAL
Structure Foundations
• Soil - all earth materials overlying the rock crust
• All loads from bridge carried by soil and/or rock
crust
• Soil Mechanics - the science dealing with the
action of soil associated with engineering
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 15
BRIDGE HYDRAULICS AND GEOTECHNICAL
Soil Bearing Capacity
• Depends on mechanical properties
– shear strength
– bearing strength
– compressibility
• Non-elastic, non-homogenous
• Mechanical properties change
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 16
BRIDGE HYDRAULICS AND GEOTECHNICAL
Bridge Foundation Types
• Spread footings
– good bearing at shallow depths
• Piles
– drilled
– driven
– drilled and driven
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 17
BRIDGE HYDRAULICS AND GEOTECHNICAL
Foundation Loads
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 18
BRIDGE HYDRAULICS AND GEOTECHNICAL
Soil Creep
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 19
BRIDGE HYDRAULICS AND GEOTECHNICAL
Stability of Hillsides and Slopes
TECHNICAL STANDARDS BRANCH
INTRODUCTION TO BRIDGES
TRANSPORTATION
Slide 20