Rock and soil anchors
offer an economical solution to temporary or permanent
stability or support problems. Designed to withstand
lateral and uplift forces, these structural members
are typically used with temporary, deep excavation
support systems, as a part of permanent retaining
walls, for dam stabilization or to resist wind-produced
uplift
forces.
Ground Anchors are
load transfer systems consisting of . . .
Anchor in stable ground
Long tendon
Connection to structure
Ground Anchor
Applications
Lateral support of walls
Resistance of hydraulic uplift
Stabilization of landslides
Resistance to overturning
Ground Anchor
Design Steps
1. Establish geotechnical conditions
2. Establish loading diagram and construction sequence
3. Develop trial anchor capacity
4. Develop anchor zone design
5. Check overall stability
6. Field test anchors
Anchor Quality Control
Items
Monitor grout
quantity and pressure
Performance
test at selected anchors
Proof test
all anchors (QA)
Evaluate tendon
elongation and creep (QA)
Proposed ASTM Test
Criteria
Performance
Test
133%
of design load (cyclic)
Load
held at 133% for 10 minutes
If
creep readings are greater than .04 inches between
the 1-minute and 10-minute readings, load held
for an additional 50 minutes
Proof
Test
120%
of design load
Load
held for 5 minutes
Creep
between 1-minute and 5-minute reading with predetermined
limits set by performance test
Current criteria recommendations
for prestressed rock and soil anchors, Post-Tensioning
Institute, Phoenix, Arizona
Corrosion Protection at Connections Exposure to the elements requires anchors to be properly protected. Measures taken might include:
Trumpets
Secondary grouting
Protective anchor caps, grouted or filled with grease
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