30-11-2012, 05:07 PM
Micropiles Design 101
[attachment=41949]
Background for Engineers
♦Fundamentals are similar to
traditional pile design
♦ However, due to the small
structural section, structural
design and stiffness can
often control
Designers Must Understand Available Tools
♦ Drilling rigs
♦ Drilling methods
♦ Available Structural
Materials
♦ Reasonable Bond
Values
♦ Quality Control
Micropile Materials
♦ Permanent Steel Pipe
– API 5CT & ASTM A252
– 80 ksi yield
– Flush joint threads
♦ Steel Reinforcement
– ASTM A615, Gr. 60 & 75
– ASTM A722, Gr. 150
– Mechanical coupling
– Hollow bars
C tG t
Star Iron Works
♦ Cement Grout
– Neat cement – ASTM C150
– W/C ratio of 0.45
– 4000 psi (min)
Design Involves:
♦Knowing the site
♦Understanding the loads
♦Understanding the geology
♦Calculations
♦Specifications
♦Quality Control
[attachment=41949]
Background for Engineers
♦Fundamentals are similar to
traditional pile design
♦ However, due to the small
structural section, structural
design and stiffness can
often control
Designers Must Understand Available Tools
♦ Drilling rigs
♦ Drilling methods
♦ Available Structural
Materials
♦ Reasonable Bond
Values
♦ Quality Control
Micropile Materials
♦ Permanent Steel Pipe
– API 5CT & ASTM A252
– 80 ksi yield
– Flush joint threads
♦ Steel Reinforcement
– ASTM A615, Gr. 60 & 75
– ASTM A722, Gr. 150
– Mechanical coupling
– Hollow bars
C tG t
Star Iron Works
♦ Cement Grout
– Neat cement – ASTM C150
– W/C ratio of 0.45
– 4000 psi (min)
Design Involves:
♦Knowing the site
♦Understanding the loads
♦Understanding the geology
♦Calculations
♦Specifications
♦Quality Control