This document discusses micropiling and heaving of piles. It begins with an overview of micropiles, including their historical background and typical applications for structural support, earth retaining structures, and foundations. Micropiles are defined as heavily reinforced, small diameter piles installed with cement grout. The document outlines the construction aspects and equipment used for micropiling, including drilling and grouting equipment. It describes the advantages of micropiles in providing high capacity support in various ground conditions and loads. Limitations include limited lateral capacity and cost effectiveness compared to conventional piling systems. The document also discusses heaving of piles from soil displacement during installation and from frost heaving in cold climates, which can displace wood pilings upward.

1. GOVERMENT ENGINEERING
COLLEGE, BHARUCH
 Name & Enrollment No. :
 Topic : Micropiling & Heaving of Piles
 Sub : Advance construction & equipments
1 KAPTAN SAGAR 130140106021
2 KASHYAP RUPESH 130140106022

2. Overview
 Historical Background
 Micropiles Defined
 Typical Application
 Advantages & Limitation
 Construction Aspects & Equipment
 Load Testing

3. Historical Background
 Dr. Fernando Lizzi (Italia) in 1950s – pali radice
 1950s – soil reinforcement mechanism for historical
structures (lightly loaded elements)
 1960s – gained acceptance and usage in Great
Britain and Germany
 1970s – introduced to U.S. and global markets
 1980s – gained acceptance in U.S.
 2000s – increasing (widespread) global use high
capacity steel and grout elements series of
proprietary efforts

4. Micropiles Defined
 Heavily reinforced, small diameter, drilled elements
installed with neat cement grout.
 Let’s dissect this :
 Heavily Reinforced – typically reinforced with drill casing
and/or high strength bars
 Small diameter – limited to ≤ 12 inches (typ. 4 to 7 inches)
 Drilled – excludes driven piles and other foundation types
 Neat Cement Grout – grout does not contain aggregate
(aggregate can be used in certain formations)

5. Classification
 Categorized based on design use & installation
means
 Used in almost any ground type
 Transfer load to a more competent layer
 Stabilize/reinforce a potential sliding mass
Design Use
 Case I: axially or laterally loaded elements
 Case II: group of elements used for soil reinforcement
and stabilization (reticulated micropiles)
Installation process
 Types A thru E
Theoretically, any combination of “Design Use” and
“Installation Process” is possible

6. Typical application
Structural
support
Earth Retaining
Structure
Foundations
Foundation
for New
Structures
Underpinning
of Existing
Structures
Scour
Protection
Repair/Replaceme
nt of Existing
Foundations
Arresting/Preve
ntion of
Movement
Upgrading of
Foundations
Capacity
Seismic
Retrofitting

7. Typical Application
In-situ
Reinforcement
Slope
Stabilization
And Earth
Retention
Ground
Strengthening
Settlement
Reduction
Structural
Stability

8. Construction Aspects
 Solid Bar Micropiles
 Drill the borehole (with/without casing)
 Install the reinforcing elements into drilled borehole
 Casing (if not same as drill casing)
 Reinforcement steel (with proper corrosion protection)
 Centralizers
 Fill the borehole with cement grout
 Typically neat cement grout; no sand added
 Hollow Bar Micropiles
 Drill and grout simultaneously (typ. a more fluid grout
used)
 After depth is reached, flush hole with structural grout
(replacing grout used for drilling)

11. Advantages
 High-performance
 High capacity – design loads up to 500+ tons
 Good for various loading
 Tension, compression, lateral, combined
 Applicable for wide range of ground conditions
 Adaptable for varying height requirements
 Used in open headroom and restricted access
 Low noise and vibration – due to drilling operation
 Can penetrate obstacles

12. Limitation
 Lateral capacity limitation for vertical micropiles
 High slenderness ratio (length/diameter)
 May not be appropriate for seismic retrofit (vertical
micropiles)
 Limited experience in their use of slope stabilization
 Not cost effective vs. conventional piling systems in
open headroom conditions
 High lineal cost relative to conventional piling
systems
 Requires good QC / QA
 Especially with grouting
 Requires specialized equipment

13. Construction Equipment
Drilling :
 Rotary only
 Drifter,
rotation/percussion
 Double Head Systems
 Sonic Head
 Drill pipe (casing),
augers
 Drill and casing bits
 Under-reaming and ring
bits
 Percussion tooling
Grout Mixers & Operation
:
 Grout Mixers
 Colloidal Mixers
 Paddle Mixers
 Grout Pumps
 Single / Double
Piston
 Screw pump

14. Load Testing
 Compression Load Test
 Tension Load Test
 Lateral Load Test
 Deformation Instrumentation

15. Heaving of Piles
Whenever piles are driven, soil is displaced. The
movements induced in the soil itself may have several un
desirable consequences, including the lifting or lateral
displacements of those piles that have already been
driven. The effects of pile and soil displacement on
foundation performance depend to the great extent upon
the type of the piles and the way in which they transfer
the load to the surrounding ground.

16. Frost Heaving of Piling
In regions of cold climate many pile formations are in
ground which is partly subject to seasonal freezing and,
therefore, may be subject to the damaging effect of frost
heaving. Frost heaving has displaced wood piling upward
as much as 14 inches in a single winter season on an
Alaska Railroad bridge near Fairbanks, Alaska. Because
of skin friction and because unfrozen ground squeezes
into the void left as the pile rises-except, perhaps, if the
base of the pile is in permafrost – the pile does not return
to its original position in summer.