i. an overview
DESCRIPTION
I. An overview. Geotechnical Features Problematical =>Need to go through the soil How doing it ?. I. An overview. Geotechnical Features Problematical =>Need to go through the soil How doing it ? What it depends of? The nature of the soil : - PowerPoint PPT PresentationTRANSCRIPT
I. An overview1) Geotechnical FeaturesProblematical => Need to go through the soil
How doing it ?
I. An overview1) Geotechnical FeaturesProblematical => Need to go through the soil
How doing it ?
What it depends of? The nature of the soil :- hard ground- soft ground
The size of the hole we need
I. An overview1) Geotechnical Features
a) Drilling precautions
Drilling consists of breaking the cohesion of soil particlesThese particles could create several problems -> How to avoid it?
• Evacuation of the destructed materials• Cooling of the drilling head
• Walls:- to avoid rock crumbling- with bentonite or casing
I. An overview1) Geotechnical Features
a) Drilling precautions
I. An overview1) Geotechnical Features
a) Drilling precautionsb) Hard ground drilling devices
The trepan:
Oldest technique
Create a shock in rock with the blade
Evacuation with water
Heavy blade
I. An overview1) Geotechnical Features
a) Drilling precautionsb) Hard ground drilling devices
The pneumatic hammer:
Most used technique
Create a rotation to get a better drilling
Metal mass moved by a flux of air in body
Could be handled or mounted in a frame
I. An overview1) Geotechnical Features
a) Drilling precautionsb) Hard ground drilling devices
The tricone:
Fastest technique (15 m per day)
Tooth made of heavy metal
Rotation process
Injection of mud and water & cooling
I. An overview1) Geotechnical Features
a) Drilling precautionsb) Hard ground drilling devices
c) Drilling a soft ground
The auger:
Most used technique
Could drill big diameters
Rapid
Also Shovels, deflection, high pressured water…
II. Precise drilling Application
1) Project Presentation
What? 300 meters long directional drilling under a river and a train way
For? A pipeline
Why? Protection of environmentGlobal costs reducedNo loose for agriculture
Need of a geotechnical survey
II. Precise drilling Application
1) Project Presentation
2) Geotechnical survey
Rapid look of the zone:- geologic map- aerial photography
Precise tests:- 3 core drillings- Radiography of the zone
Look at the results
II. Precise drilling Application
1) Project Presentation
2) Geotechnical survey3 different areas:- alluvium (sand & pebbles)-- limestone
Try to avoid alluvium=> Deepest path drilling
Need of a resistive drill to go through the limestone
How to manage the drill
II. Precise drilling Application
1) Project Presentation2) Geotechnical survey
3) Material solutions
Look at the results