Micropiles and Rock Drilling Rigs
A micropile Application
Introduction
Micropiles, sometime are called as minipiles, anchor piles or root piles, are widely used in foundations constructions.
Especially for underpinning or emergency repairs, it is an effective method to provide reinforcement.
Micropiles normally consist of high-strength, small-diameter threaded steel bar. After the injection of cement, micropiles can supply 1,000 tons strength and more. In the same time, the rough, profiled surface of the grout body also transfers tension and/or compression loads to the deep ground.
Larger diameters of all thread solid rebar are most popular in the applications of micropile reinforcement. Meanwhile, hollow bars are also increasingly used since its rapid installation and adaptability of collapsing soil conditions.
ONTON hollow bar micropiles comply in Europe with DIN 1054:2010-12 (Subsoil-Verification of the safety of earthworks and foundations), Euro code2 and EN14199/10080 standards and in America with FHWA-NHI-14-007(2015). The steel material of the hollow bar, as well as the thread deformations comply with ASTM F432 and A615.
Basic Technique of Hollow Bar Micropiles
The piles are formed from a fully threaded steel bar with a hollow core which is drilled and simultaneously grouted into soils without a casing, typically employing rotary percussive skills.
How to Install Micropile
The installation procedure for mircropile is similar to bored piling it's using drilling method.
1. Drilling and Flushing
2. Withdrawing Drilling String
3. Inserting Steel Reinforcement and Grouting
4. Completed Micropile
5. Reiforcement Result Test
Advantages
Small lightweight equipment
Low noise and vibration
Suitable for tension loads
Minimal site preparation
Rapid & efficient installation, high output
High capacity capabilities in limited access areas
Works in all soil types, ideal for collapsible soils
Cased or uncased
Technical data
| Specification | From | To |
| Bar diameter | 25mm | 127mm |
| Drill bit diameter | 42mm | 300mm |
| Pile loads | Up to 1500kN | |
| Height of rig | 2.5m | 6.0m |
| Length of rig | 1.8m | 5.4m |
Operating distance from face of wall to centre line of pile | 450mm | 500mm |
T thread Hollow Bar Micropiles - suitalbe for Titan systems
Micropiles types
Cased
Uncased
Hollow Bar
Hollow Bar Micropiles
Micropiles are available in multiple varieties, in order to meet special requirements, for example on public projects requiring certifications, ONTON also offers micropiles in specific certified grades including carbon steels and special alloys. Related test reports and certificates please contact us.
Contact us:
WhatsApp: +8613095360861
Email: neolau@ontonbolt.com
