Micropiles transfer tension or compression forces as well as cyclic loads into the ground via skin friction according to EN 14199. The TITAN micropiles have been approved by DIBt (Deutsches Institute fur Bautechnick) for permanent applications. The DIBt are the German equivalent of the BBA (British Board of Agrement), both of which are members of EOTA, the European Organisation for Technical Approvals.
The hollow bar simultaneously acts as the drilling rod, injection tube and reinforcement for the micropile. The TITAN system can be used in any type of soil, including unstable soils, without the need for temporary casing, reducing overall cost and increasing productivity on site. Injecting a cement grout through the hollow steel tendon ensures the encapsulation of the steel tendon within the bore hole from the design depth of the pile, to the surface. Additional operations such as inserting and extracting casings and complex multi-stage grouting are unnecessary.
Dynamic pressure grouting of the TITAN Micropile produces a grout body that interlocks with the surrounding subsoil. TITAN hollow steel tendons satisfy the main requirements for the steel reinforcement bars within the Micropile, which provides an excellent shear bond between the steel tendon and the grout body.
Controlled crack widths of less than 0.1mm within the grout, guarantees permanent corrosion protection and therefore TITAN Micropiles can be used for permanent applications without the need for additional corrosion protection measures.
The TITAN self drilling foundation system is a flexible solution that can be used in areas of restricted access and sites with difficult ground conditions. The system provides a high level of productivity on site, reducing overall cost and programme.
There are many applications for TITAN Micropiles these include, but are not restricted to, traditional foundations, underpinning, resisting uplift and dynamic/cyclic loads as well as geothermal installations.
- Can be installed in areas of difficult access such as basements, under bridges and tunnels
- Caseless micropile up to 196mm diameter, with a capacity of up to 9601kN
- Low settlement system
- Suitable for all soil types and ground conditions
- Designed to resist tension, compression and cyclic loads
- Restrictive access
VERSATILE AND EFFECTIVE GROUND ENGINEERING SOLUTION
Micropiles use for the construction of a new Premier Inn Hotel, Glasgow
The site for the new hotel is located on Howard Street, immediately to the west of underlying SPT subway tunnels. These had to remain fully operational for the duration of the works. The zone of influence was deemed to be a 45° line projected from the tunnel invert level to ground level. The distance from the tunnel to the closest pile position was approximately 3.5m, and the invert level of the tunnel was approximately 13.3m below ground level.
Stringent limits for vibration and movement were imposed on the tunnel and the surrounding ground. Vibration monitoring, tiltmeters and laser distance meters had been installed prior to commencement of any piling works.
The cable percussive boreholes showed the ground conditions to comprise made ground up to 4.50m thick, overlying alluvial deposits described as dense silty sand with occasional clay bands, or medium dense and dense silty sand and gravel, encountered to a maximum depth of 34.00mbgl.