Hollow Bar Micropiles are constructed using bespoke hollow, threaded steel bar which is drilled and simultaneously grouted. It is typically drilled using rotary percussive techniques and bore stability is maintained by pumping grout through the centre of the steel bar as the pile is progressed.

The steel bar is progressed into the ground using sacrificial drill bits selected to suit the ground conditions present. The steel bar forms the structural element of the pile and the grout acts as the load transfer mechanism from the steel bar to the ground to achieve the geotechnical capacity.

This technique is suitable for a variety of ground conditions and is not susceptible to issues relating to groundwater levels. This technique is particularly effective in granular soils where the geotechnical capacity regularly exceeds those calculated through conventional methods.

Sinorock Drill Injection Piles consist of a micropile (or minipile) bar that can be both drilled and injected with grout during installation. The fully threaded rod sections can be cut and coupled at any point, enabling quick and easy installation in areas of restricted access or limited headroom. 

Installation of Sinorock Drill Injection Piles causes minimal disturbance to surrounding structures. 

The system also enables additional rod sections to be added in-situ, for pile extension in poor ground where the depth of the bearing strata is unknown.

Sinorock Drill Micropiles

Simultaneous drilling and grouting ensures that the grout is continuously placed over the full depth of the micropile, enabling grout to permeate the surrounding ground and increase skin friction. 

Rotary percussive installation ensures high rates of production and provides good directional stability if obstructions are encountered. 

Applications for Sinorock Drill Injection Piles include but are not limited to: column bases, foundation upgrades, mast stabilisation, refurbishment of old structures, and gantry bases for overhead power lines on electric rail projects.