HEK screw injection pile

The HEK screw injection pile is a mixed-in-place pile system that is screwed in without any vibration and with very little noise. This pile system is particularly suitable for use in projects where vibration and/or noise nuisance are unacceptable and where large equipment has no access.

The HEK screw injection pile is manufactured by screwing a slender thick-walled steel tube into the ground, which at the bottom is outfitted with two half screw blades. By the mixing of grout with sand in the load-bearing foundation layer a mixed-in-place grout body is formed with a diameter the size of the screw tip. High pressure and tensile load capacities can thus be realized.

In weak layers, the rate of penetration of the tube will be high and a thin grout layer of approximately 40 mm will form around the tube. In the bearing sand layer, the penetration rate decreases and the sand is scraped off layer by layer and mixed with grout. The steel tube is left behind in the ground after reaching the desired depth.

When working with a limited working height, tube segments are attached to one another by threaded couplings or nozzle connections. The lower tube segment is outfitted with two screw blades and an outlet for grout mortar. After reaching the desired pile tip level, we inject extra grout. This additional quantity of injected grout produces relatively rigid deformation behavior with a positive effect on the pile’s load bearing capacity.