Borehole Inclination Tester (BIT)
BIT measures the verticality of a borehole AND of existing piles
BIT uses the auger/bucket itself as the centralizer. Eliminating the need for a heavy-to-move system.
The BIT enables fast and accurate determination of inclination in both dry and wet boreholes.
Large boreholes and diaphragm-walls may be quickly tested several times during drilling to enable real-time corrective action.
A special centralizer is attached to the BIT sensor and lowered into a standard access tube (No need for an expensive inclinometer tube). The BIT sensor includes a gyro which constantly measures and compensates the rotation of the sensor in the tube.
BackgroundAll piling specifications prescribe the allowable deviation of the pile axis from the vertical.
In diaphragm and secant walls, the specification is typically even more restrictive.
Operation for boreholes
Once the borehole has been drilled to the required depth, the inclinometer is rigidly attached to the drill bit (bucket or auger) and the depth encoder hung from the rig. The bucket is then lowered (without turning) into the open hole. The descent is stopped at predetermined depths for inclination reading and the deviation calculated in real time by integrating the inclination over depth. Having reached the bottom, the procedure is repeated on the way up to the surface. The resulting error is distributed over the whole depth
Operation for existing piles
A special centralizer is attached to the BIT sensor and lowered into a standard access tube through the depth encoder. The sensor is lowered by hand and the descent is stopped every few meters. reading stabilizes in a second or two and the process is repeated all the way down and back up to ground level. The resulting error is distributed over the whole depth.