Auger piling

Abstract

A monitoring device ( 14 ) for a continuous flight auger is connected between a continuous flight auger ( 11 ) and a drive mechanism ( 12 ) and rotates with the auger. A strain measurement arrangement provides strain signals for use in deriving the rotational torque and axial force of the auger. The axial strain and rotational torque information are used to build up a model of the ground. In particular, the shear strength of the soil can be determined which enables the maximum pile capacity to be calculated without a detailed site investigation.

1 . A monitoring device for a continuous flight auger, comprising a shaft for connection between a continuous flight auger and a drive mechanism or for connection between adjacent auger sections, the shaft comprising a coupling at each end for connection to respective couplings of the drive mechanism and/or of the auger such that the shaft rotates with the auger, the device further comprising a strain measurement arrangement for providing strain signals for use in deriving the rotational torque and axial force of the auger.  
     
     
         2 . A device as claimed in  claim 1 , wherein the strain measurement arrangement comprises a plurality of strain gauges disposed on the shaft.  
     
     
         3 . A device as claimed in  claim 1  or  2 , further comprising a pressure detection device for mounting at the lower end of the auger, and a connection arrangement for coupling signals from the pressure detection device to a receiver of the monitoring device.  
     
     
         4 . A device as claimed in  claim 3 , wherein the connection arrangement comprises a hydraulic line.  
     
     
         5 . A device as claimed in  claim 4 , wherein the receiver comprises a pressure transducer mounted on the shaft.  
     
     
         6 . A device as claimed in  claim 3 , wherein the pressure detection device comprises an electrical pressure transducer coupled to the receiver by an electrical line.  
     
     
         7 . A device as claimed in any one of  claims 3  to  6 , wherein the receiver comprises a radio transmitter for sending measured data to a control station.  
     
     
         8 . A continuous flight auger rig comprising a continuous flight auger, a drive mechanism for driving the auger into the ground, and a monitoring device as claimed in any one of  claims 1  to  7 .  
     
     
         9 . A control device for controlling the driving of a continuous flight auger, comprising a monitoring device as claimed in any one of  claims 1  to  7 , and a control means for providing control signals for the control of the drive mechanism in dependence on signals provided by the monitoring device.  
     
     
         10 . A continuous flight auger rig comprising a continuous flight auger, a drive mechanism for driving the auger into the ground, and a control device for controlling the drive mechanism as claimed in  claim 9 .  
     
     
         11 . A rig as claimed in  claim 8  or  10 , wherein the auger comprises a core and a flight, the core comprising two concentric walls.  
     
     
         12 . A rig as claimed in  claim 11 , wherein the monitoring device comprises a pressure detection device mounted at the lower end of the auger, and a hydraulic line coupling signals from the pressure detection device to a pressure transducer mounted on the shaft, and wherein the hydraulic line is defined by the spacing between the concentric walls of the core.  
     
     
         13 . A rig as claimed in any one of claims  8 ,  10 ,  11  or  12 , in which the auger comprises multiple sections.  
     
     
         14 . A monitoring device for a continuous flight auger, comprising a pressure detection device for mounting at the lower end of the auger, a pressure transducer for mounting above ground, and a hydraulic line for coupling signals from the pressure detection device to the pressure transducer.  
     
     
         15 . A device as claimed in  claim 14 , comprising a shaft for connection between a continuous flight auger and a drive mechanism or for connection between adjacent auger sections, the shaft comprising a coupling at each end for connection to respective couplings of the drive mechanism and/or of the auger such that the shaft rotates with the auger, and wherein the pressure transducer is mounted on the shaft.  
     
     
         16 . A device as claimed in  claim 15 , further comprising a strain measurement arrangement for providing strain signals for use in deriving the rotational torque and axial force of the auger.  
     
     
         17 . A continuous flight auger rig comprising a continuous flight auger, a drive mechanism for driving the auger into the ground, and a monitoring device as claimed in any one of  claims 13  to  16 .  
     
     
         18 . A control device for controlling the driving of a continuous flight auger, comprising a monitoring device as claimed in  claim 14 ,  15  or  16 , and a control means for providing control signals for controlling driving of the auger into the ground in dependence on signals provided by the monitoring device.  
     
     
         19 . A continuous flight auger rig comprising a continuous flight auger, a drive mechanism for driving the auger into the ground, and a control device for controlling the drive mechanism as claimed in  claim 18 .  
     
     
         20 . A rig as claimed in  claim 19 , wherein the auger comprises a core and a flight, the core comprising two concentric walls, and wherein the hydraulic line is defined by the spacing between the concentric walls.