Article published on ‘Perforare’ n.2 2016.
That is the aim of some drillings in Naples: JET 4000 AME / J fundamental.
We are in Naples, south of Italy, where a building collapsed. A specialized company is carrying out some drillings with a CMV 420 together with a DAT instruments JET 4000 AME / J datalogger in order to understand what has caused this collapse. This zone has many problems and, in order to avoid further weakening of this soil, it has been used cement mixture instead of water while drilling. Drillings and diagraphs aim is to understand the subsurface, the different levels that have changed after landslide and the identification of the most weak zones. Once information are studied, it will be possible to project soil consolidation. It is possible to understand geomechanical characteristics of soil thanks to real time drilling parameters. In particular, graphics in function of depth show the different stratigraphic levels of soil.
For this application, DAT instruments has two different dataloggers: JET SDP / IB, easy to use and cheap; and JET 4000 AME / J that can be implemented with jet grouting function. The jet grouting version is the one currently used in Naples. In details, the JET 4000 AME / J datalogger let display instantaneous values of graphics in function of depth and of summary reports. Additional characteristics of this equipment are: automatic start when starting to, automatic stop when pre-established depth is reached, data transfer to PC and, optional, automatic stop when rod is changed with recording stop.
The JET 4000 AME / J let record and measure, thanks to proper sensors, the following selectable parameters:
- drill depth (JET DEPTH)
- feed force (JET FORCE)
- translation rod speed (JET DEPTH)
- boring rod rotation torque (JET TORQ)
- boring rod rotation speed (JET ROT)
- mast inclination, X and Y axes (JET INCL XY)
- grout cement or water pressure (JET PRESS)
- grout flow and volume (JET FLOW)