IFCO is currently involved in the geotechnical design of the fifth runway at Amsterdam's Schiphol Airport. The company is subcontractor to main contractor Vermeer/KWS and is also carrying out a field trial of the intensive forced consolidation method for the runway on a specially constructed test site.
The test site is 175m by 93.5m and has been split into five 35m long sections. The aim of the trial is to check the efficiency of the method with regard to consolidation and to determine possible side effects with regard to the salinity of the extracted groundwater. Fellow sub-contractor Van Kessel excavated the 5m deep trenches for the trial using a trench cutter.
To monitor the trial, which is expected to last for a minimum of six months, IFCO has installed its intelligent sensor system. The system uses a central PC server that controls all the sensors in a digital network on a single loop of cable. The server identifies the sensors (all pressure sensitive), and controls the timing of the measurements. It also stores the data after carrying out preliminary processing to convert the readings into usable values for calculations. A GSM mobile link is used to transmit data to IFCO's offices in Waddinxveen, over 60km away.
In all, 176 instruments have been installed, in two networks, measuring ground settlement, groundwater level in the ground and the sand walls, porewater pressure, pump pressure, air pressure, temperature, water levels in the trenches and also rainfall.