ADAM-4000 DAQ Series Used in Berlin's Tunnel Construction Project

Introduction

When Berlin's electric utility proposed building a 9 km 9 km long 380-kV overhead line from Berlin's northern city boundary at Spandau to a transformer station in the city, it caused an uproar among citizen's groups and policy makers. Be-cause of the resistance it encountered, only 1 km of the line was built above ground. The other 8 km was built in a tunnel under Berlin. This large-scale project was completed by several builders - one of them being Philipp Holzmann AG. The portion of the project built by Philipp Holzmann AG was an underground section of the line approximately 3 km long.

System Requirements

Tunnel construction now follows a fairly standard procedure: First, several propulsion presses drill the tunnel under high pressure. Then mortar is pressed into the soil under high pres-sure in order to stabilize it. During thethird step, a concrete ring is constructed in the tunnel. Here the propulsion presses are brought in again and the ring is built using individual concrete segments. When the concrete ring is completed in one section of the tunnel, the next drilling process begins. All process data, such as the pressure of the propulsion presses, propulsion rates, air consumption, mechanical handling capacities, and operating hours are monitored, logged and archived.

System Description

Advantech ADAM modules are used in this data acquisition and monitoring process. The analog and digital signals from the sensors are fed from the tunnel over an RS-485 bus system to the monitoring PC. The length of this RS-485 bus can extend up to 2.5 km and repeaters are necessary. Two ADAM-4017 analog input modules and two ADAM-4052 digital input modules are used for data acquisition, and two ADAM-4510 repeater modules spaced approximately one kilometer apart are used to give the RS-485 signals the necessary range. The data acquisition modules are located close behind the drill. The RS-485 bus is a simple twisted pair of wires, which is pulled tight behind the propulsion press, together with the telephone line. The measured values are registered, archived and logged using the process visualization software WinLab/E, both during the drilling operation and in the stop mode. WinLab/E is a product of the German software company Graf Elektronik Systeme GmbH. The system uses 16 analog channels (4- 20mA) and 14 digital channels for data registration. The system is very flexible since the ADAM modules' upper and lower bounds, alarm bounds and designations can be changed "on-line".