A Distributed Wireless Soil Displacement Measurement System for ActiveMonitoring of the Excavation Front of a Gallery

摘要

In this paper, an innovative instrument for the measurement of the soil displacement, developed at the laboratoriesof the Departments of Civil and Information Engineering of the University of Parma and currently under patenting, ispresented. The instrument, which can be used in any application requiring soil movement measurements, has been originallydesigned for the measurement of the axial terrain displacement during gallery excavation. The methods currently inuse for this type of measurements, together with their advantages and disadvantages, are illustrated, motivating the reasonswhich have brought to the proposed innovative measurement system. The instrument allows to measure the soil displacementalong an axis perpendicular to the excavation front, during a gallery excavation, through continuous measuresbased on the use of potentiometers. The transmission system is wireless, with multi-hop communications. This eliminatesthe limitations imposed by the cables which make the reading and data collection operations difficult. In particular, thewireless technology utilized during the project is based on the Z-Wave protocol, originally developed for home applications.This wireless four-layer communication protocol is based on the creation of a network with a single controller andseveral slaves. The system has first been set and tested in the laboratories and, then, outdoor (under gravel and clay). Theobtained results are very satisfactory.