Page 6 - Deformation Monitoring

DEFORMATION MONITORING The excellence of collaboration

Geodetical Monitoring system (MSYS)

WORKFLOW 2. LEVELLING MEASUREMENTS
Moniterra implements an instrumentation and monitoring A) Buildings – structures within the influence zone
system (MSYS) that meets all the requirements specified by Levelling measurements are taken on levelling pins installed
design. For each section of the works in a project, proposals at the ground surface (road surface, sidewalks etc.) or on
are submitted for the setup of the geodetical monitoring system buildings and/or on deeply embedded rods.
to the Client .
The levelling pins on a surface or on buildings (e.g. vertical
The following are the minimum requirements to be fulfilled:
features, columns and walls) are of the embedment screw
1. GENERAL REQUIREMENTS type of galvanized steel. The installation of the pins are as deep
as necessary ensuring that they do not cause any injury to
For all instrumentation Moniterra delivers material submittal pedestrians and that they themselves do not get crooked or
sheets (MSS) to the Client together with calibration certificates damaged easily.
and installation details of each instrument. All instruments are
manufactured by recognised and experienced manufacturers Alternatively, where drilling and embedment is impossible,
and comply with the relevant standards. levelling contact pins are used with an aluminium plate or
corner and a steel ball suitably adhered to a hemispherical hole
When installing instruments, Moniterra informs the Client in of same diameter.
writing, via a standard Instrument Installation Announcement
form at least two days prior to the commencing of installation, The deep embedment levelling rods are installed inside holes of
so the Client will be able to witness the installation. approximately 500 mm depth. They consist of a solid 25 mm
diameter fully threaded rod, levelled at its top end transversely
Moniterra provides all the necessary mechanical and electrical
protection in order to prevent damage being caused to the as to its axis. The rod’s lower section is embedded, whilst its
upper section has been left free and is protected by a tube
instruments and ensure the continuity of the monitoring
program. which will also be embedded and carry a protective, strong
cover which will not protrude from the ground surface, capable
The calibration, maintenance and checks of the instruments of being removed for measurements and being put back in
are carried out in accordance with the instructions given by the place afterwards.
manufacturer.
The measurements of the levelling points are carried out with
Moniterra provides all the protection measures necessary for a precision of at least ±1 mm per kilometre and always with
protection of measuring equipment and the assured resumption open levelling routings, completely dependent from their two
of the measuring activity, within two days at the latest following ends on the levelling starting points (benchmarks) with known
an eventual damage. Any instrument that undergoes damage elevation. These bases will be installed with a permanent
is being replaced immediately. marker in areas outside the influence zone of works.
Before the inception of the measurement, all instruments are The control of the levelling benchmark network is conducted
checked to ensure correct operation and calibration according at regular time intervals (of at least three weeks). The results
to the instructions given by the manufacturer. The checking of the control of the base network are submitted to the Client.
and calibration procedures will be carried out throughout the The control measurements are carried out with levelling
operation of the instruments or whenever necessary, and as instruments having a precision of ±0.3 mm per kilometre. The
specified by the manufacturer. Moreover, when required, all the readings are being entered electronically and automatically
measurements will be adjusted to the environmental conditions transferred into a processing and entry program in the MDB.
affecting the instrument and/or the structural element under The measurement instruments and their accessories (remote
monitoring (e.g. temperature changes, humidity etc.) each
time these differ considerably from the normal conditions. The distance measurement devices, tripods etc) are serviced,
checked according to the instructions of the manufacturer and
maximum length of distance, from which measurements of
total displacements (3D) are taken, will be re-determined as will be replaced when thought necessary by Moniterra.
less than 100m and according to the existing environmental B) Ground surface above tunnels
conditions.
Sections and/or grid of pins according to the monitoring design
The data coming from measuring instruments equipped with plan are installed. The distance between the pins of each
an automatic measuring system are transmitted in real time to section is subject to the design study. On the road pavements,
the MDB through a cable or wireless system. the layout varies depending on the actual conditions.

Surface and Underground Monitoring Networks will be C) Influence zone free field (in all other cases except the
absolutely compatible and referred to the Primary and above)
Secondary Geodetic Network of the Project.
Pins are developed on a grid covering the entire influence zone.
All reference values (zero readings) are calculated for every Pins that cannot be installed (e.g. in streets with heavy traffic)
sensor after at least 4 series of measurements. can be placed and measured at any other location further to
pertinent communication with Client.

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