distance between the station point and the smaller. One of them is a full wave instru
used to test whether this technology is able improvements. In the inferior part of the la
same campaign, we used in rapid successio and the Leica C10 in order to make a
between the two instruments. As for the survey frame:
- the target and the TLS stations have bee baselines referred to the “near reference”;
- the “near reference” consists in two pillar concrete wall in the stable area located at wa
the survey one; - the two pillars were themselves conn
belonging to a NRTK Network Network Re for real time surveying service of the Camp
Castellabate and 38 Sapri km away from In view of the distance between the landsli
we made continuous GPS observations duri days. We show the scheme of the “stable fra
Figure 1. RTK Permanent GNSS Stations Once the coordinates of the permanent statio
ETRF2000 system, we calculated the adjus two pillars we used the mean value of
Starting from these two pillars, which are c we finally calculated the coordinates both o
station points, always in the European System
3. LANDSLIDE DESCRIPTION AND F
The phenomenon we are monitoring is takin Campania Region, Italy, on the left side of
a stream Fiumicello, and has caused sig both to an important state road and to a ma
line. The landslide has a very large size m affects a stretch of road and two railway
traffic in both North-South and South-N 2008 mud and soil brought by the landslide
heavy and prolonged rains has caused the tunnels and the interruption of rail traffic
south railway line in Italy for about one da active and is defined “type slow” according
of Cruden and Varnes Cruden and V movement of the soil is of the sliding rotat
typical slipping that occurs along deep surfa show the landslide and an extract of
geological map Guida and Siervo, 2010; th “marnoso-arenacee”, calcareous and clay
flysch. The first survey of the phenomenon by the Iside srl group Iside, 2007: it ha
mainly oriented to the monitoring of the are The system was basically done from a num
fixed weather stations, piezometers, inclinom and from a topographical network built upon
the landslide slope is trument and has been
ble to give significant landslide, during the
sion the Riegl VZ400 a direct comparison
een surveyed by GPS lars materialized on a
walking distance from nnected to two PS
Real Time Kinematic pania Region, far 26
the landslide. slide area and the PS,
uring two consecutive rame” in figure 1.
ns reference frame tions were fixed in the
justed positions of the of two survey days.
e considered as fixed, of the target and the
tem
D FIRST SURVEYS
king place in Pisciotta of the final portion of
significant disruptions ajor national railway
more than 10 ha and y tunnels with heavy
North directions. In ide into the river after
the blockage of both ic on the main north-
day. The landslide is ng to the classification
Varnes, 1996. The tational type, with the
rfaces. In figure 2 we f the corresponding
the rocks are a mix of ayey of the Cilento
n has been carried out has set up a system
area close to the road. umber of sensors, like
ometers, strain gauges on:
- two fixed points placed on the “ and materialized with pillars where
- about fifty vertices materialized p when measuring retro-reflective m
the rods: the micro prisms can be points with the Total Station;
- six vertices that can be measure not visible from the two fixed poin
Figure 2. Location of landslide an Since older topographical measur
available, and since we only have points, it is impossible to compu
moving material or to define pr landslide. It is however possible
accurately the movements of the in e “stable” side of the mountain
ere a total station was placed; d permanently with metal rods;
micro prisms are mounted on e measured from the two fixed
ured using GPS since they are ints.
and extract of geological map urements or older data are not
ve measurements on individual pute reliably the volume of the
precisely the area affected by ble to determine reliably and
individual observed points and
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B5, 2012 XXII ISPRS Congress, 25 August – 01 September 2012, Melbourne, Australia
159
in this way to obtain a precise information on the dynamics of the phenomenon. For all points of the topographical network
there are graphs that show the trend of the planimetric and altimetric displacements and the related velocity in the period
2005-2009. The results of the periodic measurements show that the planimetric displacements in a period of about 4 years has
been of around 7-8m while the altimetric movement has been approximately of about 2.5-3.5m. The average daily speed of
the landslide was found to be of approximately 0.5 cmday with peaks of up to 2 cm day in planimetry and of about 0.2 cmday
with peaks up to 1.5 cm day in height. The consequences of these movements are visible on a long stretch of road that
appears to be completely disrupted figure 3.
Figure 3. Deep cracks in the road
4. SURVEYING CAMPAIGNS
