the influence of slope rectification measures at Badulusirigama landslide
of Civil Engineering
OF MORATUWA-SRI LANKA
of the research. 2
of study. 3
and Objectives of the research. 4
happened initially in year 2011 causing life damages and property damages. (Amada, 2016) After, that area was
recognized as a slides affecting region. Reasons for the sliding are found to
be unplanned developments in the hilly areas. Anyway afterwards government has
taken number of rectification measures in the form of surface and sub-surface
drainage systems, reinforcement techniques and soil nailing and as well as toe
retaining structures had been adopted to stabilize the deep seated landslide at
Though these measures are
taken place it’s a must to check for the efficiency and will they are enough to
withstand sliding. In order number of monitoring devices such as extensometer,
tilt sensors, inclinometer, etc. had been installed.
These instruments help to
obtain data about the slide and by analyzing these data can determine whether
the slide is still active or not. If the rectification measures are enough then
the slide should not be still in progress. Therefore by analyzing data obtained
from about instruments, we can conclude whether these rectification measures
are enough. Base on this,
This research, will
ascertain the effectiveness of the rectification measures adopted in
Badulusirigama, by using the monitored data.
Badulusirigama area has
protected from several rectification measures after the landslide in 2011.Result
of Badulusirigama landslide if it happen again will be severe than before, in
order to prevent this case happen again we have to check for the effectiveness
of rectification measures taken.
To check effectiveness we
have to analyze data which are obtained from various instruments already
installed to monitor the land slide area.
In central part
of Sri Lanka we have hilly terrain.These areas subject to rain induced
landslides frequently. Examples for such areas are Kandy, Badulla, Nuwaraeliya,
Rathnapura, Mathale, Kegalle. Also these landslides cause for many property
damages and even life damages. These landslides causes for many drawbacks of
the country including health and sanitary drawbacks and economic and financial
drawbacks. Therefore taking actions to minimize these landslides is an
is one of such landslide took place once taking some life and property under
its custody. As that area has probability of affecting again government has
taken several measures to rectify. These rectification measures are quite
popular in case of landslides in this region of world but these can have slight
differences according to the place of installation. Therefore just taking
rectification measures may not be enough.
It’s a must to
check for the efficiency of the rectification measures. For that using some
measuring instruments, measuring data has been taken to analyze them and
conclude in the progress of land slide with the follow of rectification
There are many
families affected due to Badulusirigama landslide in 2011. And still there are some
of families live in the land sliding area around. So it’s a must to guarantee
their lives and property from such a natural disaster. By this project we can
do that ad also government need to have a good finalization on the project that
affect to citizens in country safeguarding their life and property this project
also can help in that too. And also if these measures are proved to be success
after analysis we can use them in other similar problems too. Therefore this
research is important and timely for Sri Lanka.
Scope of study
based on the process of collecting data then analyzing those data and coming to
conclusions about the efficiency using those analyzed data.
In the process
we have to collect data from already installed instruments in the project of
instruments are extensometer, inclinometer, piezometer and strain gauge which
have installed in the site of rectification, measure for the progress of slide
by measuring movement of surface, horizontal movement of subsurface,
fluctuation of ground water content and characteristics of slip surface with
rainfall. And by analyzing those data only, we should approach to a conclusion
about rectification measures. (Risk Awareness & Future Challenges, 2016)
As short comes
of the project, we can only take data from these instruments monthly or weakly
if some amendments take place within that time period that instances will be
loss by the records and that will cause for decision in certain scale. And we
hope to take decision by analyzing data collected in certain time period (1
year). So we can’t guarantee fully about the outcomes for sudden environmental
change e.g. Hurricane, earthquake, if it do not happen within the data taken
time period, therefore outcome of the research may limit to certain and usual
environment conditions only.
And also due to
connecting issues with the data collecting centers also certain drawbacks can
be taken place.
Objectives of the research
Identifying current rectification measures.
Gaining a clear picture about geotechnical instrumentation
relevant in landslide monitoring, there uses and functioning procedures.
Ascertaining the effectiveness of adapted rectification
measures in the land slide site at Badulusirigama.
Identifying the rectification methods that are more suitable
for the site, after concluding effectiveness of prevailing measures.
Discussing the suitability of the used rectification methods
in similar sites.
Data collecting from instrumentations.
the installation of the monitoring instruments and their performance will be
studied. Then data from all the instruments will be collected. This will be
done in throughout a year. Also rainfall data has to be collected according to
that area in concerned year
Data analyzing for surface movement.
from extensometer will be used for this. This gives relative movement between
two points. (Bandara, et al., 2013) Readings will be
plotted against time. Also rainfall pattern has to be considered for this
because it’s a critical factor. If there would be any errors, those will be
Data analyzing for subsurface movement.
from inclinometers and pipe strain gauges will be used for this. Inclinometer
gives the angle of movement of the sliding slope. Also depth to the failure
surface can also be obtained. (Kumar & Panigrahi, 1998) Pipe strain gauge
gives the details of the depth to the potential failure surface. (Bandara, et al., 2013)Data will be plotted
against time to study behaviour of failure surface.
Analyzing of water level fluctuation.
is done by water level meter. (Bandara, et al., 2013)Water level is a
critical factor because high water level will reduce the metric suction. Hence
factor of safety of that slope will be reduced. So water level will be
monitored. A graph will be plotted as the water level against time. Deviations
of the graph and the reason for them will be identified.
the data analyzing, we can say the effectiveness of the rectification measures
which have been already applied. Behaviour of the failure surface can be
identified. If further rectification measures would be needed, they will be
Data Collecting cost
Amada, K. (2016, October-December). Landslide
Mitigation – The Badulusirigama. (K. Amada, Ed.) JICA News From Sri Lanka,
Bandara, M. R., Somaratne, M. M., Indrathilaka, M. L.,
Amarathunga, M. N., Tsukamoto, M. S., Fujisawa, M. S., . . . Uchikura, M. Y.
(2013). The Manual forLandslide Monitoring,Analysis and Countermeasure.
NBRO & JICA DiMCEP.
Kumar, K., & Panigrahi, R. K. (1998). Instrumentation,
Monitoring and Analysis of a Landslide- A Case Study. Missouri University
of Science and Technology. New Delhi: Fourth International Conference on Case.
Risk Awareness & Future Challenges. (2016). NBRO
International Symposium (p. 351). Colombo: National Building Research