DBPapers
DOI: 10.5593/SGEM2014/B12/S2.016

ASSESSMENT OF CLIFF STABILITY AFTER THE DEMOLITION OF THE ENGINEERING FACILITIES

A. Janowski, A. Jurkowska, D. Lewczuk, J. Szulwic, A. Zaradny
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-08-7 / ISSN 1314-2704, June 19-25, 2014, Book 1, Vol. 2, 115-124 pp

ABSTRACT
As a part of an experiment, cliff in Gdynia Redlowo (southern coast of Baltic Sea, Gdansk Bay) was measured using terrestrial laser scanner. The main reason for taking up the subject of the Orlowo Cliff’s stability was a decision about controlled removal one of the war fortification elements. The main purpose of that analysis was to specify suitability of laser scanning in determination of slope’s stability after a violent event. Location of the bunker and the cliff’s condition was in danger of slumping the construction onto a narrow beach. To prevent the collapse a part of war fortifications, built during "Cold War" (50’s, XX century), had to be demolished and dumped from the top of the cliff. Considering a huge weight of a building, its localization and concern about safety of construction company team, the massive structure made of steelreinforced concrete had to be demolished using other methods than traditional ones. Despite of knocking the bunker down under supervision of construction company team, taking into consideration the weight and size of the structure, it was obvious that not only degradation of the cliff could exist but also disarrangement of its structure. Due to the above-mentioned reasons, it was assumed that survey of cliff’s geometry before and after bunker demolition is indispensable. Object registration, accomplished by ground-based laser scanner, were carried out in close vicinity of the shoreline on the toe of cliff. Two series of measurement works were performed with the co-operation of Geodetic Circle Hevelius (Gdansk University of Technology) and companies (including producer of laser scanner). Within the article, comparison of two registration series were presented. It was also assumed that there is possibility of further repetition of surveys. As a result of work in software Leica Cyclone, MeshLab, Bentley Points and the authorial one, charts of the cliff were prepared. On the basis of received data, ground movements were specified. The localization of potential landslide was ascertained and the quick method of identification areas prone to erosion was indicated.

Keywords:slope stability, sea cliff stability, terrestrial laser scanning, measurement of ground movements