Zhodnotenie dlhodobého monitorovania svahových deformácií a efektívnosti sanačných opatrení na zosuvnom území Nižná Myšľa

Abstract

In 2010, extensive slope deformations were activated in Nižná Myšľa Village, which affected a large part of the village. Due to the extent of the affected area, the severity of the manifestations and especially the catastrophic consequences they caused in the built-up area of the village, the slope failures in Nižná Myšľa were evaluated as the second most destructive landslide event in the documented history of Slovakia. Almost immediately after the devasting event, a detailed engineering geological survey followed, which provided information on the extension, nature of slope deformations and became the basis for the design of the monitoring system. Monitoring activities have been ongoing since 2011 and continue to the present. By gradual upgrade of the monitoring objects network for monitoring subsurface deformations and for groundwater regime observations, a large data set was obtained over a longer period of time. Thanks to this, the Nižná Myšľa landslide area is one of the Slovak sites where the largest network of monitoring objects is built. At the same time by monitoring, the main activity took place – remediation of the geological environment in three successive stages. The aim of this work is to provide a comprehensive overview of the implemented remediation measures, an overview of dataset obtained from monitoring of slope deformations and selected environmental components, but mainly on the basis of these data, comprehensive evaluation of monitoring data obtained by monitoring and evaluation of the development of measured parameters with technical remediation measures. From the regularly repeated analysis of the parameters as well as from the evaluations results, the most significant results for the whole period of the site monitoring are the results of inclinometric measurements of total deformations and their increments for individual phases of measurement. The area is characterized by ongoing large-scale landslide activity, especially in the southern part of the village, which was also the most affected in 2010 and represents part of the central part of Nižná Myšľa, along with the northern part on the landslide from Staničná ulica Street, including the Elementary school area up to Hlavná ulica Street. In particular, remediation works during the first, second and third stages of the landslide remediation were directed to these areas. Despite a relatively large scope of remedy works and the evaluation of their effectiveness, the vast territory affected by slope failures was only partially rehabilitated depending on the approved funds. Therefore, even the remedial measures implemented so far are only partial, mainly in connection with the persistent movement activity in individual parts of the territory and should be completed according to the proposals from the geological works carried out and taking into account the results of monitoring. The basic objective should be a gradual implementation of remediation work so as to ensure the stability of the territory to the greatest possible extent, as ensuring the complete stability of the territory is technically and financially unrealistic due to its extent, complexity and slope deformation character. In the long term, redevelopment work needs to increase the territory’s ability to withstand similar adverse climatic events as occurred in June 2010.

Keywords

• landslides
• slope monitoring
• remediation
• inclinometric measurements
• slope stability