Improvement of the Engineering Protection Systems of the Kyiv-Pechersk Lavra Reserve Territory
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ISSN 2409-9066. Sci. innov., 2019, 15(3), 37—50 https://doi.org/10.15407/scinе15.03.037 Demchyshyn, M.G., and Kril, T.V. Institute of Geological Sciences, the NAS of Ukraine, 55 b, О. Gonchar St., Kyiv, 01054, Ukraine, +380 44 486 3023, [email protected] IMPROVEMENT OF THE ENGINEERING PROTECTION SYSTEMS OF THE KYIV-PECHERSK LAVRA RESERVE TERRITORY Introduction. The territory of the Kyiv-Pechersk Lavra reserve is located in difficult engineering and geological condi- tions on the right-bank slopes of the Dnieper River valley and adjacent areas of the loess plateau. The stability and preservation of Lavra’s objects is ensured by special systems of engineering protection (retaining and water-regulating structures). Problem Statement. Most of these structures were built in different periods and did not always have proper justifica- tion and configuration. With the development of the Reserve, the conditions have changed for their operation, thus, there is a need to review their effectiveness as protective structures and to improve them. Purpose. Determination of feasibility, adequacy, efficiency, and condition of engineering protection systems of the Re- serve to improve them and to prevent emergencies. Materials and Methods. The scheme of engineering protection of the territory (scale 1:1000); the plan of the current state of the Reserve (scale 1:1000); data of engineering and geological surveys, historical and archaeological materials are used. To determine the condition of engineering protection objects, field observations have been carried out (installation of marks, photo fixation). To assess the stability of the Reserve, mechanical and mathematical principles of engineering geology have been used in conjunction with the approaches of system analysis and the theory of engineering and geologi- cal similarity. Results. The landslides in this area have been established to be caused by active erosion of the right bank of the Dnie- per River, significant amount of earthworks during the construction of the Pechersk fortress in the 17th–18th centuries, as well as by engineering structures that are inadequate to the scale and nature of geological processes and by their low efficiency. Conclusions. Improvement of engineering protection systems implies raising the level of their maintenance, combining the maintenance works with the landscaping and gardening activities, establishing a monitoring system, and taking into consideration the seasonality and abnormality of hydrometeorological processes. The implementation of the obtained R&D results will raise the effectiveness of engineering protection systems for the protection and preservation of objects of the Reserve. Keywords: engineering and geological conditions, landslide, gaps, suffusion, engineering protection, strengthening of the slopes. The formation of National Kyiv-Pechersk His- the UNESCO list) took place since 10th century torical and Cultural Reserve (hereinafter referred on the steep slopes of the Dnieper valley and the to as the Reserve) as historical and architectural adjacent areas of the forest plateau. The Reserve ensemble, the World Heritage Site (No. 527 on being located between the Spassky (Pankra tievs- ky), Lavra, and Zalavrsky Ravines, the engineer- © DEMCHYSHYN, M.G., and KRIL, T.V., 2019 ing geological conditions of the area are compli- 37 Demchyshyn, M.G., and Kril, T.V. cated by periodic activation of geological pro- slides has been caused by the construction and cesses. In order to ensure the stability and reliable operation of the TDS [2—4]. exploitation of religious buildings in the Lavra Assessing the reasonableness, adequacy, effi- area, the slopes as well as the right bank hills of ciency, and status of the Reserve’s engineering Kyiv, in general, were reinforced throughout cen- protection systems will improve the engineering turies. In particular, in his PhD work, I.M. Ky- systems for protecting the Reserve’s territory, rychko [1] has noted that despite engineers tried preserving the world-class cultural heritage, and to control landslides since ancient times, anti- preventing emergencies. landslide structures were constructed from time In this research, the historical materials and to time. Periodic destruction of buildings and materials of archeological researches concerning rock slides on the slopes were remedied without the central historical part of Kyiv, as well as the taking into account the causes of landslides and status of this territory in the past have been stu- engineering geological parameters of the hills. died; the territory and structures located there In archived historical and geological studies, as (in particular, the retaining and drainage facili- well as in newspapers and journal until the early ties) have been surveyed in order to compare 19th century, there were extremely rare descrip- their current condition with previous situation. tions and historical data on the progress of land- The territory has been analyzed based on topo- slides and efforts to control them in Kyiv, while graphic materials at a scale of 1: 1000 and 1: 500 information available in other literary sources is for some sites, using engineering and geological not sufficient. survey data, based on which changes in the out- In the last centuries, the Dnieper slopes have lines of ravine systems have been identified. Using been reinforced by doing periodical landscaping the published materials [5—8] and the materials works, constructing retaining walls, drainage, of the general schemes of anti-landslide measures, and various artificial structures. Over the past the time and nature of gravitational soil displace- decades, Kyivproject, InzhProject, and State Re- ments on the edges and depression lines of the search Institute of Civil Engineering Structu res, Spassky (Pankratievsky) and the Lavra ravine sys- have been designing the anti-landslide works for tems have been established. engineering protection of Lavra, while Special- Also, the hydrogeological conditions of the Re- ized Administration for Anti-Landslide Under- serve’s territory have been studied based on the ground Works has been providing supervision data of multi-year observations of water table in and repair works. hydrogeological wells, taking into account the ma- At the same time, there have been reported nu- terials of geophysical researches carried out wit- merous cases when landslides, sinks, and other hin the framework of project [2]. The specific exogenous geological processes (EGP) are caused features of relief, hydrography, and vegetation, by construction of engineering structures for pro- which are required for arranging the surface wa- tecting the territory or by unsatisfactory opera- ter discharge, improving the territory, reinfor- tion of the territory. Thus, within the period of cing the building foundations, and ensuring an observations, from 1939 to nowadays, the share engineering protection of the territory have been of tunnel drainage systems (TDS) in the develop- analyzed. ment of EGP on the slopes reaches 19% and is the highest among all manmade factors that af- GEOLOGICAL PRECONDITIONS fect these processes. However, despite continu- FOR THE FORMATION OF THE RESERVE’S TERRITORY ously increasing number of protective structu- The engineering and geological conditions of res, the development of various EGP has not stop- the Reserve on the slope sections from Askold's ped. Mo reover, a considerable number of land- Grave Park to the Navodnytsky Ravine are re- 38 ISSN 2409-9066. Sci. innov., 2019, 15 (3) Improvement of the Engineering Protection Systems of the Kyiv-Pechersk Lavra Reserve Territory garded as complicated. To the foot of the riversi- by the geological structure of the hills, i.e. out- de hill there adjoins a narrow (50—100 m) tract cropping of sandstones of the Poltava rock for- of the Dnieper floodplain terrace. It is covered mation. As a result of the natural development, with displaced formations, ravine alluvium, and the formed niches were used as a place of refuge pre sent-day anthropogenic formations on which for pilgrims and other people. The Far (Varan- Naberezhne Highway is constructed. The slope gian) and the Near Caves formed in the Poltava height above the normal banked-up water level of rock formations ("weak" sandstones) on the right the Kaniv Reservoir (91.5 m) is more than 100 m, and left sides of the Lavra ravine, respectively, its average steepness is 23—26°. In this section of with absolute elevations of 140—145 m and a to- the slope, there are large ravine systems: Zalavr- tal length of more than 500 m, are especially im- ska, Lavra, and Spasska (Pankratievska) ones, portant in historical terms. which partition the hill from the upper edge to With the adoption of Christianity, the caves the water cut in the Dnieper [3, 9]. be came a place of residence of the monks, as well Structurally, this site belongs to the Pechersk as a place of their burial. Since that time, they anticlinal elevation and, from surface downward, have undergone many landslides, especially, in consists of loess (up to 15 m) under which there the Near Caves after the earthquake in 1620. To- are sandy and clay rocks of the Dnieper glacial day, as a result of accidental leakages from water anthropogene complex. The hydrogeological con- pipes and improper surface water discharge sys- ditions of the Reserve’s territory are determined tems, the soil massif on which the caves are lo- by the aquifers in the Quaternary eolian-deluvial cated has been waterlogged. This leads to numer- and lacustrine-glacial deposits on the plateau (the ous collapses of vaults, destruction of brickwork Upper Lavra), in the Quaternary deluvial soils on and sinks of soil from the walls. So, in the spring of the hills, and in the Oligocene (Kharkov) sands. 2002 and in December 2003, long-term discharg- The deep (up to 80 m) Lavra ravine divides the es from the water supply pipes led to collapsing a Reserve into two almost equal parts, the Upper vault in the Near Caves. The sink was about 3 m3 and the Lower Lavras [3]. The monuments of ar- [2, 3].