RESULTS OF VIBRATION MONITORING OF VIBRO-DRIVING AND VIBRO-EXTRACTION OF SHEET PILES

The geology of St. Petersburg is represented with a heavy layer of weak structurally unstable soils. Using of vibro-extraction and vibro-driving of sheet piles in such conditions requires a particularly responsible approach in order to predict the emerging dynamic effects and the zones of their influence on the surrounding buildings and structures. Therefore, the task of looking for possible patterns describing these processes is highly relevant. For this purpose, the authors have updated the map of engineering-geological zoning according to Zavarzin with use of more than 50 reports of engineering-geological surveys. On this map the sensitive to the high-frequency vibrations soil layers are identified. Also, more than 70 reports on vibration monitoring of vibration driving and vibration extraction of sheet piles in St. Petersburg have been analyzed. The influence on the value of vibration acceleration of the following factors has been investigated: the geological features of the site, the distance to the source of vibrations, the characteristics of the vibrating hammer (operating frequency, driving force) and sheet pile (length, cross section), the location of measurements (on the ground or on a structural element of the building). The result of the work is the diagrams that clearly show the presence or absence of a relationship between the studied parameters. The absence of dependencies for some of the investigated parameters may be caused by the factors which influence cannot be predicted. These factors are the occurrence of large friction forces in the joints of sheet piles; the presence of lenses of dense soils or boulders during sheet piles driving; violations of the technological process. The zone of the influence of high-frequency dynamic impact was identified as 25 meters, which is in good agreement with the results of in-situ monitoring.

Engineering-Geological Zoning of the Railway Section by the Method of Probabilistic Assessment

The article describes the special engineering-geological zoning method of the railway territory. Permafrost geocryological conditions of the railway geological section were analyzed. The area is characterized by sporadic discontinuous permafrost. The analysis showed that the process of flooding is widely developed at the stusy area. It will have a great impact on the design and operation of the structure. The method of probabilistic assessment was used for a reasonable zonation of the territory. In result of the study, three taxa were identified that allows defining the flooded, potentially flooded, and non-flooded areas according to their geological structure. Measures for reducing the negative impact of flooding processes are recommended.

Using GIS for Engineering and Geological Zoning for Wells Construction in the Churakovskoye Oil Field

In this work, the location of the karst sinkholes not recorded during field work was mapped using satellite imagery data. Based on GIS, engineering-geological zoning of the territory was carried out by the method of distance from the nearest surface karst occurrence. The results of the sinkholes density analysis of the territory conducted using the sliding window method are presented. The complex engineering-geological zonation of the territory was carried out according to the complexity of the engineering-geological situation.

Engineering geological characteristics of Danube right bank between Kozloduy and Gorni Tsibar

The geotechnical properties of soils (clays of the Brusarci Formation and loess complex) spread over the area of Danube right bank between the town of Kozloduy and the village of Gorni Tsibar have been determined. Complex landslides and river erosion are the most important geodynamic processes in the study area. Engineering geological zoning has been carried out, with two separated zones. The second zone is characterized with most complicated geotechnical conditions due to distribution of both old landslides and recently landslide activation in some sub-zones.

Results of engineering geological zoning of Belarus territory by the abrasion risk at water reservoirs in the context of global climate change

The paper shows the reasons for the intensification of risk-forming processes in Belarus caused by "aging" of existing and the arrangement of new water reservoirs. The shores of new reservoirs located in the territory of Belarus, intensively used in the national economy and densely populated, are actively reprocessed by abrasion, leading to the development of abrasion risk. The length of the abrasion coasts has increased by more than 20 km recently, which undoubtedly has an impact on the surrounding areas, causing loss of land and economic facilities. The goal of the work is to update the regional zoning of the country's territory according to abrasive risk, which should be taken into account in the forecast calculations of the sustainable development of regions based on entirely new principles and assumptions. In this work, we used the data of long-term (covering more than 40-year-long period) field observations of the author over the abrasion process and the results of a science-based analysis. We propose (using the failure tree) an abrasion risk development model and indicators characterizing the abrasion risk, taking into account the global climate change and related warming, affecting the dynamics and extent of the process of destruction and deformation of the coast. Based on a theoretical study of the mechanism for forming the dynamic equilibrium profile of abrasion coasts and the equilibrium coastline, a criterion is suggested that characterizes the stability and development of the equilibrium profile of the coastal slope required for zoning the Belarus territory by abrasion risk. Based on the generalization of the observation results for Belarus water reservoirs and the use of the proposed indicators, we performed zoning of the country’s territory by the abrasion risk, which is of practical importance for making management decisions and designating engineering measures to prevent and mitigate risk in water bodies, as well as minimizing their effects.

INTEGRATION OF THE GEOLOGICAL INFORMATION DATABASE IN THE SYSTEM OF GEOINFORMATION MODELING

Статья посвящена вопросу интеграции базы данных геологической информации г. Владикавказа в специально разрабатываемую систему геоинформационного моделирования. С развитием высоких технологий большое распространение получили различные геоинформационные системы, предназначенные для сбора, хранения, анализа и графической визуализации пространственных данных и связанной с ними информации о представленных в ГИС-объектах. В Геофизическом институте создана карта инженерно-геологического районирования территории города Владикавказа, освещающая вопросы геологического строения, гидрогеологических условий, литологии, морфологии, тектоники, распространения различных типов грунтов на рассматриваемой территории. На территории выделены участки, характеризующиеся различной глубиной залегания галечников или мощности глинистого и суглинистого покрова на галечниках, что является основным параметром, определяющим категорию сейсмичности по СНиП-II-7-81*. На основе анализа физико-механических свойств, проведена надежная дифференциация групп грунтов с различными определяющими показателями, характеризующими категорию грунтов по их сейсмическим свойствам. Данная информация собрана в базу данных геологической информации, сформированной в виде шейп-файла с пространственной привязкой каждой скважины. Разработанная база данных используется в качестве основы в задаче геоинформационного моделирования. На основе программного обеспечения с открытым исходным кодом выполнена интеграция базы данных геологической информации г. Владикавказа в систему геоинформационного моделирования. Ключевые слова: сейсмиче The article is devoted to the integration of the geological information database of Vladikavkaz into a specially developed system of geoinformation modeling. With the development of high technologies, various geoinformation systems are widely used to collect, store, analyze and graphically visualize spatial data and associated information about the objects represented in GIS objects. The engineering geological zoning map of the Vladikavkaz city territory, covering geological structure, hydrogeological conditions, lithology, morphology, tectonics, distribution of various soil types in the considered territory, was created at the Geophysical Institute. There are areas on the territory that are characterized by the different depths of pebbles or the thickness of clayey and loamy cover on pebbles, which is the main parameter determining the category of seismicity according to construction rules and regulations «SNIP-II-7-81*». On the basis of the analysis of physical and mechanical properties, a reliable differentiation of soil groups with various determining parameters characterizing the category of soils according to their seismic properties was carried out. This information is collected in a database of geological information, formed as a shapefile with spatial reference of each well. The developed database is used as a basis in the problem of geoinformation modeling. The geodetic information database of Vladikavkaz was integrated into the system of geoinformation modeling on the basis of open source software.