Investigations At Sites Draining

Hydrogeological work and geotechnical testing when shooting are conducted to the extent necessary to justify the reclamation activities and the building structure reclamation system. The total area shooting must be grounded in technical regulations or program of research. Allowed to increase the area of photography compared to the reclaimed area of the object is not more than 1,8 times. It is mandatory to hold Preliminary desk work to assess the materials research of past years, area of study with the objective of the program or technical requirements. Geotechnical and hydrogeological research and studies on the drainage facilities are conducted to determine the causes of waterlogging and temporary excessive moisture, type of water supply in order to select the design decisions on how to drainage area and regulation of water regime. To justify the design solutions for land-reclamation should be examined following the main features of the object: – geomorphology (the structure of floodplains, terraces, valleys, basins, troughs drain; shape and area ratio of low and elevated stations, communications excess moisture from the morphological characteristics of the microrelief, the impact of micro-and macrorelief on waterlogging areas); – geotechnical (lithology and physical and mechanical properties of soils, especially nutrients (peat, sapropel)); – the nature and distribution of geological and engineering-geological processes – hydrological (availability, distribution and depth of aquifers, the hydraulic connection between them and among themselves and with surface water, balance and groundwater regime, their chemical composition, the amplitude of the fluctuations in groundwater level).

Field work must begin with a reconnaissance survey, during which identifies wetlands and redundant, wetlands, examined outcrops, landslide areas, distribution of karst, subsidence and other phenomena, the outputs of groundwater, ravines, etc. Block observations are carried out in two perpendicular directions, taking into account Stretch the major forms of relief, as well as along the river beds, lake and other natural drainage elements. In the process of engineering-geological survey should establish morphogenetic type of relief to which timed swampy land (slope, valleys, plains, etc.), identify the hazardous geological processes. If there are bailing on the territory of the ground-pressure power allowed additional exploration work, the composition and volume of which is justified in each case the program works (technical requirements). Cross-sections perpendicular to the wells should be scheduled during the main geomorphological elements – from the elevated grades (slopes, terraces, etc.) to the receiving water (river, marsh, lake) – a position of extreme well drained outside of the array on the slopes or local watersheds.

The distance between cross-sections should be taken from 500 to 700 m. Well on the alignment should be located at a distance of 300 to 500 meters depending on the geomorphological and geological and hydrogeological conditions. Other distances should be justified in the program or report on research. In the presence of at drainage systems, heavy soils underlain by impermeable, the wells should be drilled on the wing at a depth of 5 m. The number of additional wells in the complex engineering and hydrogeological survey shall not exceed 1.8 observation points (workings) of 1 km2 array drainage for pre-design study, and 2.7 points per 1 km2 array drainage for architectural and construction projects. Well depth is taken as a function of depth aquitard and its power. In case of a pressurized part of the supply wells (40% of the total) should be opened on the roof of the second surface of the aquifer. Depth of the wells should not exceed 35 m.


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