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EN: The waterworks Brest, situated on the Ljubljana Marshland, is an important element of the Ljubljana city, providing 10 % of its water supply. Water pumping is the main reason for the subsidence on the Ljubljana Marshland. Other reasons for the subsidence of the Ljubljana Marshland area include sinking of the crockery bedrock of Quaternary sediments, natural sinking of clay - grist Quaternary sediments, particularly the lacustrine clay called “polžarica”, aswell as loading of the Ljubljana Marshland surface with additional weight due to building constructions. Systematic observations by first order levelling network as well as the observations of the depth and floating benchmarks, set up directly at the pumping line, are indispensable for the assessment of subsidence due to water pumping. The article discusses the results of the geodetic observation for the ascertainment of the Ljubljana Marshland stability.SI: Vodarna Brest, ki leži na Ljubljanskem barju, je pomemben objekt za mesto Ljubljana, saj za njegove potrebe načrpa 10 % pitne vode. Po podatkih geodetskih opazovanj se Ljubljansko barje poseda. Med vzroke za posedanje površine Ljubljanskega barja lahko štejemo tonjenje kameninske podlage kvartarnih sedimentov, naravno posedanje glinasto-meljastih kvartarnih sedimentov, predvsem polžarice, in nenazadnje obremenitev površine Ljubljanskega barja z dodatno obtežbo zaradi gradenj. Da bi ugotovili intenzivnost posedanja, ki nastaja zaradi črpanja vode, potekajo na Ljubljanskem barju sistematičnaopazovanja nivelmanske mreže I. reda ter opazovanja globinskih in plavajočih reperjev, ki so stabilizirani neposredno ob trasi vodarne Brest. V članku analiziramo rezultate geodetskih opazovanj zaugotavljanje stabilnosti Ljubljanskega barja. |
