Badania ciśnień dopuszczalnych cementacji w skałach litych
Abstract
RESEARCHES OF ADMISSIBLE PRESSURES IN CEMENTATION MADE IN COHERENT ROCKS
Summary
The paper deals with the examinations of admissible pressure of cementation made within the area of the Polish Carpathians in the complexes of sandstones and conglomerates, as well as in the limestones intercalated with shales, where dips of beds are about 25 and 80º. In both cases the complexes analysed show not too great degree of tectonically disturbances and only low unit absorbing capacity amounting to 0-1 1/min/m/m. The research works were made in groups of four bore holes at a depth from 6 to 28 m, under the top of the rock basement (Figs. 2-4). Into one of the experimental bore holes water or cement grout was pressed within zones from 2 to 5 metres. In the remaining bore holes deformation of rock massif due to pressures was observed using various method of precise leveling and measuring probes. As criteria of excess pressure for a given depth zone were taken irreversible deformations of rock massif and an intense increase in unit absorbing capacity. The results of the researches within the experimental bore holes have been proved during tentative cementation. The researches have demonstrated that both criteria introduced are of fundamental importance for the proper interpretation of the results obtained. In addition, these researches prove also that Q. Zaruba's empirical formulae are here useful as well, mainly in preliminary calculations of the values of admissible pressures for the geological conditions resembling those found to occur within the basement rocks of the experimental areas.
Summary
The paper deals with the examinations of admissible pressure of cementation made within the area of the Polish Carpathians in the complexes of sandstones and conglomerates, as well as in the limestones intercalated with shales, where dips of beds are about 25 and 80º. In both cases the complexes analysed show not too great degree of tectonically disturbances and only low unit absorbing capacity amounting to 0-1 1/min/m/m. The research works were made in groups of four bore holes at a depth from 6 to 28 m, under the top of the rock basement (Figs. 2-4). Into one of the experimental bore holes water or cement grout was pressed within zones from 2 to 5 metres. In the remaining bore holes deformation of rock massif due to pressures was observed using various method of precise leveling and measuring probes. As criteria of excess pressure for a given depth zone were taken irreversible deformations of rock massif and an intense increase in unit absorbing capacity. The results of the researches within the experimental bore holes have been proved during tentative cementation. The researches have demonstrated that both criteria introduced are of fundamental importance for the proper interpretation of the results obtained. In addition, these researches prove also that Q. Zaruba's empirical formulae are here useful as well, mainly in preliminary calculations of the values of admissible pressures for the geological conditions resembling those found to occur within the basement rocks of the experimental areas.