Browsing by Subject "strain state"

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Access status: Open Access ,
Desk study into stress condition of bottom layer of thick coal bed
(Wydawnictwa AGH, 2010) Sidorenko, S. A.; Sidorenko, Andrej Aleksandrovič; Trushko, O.V.
The examined problem is to assess the stress and strain state of the bottom layers in thick regular coal seams. Design diagrams are offered that allow assessment of the impact of primary mining of the 1st layer on the state of the 2nd layer under various geotechnical conditions. A concerns both zones of the active support pressure, the previously mined areas, completely mined sites and zones bordering on the undisturbed coal massif. Regularities are established in changes in the stress state of the bottom layer at the edges of the coal massif and the pillars between the longwall faces. Conclusions are made on the rational location of mining workings at the lower horizons. A significant influence of the neighboring worked out sections is shown on the state of mining workings at the lower horizons.
Access status: Open Access ,
Wpływ temperatury na stan naprężenia i odkształcenia w otoczeniu komory siłowni elektrowni »Porąbka-Żar«
(Wydawnictwa AGH, 2005) Domańska, Danuta; Gruszka, Roman
In the paper preliminary estimation of the stress and strain state around the underground excavation under an influence of temperature is presented. Discussing problem is very important especially for the large chamber (e.g. chamber of the »Porąbka-Żar« power station is described) for which even small fluctuation of temperature can induce big changes of stresses, significant from a static point of view. The analysis presented in the paper is based on measurements that has been executed by Budokop in the excavation. The stress and delamination functions are got from measurements and temperature is taken in the chamber, are interconnected by correlation function. In accordance with expectations coming from the thermoelasticity theory (the paper includes results of approximate calculations), existence of the significant relationship between temperature field and parameters form measurements (i.e. stress and strain in the vicinity of the chamber) is found.