Sökning: "frostsprängning"

Hittade 3 avhandlingar innehållade ordet frostsprängning.

  1. 1. Freezing Temperature Flows in Railway Tunnels and its Consequence on the Rock Supporting Structure, the Rock and the Reinforcing Elements

    Författare :Anna Andrén; Lars-Olof Dahlström; Erling Nordlund; Lars O Ericsson; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tunnel; frost penetration; ice formation; freeze-thaw test; frost shattering; temperature measurement; maintenance; degradation of rock and shotcrete; cold climate; Tunnel; köldinträngning; isbildning; frystester; frostsprängning; temperaturmätning; underhåll; nedbrytning av berg och sprutbetong; kallt klimat; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

    Sammanfattning : Water in the surrounding rock mass flows into the tunnel via naturally occurring joints and via cracks caused by the blasting used to excavate the tunnel. The most common method in Sweden to reduce or prevent leakage problems are first and foremost the use of grouting. LÄS MER

  3. 2. Degradation of rock and shotcrete due to ice pressure and frost shattering

    Författare :Anna Andrén; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gruv- och berganläggningsteknik; Mining and Rock Engineering;

    Sammanfattning : In recent years the Swedish Rail Administration has observed an increased incidence of shotcrete and rock fall-outs in its tunnels, for which reason it has initiated several research projects, of which the present project entitled "Degradation of rock and shotcrete due to ice pressure and frost shattering" is one. The aim of this licentiate project was to bring together experience and information relating to ice formation and the effect of ice pressure on fault zones, cracks and, in particular, the shotcrete/rock interface. LÄS MER

  4. 3. Geographic Variation, Hybridization and Evolution in the Bladder Campions, Silene vulgaris and S. uniflora (Caryophyllaceae)

    Författare :Eva Månsby; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; Växtgenetik; Systematic botany; taxonomy; morphology; phytogeography; Plant genetics; Paternal effects; Seed polymorphism; Ecology; Ekologi; Crossing barriers; cpDNA markers; Genetic variation; Hybridization; Post-glacial migration; Allozymes; Silene vulgaris; Silene uniflora; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .;

    Sammanfattning : In the present thesis, I investigated the inter- and intraspecific variation in the Silene vulgaris/uniflora species-complex (the bladder campions). I have focused on the effects of past and present hybridization both on a large scale ? over the whole of Europe ? and on a local scale. Silene vulgaris and S. LÄS MER