• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Pullout test of rock bolts at the Lima Hydropower station : -Assessment of the test method

Ljungberg, Jakob January 2016 (has links)
During construction of dams, rock bolts are in general installed in the interface between concrete and rock as an extra safety measure against overturning failure. These bolts are however not allowed to be taken into consideration for the stability calculations of large dams. New standards and new design criterias have increased the requirements of the safety of the old dams, leading to a need for expensive rehabilitation and strengthening. It is possible that consideration of these bolts in stability calculations may lead to money being saved. In order to do so more information about the long term strength of these bolts is needed. One way of getting this information has been the destructive testing of old dugout bolts found during reconstruction works. At the Lima hydropower station in Sweden, this kind of testing was made. The test rig used had a design where a piston pressed down on the rock around the bolt in order to pull it out. The question was raised if this could affect the failure load of the bolt. In this thesis, an attempt was made to answer this question using finite element methods. Models of a rock bolt was made in Abaqus, where one model included the piston and one where it was not. The connection between the bolt and the rock was modelled with nonlinear springs and friction, and the results were then compared between the cases and with experimental data. The results showed that the resulting force-deformation curves may be affected by the piston in cases where the dominant failure mode was adhesive failure, which would influence failure loads and deformations. Since so little was known about the properties of the rock and grout at Lima however, it is difficult to say to which extent the test rig has affected these results.
2

Městský okruh Blanka, tunel Královská obora - ražená část, stavebně technologická příprava stavby / City circle road Blanka, tunnel Královská obora - mined section, preparation and building construction technology

Kobielusz, Petr January 2013 (has links)
My thesis is focused on process preparation and building construction technology of primary lining road tunnel, implemented in city part of Troja in the capital city Prague. Specifically it is a part of tunnel complex Blanka. The name of this part is Kralovská obora. If the all tunnel parts are built this tunnel complex Blanka can be complemented to already opened tunnels Zlíchovský, Mrázovka and Strahovský which are the part of city traffic circle. This technology preparation includes schedules and financial plans of the building, technological prescription for the primary tunnel lining, safety plan, control and trial/test plans, environmental plan, project of construction site, design of the main working machines, items budget of the north tunnel tube, coordination situation plan with wider relationships transport routes and technical report of building technological project.

Page generated in 0.0548 seconds