Taking as basis the way the inner temperature of a tunnel is affected by solar heat on the soil surface and the geothermal depth involved in the tunnel design and construction, the author calculates the thermal stresses that can occur within the tunnel. He applies a cylinder to to arrive at the differential equation of the isotherm and arrives at the solution t = k1 log r + k2, where t is the temperature, r is the radius and k1 and k2 are integration constants to be determined theoretically after assuming certain boundary conditions. This expression is valid for the stationary state, which is easily attained after enough time has elapsed. The constants in the system are determined by assuming that a radius of influence exists in the gallery, ri, beyond which any effect is negligible, and that the temperature inside the tunnel is then constant. Where the thermal stresses are concerned, the equations are set for the radial and tangential stresses at a given distance, and then, assuming that radial stresses at the inner and outer surfaces are nil, together with the expression of the temperature in terms of the radius previously obtained, allows the radial and tangential stresses to be calculated.

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  • Corporate Authors:

    Escuela de Ingenieros de Caminos Canales y Puertos

    Ciudad Universitaria
    Madrid 3,   Spain 
  • Authors:
    • Hacar, F
  • Publication Date: 1979-3


  • Spanish

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 217-223
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00308930
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: No. 3.167
  • Files: ITRD, TRIS
  • Created Date: Aug 27 1980 12:00AM