SITE INVESTIGATION FOR SEISMICALLY DESIGNED STRUCTURES

This paper describes some aspects of the work undertaken for two sites, of a thorough review by Nuclear Electric plc of the dynamic properties of several of its nuclear power station sites in the UK. In each case, 'best possible' estimates of the dynamic properties, required for seismic protection, were obtained by combining various laboratory and field measurements. The procedures for the seismic design of nuclear power station structures include modelling the transmission of seismic waves, through various layers of rock below the structure, then into the foundations and into the structure and its equipment. The vertical propagation of shear waves through the rock layers is the most important aspect. Energy is radiated back into the ground, as the seismic waves set the structure and its foundations into motion. To model this effect, it is necessary to know the behaviour of the ground in both compression and shear, for both horizontal and vertical wave propagation. The two sites were: (1) Sizewell, Suffolk, whose ground consists of sands and clays overlying chalk; and (2) Hinkley Point, Somerset, whose ground consists of mudstones with limestone bands. For each site, studies were made of the wave velocities and elastic properties at small strains, dynamic shear modulus decay, and damping ratio. For the covering abstract see IRRD 883023.

Language

  • English

Media Info

  • Features: References;
  • Pagination: p. 715-26

Subject/Index Terms

Filing Info

  • Accession Number: 00729295
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-7277-2513-0
  • Files: ITRD
  • Created Date: Dec 12 1996 12:00AM