THE INFLUENCE OF GRAIN SIZE ON THE SETTLEMENT OF RAILWAY BALLAST

INFLUENZA DELLA COMPOSIZIONE GRANULOMETRICA NEI FENOMENI DI ADDENSAMENTO DELLA MASSICCIATA FERROVIARIA

The settlement of railway ballast on high speed lines indicates a need for an improvement of the methods normally employed by railway engineers. This study aims at developing a new type of railway superstructure, based on an analysis of the shape, hardness, consolidation and grain size of the ballast. The tests described (volume/weight ratio, absolute specific gravity, and compression breaking point) were carried out on first class limestone aggregates from Bari-Palese, according to CNR specifications. Five different compositions of ballast were prepared on which the following tests were carried out: coefficient of particle shape by the exclusion of flat particles over 2% by weight; void index; vertical settlement by compression under repeated loading with lateral deformation constrained; modulus of elasticity of compacted materials; speed of water run-off on samples compacted by loading tests; and volume/weight ratio before and after repeated compression. Results are given in tables and graphs.

  • Availability:
  • Corporate Authors:

    Permanent International Assoc of Road Congresses

    Via Andreani 4
    Milan,   Italy 
  • Authors:
    • Abbrescia, G
    • Civitella, F
  • Publication Date: 1979-11-12

Language

  • Italian

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 447-456
  • Serial:
    • Strade
    • Volume: 81
    • Issue Number: 1187
    • Publisher: Casa Editrice la fiaccola
    • ISSN: 0373-2916

Subject/Index Terms

Filing Info

  • Accession Number: 00316590
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Sep 16 1980 12:00AM