INVESTIGATION OF A FAILED PAVEMENT

An experimental road section was designed and constructed near Griffith, N.S.W. during 1973. The pavement was extensively instrumented and its performance monitored at regular intervals after sealing. The initial design was based on pseudo-elastic finite element analyses. Samples were taken of the subgrade below the previous pavement and subjected to compaction and moisture studies. At the designed construction conditions, repeated loading triaxial testing was carried out, assuming various pavement thicknesses. The final construction depth of the conventional gravel base section considered in this paper was actually chosen by the standard procedures of the local road construction authorities but nonlinear elastic analyses were used to determine the predicted pavement responses under standard wheel loads. While the road section was being constructed, abnormally high rainfall was experienced and the test sections subsequently failed extensively. The observed performance was much poorer than predicted. Following the failure of the trial pavement, further samples were taken and tested. The only significant factor was that the moisture contents were much greater or the soil suctions much less than the design values. Consequently the resilient moduli of the subgrade were much lower than predicted. Using the new input parameters for the asconstructed pavement, the response predicted by the finite element analyses was compared with the observed response in the field. Good agreement was found for the deflections and the bowls of depression under a truck with dual wheels loaded to the standard axle loading. As the area of the test section was associated with high water tables and wet subgrades, these results do suggest that the more analytical design procedures using soil suction techniques used previously in drier areas are also applicable to wetter conditions. /Author/

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 3-12
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00170203
  • Record Type: Publication
  • Files: TRIS, ATRI
  • Created Date: Mar 7 1978 12:00AM