LOAD TESTS ON FRICTION PILES IN SAND. FIELD TESTS WITH DIFFERENT TEST PROCEDURES

PROVBELASTNING AV FRIKTIONSPAALAR. EN STUDIE AV OLIKA PROVNINGSMETODER

In Sweden pile load tests are often performed to determine the design length of friction piles in clay and sand. These load tests are normally performed on two test piles before the construction of the piling. For the load tests a number of test procedures have been used such as the CRP-method the ml-method and the cyclic loading and unloading test method. In order to find out if there are any differences between the test results derived from the different test procedures, a series of pile load tests with different test procedures on half-scale piles was performed. At the load tests four different test procedures were used. (1) load test with constant rate of penetration (CRP), (2) maintained load test (ml), (3) cyclic loading and unloading test (cyclic) and (4) load test according to ASTM. The following conclusions can be drawn from the test results. (a) the ml method gives greater settlements for a certain load than the CRP method. (b) the load settlement curves for the cyclic loaded and unloaded piles also show greater settlements for a certain load than the CRP-method.(C) the yield load determined from the cyclic loading and unloading test is on average 30% lower than the ultimate bearing capacity (pb90) determined from the CRP tests. (D) the ASTM gives hardly any information on the ultimate bearing capacity of the pile. (e) a pile which has previously been load tested settles less than a pile which is loaded for the first time and (F) if a friction pile in sand is redriven 0,2 M after a load test the influence of the previous load test is eliminated. (TRRL)

  • Corporate Authors:

    Paalkommissionen

    Ingenjoersvetenskapsakademien, Box 5073
    Stockholm,   Sweden 
  • Authors:
    • Bergdahl, U
    • Hult, G
  • Publication Date: 1979

Language

  • Swedish

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00317277
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Report/Paper Numbers: Rapport 56 Monograph
  • Files: ITRD, TRIS
  • Created Date: Feb 6 2003 12:00AM