Barrette Bi-Directional Preliminary Load Test Up to 148750 Kn

TREVI-SWISSBORING executed an unconventional bi-directional preliminary static load test on a 2.8 x 1.2 m barrette element. A very high load of 148750 kN, corresponding to 2.5 times the maximum working load, was reached to verify the ultimate bearing capacity of the element. The test was carried out in Dubai for a project located in Business Bay (Burj Khalifa district), where a tower founded on barrettes will be erected. The barrette tested was 52.5 m long with a cut-off level 8 m below the actual ground level and was executed using a hydromill with polymeric supporting fluid. The soil consisted of calcarenite and sandstone, with UCS varying from 0.1 to 10 MPa. Eight hydraulic jacks, each with a 10000 kN capacity, applied the load at 32.5 m below the cut-off level to achieve the theoretical resistance balance. In addition to the jacks, the steel reinforcement cage was equipped with 12 strain gauge levels to measure the skin friction between the soil and the barrette. The paper presents and discusses the bi-directional load test results, comparing the skin friction values achieved in the load test with those assumed in the design.