TEST PILE and Load Test Procedure Details

Test pile and load test details The pile ET4 is a bored pile with length equal to 24 m and diameter equal to 1 m. It was drilled on December 15, 2014 using by a toothed bucket under polymer suspension. For the stabilization of the upper pper portion of the borehole, temporary steel casing (33 m in length, 1.1 m in diameter)) was used. When the final depth was reached, the bottom of the borehole was cleaned using the same bucket used for drilling. dril After the de-sanding sanding of the bentonite b slurry, the instrumented cage was placed in the borehole. The tremie method of concreting was then used to pour the concrete in the borehole; the concrete had a slump of 24-25 25 cm (CIP IV, fck = 20 MPa). The pile is fully instrumented along the shaft: 8 sections are instrumented by means of Geokon vibrating wire strain gauges (Rebar Strainmeters Model 4911). The first instrumented section lies at a depth z = 0.5 m below the ground level and the last at z = 23.5 2 m. Moreover, 4 still tubes were fixed to the cage to perform integrity testing (Cross-Hole, (Cross Hole, CH, and Thermal Integrity Profile, TIP) and to use one retrievable Geokon exensometer with 3 anchors (Model ( A9) for additional strain measurements measurement during loading. In January, 2015, the integrity of the pile was checked by means of different non-destructive non techniques: PIT (Pile Integrity Testing), Testing) CH and TIP. All the results are available on o the web site (see Download data). In the next months, pile ET4 will be subjected to a static conventional axial load test. The load will be applied by means of two hydraulic jacks reacting against a steel beam, beam which is itself anchored to 4 reaction piles (continuous (c flight auger (CFA) piles 20 m in length and 0.8 m in diameter,, reinforced by 3 Dywidag bars with diameter of 36 mm). The pile head displacements will be measured by 4 Linear Vertical Displacement Transducers (LVDTs), supported by reference beams. The test procedure will follow International Standards (a compromise compromise between Eurocode 7 Part 1;; ASTM D1143 and ABNT NBR 12131). After a pre-loading pre loading stage of maximum 5%Qmax to control and adjust loading and measurement equipment, the pile will be unloaded to a small residual load. The static loading force will then be increased in steps, which will be held constant over a fixed time. time The maximum load will be removed by means of 5 unloading steps. Additional details on the pile instrumentation and on the pile position are reported in attached drawings.