Figure 3.18 shows the schematic set up for applying axial tensile loads to the test pile using hydraulic jack having capacity of 600 kN acting between the test beam and reaction frame. The length of the cores embedded in the SDCM was 1 m with another 1 m protruding out of the SDCM to perform the pullout tests. In the preparation for the test, clay cement over the top 1 m of the SDCM was removed leaving a meter of the core embedded in the DCM pile. A steel rod was connected to the test pile and the reaction frame in order to pull the prestressed concrete core pile from the DCM. The test beam was supported the by concrete box that distributed the total load to the surrounding soil. The vertical settlement of the test pile under the applied load was measured using two dial gages, which were connected to two reference beams placed on both sides of the jack. The pullout interface tests were performed in accordance with ASTM D-3689, Quick Load Test Method for Individual Piles under Static Axial Tensile Load. The load was applied in increments of 5 kN. Each load increment was maintained for 5 min. The load was applied until continuous vertical displacements occurred at a slight or no increase in load. The test program is summarized in Table 3.4.