Test types and methods
■ Performance Test
- Pull-out test : pull-out tests are conducted to investigate and prove the ground conditions proposed in the design conditions, used materials, the quality of the anchor based on the safety rate, and the preciseness of the design before actual anchor construction.
- Jacking test : Jacking tests are conducted to anchors installed under conditions identical to that of actually applied anchors, and are jacked to the actual load level. The test is conducted until the fact that stabilization in the allowed scope has been achieved is proved, regarding the anchor jacking or creep destruction.
■ Proo Test
Proof tests are conducted to prove and evaluate the fact that the performances of all the anchors are fit for the site condition.
■ Creep Test
Creep tests are conducted to judge whether the load has been decreased due to the anchor’s creep (relaxation of the strand, creep of the grout, ground, bonded anchor length), and its purpose is in determining the creep’s tendency than quantitatively judging it. Extended creep test takes a long time (about 8 hours). This test is for measuring the creep transformation of the anchor, and is required for anchors built into clay grounds that have plasticity indexes of 20 or more, and liquid limits of 50 or more.
■ Lift-Off Test
Lift-off test is conducted to confirm the tension of the ground anchor that has already been fixed. Refer to the test result as data for the malignance of the tension.