Testing

Every tieback should be individually tested. In this chapter a specific testing program is recommended which is also recommended by the Post Tensioning Institute (PTI). A standardized testing procedure simplifies communication and interpretation of the results. This procedure combines proof and performance tests on every job and includes tests for creep. As the PTI recommends, creep tests are performed when the anchor is in softer clays. In these materials the anchor often creeps and the goal of the tests is to reduce the tieback’s load to a value where excessive creep will not occur. Then the proof tests are held for a short period to ensure creep is not excessive. The tests are described in detail and some discussion of test results is included. A good testing program is essential since it is used to verify the design and modify it if necessary.