Question

What are key reasons for conducting pull-out tests for soil nails?

Answer

There are largely four bases for this examination-
(i) To verify and verify bond strength between soil and grout adopted during design of soil nails. This is major objective of conducting soil nail pull-out test.
(ii) To determine bond strength between soil and grout for future design purpose. Though, if this object is to be achieved, test nails must be loaded to determine ultimate soil or grout bond with an upper limit of 80 percent of ultimate tensile force of steel bars.
(iii) To confirm if there is any slippage, creep occurrence.
(iv) To check elastic and plastic deformations of test nails. This is observed during repeated loading and unloading cycles of soil nails.