Tieback walls are "live" and "dynamic" constructions in which residual loads on ties undergo changes with time, needing, because of that, periodical checking and maintenance. Compared to other constructions, tieback walls are the ones with very high probabilities of accident occurrences, because of difficulties of execution related to the construction sites, aggressive environments and material degradation with time. Thus, they need periodical maintenance and revision, specially in relation to the tie loading. The Brazilian Code of Practice NBR 5629 (Tieback Walls Anchored in Soil - Injected Ties in Soil - Procedure) prescribes, in relation to the ties, the necessity of instrumentation and verification of live loads. The German Code of Practice DIN 4125 adds the necessity of recognised expertise, including the need to all the technicians and contractors involved in the process to have qualification certificates.
Since 1988 the Fundação GEO-RIO has being carrying on in-situ tests to verify tie loads on tieback walls. In this paper a proposal for a methodology to verify residual load on ties of tieback walls is made, using the Instituto de Geotécnica do Rio de Janeiro - Fundação GEO-RIO's Represtressing Method. Furthermore, some experimental results of tests carried out to verify the residual loads in ties of tieback walls, in which this method has been applied, will be shown.
