AbstractA new analysis approach is devised herein to predict the response of reinforced concrete deep beams strengthened in flexure, shear or shear-flexure with fiber-reinforced polymer (FRP). The analysis approach recognizes the fact that FRP-strengthened deep beams represent a statically indeterminate idealized truss. Therefore, two parallel determinate trusses are modeled for the levels of yielding and ultimate loads. By imposing the compatibility of deflections between the two trusses at the yielding and ultimate levels, the contribution of the second truss is evaluated using the load obtained from the first truss. The nonlinear strain profile is adjusted to account for the Timoshenko first-order shear deformation contribution. The analysis procedure is examined against four different deep beams strengthened in flexure, shear, and combined shear-flexure and tested experimentally. The predicted full response agrees very well with all experimental curves. In addition, the analytical and experimental responses of five extra-deep beams are compared for added verification. Accordingly, this approach may be viewed as a unified procedure to analyze the whole spectrum of strengthened deep beams.