Effect of the surcharge added at time t_add on the OCR, using equation (6) with initial surcharge Δσ_sur corresponding to height ΔH₀ for the first part of the curve until t = 36 (weeks) and equation (7) with Δσ_add corresponding to additional surcharge height ΔH₁. The resulting curve is located below the one for the case where the total surcharge (initial and additional) is applied directly at t = 0, with equation (6)