Behavior of partially grout-filled damaged tubular members

A simple analytical expression, amenable to hand calculation, is developed for estimating the ultimate capacity of partially grout-filled damaged tubular members. The analysis is based on the simplifying assumptions that: (1) The bond between the grout and the tube wall could totally fail prior to the attainment of the ultimate capacity; and (2) grout provides sufficient support in the damaged region of the tube and makes the steel cross section fully effective. The load-carrying capacity is then obtained using a beam-column analysis similar in form to that used in the current design codes. The analysis uses the weighted average rigidity of the cross sections (taking into account the effect of the grouted segment) while using the dented section as the critical section. The first yield collapse criterion has been used. Experimental work has been conducted on 10 small-scale specimens. It is shown that the proposed expression provides acceptable lower-bound estimates of the experimental results. A parametric study is performed to establish the relationship between various parameters and their effects on the ultimate strength of partially grout-filled damaged tubes.
A model is developed for determining the ultimate strength of partially grout-filled damaged tubular members. The model is based on current design codes for beam-column analysis using the first yield collapse criterion. Analytical and experimental results were compared and the model was found to provide accurate lower-bound estimates of the experimental values. A parametric study was also performed to study the relationships between different parameters and their effects on ultimate strength.