The joints between segmental rings can withstand a certain amount of bending moment as well as axial and shear forces. Generally, in the structural analysis of tunnel segmental lining, the joints can be modeled as elastic hinges or rotational springs, and their rigidity should be demonstrated in terms of the rigidity of the joints or their rotational stiffness. Therefore, the bending moment act...

thin-walled hollow steel columns, either circular or box shaped, are commonly used as piers in bridges. recent earthquakes, e.g. hyogoken-nanbu or kobe 1995, on the other hand have shown that these columns are vulnerable to damage when subjected to earthquake loading. this paper presents a new innovative thin-walled hollow steel column fabricated of corrugated plates, “thin-walled steel columns...

tehran shomal highway passes through alborz mountains with a tunnel length of 6400 meters. there are two main tunnels. a full three-dimensional (3d) numerical analysis coupled with elasto-plastic material models was conducted on the inclined access tunnel. bending moment, axial force and the lining displacements due to the internal forces applied on the shotcrete lining are calculated. axial fo...

this paper focuses on using the recently developed extended finite element model for buckling analysis of edge cracked columns under concentric axial load. the effect of crack depth and its location on the carrying capacity of columns is studied. the effect of different boundary conditions is also investigated. numerical examples are offered to show the efficiency and effectiveness of the propo...

the use of polymer composite (frp) as a reinforcement material for the repair and strengthening of important components of reinforced concrete structures, particularly columns, has found wide spread. in this study, the effect of intermediate layer on improving the confinement behavior of reinforced concrete columns has been investigated. to achieve the objectives of the study, 14 cylindrical re...

In this paper, the modified Euler-Bernoulli beam model is presented to examine the influence of surface elasticity and residual surface tension on the critical force of axial buckling of nanotubes in the presence of rotary inertia. An explicit solution is derived for the buckling loads of microscaled Euler beams considering surface effects. The size-dependent buckling behavior of the nanotube d...

in this paper a simple model of a three story building with inclined first-story columns has presented. the stories are supposed to be rigid and are connected to axially rigid mass less columns by elasto-plastic rotational springs and linear rotational dampers. the considered model is subjected to horizontal component of fault normal pulse with different magnitudes and the governed nonlinear di...

in this paper a discrete big bang-big crunch algorithm is applied to optimal design of reinforced concrete planar frames under the gravity and lateral loads. optimization is based on aci 318-08 code. columns are assumed to resist axial loads and bending moments, while beams resist only bending moments. second-order effects are also considered for the compression members, and columns are checked...