The Influence of Overhead Cranes in the Seismic Performance of Industrial Buildings

Abstract

This paper investigates the influence of overhead cranes with a hanging mass under earthquake type loading, considering the Emilia 2012 seismic sequence. The structural layout of precast concrete industrial buildings typical of the Italian territory is considered. The equations of motion describing the behavior of the hoist load are derived, and a sensitivity analysis is carried out on simplified 3 degrees of freedom systems by solving the governing differential equations. The influence of various parameters on the roof displacement and on the horizontal load transferred by the hanging mass is addressed. The considered parameters are the relative damping of the hanging mass, the length of the hoist ropes, the earthquake record, the hysteretic type of the plastic hinges at the column base, and the behavior factor of the structural system. The results show that for a horizontal component of the considered seismic sequence the structural displacements are amplified in the case of a behavior factor greater than 2.5. A simplified modeling strategy considering small displacements is also investigated. Such model is suitable for response-spectrum analyses. Finally, a three-dimensional case study is analyzed by means of non-linear time history analyses. The results show the influence of the overhead crane on the local performance of some structural and non-structural elements, such as columns and cladding panels, especially when the assumption of rigid roof diaphragm does not apply.

Influence of Modelling Assumptions on the Seismic Risk of Industrial Precast Concrete Structures

“…In the case of explicit modelling of the overhead crane, the crane payload (M E ) was set equal to 8 kN/g. The influence of the overhead crane modelling was assessed in two ways: in the first case, the crane was modelled only in terms of mass (M D in the case of model with distributed masses or as part of M C in the case of model with lumped mass in the diaphragm centroid); in the second case, the overhead crane was modelled with an elastic element with adequate stiffness connected to the runway beams, while the mass M E of the payload was connected to the middle of the overhead crane through an elastic spring with stiffness equal to M E ·g/R (Belleri et al, 2017b). R is the assumed length of the cable, equal to half the column height (i.e.…”

Effects of Modelling Assumption on the Evaluation of the Local Seismic Response for Rc Precast Industrial Buildings

“…The plastic hinge at the base of the columns is modelled with a zero-length element considering the Modified Ibarra-Medina-Krawinkler Deterioration Model with peak-oriented hysteretic response [37]: effective yielding moment My equal to 1256 kNm, effective stiffness Ke equal to 4.37•10 4 kN/m and cyclic deterioration parameter equal to 2.734. The second model (model B) differs from model A only for the overhead crane mass mC with no account of the pay load [38], therefore m'C is equal to 1.329 kN/g. The third model (model C) is similar to model A, but the main beam-tocolumn connections are at their real position, i.e.…”

Seismic Retrofitting Solutions for Precast RC Industrial Buildings Struck by the 2012 Earthquakes in Northern Italy

“…All studies agrees that deficiencies of connections represent the main cause of collapses, followed by inadequacy of column reinforcement and foundations. Recent studies show that also the vertical component of the ground motion (Bovo and Savoia, 2019), particularly in the free field, and masses of overhead cranes and hoist loads (Belleri et al, 2017), which may be often present in industrial buildings, could have played a role in the landscape of damages.…”