Irregularities in RC Buildings: Perspectives in Current Seismic Design Codes, Difficulties in Their Application and Further Research Needs Humberto Varum, Jose Melo, Andre Furtado, and Andre Lima Seismic Response of Masonry Building Aggregates in Historie Centres: Observations, Analyses and Tests Andrea Penna, Annalisa Rosti, and Maria Rota Seismic Enforced Displacement-Based Pushover Anaiysis on Irregular In-PIan R/C Multi-storey Buildings Triantafyllos K. Makarios and Athanasios P. Bakalis Design Approach for an Irregular Hospital Building in Bucharest Dietlinde Kober, Paul Semrau, and Felix Weber Seismic Capacity of EC8 Compliant RC Frames with Irregular Vertical Distribution of Stiffness Francesca Barbagallo, Melina Bosco, Aurelio Ghersi, Edoardo M. Marino, and Pier Paolo Rossi The Effect of the Number and Height of Adjacent Buildings on the Seismic Response of Structures Behroozeh Sharifi and Gholamreza Nouri Evaluation of Torsional Parameters in Seismic Code Provisions for Multi-story Unsymmetric-Plan Buildings Luis Ardila, Juan C. Reyes, and Maria P. Moreno Multiobjective Optimization of Long Irregular RC Bridges’ Pierś Subjected to Strong Motions and Definition of Classification Tree Surrogate Models Yitor Camacho, Nuno Horta, and Mario Lopes The Słenderness of Buildings in Plan as a Structural Regularity Criterion Grigorios E. Manoukas and Asimina Athanatopoulou Evaluation of the Effectiveness of Accidental Eccentricity in Capturing the Effects of Irregular Masonry Infills Konstantinos Kostinakis and Asimina Athanatopoulou Design of Irregular Frames with Fluid Viscous Dampers Using Optimization Ohad Idels and Oren Lavan Stiffening Solution of Faęade Frames for Reducing the Eccentricity in Plan-Irregular Buildings Gabriel Moyano and Jesus-Miguel Bairan Retrofitting of Irregular Structures for Seismic Loads Using Rocking Walls Ameer Marzok and Oren Lavan Seismic Retrofitting of Irregular Mixed Masonry-RC Buildings: Case Study in Lisbon Joao Rodrigues, Jelena Milosevic Ilic, and Rita Bento Seismic Behaviour of Torsionally-Weak Buildings with and Without Base Isolators Juan C. Reyes Use of Fluid Dampers in Order to Improve the Seismic Performance of Reinforced Concrete Buildings with Asymmetric Plan-View Angelos Krystallis, Asimina Athanatopoulou, and Konstantinos Kostinakis Evaluating the Effect of the Various Directions of Seismic Input on an Irregular Building: The Former Uto City Hall Kenji Fuj ii Performance of RC Beam Column Joint with Varying Hoop Reinforcement Ashish B. Ugale and Suraj N. Khante Dynamie Identification and Structural Behavior of an Irregular School Building Riccardo Mario Azzara, Vieri Cardinali, Mario De Stefano, Marco Tanganelli, and Stefania Viti Influence of Plan Irregularity in the Seismic Vulnerability Assessment of Existing Unreinforced Masonry Buildings with RC Slabs Vieri Cardinali, Marco Tanganelli, Mario De Stefano, and Rita Bento Multidirectional Lateral Loads and Combination Rules in Pushover Analysis Cristina Cantagallo, Francesco A. Pellegrini, Enrico Spacone, and Guido Camata Effects of Column Base Flexibility on Seismic Response of Steel Moment-Frame Buildings Tomasz Falborski, Ahmand Hassan, and Amit Kanvinde Seismic Risk Assessment of Existing RC Frame-Buildings with Shear Walls Beatrice Belletti, Enzo Martinelli, Elena Michelini, Michela Tavano, and Francesca Vecchi Seismic Assessment of RC Buildings Considering the Influence of Vertical Irregularities: Framed and Wall-Frame Structures Maria-Victoria Requena-Garcia-Cruz, Rita Couto, Rita Bento, and Antonio Morales-Esteban Analysis of the Influence of Atriums in Seismic Performance of RC Primary School Buildings Beatriz Zapico-Blanco, Maria-Victoria Requena-Garcia-Cruz, Emilio Romero-Sanchez, Jaime de-Miguel-Rodrfguez, and Antonio Morales-Esteban Modified Modal Response Spectrum Analysis of Plan Irregular Highly Torsionally-Stiff Structures Under Seismic Demands Saul López, Daniel Pancardo, Mario De Stefano, Gustavo Ayala, and Yalerio Alecci