Earthquake Performance Analysis of Steel Structures with A3 Plan Irregularities

In earthquake engineering, a performance-based design method is used to determine the level of the expected performance of the structures under the earthquake effect. The level of performance is related to the damage situation that could be occurred in the structure after the earthquake. In the performance-based structural design, it is predicted that more than one damage levels emerge under one certain earthquake effect. In this study, the seismic behavior of steel structures with plan irregularities in the Turkey Building Earthquake Code in the 2018 (TBEC-2018) is investigated by the nonlinear static analysis methods. The selected steel structures are located in İzmir, Turkey. The Turkey Earthquake Code in 2018 is considered for assessing seismic performance evaluation of the selected moment-resisting frame steel building. Four different A3 type irregularity was investigated. The steel building with no irregularity in its plan. was selected as the structure of the reference. The performance goals of the five different steel structures are evaluated by applying the pushover and procedures of the TBEC-2018. The steel structures were compared by obtaining pushover curves for both the X and Y directions. The results show that the effects of A3 type irregularity should be not considered in design and buildings without irregularities are safer.

Determination of Seismic Role of Non-Structural Components On Earthquake Behaviour of RC Buildings Using Various Seismic Design Codes And Fault Distances

Performance-based building engineering requires the synchronization of performances between non-structural and structural components. However, non-structural components are not generally taken into account in structural modelling. In this study, it is aimed to examine the seismic damage effects of non-structural components (NCs) on earthquake performance of RC buildings. For this purpose, 5 multi-story RC building collapsed in a strong earthquake is modelled as three dimensional (3D) using SAP2000 software. Brick, bookcase, bedroom, armchair, washing machine, dish washer, refrigerator is selected as NC in 3D analyses. NCs are modelled as anchored and unanchored to RC building and these NCs are modelled in the RC building taking into account UBC 2018, IBC 2018, ASCE/SI 7-30 code, New Zealand code, and Eurocode 8 code. Considering these standards for anchored / non-anchored / non-NC situations, earthquake analyses are performed separately for far fault and near fault. According to 3D nonlinear seismic analyses, it is clearly seen that NCs strongly affect earthquake behaviour of RC buildings. Besides, it is strongly recommended that non-structural elements should not be ignored while modelling a RC building. Then, it is understood that anchoring or not anchoring non-structural elements to RC structures seriously changes nonlinear seismic behaviour of these structures.

On the Assessment of Masonry Structures

The conservation of existing masonry buildings has reached a greater attention especially in the Southern Europe, where such structures are widespread, and need a periodic check also because they are the testimony of the history and the architectural progress of these areas. However, the assessment of the earthquake performance level of these structures is rather difficult for many reasons: the lack of information, the high variability of adopted materials and construction techniques, the existence of several interventions occurred during their service life, etc. These circumstances make difficult to define an accurate numerical model of these structures, by which assess their safety level and design possible strengthening and retrofitting. The present research deals with these issues by discussing the non-destructive tests performed on a masonry building in Bari, which in the 1977 was converted in a church and dedicated to San Marco. The San Marco church is an isolated building, whose plan dimensions are 16 m × 23 m, and with a maximum height equal to 10.50m. The church stands in a seismic prone zone and is characterized at the ground level by barrel vaults in some parts and by wooden roofs in the remaining parts, and by a gable roof realized by wood. The experimental investigations are utilized to validate a numerical model of the structure.

Mount Athos: Restoration of an almost Extinct Type of 18th–19th C. UNESCO Masonry OX Stable

The present paper serves the purpose of presenting an extinct type of 18th–19th century masonry building, that of an ox-stable, situated in one of Europe’s most secluded areas: The Holy Monastery of Pantokrator in Mount Athos Peninsula. Architectural drawings and surveying plots of its current state can serve as a record and reference of this UNESCO site for scholars. Adding to that, an elaborated proposal for the reuse of the building is presented together with technical drawings, which were approved by Greece’s Central Archeological Council. The masonry rectangular building is founded on natural rock with masonry pillar footings of different heights. Hence, the elevation irregularity and the different elevations of the footings of the structure present an additional challenge for the structural analysis. Structural analysis with a finite element (FE) model of the restored structure was executed with SAP2000 software. Performing lateral force and response spectrum analyses, stresses and deformations at critical points of the structure were calculated. Comparing a set of simplifying structural checks with the elastic FE analysis performed, it was concluded that the proposed design is effective in improving the earthquake performance of the structure.

Reliability of Seismic Performance Assessments for Individual Buildings and Portfolios

Seismic performance and loss assessments are required in areas of Insurance, Finance and Public Policy. Providers are Structural Engineers and Risk Management Firms. There are no current procedures to evaluate the epistemic and aleatory uncertainties for such assessments. The essential issue is whether or not there is sufficient reliability in the result to use the result as the basis for risk management decisions and actions. For a single building this may be whether or not a prescribed earthquake performance level is met, life safety or if a portfolio’s vulnerability level is acceptable, whether the. loss for a given time period is less than a stated value. A method based in part on Federal Emergency Management Agency P-695, is developed for evaluating the reliability of performance and/or loss assessments for both individual and portfolios of buildings. Consideration is given to how well the building investigation and corresponding evaluation process have been performed, the qualifications of the person(s) doing the assessment, the thoroughness of the building evaluation, the technical validity of the assessment procedure or model and what computational reliabilities are presented. The method characterizes the uncertainty of each component of the assessment procedure for each building by qualitative determined assignments. The resulting reliability measure is likely to be most useful for determining whether/or not a building has acceptable life safety performance, or if a portfolio has an acceptably low loss risk over a given period of time. In both cases, the reliability must either be sufficient to warrant action, or serve to indicate need for improved assessment.

Seismic performance of a retrofitted heritage unreinforced masonry building during the 2010/2011 Canterbury earthquakes

The Heritage Hotel (formerly Old Government Buildings) is one of the architectural heritage icons of Christchurch, New Zealand. Seismic retrofitting was undertaken on the structure in 1995 to achieve the earthquake loading provisions of the 1992 standard for design loadings (NZS 4203:1992). This building is a distinguished 1909 unreinforced masonry Italian High Renaissance palazzo building. The retrofit work included the installation of new lateral load-resisting structural systems, refurbishment of individual building elements, and partial building demolition with a total cost of approximately NZ$3.75 million. Detailed observations following the 2010/2011 Canterbury earthquakes showed that the building was subject to only minor damage during the September 2010 earthquake, whereas the February 2011 event caused some damage to exterior stonework and flooding in the basement due to liquefaction. This damage was easily repaired, and the building was fully functional by September 2013. Reported herein are details showcasing the success of the seismic retrofit and post-earthquake performance observations.

Ductile iron pipeline response to earthquake-induced ground rupture

This article provides a comprehensive evaluation of ductile iron (DI) pipeline response to earthquake-induced ground deformation through the results of a large-scale testing program and a fault rupture test on a 150-mm DI pipeline with restrained axial slip joints. The test is used to validate a two-dimensional finite element (FE) model that accounts for soil–pipeline interaction with axial slip, pullout resistance, and rotation of pipe joints. The maximum strike-slip fault offset sustained by push-on, restrained, and restrained axial slip joints is presented as a function of the pipeline/fault crossing angle. DI pipeline performance is controlled by one of the following limit states; tensile, compressive, rotational joint capacity, or local buckling in the pipe barrel. A systematic FE assessment shows that pipelines with restrained axial slip joints accommodate 2–9 and 2–10 times as much fault offset as pipelines with push-on and restrained joints, respectively, for most intersection angles. The results of this work can be used for simplified design and to quantify the relative earthquake performance of different DI pipelines.