M. Dolce

Remarks on damage and response of school buildings after the Central Italy earthquake sequence

The seismic assessment of the vulnerability of existing public structures, especially school buildings, is a crucial issue in seismic prone countries. Recently, several national and regional programs and activities have focussed on the mitigation of Italian public buildings. They promote the scheduling of public buildings’ structural safety assessment and, when needed, the design and execution of strengthening interventions. Nevertheless, the three strong earthquakes that occurred in the last decade in Italy, Abruzzo (2009), Emilia (2012), and Central Italy (2016), confirmed the vulnerability of school buildings and the social importance of their quick re-opening after a damaging earthquake. In the present paper, the activities carried out on 1514 school building structures in the aftermath of the 2016 Central Italy earthquake sequence are reported and analysed. According to survey data collected by post-earthquake usability inspections, the paper analyses the school buildings characteristics, damage level and extent to structural and non-structural components as well as the correlation between seismic intensity and observed damage.

Estimation of repair costs for RC and masonry residential buildings based on damage data collected by post-earthquake visual inspection

In the immediate post-earthquake, the safety conditions of buildings are commonly evaluated by field visual inspections. Then, a second phase involves the design of repair interventions and the relevant funding requests to the government or to insurance companies. The paper discusses the data related to the 2009 L’Aquila earthquake, focusing on the empirical damage and relevant Actual Repair Costs (ARC) of damaged residential buildings derived from requests for funding presented by practitioners engaged by owners in the reconstruction process. In particular, the data collected from a set of 2500 residential Reinforced Concrete (RC) and masonry buildings are presented focussing on the construction age, number of storeys, damage extent on structural components and ARC. A damage index for each building component has been computed according to data collected by field inspections and the relationship between damage index and different classes of buildings is herein outlined. Then, a correlation between the empirical damage and ARC is determined by means of a regression analysis. The proposed relationship between empirical damage and ARC may drive decision makers, in the immediate post-earthquake, to make preliminary estimates of the repair costs, only based on quick surveys on residential buildings. The relationship may also be used as a tool to figure out repair costs based on damage scenarios.

FRP Local Retrofit of Non-Conforming RC Beam-Column Joints

Recent seismic events have clearly confirmed the vulnerability of existing reinforced concrete (RC) structures. In particular, field observation of structures damaged by L’Aquila earthquake strongly confirmed that premature failure of partially confined (i.e. exterior) beam-column joints was one of the main causes limiting the global structural seismic capacity. Poor attention to details and a lack of adequate transverse reinforcement typically lead to premature brittle shear failure of joints. To provide support to practitioners involved in the L’Aquila reconstruction process, a proper guideline which illustrates the design of local retrofit interventions on structural and non structural elements has been edited by the Italian Civil Protection Department (DPC) and the Laboratories University Network of Seismic Engineering (ReLUIS). In particular, a viable FRP strengthening strategy to increase the seismic performances of partially confined joints (design procedure and installation steps) is widely discussed and presented in the document. To validate the strengthening system recommended in this guideline, an experimental program has been carried out on as-built and FRP strengthened full scale corner RC joints (T shaped joints). After presenting the main guideline recommendations for local strengthening of existing structures, the paper focuses on the experimental program activity; in particular, the specimen design strategy and test setup definition as well as the comparative analysis of the behavior of tested joints.

Constructive Features and Seismic Vulnerability of Historic Centres Through the Rapid Assessment of Historic Building Stocks. The Experience of Ferrara, Italy

During the earthquake emergency which involved Emilia Romagna Region (Italy) since 20th of May 2012, the Italian Civil Protection Department (DPC) undertook, with prevention purposes, an extensive survey on the ordinary buildings of the historic centre of the town of Ferrara, around 30 km far from the epicentral area. The activity, carried out in close cooperation with local authorities, was aimed at enhancing the seismic emergency response of the town in case of a possible further seismic event, as well as collecting technical information on the structural characteristics of the buildings, to be elaborated and hence used for further prevention purposes. Innovative element of the project was the use of two joint survey operative tools, consisting of the AeDES form used by DPC for post-earthquake usability assessments (2007) and AS form (specific for historical building blocks) which have been experimentally combined in this occasion. Activities were coordinated by DPC and carried out in collaboration with the Architecture Department of the University of Ferrara, which provided an operative and scientific support in the whole development of the work.

EMPIRICAL DAMAGE AND ACTUAL REPAIR COSTS ON MASONRY PRIVATE BUILDINGS AFTER L’AQUILA EARTHQUAKE

In the first phase of the emergency management after the April 6, 2009, L’Aquila earthquake, field inspections were carried out through the AeDES form, a first level survey form for post-earthquake damage and usability assessment, to evaluate the usability conditions of buildings. Once the damage and usability assessment was completed, the reconstruction process of residential buildings outside the historical centre of L’Aquila and surrounding municipalities was regulated by several Ordinances of the Prime Minister. The public grant was released according to funding requests made by practitioners and checked by a proper commission entrusted by the Government. The data collected on a set of about 1,000 residential masonry buildings in terms of vulnerability class, construction age, number of storyes, empirical damage, as well as of Actual Repair Costs (ARCs) are herein discussed and presented. Building Damage Factor, DF has been computed based on the damage data of structural and non-structural component collected with the AeDES forms. A calibration of different parameters, as the damage extent and severity on each structural and non-structural component and the weight of the damage on a single component on the total repair costs of the building, was carried out. The calibration allow us to determine the best correlation between the empirical damage and ARC. The proposed relationship between empirical damage and ARC may drive decision makers, in the immediate post-earthquake, to make preliminary estimates of the repair costs, only based on quick surveys on residential buildings. The relationship may also be used as a tool to figure out repair costs based on damage scenarios. 2765 Available online at www.eccomasproceedia.org Eccomas Proceedia COMPDYN (2017) 2765-2776