ブックタイトル「煉瓦造建造物の保存と修復」英語版

概要

「煉瓦造建造物の保存と修復」英語版

in the same place with the same function. And of course, theconcept of removability or re-workability is essential, makingit possible to intervene after an earthquake to repair, rebuild,and maintain as much as possible the original material andstructure.It has come to be considered in building codes in Italyand other foreign countries, but the approach to analysis ofextant buildings is completely different from that for newconstruction and requires knowledge outside of the fielddesignated by design guidelines, therefore requiring theestablishment of a separate standard.(slide 17-18) ISO 13822 is an international standard forevaluating extant structures. Another point that needs to benoted is that most engineering models are conservative andare not necessarily appropriate as tools for explaining thepresent condition. In other words, if we were to apply designmethods for new construction to extant buildings, this wouldbe rather excessive. Excessive design may not be so costly innew construction, but in extant buildings, this could result invery high fees.In present Italy, revisions of the Building Code regardingstructure and guidelines for application are underway. Forexample, in designing for intervention to an extant structure,for seismic retrofitting, in order to assure the highest safetystandard required by the Building Code, it is necessary tomeet 80% of the seismic performance for new construction.This is the cause of excessive design.(slide 19-21) For evaluating improvements in seismicresistance, it is necessary to consider performance. Throughcomparison of different responses of similar buildings, notonly through modeling, very valuable information can beobtained. It is not only safety that can be acquired throughcalculations, but conditions which can be employed forjudgment of actual safety. Generally, in Codes and guidelines,it is important to proceed in stages for minimum intervention.The reason for this is because, at each stage, the effects canbe confirmed and corrections can be made as they becomenecessary.ITALIAN GUIDELINESProf. Eng. Claudio ModenaConservation requirements and codesSM Ingegneriainterventions on preserved buildings should be designed to "improve" and not to“retrofit”their structural performanceit is necessary to express a positive opinion on the relationship between the achievedseismic safety, through a intervention consistent with the needs of conservation, and thereference protection level, which is desirable with reference to the seismic hazard and theconditions of use; this assessment will be expressed in global terms, not only on thebasis of a numerical comparison between collapse acceleration and expectedacceleration at the site, but also considering other aspects that were qualitativelyevaluated and cannot be explicitly considered in the calculationslide 19ISO 13822????Prof. Eng. Claudio ModenaConservation requirements and codesRecent evolution of codes and guidelinesSM IngegneriaThe continued use of existing structures is of great importance because the builtenvironment is a huge economic and political asset, growing larger every year. Theassessment of existing structures is now a major engineering task.The structural engineer is increasingly called upon to devise ways for extending the life ofstructures whilst observing tight cost constraints.The establishment of principles for the assessment of existing structures is neededbecause it is based on an approach that is substantially different from the design of newstructures, and requires knowledge beyond the scope of design codes.The ultimate goal is to limit construction intervention to a strict minimum, a goal thatis clearly in agreement with the principles of sustainable development.ISO 13822 ?§7.4slide 17Prof. Eng. Claudio ModenaConservation requirements and codesRecent evolution of codes and guidelinesSM IngegneriaThe conclusion for the assessment shall withstand a plausibility check. In particular,discrepancies between the results of structural analysis (e.g. insufficient safety) and the realstructural condition (e.g. no signs of distress or failure, satisfactory structural performance) shall beexplained.Note: many engineering models are conservative and cannot always be used directly to explainan actual situation.Prof. Eng. Claudio ModenaConservation requirements and codesSM IngegneriaCRITERIA FOR THE PROPOSAL OF INTERVENTIONS FOR THE SEISMIC IMPROVEMENTOF THE ARCHITECTURAL HERITAGE- MINIMUM INTERVENTION- STEP BY STEP INTERVENTION APPROACH AND CONTROL OF EFFICIENCY/NECESSITY- LOCAL INTERVENTIONS THAT DO NOT AFFECT THE“GLOBAL”STRUCTURAL RESPONSE- REMOVABILITY- MAINTAINANCE- REPAIRABILITY- DURABILITY- RELIABLE IN ITSELF 'AND INTERACTION WITH THE REST OF THE STRUCTURE- USE MORE ALTERNATIVE MODELS AND ANALYSIS, VALIDATION / CALIBRATIONS--------------------------ASSESSMENT - IMPROVEMENT ? VERIFICATION ? RETROFITTINGFORCE- EQUILIBRIUM - in addition to, and more than that - STRESS-STRENGTHslide 20Prof. Eng. Claudio ModenaConservation requirements and codesSM IngegneriaIN THIS CONTEXT THE“KNOWLEDGE PHASE”PLAYS THE FUNDAMENTAL ROLE IN THEDESIGN PROCESSIT ALOWS FOR :? IDENTIFYING ALL THE POSSIBLE“VULNERABILITIES”? ACTUALLY THE WEACK“RINGS”OF A CHAIN REPRESNTING THE STRUCTURAL PERFORMANCES OF ANHISTORIC STRUCTURE;? AND THEN FOR INTERVENING“LOCALLY”WHERE POSSIBLE AND FEASIBLEWITHOUT CHANGING SIGNIFICANTLY THE STRUCTURAL BEHAVIOUR OF SUCHSTRUCTURE WITH THE MOST APPROPRIATE ? TRADITIONAL OR INNOVATIVE ?TECHNOLOGYslide 18slide 2151