STUDY OF STRUCTURAL CAPACITY AND SERVICEABILITY AFFECTING THE OBSTRUCTION OF RESIDENTIAL DOORS

Abstract

THE LAST CHILEAN EARTHQUAKE, OCCURRED ON FEBRUARY 27, 2010, ALLOWED ESTABLISHING IMPORTANT PATTERNS OF STRUCTURAL FAILURES IN REINFORCED CONCRETE RESIDENTIAL BUILDINGS; HOWEVER, LIMITED PROGRESS HAS BEEN MADE IN THE STUDY OF BASIC STANDARDS OF SERVICEABILITY, SUCH AS OBSTRUCTION OF DOORS. THUS, THIS STUDY FOCUSED ON MEASURING THE INFLUENCE OF DESIGN SPECIFICATIONS AND CONSTRUCTION CRITERIA OF LINTELS AND COLUMNS, IN TERMS OF OBSTRUCTION OF DOORS, CONSIDERING CAPACITY THRESHOLDS FOR CERTAIN LEVELS OF DISPLACEMENT.

THE STUDY CONSISTED OF THE DESIGN AND CONSTRUCTION OF A FULL-SCALE PROTOTYPE OF A REINFORCED CONCRETE FRAME, DESIGNED IN ACCORDANCE WITH ALL THE ACI-318-08 REQUIREMENTS, TAKING INTO ACCOUNT TYPICAL ASPECTS OF GEOMETRY AND MATERIALITY WIDELY USED BY THE REAL ESTATE INDUSTRY, FOR LOCATION AND SIZE OF DOORS. IN ORDER TO QUANTIFY THE STRUCTURAL CAPACITY OF THE PROTOTYPE AND TO STUDY THE SERVICEABILITY OF THE DOOR, A QUASI-STATIC CYCLIC TEST WAS CONDUCTED, ACCORDING TO LOAD AND DISPLACEMENT PROTOCOLS SPECIFIED IN FEMA 356 AND FEMA 461, WHICH WAS ADJUSTED BY USING VIRTUAL MODELS BASED ON A STATIC NONLINEAR ANALYSIS CALLED “PUSHOVER”.

THIS RESEARCH VERIFIED THAT, FOR DISPLACEMENT LEVELS EVEN FIVE TIMES HIGHER THAN THOSE ESTABLISHED BY CODES CONSIDERED, THE CRACKING DEGREE WAS MINIMAL AND FULLY RECOVERABLE. IT WAS ALSO FOUND THAT THE DOOR EVIDENCED MALFUNCTION WHEN THE DISPLACEMENTS WERE GREATER THAN THOSE SPECIFIED BY DESIGN ONLY, VALIDATING A HIGH DEGREE OF  ACCOMPLISHMENT OF CURRENT CODES IN TERMS OF CAPACITY AND SERVICEABILITY, WHEN DEALING WITH OBSTRUCTION OF RESIDENTIAL DOORS.