Showing papers on "Earthquake resistant structures published in 1970"

A review of the seismic resistance of prestressed concrete

Abstract: The use of prestressed concrete components has been accepted for many years for structures under gravity loading. The applications of the material are increasing rapidly, encouraged by such advantages as the possibility of pleasing architectural forms, and the suitability of prestressed concrete to modern prefabricated construction. However the use of prestressed concrete in primary seismic resistant elements such as shear walls and frames has created considerable controversy. This review is a historical trace of the approach of design and research engineers to the suitability or otherwise of prestressed concrete for earthquake resistance. It discusses such fundamental properties as stiffness, damping, energy absorption and dissipation, and ductility, all of which will affect the response and hence the structural behaviour of prestressed concrete buildings under earthquake loading.

Practical problems and costs of fabricating multistory models

Abstract: ONE OF THE FUNCTIONS OF THE CANADA EMERGENCY MEASURES ORGANIZATION IS TO REDUCE THE VULNERABILITY OF NORMAL BUILDINGS TO A VARIETY OF DYNAMIC LOADS, INCLUDING BLAST AND EARTHQUAKE. PART 1 OF THIS PAPER DESCRIBES THE PRODUCTION OF EIGHT SMALL STRUCTURES EACH WITH SEVEN STORIES AND 15 COLUMNS PER FLOOR. FOUR OF THE SEVEN-STORY MODELS HAVE BEEN DESIGNED IN ACCORDANCE WITH NORMAL STRUCTURAL ENGINEERING PRACTICE FOR DEAD LOAD, LIVE LOAD AND WIND, WHILE THE OTHER FOUR HAVE BEEN DESIGNED IN ACCORDANCE WITH THE NATIONAL BUILDING CODE (1965) REQUIREMENTS FOR EARTHQUAKE ZONE 3. THIS PAPER DISCUSSED SOME OF THE MAJOR PROBLEMS INVOLVED IN THE PLANNING PROCESS AND SPECIAL EQUIPMENT AND TECHNIQUES WHICH WERE DEVISED TO ALLOW MASS PRODUCTION OF THE 840-COLUMN CAGES AND THE 56 SETS OF SLAB REINFORCEMENT. THE DEVELOPMENT OF CASTING TECHNIQUES AND THE EVOLUTION OF FORMING TECHNIQUES ARE ALSO OUTLINED. PART 2 OF THIS PAPER DESCRIBES TECHNIQUES WHICH HAVE BEEN DEVELOPED FOR MASS PRODUCTION OF SMALL-SCALE SHEAR-WALL BUILDING MODELS USING MORTAR. IT INCLUDES A DESCRIPTION OF THE MORTAR WHICH WAS DESIGNED TO MINIMIZE SHRINKING AND TO OPTIMIZE PLACING AND CURING CONDITIONS, AS WELL AS A DESCRIPTION OF THE REUSABLE PLYWOOD FORMS WHICH WERE DEVELOPED FOR THE EXPERIMENT. THE MODELS ARE APPROXIMATELY 8 FT HIGH AND HAVE WALL THICKNESSES OF 1/2 INCH. THE PAPER ALSO INCLUDES A DISCUSSION OF THE TECHNIQUES USED IN MOUNTING THE MODEL ON A FIXED BASE AND ON ATTACHING LOADING DEVICES. /ACI/

Foundation response to seismic loading

Abstract: THE PARTIAL OR TOTAL LOSS OF STRENGTH OF SATURATED GRANULAR SOILS, PERMITTING EXCESSIVE SETTLEMENTS OF SUPERIMPOSED STRUCTURES, HAS BEEN OFTEN OBSERVED IN SEISMICALLY ACTIVE ZONES. THE FREQUENCY OF THIS TYPE OF FAILURE COULD INCREASE, EVEN IN SEISMICALLY QUIET ZONES, WITH INCREASING USE OF RECLAIMED LAND IN HEAVILY DEVELOPED AREAS. LIQUEFACTION CAN BE DESCRIBED QUALITATIVELY, AND THE MORE OBVIOUS VARIABLES INFLUENCING THE TOTAL RESPONSE HAVE BEEN DETERMINED. THIS LED TO NUMERICAL METHODS OF ANALYSIS AND THE PREDICTION OF THE PERFORMANCE OF RELATIVELY SIMPLE STRUCTURES UNDER PREVIOUSLY RECORDED SEISMIC LOADING CONDITIONS. RELEVANT IN SITU MATERIAL PARAMETERS AND THE DYNAMIC INPUT ARE ASSESSED BY A THOROUGH INVESTIGATION OF OBSERVED CASES OF LIQUEFACTION, TO ESTABLISH METHODS OF ANALYSES CAPABLE OF PREDICTING WITH SUFFICIENT ACCURACY PERFORMANCE UNDER FIELD CONDITIONS FOR DESIGN PURPOSES. THIS PAPER DESCRIBES THESE ASPECTS OF THE DYNAMIC SETTLEMENT PROBLEMS AND INVESTIGATES THEIR RELEVANCE TO THE PERTH ENVIRONMENT. THE FACTORS CONSIDERED ARE POSSIBLE SOURCES OF SEISMIC ENERGY, INTENSITIES OF RESPONSE, AREAS SUSCEPTIBLE TO CATASTROPHIC RESPONSE AND MEANS OF CONSTRUCTION TO MINIMIZE OR AVOID DAMAGE FROM THIS SOURCE. /CSIRO/