Chapter 5 Structure Loads and Responses 5.1.Dead Loads 5.2.Live Loads,Snow and Wind Loads 5.3.Earthquake Loads 5.4.Internal and External Movement 5.5.Response of structures and codes
Chapter 5 Structure Loads and Responses 5.1. Dead Loads 5.2. Live Loads, Snow and Wind Loads 5.3. Earthquake Loads 5.4. Internal and External Movement 5.5. Response of structures and codes
5.5.Response of structures and codes The response of the structure to the loadings Under the dead load the building will be stressed and deflected little. When live load is added,deflection and higher stresses are produced not seriously. -The horizontal effect of wind or earthquake can be quite serious in contrast to the dead and live load situations. -The reserve load capacity supplies the additional 'margin of safety'to take care of catastrophic forces,also keep the behavior of the structure within tolerable limits of movement
5.5. Response of structures and codes The response of the structure to the loadings - Under the dead load the building will be stressed and deflected little. - When live load is added,deflection and higher stresses are produced not seriously. -The horizontal effect of wind or earthquake can be quite serious in contrast to the dead and live load situations. -The reserve load capacity supplies the additional „margin of safety‟ to take care of catastrophic forces, also keep the behavior of the structure within tolerable limits of movement
Fig.5-6 Life history of a structure ELASTIC BEHAVIOR PLASTIC BEHAVIOR ULTIMATE LOAD RESERVE LOAD CAPACITY av01 WIND OR E.Q.LOAD 告 LIVE LOAD DEAD LOAD DEFLECTION ONLY PARTIAL OR ZER LIVE LOAD CONSIDERED TOGETHER WITH WIND OR E
Fig.5-6 Life history of a structure
Fig.5-6 Life history of a prestressed structure + PRESTRESSED LOAD CURVE NON-PRESTRESSED CURVE WIND OR E.Q.lOAD￥ LIVE LOAD DEAD LOAD (LITTLE OR NO DEFLECTION) DEFLECTION 米ONLY PARTIAL OR ZERO LIVE LOAD CONSIDERED TOGETHER WITH WIND OR三：-
Fig.5-6 Life history of a prestressed structure
Codes Modern building codes have changes the "allowable stress"approach to a more reasonable "ultimate strength"design method. A building designer should use building codes only as a reference and as a guide,but not bible.Some code requirements are excessively conservative,others are not sufficient (especially for unusual designs)
Codes Modern building codes have changes the “allowable stress” approach to a more reasonable “ultimate strength” design method. A building designer should use building codes only as a reference and as a guide, but not bible. Some code requirements are excessively conservative, others are not sufficient (especially for unusual designs)