SESSION 7 Applications of ASCE 7-10: Low-Rise Building ASCE Wind Loads

Low-rise Metal Building 250 ft 25 ft 20 ft 12 4 200 ft 100 ft Wind Truss Ridge Frame Purlin Eave Girt Wall Cable/Rod Bracing 53.3 ft ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

Loading Cases for MWFRS FIG 27.4-8, p 214 MWFRS of buildings of all heights shall be designed for Load Cases in Fig. 27.4-8 Consider all four load cases unless exceptions are met The metal building shown is normally designed without diaphragms Load Cases 2 and 4 do not apply ASCE Wind Loads

ASCE Wind Loads

Basic Load Cases: Fig 28.4-1, p 242 (see Note 8, p243) LOAD CASE A LOAD CASE B ASCE Wind Loads

P 243 ASCE Wind Loads

(GCpf) LOAD CASE A (GCpf)s for wind parallel to ridge (LOAD CASE A)  Building Surface (degrees) 1 2 3 4 5 6 1E 2E 3E 4E 0-5 .40 -0.69 -0.37 -0.29 -0.45 0.61 -1.07 -0.53 -0.43 18.4* .52 -0.47 -0.42 0.78 -0.67 -0.62 20 .53 -0.48 0.80 -0.64 (GCpf )s for wind normal to ridge (interpolated for 18.4 degrees) ASCE Wind Loads

* positive internal pressure ASCE Wind Loads

ASCE Wind Loads

* positive internal pressure Calculate pressures for “wind blowing primarily parallel to ridge”: p = qh [(GCpf) – (GCpi)] = 18(GCpf) – 3.2 (For positive internal pressure) Example: Zone 3: GCp = -0.37 (page 6-18)  = 0º p = 18(-0.37) – 3.2 = -9.9 psf Each corner of the building must be considered, in turn, as illustrated in Fig. 6-10. This action makes a total of 8 load cases for positive internal pressure. There are an additional 8 load cases for negative internal pressure for a total of 16 load cases. * positive internal pressure ASCE Wind Loads

ASCE Wind Loads

COMPARISON OF METHODS MWFRS METAL BUILDING CHAPTER 28 ENVELOPE METHOD CHAPTER 27 DIRECTIONAL METHOD ASCE Wind Loads

SIMPLIFIED METHODS From Significant Changes to the Wind Load Provisions of ASCE 7-10, p 85 (that you have) it is stated ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

NEW SIMPLIFIED METHOD FOR 60 ft < h < 160 ft CHAPTER 27 IN ASCE 7-10 ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

WIND TUNNEL TEST SAMPLES ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads

ASCE Wind Loads