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ORDINANCE NO. NS-1518 Page Ten cores. The minimum number of tests shall be two per wall or line of wall elements resisting a common seismic force, 1 per 1500 square foot of wall surface, or eight minimum whichever requires the largest number of tests or cores. The exact test or core location shall be determined at the building site by the licensed engineer or architect responsible for the seismic analysis of the subject building. The results of all tests or coring shall be recorded and reported. (3) IN PLACE SHEAR TESTS. The bed joints of the outer wythe of the masonry shall be tested in shear by laterally displaying a single brick relative to the adjacent bricks in that wythe. The opposite head joint of the brick to be tested shall be removed and cleaned prior to testing. The minimum quality mortar in 80 percent of the shear tests shall not be less than the total of 30 psi plus the axial stress in the wall at the point of the test. The shear stress shall be based on the gross area of both bed joints and shall be that at which movement of the brick is first observed. (4) CORE TESTS. A minimum number of mortar test specimens equal to the number of required cores shall be prepared from the cores and tested as specified herein. The mortar joint of the outer wythe of the masonry core shall be tested in shear by placing the circular core section in a compression testing machine with the mortar bed joint rotated 15 degrees from the axis of the applied load. The mortar joint tested in shear shall have an average ultimate stress based on the gross area of 20 psi. The average shall be made from the total number of cores made. If test specimens cannot be made from the total taken the shear value shall be reported as zero. The results of all coring and shear testing shall be reported. F. TESTING OF SHEAR BOLTS. One-fourth of all new shear bolts and dowels embedded in unreinforced masonry walls shall be tested by the Director using a torque calibrated wrench to the following minimum torques: 1/2" diameter bolts or dowels = 40 foot-lbs. 5/8" diameter bolts or dowels = 50 foot-lbs. 3/4" diameter bolts or dowels = 60 foot-lbs. No bolts exceeding 3/4' shall be used. Ail nuts shall be installed over malleable iron or plate washers when bearing on wood and heavy cut washers when bearing on steel. G. DETERMINATION OF ALLOWABLE STRESSES FOR DESIGN METHODS BASED ON TEST RESULTS. (1) DESIGN SHEAR VALUES. Design seismic in-plane shear stresses greater than permitted in Table D shall be substantiated by tests performed as specified in Section 8-2006 E (3) and (4). Design stresses shall be related to test results obtained as noted in Table G. Intermediate values below the maximum may be interpolated.