1927 086 Ordinance - Laserfiche WebLink

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shall be less than twelve (12) inches thick. The..offset for each successive coursd shall not exeeed tliree-foutths (3/4) of the thickness of the course, or after the first,couxse is laid the sides up to the bottom -of the other f. ootin.gs or top of the footings in question may be battered at the'ratio.-of nine (9) incAes horizontal to one (1) foot vertical. , , . See.135g, REIATFORCID CONCRETE FOOTINGS. The area of reinforced column foot- ings shall be gonerned by availab].e resistance of the soil.upon which they are to be pla.ced. Single 'footings may be designed as a slab. and the''area between-one face of the column and the -two opposite corr?ers eonsidered ag a. free. cantilever. Heinforc- ing rods ahould be plaeed in both directions n.nder the column parallel to the edges of the footing. The corners sY!ould be reinforced by difa,gonal rods'extenaing across the footings.. , . Sec.136. STRUCTURAL STEEL COfiU:?TS IVCASID IN CONCRETE. . Wh.ere structuralsteel columns in steel frame stru.ctures of strzctures where the loads are transmit- ted directly to steel columns, are encased in concrete, the structural steel shall be proportioned,to. carry the total dead load anci 15-16 of the total livel oad that cari be transmitted to same; and-the,'concrete shall be proportioried to carry 1.16 of the live load only;..and.in no case, shall the vnit stress in the, stx°uctural steel ex- ceed 16,000 pounds per sq. ino of net steel section, or shall the u.nit atress in the concrete exeeed 500 pounds per sq. in. of ne't concrete sectiono In column,s of thisdde,sign the eoncre -Lue shall be reinforced wi'th spiral hoop- ing of not less than 2 to 1 per cent. ., ._ , ,. . _The p:itch of the spiral shall be}uniform and not greater thaYr-l-10 of,the diameter of tr.e hooping nor greater than 3inches. The-spirals shall be secured at each intersection in such amanner as:to insure the maintaining of its form and position. No part of the concrete outside of the hooping shall be.condidered as a part of the efiective column seetion. In latticed o r open we'p structural columns it shall not be necessasy to use the hooping specified above. All structural steel which is to be encased in concrete shall be vrrapped with wire in such a manner as to ineu.re the bonding of the concrete to the`steel and no stiuctural steel Vhich is to be encased in concrete shall be p ainted o r oiled. Before -encasin,g structural, steel in concrete,, scale or rust of an4Y appreciable amount shall be removed. See.137. COLUMN SPLiCES. In all buildi,ngs hereafter to be erected t he colw umn splices shall be made in such a manner as to transmit the stresses for which tnep are designed. The connections shall be rnade by turnbuckle,*sleeve nut, slip sleeve ar by lapping the rods and bolting together in sucli a manner that the stresses will be transmitted properly: If the device used, reauires the rod to oe threaded t he fif- fective area shall be -taken at the root of the threa.d. If a slip sleeve.i siised the rods mus.t have their ends milled or equ21. The diameter of the sleeve to be riot over 1a16 inch larger than.,the..diameter of the rod. Where the bearin,o is made metal to metal tne contact shall be made?,o'as t o transmit all stresses properlyo Vdhere tne rods are in tei-Ision due to wind stresses, the connection shall be made by means of a. positive conr!cetion. The Ase of pipe sleeve-connections is p rohibited unless they fit, the rods as above described: All colwnn steel shall set directly in line with the steel belowiankly?ust be cons-L•ructed in such a inanner as to eliminate any short bends in the steel. 'The steel reinforce-