|
<br />Gnuiient, 10Jld intensity and e.ros..iOlJ chanlcteristics of I..Iope
<br />Material ,
<br />
<br />I 80S . 4 Footings shall be des igned IIJl constructed in
<br />Allowable bearing Cllpacity of the soil is not exceeded, and
<br />nw differentiA.! settlement i3 minimized. The minimum
<br />Width offootingJ shall be 12 inches (305 nun)
<br />
<br />Footings in areas with expansive soils shall be designed
<br />Ln accordance with the provisiom of Sectioo I &05.8,
<br />
<br />J 805.4./ 1.1 Design loads, Footings sba1J t>e designed for
<br />
<br />the ~ unfil von.ble effocts due to the combinations of
<br />loads speci.fied in Sectioo 1605.3, The dead load sha1I in.
<br />clued the weight of foundaticns" footings and oVerlying
<br />fill Reduced live loads, IS spectned In Section 1607.9,
<br />Are permitted to be used in designina footingJ.
<br />
<br />1805,4, 1.2 Vibnuory loads. Where machinery opeTB-
<br />tioos or other vibrations are transmitted through the
<br />foundation, consideration shall be liven in the footing
<br />design to prC'Yalt dctrimcntaJ distw-baoces of the soil.
<br />
<br />1 &05.4.2 Concrete footings, The design, rnateriala and c0n-
<br />struction of COOcrete footinp shaJJ COOlpJy with Sections
<br />1805.4.2.1 through 1&05.4.2.6 and the provisions ofCbap-
<br />ter J 8Qj.4.2.
<br />
<br />Ex.ceptioo; When: 8 specific design is no( provided, c0n-
<br />Crete footings supporting walls of light-frame coostruc-
<br />Lion are permincd to be dC3igned in accordance with
<br />Table 1805.4.2
<br />
<br />] 805,4.2. I Concrete strength. Coocrete in footings
<br />Shall have 8 spcoificd C<I01pnlsaive Jtreogth (re) ofoot
<br />Less than 2,500 poWlds per 5qWlIe inch (PSi)(J 7237 kP8)
<br />,oJ 28 days,
<br />
<br />J 805 .4.2.2 Reserved.
<br />
<br />SOILS AND FOVNDAA 110NS
<br />
<br />1805.4.2.3 J>hin 00IlCTete footings. The edgt thi~
<br />Of plain coocrcte footing! supporting walls of other than
<br />Light-frame constructioo shall not be less that 8 inches
<br />(203 nun) whm placed on soil. '
<br />Exception: For plain concrete footings SUPPOrting
<br />Group R-3 occuvanci~. the edi~ thichll:ss is permit-
<br />ted to be 6 inches (152 nun),pmvided that the footing
<br />Does not atenrl beyood a distance greater that the
<br />ThiclcneM of the footin! __n either 3ide of the 3upporled
<br />Wall.
<br />1805.4.2.4 Placement of ClJIlcrete. Coocme footings
<br />Shall not be placed through Wlllt.1 unless 8 trcmic or other
<br />method approved by the building )fficUtl is used., Where
<br />placed under Of in the ~ of water II the concrete
<br />shall be deposited by approved means to ensllTC mini-
<br />mum segregation of the mix and negligible turbulence of
<br />the water,
<br />
<br />1805.4.2,5 Protectioo of concrete. Concn:te footings
<br />s.haJ1 be protected from freezing duri.n& depositing and fCd
<br />a period of not less than five days thereafter, Water shal I
<br />Not be allowed to flow through the deposited COOCretc,
<br />
<br />1 &05.4.2.6 Forming of COfK:rct.e. Concrete footings are
<br />permitted to be cast againlt the earth where, in the opin-
<br />ion of the buiJdini official, soil cooditioo,s do DOl require
<br />funning. Where forming Is requ1red, It shall be In IICWT-
<br />dance with Olapter 6 of ACl318,
<br />
<br />1805.4.3 Masonry-unjt footings. The design, materials
<br />and construction of masonry-unit footings shall comply
<br />with Scctioos 1&05.4.3,1 end 1805.4.3,2. and the ~yisjons
<br />Of Chapter 21,
<br />
<br />Exceptioo: Where a specific design is oot provided, ma-
<br />sonry-unit footings supporting walls of light-frame con-
<br />Struction are permitted to b designed in IlCCOfdancc with
<br />Table 180:5.4.2.
<br />
<br />1805.43.1 DimaWoos, Masoory-un.it footing s.ba1.J be
<br />laid in Type M or S mortar complying with Sectioo
<br />
<br />TABLE J805.4.2
<br />FOOTINGS SUPPORTING WALLS OF LIGHT-fRAME CONSTRUcnONa.b.c.d
<br />
<br />,
<br /> WIDTH OF THICKNEsS OF
<br /> NUMBER OF FLOORS FOOTINGS FOOTING
<br /> SUPPORTED BY THE FOOTINGS. (inches) (inches )
<br /> I 12 6
<br /> 2 15 6
<br /> 3 18 8
<br /> J
<br />
<br />FOf S J' 1 inch '" 25.4 mm, I fOO(.. 304,8 rnro,
<br />a. Depth offootings sbalJ be in accordaoce with Sectioo 18052,
<br />b, The ground under the 1I00f is permitted to be excavated to the elevatioo of the top of the footing.
<br />c, Intcrior~ walb arc permitted to bo IUpported by iao1.ated footings. The f<X>tinB width and length &haJI be twice
<br />the meith shown in this table, and footings shall be spaced not more than 6 Feet on center,
<br />d, FOf thickness of foundation walls, see Section J 805.5,
<br />e, Footings are permitted to stlppor11 roof in additioo to the stipulated number of fioors, Footings supporting root' oruy
<br />Shall be as required for supporting ODe floor.
<br />( Plain COOC1tte footings for Group R-3 occupancies are permitted to be 6 inches thid.,
<br />
|