1、Designation: C890 12Standard Practice forMinimum Structural Design Loading for Monolithic orSectional Precast Concrete Water and WastewaterStructures1This standard is issued under the fixed designation C890; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes the minimum loads to be appliedwhen designing monolithic
3、or sectional precast concrete waterand wastewater structures with the exception of concrete pipe,box culverts, utility structures, and material covered in Speci-fication C478.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconv
4、ersions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practic
5、es and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C478 Specification for Precast Reinforced Concrete Man-hole Sections2.2 AASHTO Standard:Standard Specifications for Highway Bridges, 16th Edition32.3 ACI Standard:ACI 318 Building Co
6、de Requirements for Reinforced Con-crete43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 above ground structuresall structures with their baseat or above ground.3.1.2 bearing loadsthe foundation pressure reaction to allother loads acting on the structure.3.1.3 below ground str
7、ucturesall structures other thanthose with their base at or above ground.3.1.4 dead loadsthe mass of the structure and all perma-nent loads imposed on the structure.3.1.5 equipment loadsloads induced into the structure byequipment installed on mounting devices cast into the struc-ture.3.1.6 hydrosta
8、tic loadsall pressures due to the weight ofwater or other liquids.3.1.7 lateral earth loadsthe lateral pressure due to theeffective weight of adjacent earth backfill.3.1.8 lifting loadsthe forces induced into the structureduring handling at the precast plant and the construction site.3.1.9 surcharge
9、 loadsthe lateral pressure due to verticalloads superimposed on the adjacent earth backfill.3.1.10 traffc loadsall loads superimposed on the structureor adjacent earth backfill due to vehicles or pedestrians.3.1.11 water and wastewater structuressolar heatingreservoirs, septic tanks, cisterns, holdi
10、ng tanks, leaching tanks,extended aeration tanks, wet wells, pumping stations, greasetraps, distribution boxes, oil-water separators, treatment plants,manure pits, catch basins, drop inlets, and similar structures.4. Significance and Use4.1 This practice is intended to standardize the minimumloads t
11、o be used to structurally design a precast product.4.2 The user is cautioned that he must properly correlate theanticipated field conditions and requirements with the designloads. Field conditions may dictate loads greater than mini-mum.1This practice is under the jurisdiction of ASTM Committee C27
12、on PrecastConcrete Products and is the direct responsibility of Subcommittee C27.30 on Waterand Wastewater Containers.Current edition approved Sept. 15, 2012. Published October 2012. Originallyapproved in 1978. Last previous edition approved in 2011 as C890 06 (2011). DOI:10.1520/C0890-12.2For refer
13、enced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Association of State Highway and Transportatio
14、nOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.4Available from American Concrete Institute (ACI), P.O. Box 9094, FarmingtonHills, MI 48333-9094, http:/www.concrete.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
15、nshohocken, PA 19428-2959. United States15. Design Loads5.1 Dead Loads:5.1.1 Permanent vertical loads typically include the weightof the road bed, walkways, earth backfill, and access openingcovers.5.1.2 Recommended unit weights of materials for design areshown in Table 1.5.2 Traffc Loads:5.2.1 The
16、vehicle and pedestrian loadings are shown inTable 2.5.2.2 The arrangement and spacing of vehicle wheels areshown in Fig. 1 and Fig. 2.5.2.3 Distribution of Wheel Loads through Earth Fills:5.2.3.1 For structures where vehicle wheels contact the topsurface of the structure, the vehicle wheel loads wil
17、l bedistributed over an area as shown in Fig. 3. The loaded areawill be:A 5 W 3 L (1)where:A = wheel load area, ft2(m2),W = wheel width, ft (m), andL = wheel length, ft (m).5.2.3.2 For below ground structures where backfill separatesthe vehicle wheels and the top surface of the structure, thevehicle
18、 wheel loads will be distributed as a truncated pyramidas shown in Fig. 4.The loaded area will be:A 5 W11.75 H! 3 L11.75 H! (2)where:A = wheel load area, ft2(m2),W = wheel width, ft (m),L = wheel length, ft (m), andH = height of backfill between wheels and structure, ft (m).5.2.3.3 When several dist
19、ributed wheel load areas overlap,the total wheel load will be uniformly distributed over acomposite area defined by the outside limits of the individualareas. Such a wheel load distribution is shown in Fig. 5.5.2.3.4 When the dimensions of the distributed load area orthe composite distributed load a
20、rea exceed the top surface areaof the structure, only that portion of the distributed load withinthe top surface area will be considered in the design.5.2.4 The effects of impact will increase the live wheel loadsdesignated as A-16, A-12, and A-8 as shown in Table 3.TABLE 1 Unit Weights of Materials
21、Material Weight, lbf/ft3(N/m3)Concrete (plain or reinforced) 150 (23 600)Lightweight Concrete (reinforced) 100 to 130 (15 700 to 20 400)Cast Iron 450 (70 700)Steel 490 (77 000)Aluminum 175 (27 500)Earth Fill 100 to 150 (15 700 to 23 600)Macadam 140 (22 000)TABLE 2 Vehicle and Pedestrian Load Designa
22、tionsDesignation Load, max UsesA-16 (HS20-44)A16 000 lbf (71 200 N) per wheel heavy trafficA-12 (HS15-44)A12 000 lbf (53 400 N) per wheel medium trafficA-8 (H10-44)A8 000 lbf (35 600 N) per wheel light trafficA-03 300 lbf/ft2(14 400 Pa) walkwaysAThe designations in parentheses are corresponding ASSH
23、TO designations.DesignationLoad at A Load at B Load at Clbf N lbf N lbf NA-16 (HS20-44)A4 000 17 800 16 000 71 200 12 000 53 400A-12 (HS15-44)A3 000 13 300 12 000 53 400 8 000 35 600A-8 (H10-44)A2 000 8 900 8 000 35 600 6 000 26 700AThe designations in parentheses are corresponding ASSHTO designatio
24、ns.FIG. 1 Single Vehicle Traffic Loads and SpacingC890 1225.3 Hydrostatic Loads:5.3.1 The water pressure acting on any point on the outsidesurface of the structure is:PW5 WW3 HW(3)where:PW= hydrostatic pressure, lbf/ft2(Pa),WW= unit weight of water, lbf/ft3(N/m3), andHW= distance from the ground wat
25、er surface to the pointon the structure under consideration, ft (m).5.3.2 The liquid pressure acting on any point on the insidesurface of the structure is:PL5 WL3 HL(4)where:PL= liquid pressure, lbf/ft2(Pa),WL= unit weight of the liquid, lbf/ft3(N/m3), andHL= distance from the liquid surface to the
26、point on thestructure under consideration, ft (m).5.4 Lateral Earth Loads:5.4.1 The lateral earth pressure on the walls of a buriedstructure for the portion of the walls above the ground watersurface will be:PE5 K 3 WE3 HE(5)where:PE= lateral earth pressure, lbf/ft2(Pa),K = coefficient of lateral ea
27、rth pressure,WE= unit weight of the earth backfill, lbf/ft3(N/m3), andHE= distance from the surface of the earth backfill to thepoint on the structure walls under consideration, ft(m).5.4.2 The lateral earth pressure on the walls of a buriedstructure for the portion of the walls below the ground wat
28、ersurface will be:PE5K 3 WE3HE2 HW!#1K 3WE2 WW!3 HW#(6)where:PE= lateral earth pressure, lbf/ft2(Pa),K = lateral earth pressure coefficient,WE= unit weight of the earth backfill, lbf/ft3(N/m3),HE= distance from the surface of the earth backfill to thepoint on the structure under consideration, ft (m
29、),WW= unit weight of water, lbf/ft3(N/m3), andHW= the distance from the surface of the ground watertable to the point on the structure underconsideration, ft (m).5.4.3 Laboratory and field testing has shown that the valueof the lateral earth pressure coefficient depends on the yieldingof the wall of
30、 the structure relative to the earth backfill. Wallsof sectional precast concrete structures can yield by rotating,translating, or deflecting. Walls of monolithic precast concreteFIG. 2 Multiple Vehicle SpacingFIG. 3 Wheel Load AreaFIG. 4 Distributed Load AreaFIG. 5 Composite Distributed Load AreaTA
31、BLE 3 Wheel Load Increases for ImpactHeight of Backfill Between Wheel and Structure Increase0 to 12 in. (0 to 305 mm) 30 %13 to 24 in. (330 to 610 mm) 20 %25 to 35 in. (635 to 890 mm) 10 %36 in. (915 mm) or greater 0 %C890 123structures can yield by deflecting. The lateral earth pressure ona structu
32、re where the walls can yield sufficiently will beconsidered as the active pressure. The value of the lateral earthpressure coefficient for this condition can be estimated byRankines equation of:KA5 1 2 sin #/11 sin # (7)where:KA= active earth pressure coefficient, and = internal friction angle of th
33、e earth backfill, degrees.The value of KAshall be as computed or 0.30, whichever isgreater.5.5 Surcharge Loads:5.5.1 When traffic can come within a horizontal distancefrom the structure equal to one half of the height of thestructure, a lateral surcharge pressure will be applied to thewall of the st
34、ructure. Lateral surcharge pressures for thedesignated vehicle wheel loads are shown in Table 4.5.5.2 Lateral surcharge loads from traffic will be considerednegligible below a vertical distance 8 ft (2.4 m) below thewheel.5.6 Lifting Loads:5.6.1 The lifting load induced into the structure will be no
35、tless than the total dead weight of the precast unit distributedover not more than three lifting points.5.7 Cumulative Loadings:5.7.1 The cumulative vertical loading possible on the top orbase of a structure are shown schematically in Fig. 6 and Fig.7, respectively.5.7.2 The cumulative horizontal lo
36、adings possible on thewalls of a structure are shown schematically in Fig. 8.6. Loading Combinations for Above Ground Structures6.1 The design load for the top of the structure will considerthe cumulative effects of dead loads, snow loads, and either apedestrian live load if applicable, or a nominal
37、 live load of 20lbf/ft2(958 Pa). Local area building codes will be used forsnow loads.6.2 The design load for the walls of the structure willconsider both of two individual load cases.6.2.1 Load Case A Load Case A will consider a structurefull condition and will include only the internal hydrostatic
38、loads.6.2.2 Load Case B Load Case B will consider a structureempty condition and will include either the effects of wind loador horizontal vehicle impact if applicable. Local area buildingcodes or a nominal external pressure of 30 lbf/ft2(1436 Pa)will be used for wind loads.6.3 The design load for t
39、he base of the structure willconsider the applicable individual load case.6.3.1 Load Case A Load Case A is an empty structureresting on the ground and will consist of a bearing loaduniformly distributed over the base.6.3.2 Load Case B Load Case B is a full structure raisedabove the ground and will i
40、nclude the cumulative effects ofdead loads and internal hydrostatic loads.7. Loading Combinations for Below Ground Structure7.1 The design load for the top of the structure will considerthe cumulative effects of dead loads, snow loads, and trafficloads. Local area building codes will be used for sno
41、w loads.7.2 The design load for the walls of the structure willconsider both of two independent load cases.7.2.1 Load Case A Load Case A is a structure fullcondition and will include the cumulative effects of maximuminternal hydrostatic loads, minimum external hydrostatic loads,and minimum lateral e
42、arth pressure loads.7.2.2 Load Case B Load Case B is a structure emptycondition and will include the cumulative effects of maximumexternal hydrostatic loads, maximum lateral earth pressures,and lateral surcharge loads.7.3 The design load for the base of the structure willconsider the cumulative effe
43、cts of the bearing load and theexternal hydrostatic load.8. Special Loading Considerations8.1 The structural design loading for unique applicationswill also consider thrust, vibration, and ice loads applicable.8.2 The structural design for below ground structures willalso consider buoyancy effects,
44、if applicable, and proportionthe structure to assure an adequate flotation safety factor.8.3 The structural design loading will also consider thestresses due to the effects of concrete shrinkage and thermalmovement. The reinforcing steel provided in areas of thestructure subject to such stresses wil
45、l equal or exceed theminimum amounts required by the referenced reinforced con-crete design standards in Section 4.TABLE 4 Lateral Surcharge PressuresDesignation Lateral Surcharge PressureA-16 (HS20-44)A80 lbf/ft2(3830 Pa) per wheelA-12 (HS15-44)A60 lbf/ft2(2873 Pa) per wheelA-8 (H10-44)A40 lbf/ft2(
46、1915 Pa) per wheelAThe designations in parentheses are corresponding ASSHTO designations.FIG. 6 Cumulative Vertical Top LoadsFIG. 7 Cumulative Vertical Base LoadsC890 1248.4 Lifting inserts which are embedded or otherwise at-tached to the structure will be designed for four times themaximum load tra
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