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Home My WebLink AboutSTRUCTURAL ENGR. CALCS - Zimmerman, Frank - 710 N 2nd E - Central Park - Sign Variance1 8/21/00 12:42 PM Structural Engineering Calculations for: Central Park Rexburg, ID Single column sign, 24' overall height Index Title .................1 Specifications .................2 Wind Loads .................3 Steel Column .................4 Footing .................5 Plate Connection .................6 Drawing .............. 7 Young Electric Sign Company By: Don Rolfe Check: Ben Janes Sign Engineering 3.1 (C) 1998 Young Electric Sign Company 8/21/00 12:42 PM SPECIFICATIONS Project: Central Park Descript: Single column sign, 24' overall height Steel... Design and fabrication according to AISC-ASD, 9th edition. Plate, angle, channel, tee and wide flange: ASTM A36, Fy = 36 ksi. Round pipe: ASTM A53 Grade B or equivalent, Fy = 35 ksi. High strength bolts: ASTM A325, non -slip critical (bearing type), snug tight. Welding... Design and fabrication according to AWS D1.1, current edition. AWS certification required of all structural welders. E70XX electrodes for SMAW processes. F7X-EXXX electrodes for SAW processes. Concrete... Design and construction according to ACI 318-95. Compressive strength at 28 days, fc= 2,500 psi minimum. Concrete poured into constrained earth excavations must cure under proper conditions for 4 days prior to sign box installation. ( Exception: if the overall height of the sign is less than 20 feet and the sign pole is adequately braced against wind loads for a minimum of 4 days, the sign box may be installed the same day as the as the footing is poured. ) For pier and caisson footings, concrete must be poured against undisturbed earth. Maintain a minimum 3" concrete cover over all steel embeded in concrete below grade. Sign Engineering 3.1 (C) 1998 Young Electric Sign Company 13 8/21/00 12:42 PM WIND LOADS Project: Central Park Descript: Single column sign, 24' overall height Ref: Uniform Buildina Code 1997 Basic Wind Speed= 80 mph, UBC figure 16-1 Exposure= C flat terrain, generally open for 1/2 mile. Cq= 1.4 signs, flagpoles and lightpoles, UBC table 16-H Calculation of Design Wind Pressures Height (ft): (qs) (Ce) (Cq) = Wind Pressure 15 16.4 1.06 1.4 24.3 psf 20 16.4 1.13 1.4 25.9 psf 25 16.4 1.19 1.4 27.3 psf 30 16.4 1.23 1.4 28.2 psf 40 16.4 1.31 1.4 30.0 psf 60 16.4 1.43 1.4 32.8 psf 80 16.4 1.53 1.4 35.1 psf 100 16.4 1.61 1.4 36.9 psf 120 16.4 1.67 1.4 38.3 psf 160 16.4 1.79 1.4 41.1 psf 200 16.4 1.87 1.4 42.9 psf 300 16.4 2.05 1.4 47.0 psf 400 16.4 2.19 1.4 50.2 psf Sign Engineering 3.1 (C) 1998 Young Electric Sign Company A 12:42 PM STEEL COLUMN DESIGN Project: Central Park Descript: Single column sign, 24' overall height Ref: Manual of Steel Construction, AISC 9th Edition Areas Subject to Wind Forces Height Width Area Centroid Wind 1) top cabinet 6.334 9.670 61.250 20.840 27.30 2) support 0.500 0.600 0.300 17.420 25.92 3) bottom cabinet 5.084 8.000 40.672 14.630 24.31 4) support 12.084 0.600 7.250 6.042 24.31 5) (in^3) (ksi) 0.000 P 0.00 6) -4.75 17.54 0.000 29.90 0.00 7) P 6"(.280) 0.000 17.54 0.00 8) 8.50 7.8 0.000 0 0.00 Calculation of Design Forces at Critical Heights y (ft) M(#') V(#) y (ft) M(#') V(#) @ grade 50,510 2,845 0.00 0 0 17.54 5,517 1,672 0.00 0 0 24.00 0 0 0.00 0 0 Column Support Design Table # of Column Column Length Start End Sleeve S act fb Cols Type Size Fb= Elev Elev Depth P 6"(.280) d/t (P, TS) so... (ft) (ft) (ft) (in) (in^3) (ksi) 1 P 10"(.365) 22.29 -4.75 17.54 N/A 29.90 20.3 1 P 6"(.280) 6.46 17.54 24.00 0.0 8.50 7.8 Allowable Bending Stresses Column Type Column Size Criteria Stress increase factor= 1.00 P 10"(.365) d/t <3300/Fy so... Fb= 0.66Fy= 23.1 ksi P 6"(.280) d/t <3300/Fy so... Fb= 0.66Fy= 23.1 ksi 0.00 0.00 help 0 so... Fb= 0 0.0 ksi 0.00 0.00 help 0 so... Fb= 0 0.0 ksi 0.00 0.00 help 0 so... Fb= 0 0.0 ksi 0.00 0.00 help 0 so... Fb= 0 0.0 ksi Sign Engineering 3.1 (C) 1998 Young Electric Sign Company r2 8/21/00 12:42 PM LATERAL BEARING PIER AND CAISSON FOOTINGS Project: Central Park Descript: Single column sign, 24' overall height Ref: Uniform Building Code 1997 (Sec. 1806.8) # Footings= 1 Moment/Footing, M= 50,510 Ib -ft Pass let soil res, q= 200 psf Composite Centroid, h= 17.75 ft Equiv Concentrated Load, P= M/h= 2,845 Ib Rectangular Pier Width, W= 8.0 ft, parallel to sign face Length, L= 7.0 ft, perpendicular to sign face Depth, D= (A/2)(1 + SQR(1 + (4.36h)/A))= 4.8 ft S1= (2)(q)(D/3)= 652 psf b= Sgrt(W^2 + L^2)= 10.6 ft A= (2.34)(P) / (S1)(b)= 1.0 Concrete Volume Outside Width of Column= 10.75 in Depth of Column in Footing= 4.75 ft Volume of Concrete per Footing= 9.9 cubic yards (+-) Total Order Volume of Concrete= 9.9 cubic yards (+-) Sign Engineering 3.1 (C) 1998 Young Electric Sign Company 56 8/23/00 10:52 AM SPREAD FOOTINGS Project: Central Park Descript: Single column sign, 24' overall height Ref: Uniform Building Code 1997, ACI 318-95 Concrete Design for Overturning # of Footings= 1 Allowable Bearing Pressure, q= 2,000 psf, at grade Wind Load Moment at Grade, Md= 5.05E+04 Ib -ft / footing Wind Load Shear at Grade, V,d= 2,845 Ib / footing Estimated Depth to Toe, Dr= 5.0 ft Total Design Moment, M,,t= 6.47E+04 Ib -ft / footing, Mwl + (V„,l)(DP) Required Stabilizing Moment, Ms 9.71 E+04 Ib -ft, 1.5 x Mtot Weight of Sign and Columns, W= 1,840 Ib / footing Concrete Density, p= 145 pcf, normal type I Width, B= 8.0 ft, parallel to sign face Length, L= 7.0 ft, perpendicular to sign face Required Depth, Df= 3,2 ft, =(2Ms - W L) / (p B LA2) Actual Depth to be Used= 5.0 ft Sign Weight + Footing Weight, P= 42,440 lbs Service Load Eccentricity= M/P, e= 1.53 ft OUTSIDE KERN Soil Pressure at Rotation Toe, q., 1,791 psf, service load pressure at bearing depth q allowed= min(3 or 1+0.2(d-1)) x q= 3,600 psf at bearing depth, 1997 UBC Tbl. 18-1-A OK Total Order Volume of Concrete= 7 cubic yards (+-) Loads for Strength Design Factored Dead Load, Pu= 44,562 lbs, 1.05 P Factored Wind Load Moment, Mu= 6.44E+04 Ib -ft, 1.275 Ml Factored Load Eccentricity= M„/P,,, a, 1.45 it OUTSIDE KERN Factored q,A,x 1,807 psf Factored q,,,= 0 psf Bearing Length, a= 6.16 ft a>L/2 Rectangular Comp Block: q1= 781.1255 psf R1= 2.19E+04 lbs d1= 1.75 ft Wedge Comp Block: q2= 1026 psf R2= 1.44E+04 lbs d2= 2.33 ft Factored Moment in Concrete, M,,,= 7.18E+04 Ib -ft Sign Engineering 3.1 (C) 1998 Young Electric Sign Company G41 - 8/23/00 G8/23/00 10:52 AM STEEL REINFORCEMENT ANALYSIS Project: Central Park Descript: Single column sign, 24' overall height Ref: Uniform Building Code 1997, ACI 318-95 Width of strip to analyze, b= Effective depth of beam, d= Compressive strength of concrete, fc= 12.00 in 56.00 in, providing 3"+ cover 2,500 psi B1= 0.85 Area of tension reinforcing, As= 0.60 sq in, per 12" strip Yield strength of reinforcing, fy= 60,000 psi, using Grade 60 deformed bar Maximum reinforcement ration= 0.0134 as 75% of balanced ratio Actual reinf ratio, p= 2(As/(b x d))= 0.0018 counting top and bottom bars Minimum reinforcement ratio= 0.0018 temperature and shrinkage Depth of Whitney rectangular stress block, a= (As x fy)/(0.85 x f x b)= 1.41 in Depth of neutral axis, x= a/B1= 1.66 in Nominal moment capacity of a 12" strip, Mn= (As x fy)(d-(a/2))= 1.66E+05 Ib -ft Design moment capacity of a 12" strip, (phi]Mn= 0.9 x Mn= 1.49E+05 Ib -ft Actual factored moment on a 12" strip of the footing= 8.97E+03 Ib -ft OK Use two mats of reinforcing, top and bottom (3" cover) of: # 7 bars at 12" OC perpendicular to sign face # 7 bars at 12" OC parallel to sign face Sign Engineering 3.1 (C) 1998 Young Electric Sign Company 8/27/00 12:42 PM PLATE TO PLATE BOLTED CONNECTION Project: Central Park Descript: Single column sign, 24' overall height Ref: AISC Steel Manual, 9th Edition Plate Design # of Plate Conn. at this Elevation= 1 Ib, = Tin Total Bending Mom. at Plate Elev., M= 5,517 Ib -ft, from "Columns" sheet Minimum Column Dimension, OD= 5.300 in, perpendicular to sign face Number of Bolts, n= 2 per line front and back Bolt Line Spacing, L= 11.00 in, from front to back Base Plate Dimensions: N= 14.00 in B= 14.00 in Tension per Bolt Line, T= 6,019 Ib, = M/L (simple moment couple) Maximum Moment on the Plate, Mpl= 17,153 Ib -in, = (T)((L-OD)/2) Plate Thickness w/o Gussets, t= 0.45 in, = Sgrt((6M)/(Fb B) (2 matching plates greater than or equal to the calculated thickness) Bolt Design (using A325N High Strength Bolts, bearing connection) Tension per Bolt, Tb= 3,009 Ib, = Tin Required Area for Bolt, Ab= 0.07 sq in, = Tb/Ft, using Ft= 44,000 psi Min. Bolt Diameter, Db= 0.30 in Actual Bolt Diameter to by Used= 1.00 in, A325N High Strength Bolts Total Shear Load at Plate Elevation, V= 1,672 Ib, see "Column" sheet Shear stress per bolt, fv= 1,064 psi, = V/(n Ab) Allowed Tension Stress with Shear, Ft= 43,943 psi, = sgrt(FtA2 - 4.39(fv)A2) Actual Tension Stress per Bolt, ft= 3,832 psi, = Tb/Ab OK Bearing is negligible. Sign Engineering 3.1 (C) 1998 Young Electric Sign Company eneineeRine • JOB NAME CENTRAL PARK LOCATION REXBURG, ID DATE 8/21/00 BYD.R./B.J. DESCRIPTION SIGN 5TRUCTURE JOB NO. OGD BHT '7 OF L p _I N b"(.280)P I PE ASTM A53B (EXISTING, 1 W PLATE) F$•� , 10"(.365) PIPE ASTM A55B 22'-4" LONG Ig4i7 UBG SOmph G 1'-2" 1 #-7 BAR A615 GRADE 60 ®12" O.C. EACH DIR. TOPE BOTT. MIN. 5" COVER PL,4TE CONN. SCALE : 1 1/2" = 1'-0: 1 1/2" = 1'-O" UBC SOIL CLA55 4 r 'ISANDY-CLAY. �/ �� I" DIA. � IF SOIL oENGINEER ICONDITIONS \\ ! lY1 -:- s• Pb= 2,500p5i @ 28 DAYS #9 REINF. BAR, -0" BOLTS STRUCTURAL n SCALE: I/4" = I' -O" (4) Fle: F\Lrq rcc•:ngA,prt, vdngsVC�rrertACenbal °ark Rex0,rg. dwg S" t. Lerre. :�t Ycdfiea: h..g 21, 2000 - '_48,, PL 3/4 x , �� 14 x I'-2 �� Q �- Q ASTM A56 _ 43 04EXISTING TO MATCH r I/4 Ei0 1/4 TELESCOPIC 1 #-7 BAR A615 GRADE 60 ®12" O.C. EACH DIR. TOPE BOTT. MIN. 5" COVER PL,4TE CONN. SCALE : 1 1/2" = 1'-0: 1 1/2" = 1'-O" UBC SOIL CLA55 4 r 'ISANDY-CLAY. CONTACT � IF SOIL oENGINEER ICONDITIONS DIFFER. 4SEE ! lY1 -:- s• Pb= 2,500p5i @ 28 DAYS #9 REINF. BAR, -0" PLAN ABOVE STRUCTURAL ELEVATION SCALE: I/4" = I' -O" Fle: F\Lrq rcc•:ngA,prt, vdngsVC�rrertACenbal °ark Rex0,rg. dwg S" t. Lerre. :�t Ycdfiea: h..g 21, 2000 - '_48,, Uo"I vv avil la. al Fnn oul 400 vC80 IZDW ,, 1UAHV NALLS wjuljz ®enooneeAinG JOB NAME CENTRAL PARK LOCATIONREXBUR�, ID GATE 5I2I/00 BYD.R./B.J. DESCRIPTION 516N 51RUCTURE JOB NO. 060 5HT '7 OF wescoo V ,I in AIR ro\ D 6"(.2&0)PIPE ASTM A53B (EXISTINcs, w/ PLATE) 1011(.565) PIPE ASTM A555 ri 22'-4" LON& E' Iggi UBC SOrnph C NA'4Rr st utq quet4m- wq � Ta gE V��l�►�+Y� d W 0 0 'I'DIA. A525 BOLTS (4) 4PL 5/4 x 14 x I'-2 _ ASTM A56 TO MATCH 1/4 E?01 EXISTIN6 1/4 TELESCOPIC PLATE CONN. SCAN 1/2" = 1'-0" t i — UBC SOIL GLASS 4 SANDY -CLAY. CONTACT EN6INEER IP SOIL = GONDITIONS DIPPER. ( f'c 2,500pai ®2S DAYS STnCTURAL ELEVATION SCALE : 1/4" = 1'_0" File: F:\Engineering\Drawings\Current\Centroi Park Re,burg.dwg Sheet: Letter Last Modified: Aug 21, 2000 — 1:20pm