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HomeMy WebLinkAboutANTENNA MOUNT ANALYSIS - 19-00764 - 117 N 2nd E - Verizon Wireless - Cell Tower Utah Market Office 7896 South Highland Drive Suite 200 Cottonwood Heights, UT 84121 Tel (801) 463-1020 www.taec.net November 14, 2019 Verizon Wireless 9656 South Prosperity Road West Jordan, UT 84088 Subject: Antenna Mount Analysis Site Designation: ID6 Rexcamp 117 North 2nd East Rexburg, Idaho This letter is to confirm TAEC’s structural assessment of the existing Verizon Wireless antenna mounting system at the site noted above. The intent of the review is to determine if the proposed modification of antennas and equipment will exceed the structural capacity of the mounting system. The analysis assumes compliance with the 2015 IBC with Idaho amendments and TIA-222-G “Structural Standard for Antenna Supporting Structures and Antennas”, using a 115 mph ultimate wind speed converted to a 90 mph (3-sec gust) nominal design wind speed with no ice (IBC 1609.1.1-Exception 5), and a 50 mph wind speed with 1/4" ice thickness. The proposed equipment will be mounted to an existing T-Arm mount attached to the tower structure at a rad center elevation of 66.5’ above ground level. Existing equipment and mount structural data has been obtained from a tower mapping by Geostructural dated 11/07/2019. All existing geometry is assumed to be consistent with these documents. The equipment loading considered for this analysis is shown in the following table. Sector Existing Proposed Alpha (310°) (1) Antel BXA-80090-8CF Antenna (2) Amphenol HEX656CW0000G Antenna (1) ALU B4 RRH2x60 (1) ALU B25 RRH4x30 (1) Raycap RRODC-3515-PF-48 (1) Antel BXA-80090-8CF Antenna (2) Amphenol HEX656CW0000G Antenna (1) Ericsson RRUS 4449 (1) Ericsson RRUS 8843 (1) Raycap RRODC-3515-PF-48 Beta (70°) (1) Antel BXA-80090-8CF Antenna (2) Amphenol HEX656CW0000G Antenna (1) ALU B4 RRH2x60 (1) ALU B25 RRH4x30 (1) Raycap RRODC-3515-PF-48 (1) Antel BXA-80090-8CF Antenna (2) Amphenol HEX656CW0000G Antenna (1) Ericsson RRUS 4449 (1) Ericsson RRUS 8843 (1) Raycap RRODC-3515-PF-48 Gamma (200°) (1) Antel BXA-80063-8CF Antenna (2) Amphenol HEX656CW0000G Antenna (1) Antel BXA-80063-8CF Antenna (2) Amphenol HEX656CW0000G Antenna Utah Market Office 7896 South Highland Drive Suite 200 Cottonwood Heights, UT 84121 Tel (801) 463-1020 www.taec.net (1) ALU B4 RRH2x60 (1) ALU B25 RRH4x30 (1) Ericsson RRUS 4449 (1) Ericsson RRUS 8843 By engineering analysis and comparison, the existing antenna mounts have adequate capacity to support the proposed loading as shown herein without causing an overstress condition. This analysis assumes the existing mounts were installed per manufacturer’s recommendations, and are in adequate condition to carry their full design capacity. This analysis pertains to the final installed condition under static weight and wind loading only. Analysis and certification of the existing tower structure may be performed by others and will be submitted separately. Sincerely, Emilio Mario Valerio Hernandez, PE Search Information Coordinates:43.829217, -111.779125 Elevation:ft Timestamp:2019-11-14T17:29:39.196Z Hazard Type:Seismic Reference Document: ASCE7-10 Risk Category:II Site Class:D MCER Horizontal Response Spectrum Design Horizontal Response Spectrum Basic Parameters Name Value Description SS 0.446 MCER ground motion (period=0.2s) S1 0.157 MCER ground motion (period=1.0s) SMS 0.644 Site-modified spectral acceleration value SM1 0.341 Site-modified spectral acceleration value SDS 0.429 Numeric seismic design value at 0.2s SA SD1 0.227 Numeric seismic design value at 1.0s SA Additional Information Name Value Description SDC D Seismic design category Fa 1.443 Site amplification factor at 0.2s Fv 2.171 Site amplification factor at 1.0s CRS 1.033 Coefficient of risk (0.2s) CR1 1.066 Coefficient of risk (1.0s) PGA 0.158 MCEG peak ground acceleration FPGA 1.485 Site amplification factor at PGA Map data ©2019 Google 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Period (s) 0.00 0.10 0.20 0.30 0.40 0.50 0.60 Sa(g) 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Period (s) 0.00 0.10 0.20 0.30 0.40 Sa(g) ATC Hazards by Location https://hazards.atcouncil.org/#/seismic?lat=43.829217&lng=-111.77912... 2 of 2 11/14/2019, 9:30 AM Search Information Coordinates:43.829217, -111.779125 Elevation:ft Timestamp:2019-11-14T17:28:19.681Z Hazard Type:Wind ASCE 7-16 MRI 10-Year 75 mph MRI 25-Year 81 mph MRI 50-Year 86 mph MRI 100-Year 91 mph Risk Category I 99 mph Risk Category II 106 mph Risk Category III 112 mph Risk Category IV 117 mph ASCE 7-10 MRI 10-Year 76 mph MRI 25-Year 84 mph MRI 50-Year 90 mph MRI 100-Year 96 mph Risk Category I 105 mph Risk Category II 115 mph Risk Category III-IV 120 mph ASCE 7-05 ASCE 7-05 Wind Speed 90 mph The results indicated here DO NOT reflect any state or local amendments to the values or any delineation lines made during the building code adoption process. Users should confirm any output obtained from this tool with the local Authority Having Jurisdiction before proceeding with design. Disclaimer Hazard loads are interpolated from data provided in ASCE 7 and rounded up to the nearest whole integer. Per ASCE 7, islands and coastal areas outside the last contour should use the last wind speed contour of the coastal area – in some cases, this website will extrapolate past the last wind speed contour and therefore, provide a wind speed that is slightly higher. NOTE: For queries near wind- borne debris region boundaries, the resulting determination is sensitive to rounding which may affect whether or not it is considered to be within a wind-borne debris region. Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions. While the information presented on this website is believed to be correct, ATC and its sponsors and contributors assume no responsibility or liability for its accuracy. The material presented in the report should not be used or relied upon for any specific application without competent examination and verification of its accuracy, suitability and applicability by engineers or other licensed professionals. ATC does not intend that the use of this information replace the sound judgment of such competent professionals, having experience and knowledge in the field of practice, nor to substitute for the standard of care required of such professionals in interpreting and applying the results of the report provided by this website. Users of the information from this website assume all liability arising from such use. Use of the output of this website does not imply approval by the governing building code bodies responsible for building code approval and interpretation for the building site described by latitude/longitude location in the report. Map data ©2019 Google ATC Hazards by Location https://hazards.atcouncil.org/#/wind?lat=43.829217&lng=-111.779125&... 2 of 2 11/14/2019, 9:28 AM Site #:Date: Site Name:Design by: TIA-222-G Wind Loading ASCE 7-10 Ultimate Wind Speed Vult=115 mph (3-sec gust) TIA-222-G Design Wind Speed Vasd=90 mph (3-sec gust)Annex B 3 sec Gust w/ice Vice=50 mph Annex B Design ice thickness ti=0.25 inches Annex B Escalated ice thickness tiz=0.54 inches Gust Effect Factor GH=1.00 Section 2.6.7 & 2.6.9 Wind Direction Factor Kd=0.85 Table 2-2 Structure Class/Risk Cat.II Exposure Category C Topographic Category 1 Crest Height 0 feet Avg. Equipment Height h=76 feet Velocity Pressure Coefficient Kz=1.19 Table 2-4 Topographic Coefficient Kzt=1.00 Table 2-5 Wind Importance Factor Iwind=1.00 Table 2-3 Wind + Ice Importance Factor Iwind+ice=1.00 Appurtenance Shielding Factor Ka=1.00 2.6.9.2 Velocity Pressure q=21.1 psf Velocity Pressure, q z = 0.00256 * K z * K zt * K d * V 2 * I Critical Sector Appurtenance Loading Wind pressure (p Front Side Front Side no ice w/ ice qz * GH * Ka no ice w/ ice no ice w/ice Amphenol HEX656CW0000G 8.59 5.62 9.01 6.05 51 52 21.1 181 59 118 39 Ericsson 8843 RRU 2.00 1.72 2.30 2.00 75 80 21.1 42 15 36 13 Ericsson 4449 RRU 2.00 1.45 2.30 1.71 70 74 21.1 42 15 30 11 Raycap RxxDC-3315-PF-48 3.88 2.61 4.30 2.99 32 38 21.1 82 28 55 19 Antel BXA-80063-8CF 10.67 5.53 11.20 6.18 24 25 21.1 225 73 116 40 Antel BXA-80090-8CF 8.29 6.45 8.85 7.05 23 24 21.1 175 58 136 46 Project Information CaAa w/ no ice (ft2)CaAa w/ ice (ft2)Weight(lb) Front Face Forces (lb) VZW ID6 Rexcamp 11/14/2019 EV Side Face Forces (lb)Description Project: VZW ID6 Rexcamp Date: 11-15-2019 By: EV Antenna Mount Analysis Antenna Mount Frame The antenna mount frame was analyzed using Risa-3D, a general purpose 3-dimensional structural analysis software. The software was used to compute member forces and support reactions for critical wind load cases as defined in TIA-222-G. The software was also used to perform steel code checks per AISC 14th ed. (LRFD). Risa-3D output is attached. Lateral Seismic Loading Per TIA-222-G Section 2.7.3, seismic effects may be ignored for this site due to the earthquake spectral response acceleration at short periods (Ss) being less than or equal to 1.0. Site specific ground motion parameters were obtained from USGS earthquake hazard maps using soil site class D, attached to this report. 7896 South Highland Drive Suite 200 Cottonwood Heights, UT 84121 Tel. (801) 463-1020 Page 1 of 5 Project: VZW ID6 Rexcamp Date: 11-15-2019 By: EV Pipe to boom connection check (2) 1/2" dia. U-bolts in 3/8" th. plate, A307 min. assumed bolt grade, A36 assumed plate grade. ≔db 0.5 ≔Ab =⋅db 2 ―4 0.196 2 ≔N 2 Max member forces at connection per Risa-3D output, ≔A 135 ≔Vy 183 ≔Vz 218 Bolt tension,≔ft =― Vz N 109 Bolt shear,≔fv = ‾‾‾‾‾‾‾‾‾‾‾ +⎛ ⎜⎝ ―A N ⎞ ⎟⎠ 2 ⎛ ⎜ ⎝ ―Vy N ⎞ ⎟ ⎠ 2 114 Bolt Shear Strength:≔ϕrnv =⋅20.3 Ab 3986 (AISC Table 7-1) =⎛⎝,,<fv ϕrnv “OK” “N.G.” ⎞⎠“OK” = ⎛ ⎜ ⎝ ,,<―― fv ϕrnv 0.3 “No Combined Check Req” “Check Combined” ⎞ ⎟ ⎠ “No Combined Check Req” Bolt Tension Strength:≔ϕrnt =⋅33.8 Ab 6637 (AISC Table 7-2) =⎛⎝,,<ft ϕrnt “OK” “N.G.”⎞⎠“OK” Steel Bearing Strength:≔Fu 58 ≔t 0.375 Edge Dist,≔Le 0.75 ≔Lc =-Le ――――― +db 0.125 2 0.4375 ≔ϕ 0.75 ≔ϕrnb =⋅⋅⋅ϕ 1.24 Fu tLc 8850 =⎛⎝,,<fv ϕrnb “OK” “N.G.” ⎞⎠“OK” 7896 South Highland Drive Suite 200 Cottonwood Heights, UT 84121 Tel. (801) 463-1020 Page 2 of 5 Project: VZW ID6 Rexcamp Date: 11-15-2019 By: EV Stand-off to boom connection check (4) 5/8" dia. bolts in 3/8" th. plate, A307 min. assumed bolt grade, A36 assumed plate grade. ≔db 0.625 ≔Ab =⋅db 2 ―4 0.307 2 ≔N 4 Max member forces at connection per Risa-3D output, ≔A 312 ≔Vy 209 ≔Vz 390 Bolt tension,≔ft =― Vz N 98 Bolt shear,≔fv = ‾‾‾‾‾‾‾‾‾‾‾ +⎛ ⎜⎝ ―A N ⎞ ⎟⎠ 2 ⎛ ⎜ ⎝ ―Vy N ⎞ ⎟ ⎠ 2 94 Bolt Shear Strength:≔ϕrnv =⋅20.3 Ab 6228 (AISC Table 7-1) =⎛⎝,,<fv ϕrnv “OK” “N.G.” ⎞⎠“OK” = ⎛ ⎜ ⎝ ,,<―― fv ϕrnv 0.3 “No Combined Check Req” “Check Combined” ⎞ ⎟ ⎠ “No Combined Check Req” Bolt Tension Strength:≔ϕrnt =⋅33.8 Ab 10370 (AISC Table 7-2) =⎛⎝,,<ft ϕrnt “OK” “N.G.”⎞⎠“OK” Steel Bearing Strength:≔Fu 58 ≔t 0.375 Edge Dist,≔Le 0.875 ≔Lc =-Le ――――― +db 0.125 2 0.5 ≔ϕ 0.75 ≔ϕrnb =⋅⋅⋅ϕ 1.24 Fu tLc 10114 =⎛⎝,,<fv ϕrnb “OK” “N.G.” ⎞⎠“OK” 7896 South Highland Drive Suite 200 Cottonwood Heights, UT 84121 Tel. (801) 463-1020 Page 3 of 5 Project: VZW ID6 Rexcamp Date: 11-15-2019 By: EV Stand-off connection check (4) 5/8" dia. bolts in 6"x4" pattern, A307 min. assumed bolt grade. ≔db 0.625 ≔Ab =⋅db 2 ―4 0.307 2 ≔N 4 Max reactions at connection per Risa-3D output, ≔X 642 ≔Y 444 ≔Z 795 ≔Mx ⋅437 ≔My ⋅635 ≔Mz ⋅12 Standoff arm: Square tube weld properties: ≔d 4 ≔t 0.1875 ≔dT =+dt4.188 ≔r =―dT 2 2.094 ≔p =4 dT 16.75 ≔Sw =――― ⋅4 dT 2 3 23.38 2 ≔Jw =――― ⋅4 dT 3 3 97.9 3 Weld force,≔V ‾‾‾‾‾‾‾+X2 Y2 ≔fweld = ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ + ⎛ ⎜ ⎝ ++――My Sw ――Mx Sw ―Z p ⎞ ⎟ ⎠ 2 ⎛ ⎜ ⎝ +―V p ――⋅Mz r Jw ⎞ ⎟ ⎠ 2 600 ― Allowable Weld force,≔Tw 0.1875 ≔Fyw 70 ≔ϕ 0.75 ≔Fallow =⋅⋅⋅ϕ ―― ‾‾2 2 Tw 0.6 Fyw 4176 ― =⎛⎝,,<Fallow fweld “N.G.” “OK” ⎞⎠“OK” Bolt check ≔r =‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾2 ⎛⎝+((3 )) 2 ((2 )) 2 ⎞⎠3.606 ≔J =⋅⋅4 r2 Ab 15.953 4 7896 South Highland Drive Suite 200 Cottonwood Heights, UT 84121 Tel. (801) 463-1020 Page 4 of 5 Project: VZW ID6 Rexcamp Date: 11-15-2019 By: EV Bolt shear,≔fv =⋅Ab ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ +⎛ ⎜⎝ +――X NAb ⋅⋅.707 Mz ―r J ⎞ ⎟⎠ 2 ⎛ ⎜⎝ +――Y NAb ⋅⋅.707 Mz ―r J ⎞ ⎟⎠ 2 205 Bolt tension,≔ft =++―Z N ――― My ⋅6 2 ――― Mx ⋅4 2 1489 Bolt Shear Strength:≔ϕrnv =⋅20.3 Ab 6228 =⎛⎝,,<fv ϕrnv “OK” “N.G.”⎞⎠“OK” = ⎛ ⎜ ⎝ ,,<――fv ϕrnv 0.3 “No Combined Check Req” “Check Combined” ⎞ ⎟ ⎠ “No Combined Check Req” Bolt Tension Strength:≔ϕrnt =⋅33.8 Ab 10370 (AISC Table 7-2) =⎛⎝,,<ft ϕrnt “OK” “N.G.” ⎞⎠“OK” 7896 South Highland Drive Suite 200 Cottonwood Heights, UT 84121 Tel. (801) 463-1020 Page 5 of 5 TAEC EV VZW ID6 Rexcamp Antenna Mount SK - 2 Nov 14, 2019 at 11:10 AM ID6 Rexcamp_Antenna mount_20... M1 M2 M3 M4 M 5 Y XZ Envelope Only Solution TAEC EV VZW ID6 Rexcamp Antenna Mount SK - 3 Nov 14, 2019 at 11:11 AM ID6 Rexcamp_Antenna mount_20... -8lb/ft -8lb/ft -70lb -75lb Y XZ Loads: BLC 1, Dead Envelope Only Solution TAEC EV VZW ID6 Rexcamp Antenna Mount SK - 4 Nov 14, 2019 at 11:11 AM ID6 Rexcamp_Antenna mount_20... -19lb/ft -5lb/ft -19lb/ft -5lb/ft -6lb/ft -9lb/ft -30lb -36lb Y XZ Loads: BLC 2, Wind-X Envelope Only Solution TAEC EV VZW ID6 Rexcamp Antenna Mount SK - 5 Nov 14, 2019 at 11:11 AM ID6 Rexcamp_Antenna mount_20... -4lb/ft -29lb/ft -5lb/ft -29lb/ft -5lb/ft -6lb/ft -42lb -42lb Y XZ Loads: BLC 3, Wind-Z Envelope Only Solution