structural analysis of water tank for proposed t …
TRANSCRIPT
STRUCTURAL ANALYSIS OF WATER TANK
FOR PROPOSED T-MOBILE EQUIPMENT
118’ WATER TANK
201 137TH STREET
OCEAN CITY, MD 21842
SITE NAME: OCEAN CITY NORTH
SITE ID: 7SAL048A
PROJECT NAME: 2021 ANCHOR & L600
Prepared For:
T-Mobile Northeast LLC
12050 Baltimore Avenue
Beltsville, MD 20705
Prepared by:
Advantage Engineers 7151 Columbia Gateway Drive, Suite A, Columbia, MD 21046 – (443) 367-0003
November 16, 2021 – AE Project # P-022143
TABLE OF CONTENTS
1.0 OBJECTIVE
Table 1 – Documentation
2.0 EXISTING & FINAL APPURTENANCES
Table 2 – Existing Discrete and Linear Appurtenances
Table 3 – Final T-Mobile Discrete and Linear Appurtenances
3.0 ANALYSIS STANDARDS
4.0 ANALYSIS METHOD
5.0 ANALYSIS ASSUMPTIONS
6.0 CONCLUSION
APPENDIX A CALCULATIONS
APPENDIX B ASCE 7 HAZARDS REPORT
November 16, 2021
Site Name: OCEAN CITY NORTH
Site ID: 7SAL048A
Project Name: 2021 ANCHOR & L600
1
1.0 OBJECTIVE
The objective of this report is to analyze the structural impact of the proposed T-Mobile installation on the
water tank supporting the antenna mounts at the above referenced address.
Advantage Engineers (AE) has reviewed the following documentation which was used as the basis for this
assessment:
Table 1 -- Documentation
DOCUMENT DESCRIPTION DATE
L700 Structural Analysis Maser, Project # 15951003A 10-20-15
Water Tank Mapping TEP, Job # 74714-62288 12-23-16
Mount Analysis Armor Tower, Project TMO 7SAL048A 06-08-21
T-Mobile RFDS Version 7 06-11-21
2.0 EXISTING & FINAL APPURTENANCES
Below is a list of the existing and final discrete and linear appurtenances located on the water tank that
were considered in this analysis:
Table 2 -- Existing Discrete and Linear Appurtenances
RAD CENTER APPURTENANCE1 MOUNT COAX
123’-0” Ocean City
(1) 5’ Dish
(1) 4’ Dish
(1) 2’ Dish
(1) 15’ Omni
(3) Tripods on
Top of Tank
(3) 7/8
(1) Microwave
Trunk
115’-0” Verizon
(6) X7C-FRO-840-V
(3) X7C-865-V
(3) AHCA
(3) B13 RRH4X30
(3) B25 RRH4X30-4R
(6) ETW200VS12UB
(12) Tripods w/
Horizontals on Tank
(12) 1-5/8
(3) 6x12 Hybrid
93-0” T-Mobile
(3) AIR21 B2A_B4P
(3) LNX-6515DS-A1M
(3) AIR32 B66A_B2A
(3) RRUS11 B12
(3) Twin Style 1B AWS TMA
(3) Sector Frames
on Legs
(12) 1-5/8
(3) 6x12 Hybrid
(1) 9x18 Hybrid
1- Italic represents equipment to be removed; Not considered in this analysis
Table 3 -- Final T-Mobile Discrete and Linear Appurtenances
RAD CENTER APPURTENANCE2 MOUNT COAX
93’-0”
(3) APXVAALL24_43-U-NA20
(3) AIR6449 B41
(3) VV-65A-R2B
(3) RADIO 4480 B71+B85A
(3) RADIO 4460 B25+B66
Use Existing
(3) 6x12 Hybrid
(1) 9x18 Hybrid +
(2) 6x12 Hybrid
2- Bold represents proposed equipment
November 16, 2021
Site Name: OCEAN CITY NORTH
Site ID: 7SAL048A
Project Name: 2021 ANCHOR & L600
2
3.0 ANALYSIS STANDARDS
The following design standards were used for this assessment:
Building Code: IBC 2018
Risk Category: IV
Wind Speed: 140 mph
Exposure Category: D
Topographic Category: 1
The following ASD load combinations were used for this analysis:
• 1.0 D + 0.6 W
• 1.0 D + 0.7 E
4.0 ANALYSIS METHOD
The analysis approach used in this report is founded on the premise that if the supporting structure, which
will be used to support the proposed equipment, is structurally adequate per the aforementioned codes
and standards, then the proposed equipment may be placed at the desired location. Calculations for this
analysis are provided in the Appendices of this report.
5.0 ANALYSIS ASSUMPTIONS
• The structure was built in accordance with the manufacturer’s specifications
• The structure has been maintained in accordance with the manufacturer’s specification
• All structure components are in sufficient condition to carry their full design capacity
• All mount members were properly installed
• All appurtenances were properly installed
If any assumptions are not valid or have been made in error, AE should be notified to determine the effect
on the structural integrity of the structure.
6.0 CONCLUSIONS
AE has determined that an overall structural analysis of the water tank is not required per IEBC 2018
because the proposed vertical loading represents an increase of less than 5% in the tank’s design vertical
loads. In addition, seismic controls the tank’s global lateral system; therefore, the proposed lateral loading
represents an increase of less than 10% in the tank’s design lateral loads. Thus, the proposed T-Mobile
equipment can be installed as intended.
The conclusions and recommendations reached in this analysis are only applicable for the components of
the structure directly supporting the previously listed T-Mobile telecommunications equipment. Any
deviation of the support, load, placement, etc. will require AE to generate an additional structural analysis.
Further, no structural qualification is made or implied by this analysis for any existing structural members
not directly impacted by the T-Mobile installation. AE reserves the right to append or modify this report as
more information becomes available.
November 16, 2021
Site Name: OCEAN CITY NORTH
Site ID: 7SAL048A
Project Name: 2021 ANCHOR & L600
3
If you have any questions, comments, or if you would like to discuss this in further detail, please feel free
to contact me at (443) 367-0003.
For Advantage Engineers:
Drew R. Mundt, PE
Maryland Professional Engineer
MD License #49864
Professional Certification. I hereby certify that these documents
were prepared or approved by me, and that I am a duly licensed
professional engineer under the laws of the State of Maryland,
License No. 49864, Expiration Date: 03-15-2022
11/16/2021
APPENDIX A
CALCULATIONS
Advantage Engineers, LLC Date: 07/13/20217151 Columbia Gateway Dr, Suite A Prepared By: DRM
Columbia, MD 21046 Job Number: P-022143
Applicable Codes: ASCE 7-16
Site Specific Inputs
Location:Structure Type: G: 0.85 Section 26.11.1Ultimate Wind Speed: 140 mph ASCE 7 Hazards Report Kd: 1.00 Section 26.6Risk Category: IV Section 1.5 Kd app: 0.85 Section 26.6Ground Elevation of Base: 6.48 ft Ke: 1.00 Section 26.9Exposure Category: D Section 26.7.3 Kzt: 1.00 Section 26.8.2Ground Snow Load: 20 psf ASCE 7 Hazards Report pf: 24.0 psf Section 7.3
Tank Wind Load: 194.6 kip Tank Dead Load: 6256.7 kip
Additional Wind Load Additional Dead LoadT-Mobile: 8.43 kip T-Mobile: 2.11 kipVerizon: 15.63 kip Verizon: 2.43 kipOcean City: 4.75 kip Ocean City: 0.45 kipCoax: 9.11 kip Coax: 2.58 kipTotal: 37.92 kip Total: 7.56 kip
Wind Load Increase: 19.49% Dead Load Increase: 0.12%
Water Tank Analysisfor T-Mobile
7SAL048A
2021 ANCHOR & L600
The proposed loading represents an increase of less than 5% in the water tank’s design vertical loads.
Seismic loading controls the water tank’s lateral system. Additionally, the proposed lateral seismic loading is less than a 10% increase in the water tank’s design lateral seismic loading.
Full analysis of the water tank is not required.
Water Tank Loading Increase Check Per 2018 IEBC, Sections 807.4 & 807.5
Multi-Leg
IBC 2018
Site Specific Outputs
Ocean City, MD
Water Tank Original Design Loading
Advantage Engineers, LLC Date: 07/13/20217151 Columbia Gateway Dr, Suite A Prepared By: DRM
Columbia, MD 21046 Job Number: P-022143
Tank Top Height: 118 ft Elevation: 103.33 ft Cf: 0.5
Tank Bottom Height: 74 ft Kz: 1.44 Area: 2354.33 ft2
Tank Diameter: 62.5 ft qz: 72.29 psf Wind Load: 30.72 psf
Flat Wall Height: 14.5 ft Total Force: 72.34 kip
Tank Volume: 750000 gal
MemberTop
Height (ft)
Length
(ft)
Diameter/
Width (in)Shape
Elevation
(ft)Kz
qz
(psf)Cf Area (ft2) Force (plf) Quantity
Total Force
(kip)
Leg 88.75 88.75 36.00 Round 59.17 1.31 65.61 0.70 266.25 117.12 7 72.76
Riser 74.00 74.00 96.00 Round 49.33 1.27 63.57 0.61 592.00 264.77 1 19.59
Strut 43.33 28.00 8.00 Flat 43.33 1.24 62.15 2.00 18.67 70.44 7 13.81
Top Diagonal 88.75 53.50 1.75 Round 70.92 1.35 67.71 1.20 7.80 10.07 14 7.54
Bottom Diagonal 43.33 51.50 1.75 Round 26.16 1.13 56.93 1.20 7.51 8.47 14 6.11
Top Horizontal 74.00 31.25 1.00 Round 74.00 1.36 68.21 1.20 2.60 5.80 7 1.27
Bottom Horizontal 43.33 31.25 1.00 Round 43.33 1.24 62.15 1.20 2.60 5.28 7 1.16
122.23
Water Tank Member Loads
Water Tank Loads
Water Tank Analysisfor T-Mobile
7SAL048A
2021 ANCHOR & L600
Advantage Engineers, LLC Date: 07/13/20217151 Columbia Gateway Dr, Suite A Prepared By: DRM
Columbia, MD 21046 Job Number: P-022143
Antenna Centerline (AGL): 93 ft
Velocity Pressure Coefficient Kz: 1.41 Section 26.10.1Velocity Pressure qz: 60.33 psf Section 26.10.2
Appurtenance Height (in) Width (in) Depth (in)Weight
(lbs)Cf EPAa (ft2) Force (lbs) Quantity Total Force (kip)
Total Weight
(kip)
APXVAALL24_43-U-NA20 96 24 8.5 123 1.35 21.60 1107.71 3 3.32 0.37
AIR 6449 B41 33.1 20.5 8.3 103 1.31 6.17 316.62 3 0.95 0.31
VV-65A-R1B 54.7 12.0 4.6 24.7 1.36 6.20 318.11 3 0.95 0.07
RADIO 4480 B71+B85A 21.8 15.7 7.5 84 1.31 3.11 159.25 3 0.48 0.25
RADIO 4460 B25+B66 19.6 15.7 12.1 109 1.30 2.79 142.92 3 0.43 0.33
Member Length (in) Width (in) TypeWeight
(lbs)Cf EPAa (ft2) Force (plf) Quantity Total Force (kip)
Total Weight
(kip)
Pipe Mount 72 2.375 Round 20.8 1.20 1.43 12.18 6 0.44 0.12
Pipe Mount 96 2.375 Round 27.8 1.20 1.90 12.18 3 0.29 0.08
Horizontal 120 2.375 Round 34.7 1.20 2.38 12.18 6 0.73 0.21
Support Pipe 144 4.5 Round 120.9 1.20 5.40 23.08 3 0.83 0.36
8.43 2.11
Water Tank Analysisfor T-Mobile
7SAL048A
2021 ANCHOR & L600
Member Weight & Wind Forces
Appurtenance Weight & Wind Forces
T-Mobile Loading
Advantage Engineers, LLC Date: 07/13/20217151 Columbia Gateway Dr, Suite A Prepared By: DRM
Columbia, MD 21046 Job Number: P-022143
Antenna Centerline (AGL): 115 ft
Velocity Pressure Coefficient Kz: 1.47 Section 26.10.1Velocity Pressure qz: 62.60 psf Section 26.10.2
Appurtenance Height (in) Width (in) Depth (in)Weight
(lbs)Cf EPAa (ft2) Force (lbs) Quantity Total Force (kip)
Total Weight
(kip)
X7C-FRO-840-V 98.5 18.8 9.1 58 1.37 17.63 937.93 6 5.63 0.35
X7C-865-V 96 12.5 7.1 40 1.42 11.86 630.86 3 1.89 0.12
AHCA 13.3 11.6 6.5 36.8 1.30 1.40 74.25 3 0.22 0.11
B25 RRH4X30-4R 21.4 12 7.2 51 1.31 2.34 124.60 3 0.37 0.15
B13 RRH 4X30 20.9 11.8 7.5 55.6 1.31 2.25 119.64 3 0.36 0.17
ETW200VS12UB 6.3 7.7 3.1 6.6 1.30 0.44 23.30 6 0.14 0.04
Member Length (in) Width (in) TypeWeight
(lbs)Cf EPAa (ft2) Force (plf) Quantity Total Force (kip)
Total Weight
(kip)
Pipe Mount 96 2.375 Round 27.8 1.20 1.90 12.64 15 1.46 0.42
Kicker 72 3 Flat 29.4 1.97 2.95 26.16 24 3.63 0.71
Horizontal Angle 150 3 Flat 61.3 2.00 6.25 26.61 6 1.92 0.37
15.63 2.43
Water Tank Analysisfor T-Mobile
7SAL048A
2021 ANCHOR & L600
Member Weight & Wind Forces
Verizon Loading
Appurtenance Weight & Wind Forces
Advantage Engineers, LLC Date: 07/13/20217151 Columbia Gateway Dr, Suite A Prepared By: DRM
Columbia, MD 21046 Job Number: P-022143
Antenna Centerline (AGL): 123 ft
Velocity Pressure Coefficient Kz: 1.49 Section 26.10.1Velocity Pressure qz: 63.34 psf Section 26.10.2
Appurtenance Height (in) Width (in) Depth (in)Weight
(lbs)Cf EPAa (ft2) Force (lbs) Quantity Total Force (kip)
Total Weight
(kip)
5' Dish 60 60 12 80 1.30 32.50 1749.74 1 1.75 0.08
4' Dish 48 48 12 60 1.30 20.80 1119.83 1 1.12 0.06
2' Dish 24 24 6 40 1.30 5.20 279.96 1 0.28 0.04
15' Omni 180 3 3 10 1.20 7.50 403.79 1 0.40 0.01
Member Length (in) Width (in) TypeWeight
(lbs)Cf EPAa (ft2) Force (plf) Quantity Total Force (kip)
Total Weight
(kip)
Pipe Mount 96 2.375 Round 27.8 1.20 1.90 12.79 3 0.29 0.08
Kicker 72 3 Flat 29.4 1.97 2.95 26.47 6 0.91 0.18
4.75 0.45
Water Tank Analysisfor T-Mobile
7SAL048A
2021 ANCHOR & L600
Member Weight & Wind Forces
Ocean City Loading
Appurtenance Weight & Wind Forces
Advantage Engineers, LLC Date: 07/13/20217151 Columbia Gateway Dr, Suite A Prepared By: DRM
Columbia, MD 21046 Job Number: P-022143
Carrier # of Coax # of Rows Width (in) Length (ft)Elevation
(ft)kz
qz
(psf)Cf
Area
(ft2)Force (plf) Force (kip)
Dead Load
(kip)
T-Mobile 6 3 5.94 85.0 56.7 1.30 65.12 1.2 42.075 32.88 2.79 0.51
Verizon 15 3 5.94 107.0 71.3 1.35 67.78 1.2 52.965 34.22 3.66 1.61
Ocean City 4 2 3.96 115.0 76.7 1.37 68.64 1.2 37.95 23.10 2.66 0.46
Coax Loading
Water Tank Analysisfor T-Mobile
7SAL048A
2021 ANCHOR & L600
Advantage Engineers, LLC Date: 07/13/20217151 Columbia Gateway Dr, Suite A Prepared By: DRM
Columbia, MD 21046 Job Number: P-022143
Soil Class: D Ie: 1.5 Table 1.5-2
SDS: 0.095 ASCE 7 Hazard Tool R: 3 Table 15.4-2
SD1: 0.058 ASCE 7 Hazard Tool Ct: 0.02 Table 12.8-2
TL: 8 s ASCE 7 Hazard Tool x: 0.75 Table 12.8-2
h: 74 ft Water Tank Dead Load supported at Riser Height T: 0.50 s Section 12.8.2.1
Cs: 0.0475 Section 12.8.1.1
Total Seismic Base Shear: 297.19 kip 0.7 E 208.03 kip ASCE 7 Load Combination 8
Total Wind Force: 232.49 kip 0.6 W 139.49 kip ASCE 7 Load Combination 5
The originally designed seismic forces are greater than the proposed lateral forces.
Seismic Loading
Total Lateral Forces Governing Lateral Load Check
Water Tank Analysisfor T-Mobile
7SAL048A
2021 ANCHOR & L600
APPENDIX B
ASCE 7 HAZARDS REPORT
ASCE 7 Hazards ReportAddress:No Address at This Location
Standard: ASCE/SEI 7-16
Risk Category: IV
Soil Class: D - Default (see Section 11.4.3)
Elevation: 6.48 ft (NAVD 88)
Latitude:Longitude:
38.441979
-75.055137
Wind
Results:
Wind Speed: 140 Vmph
10-year MRI 78 Vmph
25-year MRI 87 Vmph
50-year MRI 95 Vmph
100-year MRI 102 Vmph
Data Source: ASCE/SEI 7-16, Fig. 26.5-1D and Figs. CC.2-1–CC.2-4, and Section 26.5.2
Date Accessed: Mon Jul 12 2021
Value provided is 3-second gust wind speeds at 33 ft above ground for Exposure C Category, based on linear interpolation between contours. Wind speeds are interpolated in accordance with the 7-16 Standard. Wind speeds correspond to approximately a 1.6% probability of exceedance in 50 years (annual exceedance probability = 0.00033, MRI = 3,000 years).
Site is in a hurricane-prone region as defined in ASCE/SEI 7-16 Section 26.2. Glazed openings shall be protected against wind-borne debris as specified in Section 26.12.3.
Page 1 of 3https://asce7hazardtool.online/ Mon Jul 12 2021
SS : 0.089
S1 : 0.036
Fa : 1.6
Fv : 2.4
SMS : 0.143
SM1 : 0.086
SDS : 0.095
SD1 : 0.058
TL : 8
PGA : 0.043
PGA M : 0.068
FPGA : 1.6
Ie : 1.5
Cv : 0.7
Design Response Spectrum
S (g) vs T(s)a
MCE Response SpectrumR
S (g) vs T(s)a
Design Vertical Response Spectrum
S (g) vs T(s)a
MCE Vertical Response SpectrumR
S (g) vs T(s)a
Seismic
Site Soil Class:
Results:
Seismic Design Category
D - Default (see Section 11.4.3)
A
Data Accessed:
Date Source:
Mon Jul 12 2021USGS Seismic Design Maps based on ASCE/SEI 7-16 and ASCE/SEI 7-16 Table 1.5-2. Additional data for site-specific ground motion procedures in accordance with ASCE/SEI 7-16 Ch. 21 are available from USGS.
Page 2 of 3https://asce7hazardtool.online/ Mon Jul 12 2021
Snow
Results:
Ground Snow Load, p : 20 lb/ftg
2
Elevation: 6.5 ft
Data Source: ASCE/SEI 7-16, Table 7.2-8
Date Accessed: Mon Jul 12 2021
Values provided are ground snow loads. In areas designated "case study required," extreme local variations in ground snow loads preclude mapping at this scale. Site-specific case studies are required to establish ground snow loads at elevations not covered.
The ASCE 7 Hazard Tool is provided for your convenience, for informational purposes only, and is provided “as is” and without warranties of any kind. The location data included herein has been obtained from information developed, produced, and maintained by third party providers; or has been extrapolated from maps incorporated in the ASCE 7 standard. While ASCE has made every effort to use data obtained from reliable sources or methodologies, ASCE does not make any representations or warranties as to the accuracy, completeness, reliability, currency, or quality of any data provided herein. Any third-party links provided by this Tool should not be construed as an endorsement, affiliation, relationship, or sponsorship of such third-party content by or from ASCE.
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