Butner_Tower Procurement Package_11-07-2024_R1.pdf

Tower Procurement Package Butner

November 07, 2024 Revision 1

3227 Wellington Court Raleigh, NC 27615 (919) 782-2710

Site Name: Butner

Site Address: 300 Veasey Road, Butner, NC 27509

Latitude: 36.143244 °

Longitude: -78.767803°

Structure Type: Proposed 380.0-ft Self Support Tower

Contact Information:

Contact the owner with questions regarding the content of this Document. All questions or concerns shall be directed to the contact stipulated in the Bid Document.

Design Capacity: The tower shall be designed so that, once installed with all loading as shown in Table 1 - Design Antenna/Coax Loading, the tower superstructure and substructure shall NOT exceed 95% of its capacity. If, upon evaluation, the design computes to be at a greater stress level than specified the bid will not be accepted. All bidders must provide design calculations verifying that this Design Capacity Requirement is met; see “Deliverables” for details.

Materials: Tower structures shall utilize structural steel round or polygonal poles only. No other materials or shapes shall be given consideration. Structural bolts must meet the ASTM A325 specification, or equivalent if approved by the design engineer of record.

Design Fall Radius:

No Fall Radius Required Fall Radius Required from Centerline of Tower: 50-ft

Standard: ☒ As a minimum, all towers shall be designed to the requirements of ANSI/TIA-222-G, including released addendums

Design Wind Speed:

☒ 120 mph ultimate 3-second gust wind speed (converted to an equivalent 93 mph nominal 3-second gust wind speed per Section 1609.3.1 for use with TIA-222-G) as required by the 2018 North Carolina State Building Code (2015 IBC) and ASCE 7-10.

Structure Class: ☐

Structure Class I – Low Hazard Structure Class II – Significant Hazard (Default) Structure Class III – Substantial Hazard

Risk Category: ☐

Risk Category I – Low Hazard Risk Category II – Moderate Hazard (Default) Risk Category III – Substantial Hazard Risk Category IV – Essential Hazard (Essential Communications)

Topographic Category:

Category I – No abrupt changes in general topography Category II – Structures located at or near the crest of an escarpment Category III – Structures located in the upper half of a hill Category IV – Structures located in the upper half of a ridge Category V – Wind speed up criteria based on a site-specific investigation (see attached)

Exposure Category:

Exposure B – Urban and Suburban Areas Exposure C – Open Terrain where Exposure B or D does not apply.

Exposure D – Flat, Unobstructed Shorelines

Design Ice Loading:

Not required ANSI/TIA-222-H: x.xx inch escalating with a xx mph 3 second gust wind speed ANSI/TIA-222-G: 0.75 inch escalating with a 30 mph 3 second gust wind speed ANSI/TIA/EIA-222-F: x.xx inch escalating with an xx mph fastest mile wind speed

November 07, 2024

Seismic: ☒

Seismic Ss: 0.145 / Seismic S1: 0.073 / Seismic TL: 8 Ss exceeds 1.0. Seismic loads shall be evaluated in accordance with the Standard

Tower Finish: ☒

Galvanized Painted per FAA Advisory Circular AC 70/7460-1K Painted per Local Requirements All structural steel products shall be hot dip galvanized in accordance with ASTM A123 specifications. Tower manufacturer shall produce documentation verifying the appropriate galvanizing process is utilized. All steel hardware shall be galvanized in accordance with ASTM A153 or ASTM B695 specifications

Tower Lights: ☐

Not Required Tower lighting system with E2 Avian Compliant Obstruction Lighting System (white strobes by day, and red lights at night). Beacons and Obstruction lights shall be all LED and Dual Red/White medium intensity and shall meet the requirements of FAA Advisory Circular AC 70/7460-1K.

Towers 200-ft to 350-ft Tower lighting system with E2 Avian Compliant Obstruction Lighting System (white strobes by day, and red lights at night). Beacons and Obstruction lights shall be all LED and Dual Red/White medium intensity and shall meet the requirements of FAA Advisory Circular AC 70/7460-1K. A lighting system by Drake Lighting, that complies with the FAA regulation, is required.

Towers over 350-ft

Grounding: ☒ Grounding, lightning protection, and surge protection systems shall be installed as required in compliance with R56 specifications and the construction documents. Coordinate with the Duke Energy bid administrator for the portion of tower grounding scope of work as shown in the construction documents. Minimum of the tower ground ring, connections from the ring to the tower, the bottom tower ground bar, and the connection from the tower ground ring to the bottom ground bar shall be included.

Climbing Facilities:

Not Required A safety fall protection system incorporating a 3/8” diameter stainless steel cable meeting OSHA/ANSI specifications shall be installed the full height of the structure on a full height face mounted external ladder. Additionally, step pegs are required on all three tower legs to the height of the mid markers.

A safety fall protection system incorporating a 3/8” diameter stainless steel cable meeting OSHA/ANSI specifications shall be installed the full height of the pole with full height step pegs.

Ice Bridge: ☒

Not required; Another contractor to provide Provide an option for Ice Bridge

Transmission Ladder:

Not required; carrier to provide Provide (1) Transmission Ladder. Include “per foot” pricing.

Foundation: ☐

Provide Preliminary Design using Presumptive Soil Parameters per the TIA-222-G Standard (Annex F). A Geotechnical Report will be provided later for the final foundation design.

Design with Geotechnical Report provided. In accordance with ANSI/TIA-222-G, Annex A, Section A.9.0, the tower manufacturer shall ensure the proper development of anchor rods and anchorage materials.

Antenna Mounts: ☐

Not required; Antenna Mounts provided by carrier.

Provide mounts per Table 1 – Design Antenna/Coax Loading

November 07, 2024

Additional Design Requirements

Structural Guidelines:

All leg capacities for lattice towers shall be computed utilizing a global effective length factor (K) of 1.0. All leg capacities shall be calculated utilizing the working points between panel points. Utilizing the side (gusset) plate length to reduce the un-braced length of the leg is not permitted. Leg members must consist only of steel solid rod and angle members.

Tubular steel leg members are not permitted (Not applicable to monopoles).

For round leg latticed towers, bracing member capacities shall be calculated considering the effective length to be the span between the weld lines of the gusset plates at the face of the round legs for both out-of-plane and in-plane buckling modes (Not applicable to monopoles).

Hardened galvanized flat washers (ASTM F436) shall only be used in fully tensioned bolted connections and connections that utilize oversized or slotted holes.

Linear Appurtenances:

The tower analysis model shall include all feed lines, feed line ladders, step pegs, climbing ladder and safety climb.

Discrete Appurtenances:

Effective Projected Area (EPA)A for antennas shall be determined according to TIA-222-G, Section 2.6.9.2, Design Wind Force on Appurtenances. If antenna or mount areas are specified, the provided values shall be used in lieu of calculated values. If height, width, and depth dimensions are provided by the antenna manufacturer, the panel shall be treated as a flat rectangular panel. Force coefficients shall be determined based on antenna aspect ratios and multiplied by the projected areas to calculate front and side EPAs.

Wind tunnel test results shall NOT be used unless the results have been provided to ETS and proposed effective areas have been approved. Back-calculating wind areas from published antenna manufacturer’s wind loads are prohibited.

Deliverables: [Once awarded, Final Deliverables shall bear the seal of a North Carolina Professional Engineer]

A PDF softcopy of all deliverables shall be sent to ETS for recording purposes. All tower designs shall be complete with the following:

General Notes Profile drawing (with tower reactions, design drawings, materials grades and referenced codes and standards shall be clearly shown) Foundation design drawings Supporting design calculations for tower and foundation Listing of main structural members Mount documentation specifically showing total EPA

November 07, 2024

Table 1 - Design Antenna/Coax Loading

Notes:

A-Leg orientation is set to an azimuth of ~10 degrees. The final orientation is set per the issued construction drawings

1) Minimum Total Mount EPA per latest vendor documentation

2) Ice Shields over all Microwaves are to be supplied, but installed by others

3) Reserved Loading to be included in initial tower design

4) The builder will supply side arms with side struts for all dipole and omni antennas listed above. However, tower manufacturer shall design tower so that all side arms with side struts are included in the loading.

5) The builder will supply microwave pipe mounts, side arms, and high wind kits for all microwaves listed above. However, the tower manufacturer shall design the tower so that all microwaves have pipe mounts, side arms, and high wind kits that are included in the loading.

November 07, 2024

Appendix A

Verification of Design Loads

ASCE Hazards Report Address:

No Address at This Location

Standard: ASCE/SEI 7-10 Latitude: 36.143244

Risk Category: IV Longitude: -78.767803

Soil Class: D - Stiff Soil Elevation: 385.4451840993373 ft

(NAVD 88)

Wind

Results:

Wind Speed 120 Vmph

10-year MRI 76 Vmph

25-year MRI 84 Vmph

50-year MRI 90 Vmph

100-year MRI 96 Vmph

Data Source: ASCE/SEI 7-10, Fig. 26.5-1B and Figs. CC-1–CC-4, and Section 26.5.2, incorporating errata of March 12, 2014Date Accessed: Thu Oct 24 2024

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 7-10 Standard. Wind speeds correspond to approximately a 3% probability of exceedance in 50 years (annual exceedance probability = 0.000588, MRI = 1,700 years).

Site is not in a hurricane-prone region as defined in ASCE/SEI 7-10 Section 26.2.

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SS : 0.145

S1 : 0.073

Fa : 1.6

Fv : 2.4

SMS : 0.232

SM1 : 0.176

SDS : 0.155

SD1 : 0.117

TL : 8

PGA : 0.067

PGA M : 0.107

FPGA : 1.6

Ie : 1.5

Seismic Design Category: C Design Response Spectrum

S (g) vs T(s)a

MCE Response SpectrumR

S (g) vs T(s)a

Seismic

D - Stiff SoilSite Soil Class:

Results:

Data Accessed: Thu Oct 24 2024

Date Source:

USGS Seismic Design Maps based on ASCE/SEI 7-10, incorporating Supplement 1 and errata of March 31, 2013, and ASCE/SEI 7-10 Table 1.5-2. Additional data for site-specific ground motion procedures in accordance with ASCE/SEI 7-10 Ch. 21 are available from USGS.

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Ice

Results:

Data Source:

Date Accessed:

Ice Thickness: 0.75 in.

Concurrent Temperature: 15 F

Gust Speed 30 mph

Standard ASCE/SEI 7-10, Figs. 10-2 through 10-8

Thu Oct 24 2024

Ice thicknesses on structures in exposed locations at elevations higher than the surrounding terrain and in valleys and gorges may exceed the mapped values.

Values provided are equivalent radial ice thicknesses due to freezing rain with concurrent 3-second gust speeds, for a 50-year mean recurrence interval, and temperatures concurrent with ice thicknesses due to freezing rain.

Thicknesses for ice accretions caused by other sources shall be obtained from local meteorological studies. Ice thicknesses in exposed locations at elevations higher than the surrounding terrain and in valleys and gorges may exceed the mapped values.

The ASCE 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 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.

ASCE does not intend, nor should anyone interpret, the results provided by this Tool to replace the sound judgment of a competent professional, having knowledge and experience in the appropriate field(s) of practice, nor to substitute for the standard of care required of such professionals in interpreting and applying the contents of this Tool or the ASCE standard.

In using this Tool, you expressly assume all risks associated with your use. Under no circumstances shall ASCE or its officers, directors, employees, members, affiliates, or agents be liable to you or any other person for any direct, indirect, special, incidental, or consequential damages arising from or related to your use of, or reliance on, the Tool or any information obtained therein. To the fullest extent permitted by law, you agree to release and hold harmless ASCE from any and all liability of any nature arising out of or resulting from any use of data provided by the ASCE Hazard Tool.

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November 07, 2024

Appendix B

Site Vicinity and Location Map

Exposure Category C Topographic Category I

Legend

36.143244,-78.767803

Feature 1

1 mi

N

N Image © 2024 Airbus

Image © 2024 Airbus

Image © 2024 Airbus