S t r u c t u r a l D e s i g n o f A n t e n n a F r a m e a n d A n a l y s i s o f C L & P T o w e r A T & T M o b i l i t y S i t e R e f : C T 2 1 1 7 C L & P S t r u c t u r e N o . 7 8 3 7 8 ’ E l e c t r i c T r a n s m i s s i o n L a t t i c e T o w e r 2 0 0 E d g e m a r k A c r e s M e r i d e n , C T C E N T E K P r o j e c t N o . 1 3 3 0 5 D a t e : J a n u a r y 7 , 2 0 1 4 R e v 4 : O c t o b e r 6 , 2 0 1 4 Prepared for: AT&T Mobility 500 Enterprise Drive, Suite 3A Rocky Hill, CT 06067 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 T a b l e o f C o n t e n t s SECTION 1 - REPORT § INTRODUCTION § PRIMARY ASSUMPTIONS USED IN THE ANALYSIS § ANALYSIS § DESIGN BASIS § RESULTS § CONCLUSION SECTION 2 - CONDITIONS & SOFTWARE § STANDARD ENGINEERING CONDITIONS § GENERAL DESCRIPTION OF STRUCTURAL ANALYSIS PROGRAMS § RISA 3-D § PLS TOWER SECTION 3 - DESIGN CRITERIA § CRITERIA FOR DESIGN OF PCS FACILITIES ON OR EXTENDING ABOVE METAL ELECTRIC TRANSMISSON TOWERS § NU DESIGN CRITERIA TABLE § PCS SHAPE FACTOR CRITERIA § WIRE LOADS SHEET SECTION 4 - DRAWINGS § T-1 TITLE SHEET § N-1 DESIGN BASIS AND GENERAL NOTES § N-2 EARTHWORK AND FOUNDATION CONSTRUCTION NOTES § N-3 CONCRETE CONSTRUCTION NOTES § N-4 STRUCTURAL STEEL NOTES § MI-1 MODIFICATION INSPECTION REQUIREMENTS § S-1 TOWER ELEVATION AND FEEDLINE PLAN § S-2 FOUNDATION REINFORCEMENT DETAILS § S-3 TOWER REINFORCEMENT DETAILS § S-4 ANTENNA FRAME ELEVATIONS § S-5 ANTENNA FRAME PLAN AND DETAILS TABLE OF CONTENTS TOC-1 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 SECTION 5 - EIA/TIA-222-F LOAD CALCULATIONS FOR ANTENNA FRAME § ANTENNA FRAME WIND & ICE LOAD SECTION 6 - ANTENNA FRAME DESIGN PER EIA/TIA-222F § LOAD CASES AND COMBINATIONS (TIA/EIA LOADING) § RISA 3-D ANALYSIS REPORT § MAST CONNECTION ANALYSIS SECTION 7 - NECS/NU LOAD CALCULATIONS FOR OBTAINING REACTIONS APPLIED TO UTILITY STRUCTURE § ANTENNA FRAME WIND LOAD SECTION 8 – ANTENNA FRAME ANALYSIS PER NESC/NU FOR OBTAINING REACTIONS APPLIED TO UTILITY STRUCTURE § LOAD CASES AND COMBINATIONS (NESC/NU LOADING) § RISA 3-D ANALYSIS REPORT SECTION 9 - PLS TOWER RESULTS FROM ANTENNA FRAME REACTIONS CALCULATED IN RISA WITH NESC/NU CRITERIA § COAX CABLE LOAD ON CL&P TOWER CALCULATION § PLS REPORT § LOCAL STRESS CHECK – UNREINFORCED SECTION § LOCAL STRESS CHECK – REINFORCED SECTION § FOUNDATION ANALYSIS SECTION 10 - REFERENCE MATERIAL § RFDS SHEET § EQUIPMENT CUT SHEETS TABLE OF CONTENTS TOC-2 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 I n t r o d u c t i o n The purpose of this report is to design a proposed antenna mast and analyze the existing 78’ CL&P tower located at 200 Edgemark Acres in Meriden, CT for the proposed AT&T Mobility antenna installation. The proposed loads consist of the following: § AT&T MOBILITY (Proposed): Antennas: Six (6) Andrew CCI HPA-65R-BUU-H8 panel antennas, three (3) Andrew CCI OPA-65R-LCUU-H8 panel antennas and eighteen (18) CCI BPDB7823VG12A TMA’s mounted on a Site-Pro Ultra-Low Profile Platform p/n ULP12-496 with a RAD center elevation of 88-ft above grade. Coax Cables: Thirty-six (36) 1-5/8”Æ coax cables running on two (2) legs of the existing tower as indicated in section 4 of this report. P r i m a r y a s s u m p t i o n s u s e d i n t h e a n a l y s i s § Allowable steel stresses are defined by AISC-ASD 9thedition for design of the ANTENNA Mast and antenna supporting elements. § ASCE Manual No. 10-97, “Design of Latticed Steel Transmission Structures”, defines allowable steel stresses for evaluation of the CL&P utility tower. § All utility tower members are adequately protected to prevent corrosion of steel members. § All proposed antenna mounts are modeled as listed above. § All coaxial cable will be installed as indicated in Section 4 of this report. § ANTENNA Mast will be properly installed and maintained. § No residual stresses exist due to incorrect tower erection. § All bolts are appropriately tightened providing the necessary connection continuity. § All welds conform to the requirements of AWS D1.1. § ANTENNA Mast and utility tower will be in plumb condition. § Utility tower was properly installed and maintained and all members were properly designed, detailed, fabricated, and installed and have been properly maintained since erection. § Any deviation from the analyzed loading will require a new analysis for verification of structural adequacy. REPORT SECTION 1-1 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 A n a l y s i s Structural design of the antenna frame was independently completed using the current version of RISA- 3D computer program licensed to CENTEK Engineering, Inc. The antenna mast consisting of a HSS12.5”x0.625” conforming to ASTM A500 Grade 42 (Fy = 42ksi) mounted on a 18’-6” antenna frame connected at eight points to the existing tower was analyzed for its ability to resist loads prescribed by the TIA/EIA standard. Section 5 of this report details these gravity and lateral wind loads. NESC prescribed loads were also applied to the antenna mast in order to obtain reactions needed for analyzing the CL&P tower structure. These loads are developed in Section 7 of this report. Load cases and combinations used in RISA-3D for TIA/EIA loading and for NESC/NU loading are listed in report Sections 6 and 8, respectively. An envelope solution was first made to determine maximum and minimum forces, stresses, and deflections to confirm the selected section as adequate. Additional analyses were then made to determine the NESC forces to be applied to the CL&P tower structure. The RISA-3D program contains a library of all AISC shapes and corresponding section properties are computed and applied directly within the program. The program’s Steel Code Check option was also utilized. The forces calculated in RISA-3D using NESC guidelines were then applied to the CL&P tower using PLS-Tower. Maximum usage for the tower was calculated considering the additional forces from the mast and associated appurtenances. D e s i g n B a s i s Our analysis was performed in accordance with EIA-222-F-1996, ASCE Manual No. 10-97, “Design of Latticed Steel Transmission Structures”, NESC C2-2007 and Northeast Utilities Design Criteria. The CL&P tower structure, considering existing and future conductor and shield wire loading, with the proposed antenna mast was analyzed under two conditions: § UTILITY TOWER ANALYSIS The purpose of this analysis is to determine the adequacy of the existing utility structure to support the proposed antenna loads. The loading and design requirements were analyzed in accordance with the NU Design Criteria Table, NESC C2-2007 ~ Construction Grade B, and ASCE Manual No. 10-97, “Design of Latticed Steel Transmission Structures”. Load cases considered: Load Case 1: NESC Heavy Wind Pressure..…………………………….. 4.0 psf Radial Ice Thickness….……………………. 0.5” Vertical Overload Capacity Factor…………. 1.50 Wind Overload Capacity Factor……………. 2.50 Wire Tension Overload Capacity Factor…… 1.65 Load Case 2: NESC Extreme Wind Speed..………………………………. 110 mph(1) Radial Ice Thickness….……………………. 0” Note 1: NESC C2-2007, Section25, Rule 250C: Extreme Wind Loading, 1.25 x Gust Response Factor (wind speed: 3- second gust) REPORT SECTION 1-2 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 § ANTENNA FRAME ANALYSIS ANTENNA mast, appurtenances and connections to the utility tower were analyzed and designed in accordance with the NU Design Criteria Table, TIA/EIA-222-F, and AISC-ASD standards. Load cases considered: Load Case 1: Wind Speed………………………………... 85 mph(2) Radial Ice Thickness….……………………. 0” Load Case 2: Wind Pressure..……………………………. 75% of 85 mph wind pressure Radial Ice Thickness….…………………….. 0.5” Note 2: Per NU Mast Design Criteria Exception 1. R e s u l t s § ANTENNA FRAME ASSEMBLY The antenna frame was determined to be structurallyadequate. Stress Ratio Member Result (% of capacity) HSS12.5”x0.625” Mast 44.2% PASS HSS 6x6x3/8 Brace 89.0% PASS Mast Connection to CL&P Tower 81.6% (1) PASS Note 1 – 1/3 increase in allowable stress not used for connection to tower per OTRM 059. § UTILITY TOWER This analysis finds that the subject utility structure is adequate to support the existing ANTENNA mast and related appurtenances. The tower stresses meet the requirements set forth by the ASCE Manual No. 10-97, “Design of Latticed Steel Transmission Structures”, for the applied NESC Heavy and Hi-Wind load cases. The detailed analysis results are provided in Section 9 of this report. The analysis results are summarized as follows: With the proposed tower reinforcements detailed in Section 4 of this report a maximum usage of96.54% occurs in the utility tower under theNESC Extreme loading condition. TOWER SECTION: The utility structurewith the proposed tower reinforcements detailed in Section 4 of this report was found to be within allowable limits. Stress Ratio Tower Member Result (% of capacity) Angle Leg13X 96.54% PASS § FOUNDATION AND ANCHORS The existing foundation consists of four (4) 16-inx25-in tapering to 28-inx25-in x 6.25-ft long reinforced concrete piers on four (4) 4-ft-6-in square x 2-ft thick reinforced concrete pads. The base of the tower is connected to the foundation by one (1) anchor stub per leg. Foundation information was obtained from a foundation exploration conducted on May 5, 2014. REPORT SECTION 1-3 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 BASE REACTIONS: From PLS-Tower analysis of CL&P tower based on NESC/NU prescribed loads. Load Case Shear Uplift Compression NESC Heavy Wind 25.29 kips 26.19 kips 80.81 kips NESC Extreme Wind 60.66 kips 1113.12 kips 130.05 kips Note 1 – 10% increase to be applied to the above tower base reactions for foundation verification per OTRM 051 Note 1 – Reactions are combined leg reactions. FOUNDATION: The foundationwith the proposed reinforcements detailed in Section 4 of this report was found to be within allowable limits. Foundation Design Allowable Proposed Result Limit Limit Loading (2) Reinforced Conc. Pad Overturning 1.0 FS (1) 1.66 FS (1) PASS and Pier Note 1: FS denotes Factor of Safety Note 2: 10% increase to PLS base reactions used in foundation analysis per OTRM 051. C o n c l u s i o n s a n d R e c o m m e n d a t i o n s This analysis shows that the subject utility tower with the proposed reinforcements outlined below and detailed in Section 4 of this report is adequateto support the proposed AT&T equipment installaiton. · Replacement of sixteen (8) L1-3/4x1-3/4x3/16 diagonal members with L2x2x5/16. · Replacement of two (2) L2x2x3/16 horizontal members with L2x2x1/4. · Installation of one (1) 27’x27’x3.5’ reinforced concrete mat. The analysis is based, in part on the information provided to this office by Northeast Utilities and AT&T Mobility. If the existing conditions are different than the information in this report, CENTEK engineering, Inc. must be contacted for resolution of any potential issues. Please feel free to call with any questions or comments. Respectfully Submitted by: Timothy J. Lynn, PE Structural Engineer REPORT SECTION 1-4 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 S T A N D A R D C O N D I T I O N S F O R F U R N I S H I N G O F P R O F E S S I O N A L E N G I N E E R I N G S E R V I C E S O N E X I S T I N G S T R U C T U R E S All engineering services are performed on the basis that the information used is current and correct. This information may consist of, but is not necessarily limited to: § Information supplied by the client regarding the structure itself, its foundations, the soil conditions, the antenna and feed line loading on the structure and its components, or other relevant information. § Information from the field and/or drawings in the possession of CENTEK engineering, Inc. or generated by field inspections or measurements of the structure. § It is the responsibility of the client to ensure that the information provided to CENTEK engineering, Inc. and used in the performance of our engineering services is correct and complete. In the absence of information to the contrary, we assume that all structures were constructed in accordance with the drawings and specifications and are in an un-corroded condition and have not deteriorated. It is therefore assumed that its capacity has not significantly changed from the “as new” condition. § All services will be performed to the codes specified by the client, and we do not imply to meet any other codes or requirements unless explicitly agreed in writing. If wind and ice loads or other relevant parameters are to be different from the minimum values recommended by the codes, the client shall specify the exact requirement. In the absence of information to the contrary, all work will be performed in accordance with the latest revision of ANSI/ASCE10 & ANSI/EIA-222. § All services are performed, results obtained, and recommendations made in accordance with generally accepted engineering principles and practices. CENTEK engineering, Inc. is not responsible for the conclusions, opinions and recommendations made by others based on the information we supply. CONDITIONS & SOFTWARE SECTION 2-1 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 G E N E R A L D E S C R I P T I O N O F S T R U C T U R A L A N A L Y S I S P R O G R A M ~ R I S A - 3 D RISA-3D Structural Analysis Program is an integrated structural analysis and design software package for buildings, bridges, tower structures, etc. Modeling Features: § Comprehensive CAD-like graphic drawing/editing capabilities that let you draw, modify and load elements as well as snap, move, rotate, copy, mirror, scale, split, merge, mesh, delete, apply, etc. § Versatile drawing grids (orthogonal, radial, skewed) § Universal snaps and object snaps allow drawing without grids § Versatile general truss generator § Powerful graphic select/unselect tools including box, line, polygon, invert, criteria, spreadsheet selection, with locking § Saved selections to quickly recall desired selections § Modification tools that modify single items or entire selections § Real spreadsheets with cut, paste, fill, math, sort, find, etc. § Dynamic synchronization between spreadsheets and views so you can edit or view any data in the plotted views or in the spreadsheets § Simultaneous view of multiple spreadsheets § Constant in-stream error checking and data validation § Unlimited undo/redo capability § Generation templates for grids, disks, cylinders, cones, arcs, trusses, tanks, hydrostatic loads, etc. § Support for all units systems & conversions at any time § Automatic interaction with RISASection libraries § Import DXF, RISA-2D, STAAD and ProSteel 3D files § Export DXF, SDNF and ProSteel 3D files Analysis Features: § Static analysis and P-Delta effects § Multiple simultaneous dynamic and response spectra analysis using Gupta, CQC or SRSS mode combinations § Automatic inclusion of mass offset (5% or user defined) for dynamic analysis § Physical member modeling that does not require members to be broken up at intermediate joints § State of the art 3 or 4 node plate/shell elements § High-end automatic mesh generation — draw a polygon with any number of sides to create a mesh of well-formed quadrilateral (NOT triangular) elements. § Accurate analysis of tapered wide flanges - web, top and bottom flanges may all taper independently § Automatic rigid diaphragm modeling § Area loads with one-way or two-way distributions § Multiple simultaneous moving loads with standard AASHTO loads and custom moving loads for bridges, cranes, etc. § Torsional warping calculations for stiffness, stress and design § Automatic Top of Member offset modeling § Member end releases & rigid end offsets § Joint master-slave assignments § Joints detachable from diaphragms § Enforced joint displacements § 1-Way members, for tension only bracing, slipping, etc. CONDITIONS & SOFTWARE SECTION 2-2 CENTEKEngineering, Inc. Structural Analysis – 78-ft CL&P Tower # 783 AT&T Mobility Antenna Upgrade – CT2117 Meriden, CT Rev 4 ~ October 6, 2014 § 1-Way springs, for modeling soils and other effects § Euler members that take compression up to their buckling load, then turn off. § Stress calculations on any arbitrary shape § Inactive members, plates, and diaphragms allows you to quickly remove parts of structures from consideration § Story drift calculations provide relative drift and ratio to height § Automatic self-weight calculations for members and plates § Automatic subgrade soil spring generator Graphics Features: § Unlimited simultaneous model view windows § Extraordinary “true to scale” rendering, even when drawing § High-speed redraw algorithm for instant refreshing § Dynamic scrolling stops right where you want § Plot & print virtually everything with color coding & labeling § Rotate, zoom, pan, scroll and snap views § Saved views to quickly restore frequent or desired views § Full render or wire-frame animations of deflected model and dynamic mode shapes with frame and speed control § Animation of moving loads with speed control § High quality customizable graphics printing Design Features: § Designs concrete, hot rolled steel, cold formed steel and wood § ACI 1999/2002, BS 8110-97, CSA A23.3-94, IS456:2000,EC 2-1992 with consistent bar sizes through adjacent spans § Exact integration of concrete stress distributions using parabolic or rectangular stress blocks § Concrete beam detailing (Rectangular, T and L) § Concrete column interaction diagrams § Steel Design Codes: AISC ASD 9th, LRFD 2nd & 3rd, HSS Specification, CAN/CSA-S16.1- 1994 & 2004, BS 5950-1-2000, IS 800-1984, Euro 3-1993 including local shape databases § AISI 1999 cold formed steel design § NDS 1991/1997/2001 wood design, including Structural Composite Lumber, multi-ply, full sawn § Automatic spectra generation for UBC 1997, IBC 2000/2003 § Generation of load combinations: ASCE, UBC, IBC, BOCA, SBC, ACI § Unbraced lengths for physical members that recognize connecting elements and full lengths of members § Automatic approximation of K factors § Tapered wide flange design with either ASD or LRFD codes § Optimization of member sizes for all materials and all design codes, controlled by standard or user-defined lists of available sizes and criteria such as maximum depths § Automatic calculation of custom shape properties § Steel Shapes: AISC, HSS, CAN, ARBED, British, Euro, Indian, Chilean § Light Gage Shapes: AISI, SSMA, Dale / Incor, Dietrich, Marino\WARE § Wood Shapes: Complete NDS species/grade database § Full seamless integration with RISAFoot (Ver 2 or better) for advanced footing design and detailing § Plate force summation tool CONDITIONS & SOFTWARE SECTION 2-3