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- Should step pegs and safety climb be included in ... (677348 views)
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- I have a question regarding TIA-222-H Clause 2.6.9 & ... (2021-09-22 18:19)
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- Section 13.3 question regarding plumb measurement of monopoles; submitted ...
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- Section 15.5 indicated "A feasibility report shall state ...
- Section 2.6.6 Calculating the topographic factors
- As everyone is aware, many jurisdictions are now adopting ...
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- The definition of Z in sections 2.6.5.2, 2.6.6.4, and ...
- If Ca=1.5 is used for a rectangular cluster of ...
- Section 2.6.5.2 “Velocity Pressure Coefficient”Question: Shall “z” in the ...
- Section 4.9.9: I'm using this section to calculate the ...
- Section 2.6.6.4 - Rev-G provides a simplified method of ...
- WHICH IS THE unbraced length "L" TO CONSIDER, ACCORDING ...
- Does section 2.8.2 Limit State Deformations of ANSI/TIA 222-G ...
- Where it has been suggested in previous posts that ...
- We understand section 2.6.4.1 to apply only to areas ...
- Waveguides, downleads, and other cables are frequently strapped to ...
- Should step pegs and safety climb be included in ...
- Section 3.6.2 note 1 regarding pattern loading and tower ...
- Approximately when will the next revision or amendment to ...
- I have a tower for which the plumb and ...
- In Section 4.4.1 of TIA/EIA-222-G December 2009 the minimum ...
- Section 3108.1 of the 2012 IBC eliminates the 222-G ...
- Section 9.6 What is the intent of the grade ...
- One thing I recently noticed was in Table C1, ...
- Regarding recent FAQ 1128: would it be possible to ...
- I’m trying to determine if a pad & pier ...
- Is it the intention of drafters of the TIA ...
- Section 2.6.5: Addendum 2 defines Exposure Category C as ...
- Section 5.4.2 gives requirements for Non Pre-Qualified Steel stating ...
- Which of the states adhere to the Rev G ...
- In Section 4.5.1, the following language is used:"A multiple ...
- Shall “z” in the equation be based on mid-height ...
- Section 4.9.9: I’m using this section to calculate the ...
- Section 2.6.6.4 - Rev-G provides a simplified method of ...
- Which is the unbraced length to consider, according to ...
- I am a commercial building reviewer for the City ...
- Does section 2.8.2 Limit State Deformations of ANSI/TIA 222-G ...
- Can section 2.8.2 also be applied to a TIA-222-F ...
- Table 4-6 provides slenderness requirements for horizontal members, specifically ...
- Where it has been suggested in previous posts that ...
- One thing I recently noticed was in Table C1, ...
- In Section 4.5.1, the following language is used:"A multiple ...
- Is it acceptable to use Ka = 0.6 for ...
- For double angles, are the modified (KL/r)m equations shall ...
- K is not mentioned on the right side of ...
- Is (KL/r)o shall include the curves defined in Table ...
- Section 4.9.8. Does the definition of Guy Assembly Link ...
- Section 12 Climbing Facilities in TIA-222-GWhat is the strength ...
- Section 12 Climbing Facilities TIA-222-GWhat is the strength requirement ...
- Section 4.5.3 Built-Up Members states that "A minimum of ...
- Referencing Section 2.3.2, Exception 4 and Note 3; for ...
- Is there any back up material for the usage ...
- I am a structural engineer in Oregon, and I ...
- Section 2.6.1: In the definitions section of 2.6.1, a ...
- Does TIA-222-G include any consideration of loads other than ...
- Should mounts be subjected to Section 15 requirements that ...
- Hello,The effective projected area of transmission lines mounted in ...
- Section 2.6.9My question is regarding how to determine the ...
- Hello. A question was asked about the validity of ...
- The inspection intervals are recommended. Can I extend the ...
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- Section A.2.2 and Table 2-1 establish the classification of ...
- Section A.2.2 and Table 2-1 establish the classification of ...
- The industry is on the verge of the release ...
- Do T-Arm mounts classify as Sector Mount or a ...
- When an EPA at an elevation is specified in ...
- Use of Survival wind speed with ANSI/TIA-222H : There ...
- Section 15.7 Exemption 7, states to use a 50% ...
- Do T-Arm mounts classify as Sector Mount or a ...
- Section 15.7 Exemption 7, states to use a 50% ...
- Can ASCE 7-16 wind maps be used per TIA-222-G ...
- I have a question regarding TIA-222-H Clause 2.6.9 & ...
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1 2 8 A C D F H I K O R S T U W
- Some antenna manufacturers provide flat equivalent area and few of them just provide the dimensions. How can we address the CaAa without ice and with ½” ice for discrete appurtenance without flat equivalent area known?s
Section 2.3.10 of Revision F provides a defined method for computing the effective projected area of appurtenances including ... - Section 4.6.3.2 question regarding shear lag factor; submitted 9/15/2010
QUESTION: Is it acceptable to ignore the 0.9 upper limit on the shear lag factor specified in TIA-222-G Section 4.6.3.2 in ... - Section 2.6.9.2What does the term “In the absence of more accurate data” mean?
The standard provides force coefficients for basic appurtenance shapes as provided in Table 2-8 and for generic microwave antennas as provided ... - Section 2.6.9.2Is it acceptable to use the results of Computational Fluid Dynamics (CFD) testing as a substitute to the requirements outlined in section 2.6.9.2? If so, what conditions must be meet? If so, can we claim the tower is compliant with TIA-222-G if the wind tunnel data is used?
Many variables affect the outcome of CFD computations. CFD computations are theoretical models that do not include all of the complex ... - Section 2.6.9.2Can I use loading that is less than the values prescribed by the written TIA-222-G and claim compliance with the standard? If so, under what conditions?
The standard provides force coefficients for basic appurtenance shapes as provided in Table 2-8 and for generic microwave antennas as provided ... - Section 2.6.9.2Is it acceptable to use the results of wind tunnel testing as an acceptable substitute to the requirements outlined in section 2.6.9.2? If so, what conditions must be meet? If so, can we claim the tower is compliant with TIA-222-G if the wind tunnel data is used?
Many variables affect the outcome of wind tunnel testing. Wind tunnel tests do not include all of the complex interdependent issues ... - Section 15.4 question regarding Changed Conditions Requiring a Structural Analysis; submitted 2/14/2007
QUESTION: I would like to understand a bit more about the intent of Section 15.4 "Changed Conditions Requiring ... - Section 15.4 question regarding existing tower re-analysis; submitted 12/31/2007
QUESTION: I was looking for clarification as to whether or not it is a requirement of TIA-222-G to complete a structural analysis ... - Section 13.3 question regarding plumb measurement of monopoles; submitted 7/20/2011
QUESTION: My question involves the plumb measurements of monopoles obtained through our regular tower inspections. It is often difficult to obtain accurate field ... - Section 2.6.6 Calculating the topographic factors
Question: Section 2.6.6 (2.6.6.1 and 2.6.6.2) My colleagues and I have been discussing the proper method of determining which topographic category ... - Section 2.7.3 states “Further, …earthquake effects may be ignored when the total seismic shear is less than 50% of the total horizontal wind load without ice.” Does ignoring earthquake effects include the seismic considerations of Section 9.6, since the tower structure itself would be capable of satisfying that requirement?
The intent of Section 9.6 is to address isolated foundations for latticed towers in high seismic areas. Section 9.6 does ... - Section 2.6.5.2 “Velocity Pressure Coefficient”Question: Shall “z” in the equation be based on mid-height of panels of lattice structures or is it a centroid location of lattice structures panel? For example if the length of panel (Bracing type = X-Brace) is 10 ft then z should be = 5 ft or based on the centroid location.
Per Section 2.6.5.2 the Velocity Pressure Coefficient may be based on the mid-height of the section. The intent was to ... - Section 4.9.9: I'm using this section to calculate the tension capacity of a solid round guy anchor shaft. For this case the V/n factor is 0. For the value of Phi Rnt this section refers me to Section 4.9.6.1. Under this section for a solid round un-threaded anchor shaft I assume An can equal Ag. Fub is defined as the specified minimum tensile strength. This description alludes to Fub=Fy but I believe the intent was for Fub to = Fu. Can you verify that per 4.9.6.1 the guy anchor rod tension capacity is .8*Fu*Ag?
Section 4.9.9 is intended to apply to anchor bolts (Anchor Rods per latest AISC terminology). Section 4.6.3 applies to guy ... - Section 2.6.6.4 - Rev-G provides a simplified method of calculating Kzt that differs from the method provided in Figure 6-4 of ASCE7. The resulting wind pressures when using the Rev-G method are often significantly higher than those calculated using the ASCE7 method. Is it acceptable to use ASCE7 wind pressures instead of defaulting to Rev-G wind pressures when Kzt>1?
Per Section 2.6.6.2 Category 5 allows the use of site-specific investigation. A.2.6.6 states that ASCE 7-02 is an acceptable methodology ... - Should step pegs and safety climb be included in the Ra calculations for determining the appropriate Cf and additional linear appurtenance wind area calculated for TIA-G? It appears that in the transition from TIA-E to F to G the additional drag to the structure from step pegs and safety climb have already been accounted for.In TIA-E the force coefficients for tubular pole structures were less than those in TIA-F and TIA-G.In TIA-E, foot note 3 states that when step bolts… are attached to the outside of a tubular pole structure the Cf factor must be multiplied by 1.3.TIA-F removed this footnote but increased the force coefficients by 1.3 (except for the subcritical cases for which the force coefficient is 1.2). Presumably the footnote was removed and the values and formulas in the force coefficient table were revised so that the drag of step pegs and safety climb would be considered in the table rather than by footnote. TIA-G is using similar force coefficients as TIA-F (about 1.3 times that of TIA-E and presumably accounting for the drag increase due to step pegs and safety climb) but then state to include linear appurtenances such as ladders… or other similar projections in the Ra calculation. Step pegs and safety climb are not specifically mentioned but would be “similar projections”. If step pegs and safety climb are included in the Ra factor it seems that these linear appurtenances are being double counted when determining the additional drag on the structure.Based on the above discussion, in the calculation of Ra can the area of step bolts and safety cable be ignored?
The force coefficients (Cf), from Table 2-7 for pole structures account for a degree of attachments commonly attached to communication pole ... - Section 3.6.2 note 1 regarding pattern loading and tower cantilevers Consider cantilevers that are very short relative to the span between the top two guy levels; for example, a 9' cantilever above a 60' span, or a 30' cantilever above a 200' span (both of those examples, the cantilevers are 15% of the span below, and their length happens to be less than three times the tower face width).This seems somewhat similar to the situation covered by note 3, where it is clearly pointless to consider a short span between two guy elevations as an independent span. In the case of note 3, "short span" length is defined as three times the face width. Note that those cantilevers are also short relative to the vertical scale of turbulence or correlation length (roughly 165 to 200 feet according to Gerstoft & Davenport, 1986, "A Simplified Method for Dynamic Analysis of A Guyed Mast.") Also, applying the mean wind to a short cantilever and the full wind to the rest of the tower is practically no different than applying the full wind to the entire tower (which 222-G does not require for towers greater than 450 ft in height). The question is: for towers greater than 450 ft in height, would it be acceptable to treat short cantilevers as part of the span between the top two guy levels? For example, in load case 1, the mean wind pressure would be applied to the short cantilever and the span between the top two guy levels, and in load case 2 the mean wind would be on the span between the 2nd and 3rd guy levels from the top, etc.
A short span cantilever may not govern the results, however the requirement to continue pattern loading for a distance equal to ... - Section 3108.1 of the 2012 IBC eliminates the 222-G exceptions related to seismic design and it changes the horizontal extent of escarpments. Did the 222-G committee submit comments on those two proposed provisions during the development of 2012? If so, what were the comments? If not, does the committee agree with those provisions?
Yes, the committee did collaborate with the escarpment provisions. Corresponding changes to the escarpment provisions are planned to be ... - Section 9.6 What is the intent of the grade beam, similar device, or other approved method to resist a portion of the base seismic shear? Is it to resist differential foundation displacements during a seismic event, to resist the effects of liquefaction, or both? If differential displacements is a concern, what is the allowable displacement? Does the same force requirement (2/3 of the total base shear) apply for 3-legged and 4-legged structures alike?
The intent of the grade beam is to minimize differential displacement. Liquefaction is a separate site specific concern. ... - Section 2.6.5: Addendum 2 defines Exposure Category C as "Sites located in Exposure B terrain that are located further than two miles but less than twenty times the height of the structure from an Exposure D terrain." That region is only possible for towers more than 528 feet tall. Did the authors mean "...less than two miles but more than twenty times the height..." That would make more sense and coordinate with the definition of Exposure D.
This provision is intended for tall structures where the 20 x the height of the structure was considered overly conservative when ... - Section 5.4.2 gives requirements for Non Pre-Qualified Steel stating the elongation shall be less than 18%. Where this is a change from the previous code, is there a way to justify keeping the old towers/ poles that used steel with lower elongation, when there is a change on loading for the structure?
Section 5.4.2 gives requirements for Non Pre-Qualified Steel stating the elongation shall be less than 18%. Where this is a change ... - Shall “z” in the equation be based on mid-height of panels of lattice structures or is it a centroid location of lattice structures panel? For example if the length of panel (Bracing type = X-Brace) is 10 ft then z should be = 5 ft or based on the centroi
Per Section 2.6.5.2 the Velocity Pressure Coefficient may be based on the mid-height of the section. The intent was to ... - Section 4.9.9: I’m using this section to calculate the tension capacity of a solid round guy anchor shaft. For this case the V/n factor is 0. For the value of Phi Rnt this section refers me to Section 4.9.6.1. Under this section for a solid round un-t
Section 4.9.9 is intended to apply to anchor bolts (Anchor Rods per latest AISC terminology). Section 4.6.3 applies to guy ... - Section 2.6.6.4 - Rev-G provides a simplified method of calculating Kzt that differs from the method provided in Figure 6-4 of ASCE7. The resulting wind pressures when using the Rev-G method are often significantly higher than those calculated using the A
Per Section 2.6.6.2 Category 5 allows the use of site-specific investigation. A.2.6.6 states that ASCE 7-02 is an acceptable methodology ... - Section 4.9.8. Does the definition of Guy Assembly Link Plate in this Standard include all guy anchor fan plates and welded guy connection lug plates?
No, Section 4.9.8 is for a link plate, not a fan plate or a guy lug. The criteria provided in ... - Section 12 Climbing Facilities in TIA-222-GWhat is the strength capacity of a 5/8" step bolt/peg and how is it measured?
The minimal nominal strength required is 250 lb per Section 12.4. Note that a 1.5 load factor must be applied ... - Section 12 Climbing Facilities TIA-222-GWhat is the strength requirement of a welded step bolt/peg bracket?
The step bolt/peg bracket must meet the strength requirements of Section 12.4, which is a nominal load of 250 lb, with ... - Section 4.5.3 Built-Up Members states that "A minimum of two bolts shall be used at each intermediate connector point when the connected width (i.e. connected leg width of a double angle) of a compression member exceeds 4 in." I could not find any reference to the two bolt per intermediate connector requirement in the AISC steel manual, and do not believe I have seen this on towers with large double angle diagonals. Does this mean that the two bolts shall be at each stitch location side by side, aligned with the axis of buckling, or the two bolts shall be aligned with the axis of the applied compressive force? Also, does this two bolt requirement apply to built-up members consisting of other shapes, such as channel leg reinforcement on the apex of a bent plate leg, or flat plate reinforcement on a monopole?
Section 4.5.3 does not specify the orientation of multiple bolt connections at intermediate connection points for a built up member. ... - Section 2.6.1: In the definitions section of 2.6.1, a 50-year mean recurrence interval is specified for wind on ice loading. However, in 2.6.8 a limit state factor of 2.0 is used. Per ASCEC10.4.6 paragraph 2, this factor of 2 is for a 500-year mean recurrence interval, not a 50-year mean recurrence interval. Therefore, if we are to design for a 50-year interval we must use a factor of 1.0, not 2.0. Will TIA acknowledge this fact and allow our company to use a factor of less than 2.0?If not, please explain your reasoning for using this 500-year storm event factor. Also, if TIA is unwilling to change said equation, is it acceptable to ask the jurisdiction to wave this factor in favor of the 50-year factor of 1.0?
The TIA-222-G Standard is based on limit state design and it is necessary to convert 50-year recurrence ice loading to 500-year ... - Should mounts be subjected to Section 15 requirements that would be applied to the supporting structure? Does Section 15.4 Changed Conditions Requiring a Structural Analysis apply to mounts as well as the supporting structure?
Although Section 15 applies to the evaluation of an existing supporting structure, mount or antenna, it is not the intent to ... - Section 2.6.9My question is regarding how to determine the wind loading on a triangular shroud that is surrounding all equipment on a monopole. This question encompass all shrouds of this nature, but the shroud in question for this particular case was 6’ tall by 13’ wide on a 48” diameter round pole. There were a few methods discussed based on our interpretation of the code. These interpretations are presented below. Please advise if which method(s) are recommended by the TIA.For the first case we considered the shroud as a truss type mount with a solidity ratio of 1.0. The code specifies to determine the wind area as though the platform were a section of a latticed structure in accordance with section 2.6.9.1. Since we have a solid face, using this equation with a solidity ratio of 1.0 will give us a Cf of 2.1. There was an argument that this section was for lattice tower and would not apply to monopoles, but we do not believe this is the intent of the code. Section 2.6.9.2.3 mentions no shielding shall be considered for the supporting structure, but we neglected the EPA of the pole structure shielded by the shrouds based on the limit stated in 2.6.9/2.6.9.1. For the second case we considered the shrouds as appurtenances. Using a Ca = 1.2 and Ka = 1.0 (per section 2.6.9.4 we cannot use a Ka less than 1.0) we came up with front and side EPA for the shrouds and modeled one off each face. We did not consider the shrouds to shield each other and although there are is not a reference for shielding the pole for appurtenances, we considered both methods above to shield the pole section within the shrouded region.The last method, which we did not agree with, proposed to treat the shroud as an appurtenance, but to allow shielding to the appurtenances (shrouds) on the other faces along with using a Ka=1.0. This gives an EPA of 94 sf. We believe this to be very aggressive and would recommend using one of the methods described above. Example calculations for this particular shroud are shown below. The shroud is 6’ tall by 13’ wide on a 48” diameter round pole.Pole EPA: 0.6x4’x6’ = 14.4 sfShroud as Mount:Cf: 3.4(1.0)^2 – 4.7(1.0) + 3.4 = 2.1EPA: 2.1x6x13 = 163.8 sfEPA minus pole = 149.4 sf Shroud as Appurtenances (did not consider side area):Ca: 1.2EPAn: 1.2x6x13 = 93.6 sfETAt: 0Ka= 1.0EPA = 1.0 [93.6 + 2 x 93.6 x Cos(60)^2] = 140.4 sfEPA minus pole = 126 sfShroud as Appurtenances (shielding allowed):EPAn: 1.2x6x13 = 93.6 sf
The intent of the Standard is to calculate the effective projected area of a discrete appurtenance in accordance with Section 2.9.6.2. ... - Section A.2.2 and Table 2-1 establish the classification of structures based on reliability (I, II and III). What would be the classification of a communication tower installed inside of an electrical substation facility? What does the default structure classification means?
The Standard outlines the reliability requirements of communication structures by specifying the appropriate structural classification (I, II, and III) based on ... - Section A.2.2 and Table 2-1 establish the classification of structures based on reliability (I, II and III). What would be the classification of a communication tower installed inside of an electrical substation facility? What does the default structure classification means?
The Standard outlines the reliability requirements of communication structures by specifying the appropriate structural classification (I, II, and III) based on ...