Quick Pole Validation

 

On this webpage we outline the results of our self-evaluation of Quick Pole, following the suggested Code Compliance Format.

These results are presented in the following order:

  1. Statement of Code Compliancy.
  2. Sags & Tensions
  3. Unguyed Structure Response
  4. Guyed Structure Response
  5. Non-Linear
  6. Foundation

Statement of Code Compliancy

Using the template provided against CSA C22.3 No.1 Overhead Systems Standard (2015), the following summary results are provided:

CSA Code Compliance Summary

Users are encouraged to review the detailed clause by clause responses in this file.

Sags & Tensions

Using the templates provided, these results are divided into Level Span and Un-level Span tests. To assist users in replicating these results, the following two Quick Pole project files: File1, File2 are being made available. The first one covers the Level Span tests, while the second covers the unlevel span tests.

Level Span Tests

Here are the Test Results from Quick Pole and the required comparison with another leading software tool:

Quick Pole Level Span Results

Percentage Comparisons

Un-Level Spans

Again, following the templates provided, the results of Quick Pole have been compared with another leading software tool and found to be in close agreement.

 

Unlevel Quick Pole Results

 

Unguyed Structure Response

 

Using the templates provided, these are the results of our tests against Quick Pole:

Unguyed Poles

To assist users in replicating these results, the following two Quick Pole project files: File1, File2 are being made available. The first one covers all of the ANSI based tests. The last one covers the CSA based test.

Guyed Structure Response

 

Using the templates provided, these are the results of our tests against Quick Pole. You can also use these Quick Pole Project Files to duplicate these results for yourself. For exact results, please ensure that the Line Grade is set to "No Overload Factors" so that the applied and static loads are not amplified.

Quick Pole Guyed Results

When compared to another software tool, Quick Pole compares as follows:

Quick Pole Deviations for Guyed Response

As a further test to validate that Quick Pole's model gives the same results with loads placed at different angles, the first and last four tests are compared directly:

Quick Pole Guyed Response from different angles

Non-Linear

Following the suggestions to test here, here are the answers w.r.t Quick Pole. They are broken down into three main sections:

  1. P- Delta like tests
  2. Guying Non-Linearity
  3. Attachment Load Non-Linearity

Both P-Delta and Guying Non-linearity combined are required to say prove the software tool implements a full Geometric Non-Linear Analysis.

P-Delta

The following are the results of our tests against another software tool:

P-Delta tests of Quick Pole

The results for NESC rated poles have the higher Modulus of Elasticity values. Both sets of results track very good. Especially when you note that almost all real pole structures will have some form of support which will limit the range of pole deflection possible. Here are the Quick Pole project files you can use to help validate these results yourself.

Guying Non-linearity

The following are our tests of Quick Pole:

Guying Nonlinearity of Quick Pole

These results show a couple specific key points:

  1. The stronger class of pole handles more of the load itself (stiffer poles deflect less).
  2. While the actual load was applied in the X direction and the guy/anchor was oriented in the Z direction (90 degrees out of line), the guy is able to take some of the load because it's model is updated to be not exactly in the Z direction as the pole deflects. If Quick Pole did not implement guying non-linearity, the guy loads shown above would have been zero.
  3. Here are the Quick Pole project files you can use to help validate these results yourself.

Attachment Load Non-linearity

The loads that can change in response to the movement of the pole are the attachments that span to other poles. Wire attachments will have a starting maximum tension that would be applied to the poles. If the poles move towards each other, this lessens the tension. Conversely, poles that try to move apart result in an increase in wire tensions. The wires will behave this way regardless of what situation is causing the effect. In practice, two main situations arise:

  1. Balancing of un-equal inline tensions. Some software tools use an average span length for both sides of the pole before calculating their tensions. Quick Pole calculates tensions based on actual span lengths and then shows the end result of the pole deflecting/stressing and the wire tensions changing.
  2. Support of wind load applied to a pole by wire attachments going to poles in lateral directions. This is a minor impact and is more of a Geometric Nonlinearity related to the attachment loads. Since the span lengths are long compared to the pole's deflection, the angles created are small and therfore the impacts are small. Quick Pole allows the user to enable/disable this feature, whose results can be seen in the Attachment Load Changes report.

As an extreme example that shows this effect,refer to this project. It has five 556.5 ASC Dahlia conductors attached in one direction from an unsupported 40ft Class 4 WRC cedar pole. Under CSA Heavy Loading, the maximum tension applied to the pole by each of the wires is 10990 Newtons, or 25% RTS. Under this load from all five wires, the pole's tip deflects about 1.87 meters, which in turn reduces the tension in these wires to about 3% RTS. Again, this is an extreme example that is not typical; but sufficient to demonstrate the ability of Quick Pole to re-calculate wire tensions during the analysis procedure as the pole deflects.

1
40 Ft CL 4 , Western Red Cedar. Overall Utilization based on Fibre Stress after Nonlinear Analysis= 115 %
Pole dimensions based on CSA O15-2015
Worst Wind Direction for Pole Loading is 180°
Analysis Iterations fixed near 2000. Achieved Global Structure Force Imbalance of 870 Newtons and a Worst Nodal Imbalance of 860 Newtons (Abs(FX)+Abs(FZ)).
Global Structure Force Imbalance Threshold set at 1000 Newtons
Nodal Structure Force Imbalance Threshold set at 1000 Newtons
Analysis Innacuracy estimated at 0.9 % based on a Force range of 92134 Newtons at the Worst Nodal Force Imbalance location (Node# 24).
( Analysis Options: , Guying Geometric Analysis, Attachment Non-linearity, Attachment Geometric Analysis )

Attachments (5)

90°, H= 10m, 556.5 ASC Dahlia: Capacity OK @ 42 % Utilization (10990 N, 25 % RTS)

Wire tension set to default tensions on file for Utility Standards Forum. Initial Stringing Tension set to 2856 Newtons at 10.0 °C and a Ruling Span of 45.0 m.
Clearance Type: Roadway (8.473 m), Requirement= 4.75 m 0-750VAC/DC
(Tension Range after analysis was 3 % to 25 % RTS)

90°, H= 10m, 556.5 ASC Dahlia: Capacity OK @ 42 % Utilization (10990 N, 25 % RTS)

Wire tension set to default tensions on file for Utility Standards Forum. Initial Stringing Tension set to 2856 Newtons at 10.0 °C and a Ruling Span of 45.0 m.
Clearance Type: Roadway (8.473 m), Requirement= 4.75 m 0-750VAC/DC
(Tension Range after analysis was 3 % to 25 % RTS)

90°, H= 10m, 556.5 ASC Dahlia: Capacity OK @ 42 % Utilization (10990 N, 25 % RTS)

Wire tension set to default tensions on file for Utility Standards Forum. Initial Stringing Tension set to 2856 Newtons at 10.0 °C and a Ruling Span of 45.0 m.
Clearance Type: Roadway (8.473 m), Requirement= 4.75 m 0-750VAC/DC
(Tension Range after analysis was 3 % to 25 % RTS)

90°, H= 10m, 556.5 ASC Dahlia: Capacity OK @ 42 % Utilization (10990 N, 25 % RTS)

Wire tension set to default tensions on file for Utility Standards Forum. Initial Stringing Tension set to 2856 Newtons at 10.0 °C and a Ruling Span of 45.0 m.
Clearance Type: Roadway (8.473 m), Requirement= 4.75 m 0-750VAC/DC
(Tension Range after analysis was 3 % to 25 % RTS)

90°, H= 10m, 556.5 ASC Dahlia: Capacity OK @ 42 % Utilization (10990 N, 25 % RTS)

Wire tension set to default tensions on file for Utility Standards Forum. Initial Stringing Tension set to 2856 Newtons at 10.0 °C and a Ruling Span of 45.0 m.
Clearance Type: Roadway (8.473 m), Requirement= 4.75 m 0-750VAC/DC
(Tension Range after analysis was 3 % to 25 % RTS)


Foundation

Following the suggestions to test here, here are the answers w.r.t Quick Pole:

Foundation Validation

For comparison with others, below we openly share the Soil Parameters used with the methods shown above.

Soil Parameters

 

Example of Soil Failure from Lateral Loads around a pole

Street / Lead

Unnamed (1)
1
1
40 Ft CL 4 Overall Utilization = 110 % ; Fibre Stress Utilization= 110 %, Estimated Vertical Load Utilization = 2 %
Pole Stresses are only based on a Linear Analysis (not Nonlinear) based on Project Setting.
The Soil around the pole CANNOT support the Pole's Groundline Moments (104134 N-M) required.
Required Depth of Setting = 1.991 m. Current Depth of Setting = 1.829 m. Soil Class= 1
Worst Wind Direction for Pole Loading is 90°
The Vertical Load capacity of the Soil directly below the pole is within defined limits.
Capacity = 139 KN (1819 Kpa Bearing Capacity + 4 KN skin resistance. Soil Safety Factor= 1). Load = 9 KN
Attachments (1)
0°, H=9.754m, Point Load: Tensile Force= 10.676 KN

 

Example of Push brace being pulled out of the ground and the Soil Capacity trying to resist

Unnamed (1)

1
1
40 Ft CL 4 Overall Utilization = 76 % ; Fibre Stress Utilization= 76 %, Estimated Vertical Load Utilization = 53 %
Pole Stresses are only based on a Linear Analysis (not Nonlinear) based on Project Setting.
Soil Groundline Moment tests were not performed since the pole is guyed. Groundline Moments = 13937 N-M.
Worst Wind Direction for Pole Loading is 90°
The Vertical Load capacity of the Soil directly below the pole is within defined limits.
Capacity = 139 KN (1819 Kpa Bearing Capacity + 4 KN skin resistance. Soil Safety Factor= 1). Load = 45 KN
Attachments (3)
0°, H=9.754m, Point Load: Tensile Force= 10.676 KN
H= 9.363m, TRANS 10KVA: Weight= 94 Kg
180°, H= 7.254m, Push Brace: Push Brace is in Tension of 36.7 KN.
Push Brace is being pulled out of the ground !
Push Brace weight of 2.059 KN plus factored soil resistance of 3.6 KN is not enough.
Net Positive (upward) Force = -31.035 KN

 

Example of Push brace lifting the supported pole out of the ground and the Soil Capacity trying to resist

Street / Lead

Unnamed (1)
1
1
40 Ft CL 4 Overall Utilization = 77 % ; Fibre Stress Utilization= 77 %, Estimated Vertical Load Utilization = 9 %
Pole Stresses are only based on a Linear Analysis (not Nonlinear) based on Project Setting.
Soil Groundline Moment tests were not performed since the pole is guyed. Groundline Moments = 14413 N-M.
Worst Wind Direction for Pole Loading is 90°
Pole is being lifted out of the ground !
Pole and Attachment weights plus factored soil resistance of 5 KN is insufficient.
Net Positive (upward) Force = -11 KN
Attachments (3)
0°, H=9.754m, Point Load: Tensile Force= 10.676 KN
0°, H= 7.254m, Push Brace:
Push Brace Compression Forces of 32 KN requires a 35 ft Cl 5 pole. This class Push Brace has a Factored Compression Capacity of 181 KN.
The Vertical Load Capacity of the Soil directly below the Push Brace is within defined limits.
Factored Soil Vertical Load Capacity = 78.4 KN. Net Vertical Loads = 31.2 KN