american piledriving equipment inc. helical pile ... · the test was performed according to astm...

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www.trekgeotechnical.ca 1712 St. James Street | Winnipeg, Manitoba R3H 0L3 | Tel 1.204.975.9433 | Fax 1.204.975.9435

American Piledriving Equipment Inc.

Helical Pile Installation and Testing Observations Near Gillam, MB

Prepared for: Mr. Paul Suver American Piledriving Equipment Inc. 7032 South 196 Street Kent, WA 98032 Project Number: 0151 001 00 Date: July 10, 2015

Distribution: Mr. Paul Suver

Quality Engineering | Valued Relationships

www.trekgeotechnical.ca 1712 St. James Street | Winnipeg, Manitoba R3H 0L3 | Tel 1.204.975.9433 | Fax 1.204.975.9435

July 10, 2015 Our File No. 0151 001 00 Mr. Paul Suver American Piledriving Equipment Inc. 7032 South 196 Street Kent, WA 98032

RE: Summary report

TREK Geotechnical Inc. is pleased to submit our Final Report following observation of helical piles and static pile load testing on a site near Gillam, Manitoba.

Please contact Kent Bannister of our office if you have any questions. Thank you for the opportunity to serve you on this assignment.

Sincerely,

TREK Geotechnical Inc. Per:

Kent Bannister, M.Sc., P.Eng. Senior Geotechnical Engineer

Tel: 204.975.9433 KB:jh Encl.

American Piledriving Equipment Inc. Helical Pile Installation and Testing Observations Near Gillam, MB

Our File No. 0151 001 00 Page ii July 2015

Table of Contents

Letter of Transmittal

Revision History and Authorization Signatures

1.0 Introduction ................................................................................................................................ 3

2.0 Background and Existing Information ....................................................................................... 3

3.0 Field Program ............................................................................................................................. 3

3.1 Pile Installation Observations .......................................................................................... 3

3.2 Static Tensile Pile Load Testing ...................................................................................... 6

4.0 Summary .................................................................................................................................... 9

5.0 Closure ........................................................................................................................................ 9

List of Tables

Table 1 Torque Readings Observed During Installation of Pile #1 ............................................... 5



Table 4 Summary of Measurements for Tensile Load Test .......................................................... 9

List of Figures

Figure 01 Photo of Pile Load Test Configuration

Figure 02 Plot of Load vs. Deflection for Tensile Pile Load Test


Our File No. 0151 001 00 Page 3 July 2015

1.0 Introduction

This report summarizes the results of work performed by TREK Geotechnical Inc. (TREK) during installation and testing of helical piles near the Keewatinohk Converter Station outside of Gillam, MB. The terms of reference for the investigation are included in our proposal to Mr. Paul Suver of American Pile Driving Equipment Inc. (APE) on March 27, 2015. The scope of work included an observation and documentation (summary report) of a trial helical pile installation and load testing .

2.0 Background and Existing Information

APE was commissioned to install several piles to demonstrate they were able to reach sufficient embedment depths with their equipment and verify pile capacities through a static pile load test. Pile installation was completed by Graham Brothers Construction. Three piles were installed on a cleared pad near the converter station (near tower site 18) for the Keewatinohk collector lines. Sub-surface information from drilling in the area was not made available to TREK; however based on our experience at the Keewatinohk site, we anticipate that soil conditions consist of a variable thickness of interlayered compact to dense silts and sands or stiff to very clays overlying very stiff to hard clay tills. The site is located within the zone of discontinuous permafrost.

3.0 Field Program

3.1 Pile Installation Observations

TREK observed the installation of 1 vertical pile and two battered piles on the test pad. Installation observations for each pile are summarized in the following sections. All piles had a single helix with a diameter of 0.61 m and a pile shaft diameter of 298 mm with a 15 mm wall thickness.

Pile # 1 – Standard Vertical Installation – Installed on April 7, 2015

Prior to installation of the pile, a pilot hole was pre-drilled to 17.4 m (57 feet) using a 305 mm diameter downhole hammer. Total time to drill to 17.4 m was 45 minutes. Following pre-drilling, a pile was installed to the full depth of the pilot hole where installation was terminated due to high torque readings. A summary of torque readings with depth is provided in Table 1.



Table 1. Torque Readings Observed During Installation of Pile #1.

Depth Torque

(m) (ft) (kN-m) (ft-lbs)

1.5 5 0.5 12000

3.0 10 0.0 800

3.7 12 0.4 9900

4.6 15 0.6 15000

5.5 18 1.5 34600

6.1 20 1.6 37500

6.9 22.5 1.7 41000

7.6 25 1.1 27000

8.4 27.5 0.8 19000

9.1 30 1.3 30000

9.9 32.5 0.7 16000

10.7 35 0.8 20000

11.4 37.5 1.3 30000

12.2 40 1.1 25000

13.0 42.5 0.9 21000

13.7 45 1.4 34000

14.5 47.5 2.0 47000

15.2 50 1.2 28000

16.0 52.5 1.1 25000

16.8 55 1.2 29000

17.1 56 4.4 105000

17.4 57 8.4 200000



Pile # 2 – Battered at 45 degrees

Pile #2 was installed at a 45 degree batter without pre-drilling on April 8th. The installation was terminated at a depth of 11.6 m (38 feet). A summary of torque readings with depth is provided in Table 2.


Pile Length Torque


0.0 0 0.2 4500

0.8 2.5 2.0 48000

1.5 5 1.9 44000

3.0 10 2.4 58000

3.8 12.5 3.0 71000

4.6 15 3.5 82000

5.3 17.5 2.9 70000

5.5 18 3.5 83000

6.1 20 7.0 165000

6.9 22.5 6.7 160000

7.6 25 6.6 156000

8.4 27.5 6.4 151000

9.1 30 6.9 163000

9.9 32.5 6.5 154000

10.7 35 5.3 126000

11.3 37 4.2 99000

11.6 38 4.3 103000



Pile # 3 – Battered at 45 degrees

Pile #3 was installed at a 45 degree batter without pre-drilling on April 8th. The installation was terminated at a depth of 11.4 m (37.5 feet). A summary of torque readings with depth is provided in Table 3.


Pile Length Torque


1.5 5 4.6 110000

3.8 12.5 4.4 104000

4.6 15 4.6 110000

5.3 17.5 6.4 152000

6.1 20 5.5 131000

6.9 22.5 4.6 108000

7.6 25 4.0 94000

8.4 27.5 4.2 100000

9.1 30 3.6 85000

9.9 32.5 3.5 84000

10.7 35 4.1 97000

11.4 37.5 5.9 140000

3.2 Static Tensile Pile Load Testing

The maximum design tensile (uplift) load required by Manitoba Hydro for this transmission line is 445 kN (100 kips). A static tensile pile load test was performed on vertical pile #1 to determine the pile deflections at the design load and to about 120% of the design load. The test was set-up and run by APE staff under the supervision of TREK personnel. The test was performed according to ASTM Standard D3689-07 standards using the quick test methodology. A photo of the test configuration is shown in Figure 1.



Figure 1. Photo of Pile Load Test Configuration

The initial load test on April 8th was carried up to 427 kN (96 kips) at which point the test was terminated when the reference beam inadvertently contacted the ground adjacent to the pile. The pile was then unloaded, the reference beam reset and a second test was carried out on April 9th. Loads were incrementally raised to a maximum load of 534 kN (120 kips) which was held for 35 minutes at which time a total deflection of 3.3 mm (0.128 inches) was observed. The pile was then incrementally offloaded. Upon complete removal of the load, a permanent deflection of 0.8 mm (0.032 inches) was measured. Loading and pile deflection observations from the April 9th test are summarized in Table 4 and in Figure 2.

On completion of the load test the pile was reloaded rapidly to twice the design load to attempt to get a feel for the maximum pile capacity. The pile was loaded to 890 kN (200 kips) and the load was held for 5 minutes at which time a deflection of 7.2 mm was observed.



Table 4. Summary of Measurements for Tensile Load Test.

Figure 2. Plot of Load vs. Deflection for Tensile Pile Load Test

Load Time Load Time Load Time

kN (kip) (minutes) (mm) (inches) kN (kip) (minutes) (mm) (inches) kN (kip) (minutes) (mm) (inches)

0 0 0.0 0 0 1.6 0.064 0 3.2 0.127

0 0.1 0.004 2.5 1.6 0.064 5 3.2 0.126

2.5 0.1 0.005 5 1.6 0.064 0 3.0 0.118

5 0.2 0.006 0 1.8 0.072 5 2.9 0.116

0 0.3 0.013 2.5 1.8 0.072 0 2.7 0.107

2.5 0.3 0.013 5 1.8 0.072 3 2.7 0.106

5 0.4 0.014 0 2.0 0.078 5 2.7 0.106

0 0.6 0.022 2.5 2.0 0.078 9 2.7 0.106

2.5 0.6 0.022 5 2.0 0.078 0 2.2 0.088

5 0.6 0.022 0 2.2 0.087 3 2.2 0.088

0 0.8 0.031 2.5 2.2 0.087 5 2.2 0.088

2.5 0.8 0.031 5 2.2 0.087 0 1.9 0.075

5 0.8 0.031 0 2.4 0.095 2.5 1.9 0.074

0 1.0 0.04 2.5 2.4 0.095 5 1.9 0.074

2.5 1.0 0.04 5 2.4 0.095 0 1.5 0.06

5 1.0 0.039 0 2.7 0.108 3 1.5 0.06

0 1.1 0.045 2.5 2.7 0.108 5 1.5 0.06

2.5 1.1 0.045 5 2.7 0.108 0 0.9 0.035

5 1.1 0.044 0 3.1 0.122 2.5 0.9 0.034

0 1.3 0.052 2.5 3.1 0.122 5 0.9 0.034

2.5 1.3 0.051 12 3.1 0.124 10 0.9 0.035

5 1.3 0.051 15 3.1 0.123 12.5 0.8 0.032

0 1.4 0.057 20 3.1 0.123 15 0.8 0.032

2.5 1.4 0.057 30 3.3 0.128

5 1.4 0.056 35 3.3 0.128

Deflection

0

249 (56)

178 (40)

107 (24)

Deflection Deflection

320 (72)

391 (88)

463 (104)

463 (104)

498 (112)

534 (120)

(Max.

Load)

249 (56)

285 (64)

320 (72)

356 (80)

391 (88)

427 (96)

36 (8)

71 (16)

107 (24)

142 (32)

178 (40)

214 (48)

Max. Test Load (534 kN)

Design Load (445 kN)



4.0 Summary

One vertical pile and two battered helical piles were successfully installed near the Keewatinohk site in northern Manitoba. The vertical pile was installed in a pilot hole to a depth of 17.4 m (57 feet), demonstrating that this installation method could be used to advance piles to significant depths in the soil type present at the test site. The battered piles were installed without using a pilot hole to a maximum depth of 11.6 m (38 feet), demonstrating that advancement to this depth is possible without pre-drilling; the torque values measured at the termination depth(s), suggests that further advancement of the battered piles may have been possible.

A tensile pile load test on the vertical pile confirmed that the design capacity of 445 kN (100 kips) could be reached with deflections of 2.3 mm. At the maximum test load of 534 kN (120 kips) (120% of the design load), 3.1 mm of displacement was initially measured. Following a holding period of 35 minutes (at the maximum load), an additional 0.2 mm of displacement (3.3 mm total) was measured suggesting that creep movements at 120% higher than the deign load would be acceptable considering the transient nature of transmission line loading.

Following completion of the pile load test the pile was rapidly loaded to twice the design load (890 kN or 200 kips) and a final deflection of 7.2 mm was observed.

5.0 Closure

The geotechnical information provided in this report is in accordance with current engineering principles and practices (Standard of Practice). The findings of this report were based on information provided (field investigation and laboratory testing). Soil conditions are natural deposits that can be highly variable across a site. If subsurface conditions are different than the conditions previously encountered on-site or those presented here, we should be notified to adjust our findings if necessary.

All information provided in this report is subject to our standard terms and conditions for engineering services, a copy of which is provided to each of our clients with the original scope of work, or a mutually executed standard engineering services agreement. If these conditions are not attached, and you are not already in possession of such terms and conditions, contact our office and you will be promptly provided with a copy.

This report has been prepared by TREK Geotechnical Inc. (the Consultant) for the exclusive use of American Piledriving Equipment Inc. (the Client) and their agents for the work product presented in the report. Any findings or recommendations provided in this report are not to be used or relied upon by any third parties, except as agreed to in writing by the Client and Consultant prior to use.

american piledriving equipment inc. helical pile ... · the test was performed according to astm...

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