12 Steps to Install Square Shaft and Round Rod Anchors

Posted by Tim Staelens on Apr 17, 2019 3:09:00 PM
  1. Once all safety concerns have been addressed, attach the Kelly bar adapter and installing tool assembly to the Kelly bar on the installing truck.
  2. Insert the upper end of the anchors’ lead section into the installing tool. Position the anchor at the desired guy location and at a near vertical position; screw the first helix into the ground.
  3. When the first helix is buried, begin to make the angular adjustment for the desired guying angle.
  4. Remember, final angular adjustments should be made before the second helix penetrates the ground.
  5. When the installing tool becomes 12”-18” from the ground, disconnect it from the section in the ground and reconnect it to the next extension.
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Topics: Anchors

Maintaining your Anchor Tools

Posted by Tim Staelens on Mar 11, 2019 1:07:00 PM

As with most mechanical devices, CHANCE® anchor-installing tools periodically require maintenance checks to ensure peak performance.

TORQUE INDICATOR

In the case of the shear-pin torque limiter, (see drawing below to the right) you should be able to rotate the tool shear halves independently from one another using a smooth-turning action. If rotation cannot be done by hand or if movement is challenging, disassemble the torque indicator to check the thrust bearing, washers and/or pin for wear.

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Topics: Anchors

7 Steps to Install Expanding Rock Anchors

Posted by Tim Staelens on Feb 13, 2019 11:25:00 AM
  1. Choose anchor site carefully. Rock anchors will only perform effectively in solid competent rock (Class 0 Soil).
  2. Drill the hole into the competent rock a minimum depth of 12 inches along the drill steel. Be sure to drill so that the anchor rod will be in line with the guy.
  3. Holes should be drilled so the diameter is optimally an 1/8th inch larger than the diameter of the unexpanded anchor. For example, the hole drilled for a R315 is 1-7/8 inch diameter. However, drill bits are usually available in 1/4 inch increments. In practice, a 2 inch diameter hole is drilled for the R3_ series anchors and a 2-1/2 inch dia. hole is drilled for the R1_series anchors. Be sure to thoroughly clean the drilled hole of rock dust and debris.
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Topics: Anchors

How to Use Power-Installed Screw Anchors

Posted by Tim Staelens on Dec 17, 2018 3:12:00 PM

"Proper alignment" and "down pressure" are simple phrases to summarize proper anchor installation technique. The Power Installed Screw Anchor (PISA®) wrench transmits torque from the digger’s Kelly bar to the anchor hub. Note: The anchor rod only has to be of sufficient diameter to support the guy load.

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Topics: Anchors

Use Proper Tooling in Anchor Installation

Posted by Tim Staelens on Nov 13, 2018 10:38:00 AM

It is essential to use installing tools and anchors that are properly rated for trucks during the installation of power-installed screw anchors (PISA®). The high torque energy used in installing high-strength anchors requires the control of hazardous torque, which can be safely completed by proper tools. 

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Topics: Anchors

Understanding Grouted Rock Anchors

Posted by Tim Staelens on Nov 5, 2018 3:07:00 PM

The CHANCE® grouted rock anchor is designed to be used in situations where the soil is too rocky to use screw anchors, and the rock is fractured preventing the use of wedge style rock anchors. The forged knob on the end of the anchor along with any extension couplings provides the interference fit with the grout. The holding capacity of the anchor is dependent on the bond stress between the rock and the grout. The grouted rock anchor is designed to be used in line with the guy. Failure to install within 5° of alignment with the guy load will significantly lower strength.

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Topics: Anchors

Evaluating Utility Foundations During Storm Restoration

Posted by Hubbell Power Systems on Sep 10, 2018 1:45:00 PM

Rising water can damage or weaken existing transmission line and substation utility foundations. In flooded areas, drilled shafts and driven piles need to be inspected to determine if damage has occurred as a result of erosion. Here’s what you need to check:

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Topics: Anchors, Foundations

The Science of Soil Mechanics & Holding Capacity

Posted by Tim Staelens on Jul 23, 2018 3:41:00 PM

Historical Analysis

During the early development of the screw anchor, the load resistance of an installed anchor could not be predicted with adequate accuracy. Specific information on soil conditions was lacking, making anchor selection more or less a guess. With little consideration for soil variations, the effects of seasonal weather changes or drainage, soils were classified as: either sand, clay, hardpan or swamp. At that time, there was not a definitive explanation for the soil conditions.

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Topics: Anchors

5 Tips to Inspecting Guy Anchors after a Storm

Posted by Hubbell Power Systems on Sep 13, 2017 2:07:00 PM

When utility crews are dealing with the aftermath of storms, they cannot forget to evaluate how the guy anchors have been impacted.  Rebuilding the overhead lines depends more than ever on the holding capacity of the guy anchor.

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Topics: Construction, Anchors