FOUNDATION DESIGN FOR NORMAL SOIL

The standard foundation drawing below is provided for "normal" soil conditions. Normal soil conditions are defined as a cohesive soil with an allowable bearing capacity of 4000 psf and an allowable net horizontal pressure of 400 psf per lineal foot of depth to a maximum of 4000 psf. If your application requires that the tower be installed on other than normal soil conditions, contact your local geotechnical consultant.

A hole should be excavated to the minimum dimensions suggested and forming is not required provided the excavation will hold its walls. If forming is required, a strong, well-constructed plywood form will be necessary.

Four standard anchor types are referenced in the 1st chart below. Select the proper anchor based on the number assigned to the bottom 8-foot section of your tower.

To download an electronic copy of this soil foundation drawing, click on the link below:

Soil Foundation Drawings and Notes.pdf

Titan self-support towers utilize a set of three, 4 foot long, 'ANCHOR STUB LEGS' which become encased inside the poured concrete foundation.

This photo shows what the ANCHOR STUB LEGS look like. They are 60 degree angle, to match the same shape of the tower legs. As shown in the photo, ANCHOR STUB LEGS have 4 holes punched in the top end. These are the 'splice' holes which mate up with corresponding splice holes in the bottom 8' section of the tower. It is necessary to ensure that after concrete pouring, these splice holes will remain above the finished level of the concrete. Therefore, if the tower ever needs to be relocated, only the stub legs will be lost. The tower sections can be easily unbolted and moved to a new site.

	This photo shows how the 4ft long ANCHOR STUB LEGS are easily installed onto an 8ft tower bottom section. As shown in the photo, each tower section is tapered from bottom to the top.

This photo provides a visual understanding of the 60 degree angle on each tower section leg and ANCHOR STUB LEG.

For those customers who prefer a slightly simpler foundation anchor method,
Trylon TSF sells a separate accessory called a 4' SHORT FOUNDATION KIT,
which eliminates the need to attach stub legs onto an 8' tower section. These 4' SHORT FOUNDATION KITS are sold separately. See TITAN SELF-SUPPORT ACCESSORIES for more details on that item.

The reinforcing bars are required as indicated on the PDF drawings and charts above. Once they are in place, the 4 ft. long Anchor Stub Legs (provided with tower) can be attached to the bottom section. Then this assembly can be positioned over the excavation.

Care should be taken at this point to ensure that the splice bolts to the anchor stub legs will be above the finished level of the concrete surface and that the first section is truly vertical.

Using a high-quality spirit level or transit, check the verticality of the section. If a spirit level is used, place it on the top of the legs on all three tower faces. Be sure to secure the tower and stub legs against movement while the concrete is being poured.

Concrete should cover all rebar to a depth of 3 inches and reach strength of 3,000 PSI at 28 days. Allow proper curing of the foundation prior to installing the balance of the tower (at least one week is recommended).

If the concrete has not been poured against an undisturbed surface, it will be necessary to backfill with more granular material, compacted in layers of not more than 6 inches.

FOUNDATION NOTES:

Concrete

• Concrete construction shall conform to the requirements of CSA Standard A-23 or similar ASTM Standard.
• Reinforcing steel shall be grade 50 deformed bars and shall have minimum concrete cover of 3 inches.

Foundations

• All foundations shall be kept dry, by pumping if necessary, before pouring concrete and shall be kept dry until backfill is in place.
• Backfill with granular material compacted in layers of not more than 6 inches.
• Backfill shall be placed so as to prevent accumulation of water around foundations or anchors.

Designs

• Soil anchorage shown has been based on normal dry soil assumptions. These are as follows:
  
  
  • Unit weight of compacted soil is greater than 100 pounds per cubic foot.
  • Water table is at a depth greater than 8' below grade.
  • Coefficient of passive earth pressure greater than 3.2
  • Coefficient of active earth pressure is approximately 0.3
  • Organic materials are not present in the soil.
  • Soil is not acidic.
  • The allowable bearing pressure of the soil at the 5' depth shall be greater than 3500 pounds per square foot.

• The installed foundation will have a safety factor of greater than 1.2 when installed as described (the tower will fail prior to foundation failure).
• Design ultimate loads are as per table above.
• Figures and notes represent Trylon TitanTM soil foundations.
• Maximum frost penetration of 3' presumed.
• Anchor number one shall be used for towers with the bottom section having a number of 2, 3, 4, 5 or 6.
• Anchor number two should be used for towers with the bottom section having a number 7 or 8.
• Anchor number three should be used for towers with the bottom section having a number 9, 10, 11, 12.
• Anchor number four should be used for towers with the bottom section having a number of 13.

General

• The tower shall be centered on the concrete cross-section such that dimension 'A' equals dimension 'A'.
  

For an electronic pdf copy of these foundation notes and general instructions, download from the following two links:

Soil Foundation Design Notes.pdf
Soil Foundation Design General Instructions.pdf

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ROCK FOUNDATION DESIGN
	Titan Towers offer special "base foot weldments" and rock bolts for geographic areas where rock anchorage is required. These foot weldments are used in lieu of the 4-ft. anchor stub legs provided with each Titan tower.

The Titan base foot weldments are designed with the same 60-degree angle as the legs of the Titan tower. Therefore, they are a perfect fit for the bottom of the tower leg and are easily attached to the legs by bolting through the 4 pre-stamped holes. The bottom plate of the foot weldment also has pre-stamped holes that are ready to receive the 5 ft. long rock bolts (ordered separately).

There is a different base foot weldment for each tower section. The base foot weldments for sections #2 through #12 have only one hole. The base foot weldment for section #13, however, has two holes as illustrated in the drawings below.

Foundation Notes:

• Drill hole to proper diameter (D) and depth. Note that the total depth of hole required should be 10 inches deeper than the rock bolt embedment length. Hole should then be cleaned out.
• Place bolt in accordance with the manufacturers instructions.
• The rock bolts shall also be grouted in place using a non-ferrous, shrinking grout having a minimum compressive strength of 27.5 MPa.

Design Notes:

• Rock anchorage shown has been based on sound unfractured rock assumptions.
• The installed foundation will have a safety factor of greater than 1.2 when installed as described (the tower will fail prior to foundation failure)
• Design ultimate loads are as per table below.
• Figures and notes represent Trylon TitanTM rock foundations.
• Anchor number one should be used for towers with the bottom section having a section number of 2, 3, 4, 5 or 6.
• Anchor number two should be used for towers with the bottom section having a section number of 7 or 8.
• Anchor number three should be used for towers with the bottom section having a section number of 9, 10, 11 or 12.
• Anchor number four should be used for towers with the lowest section having a section number of 13.

To download an electronic copy of all the Rock Foundation drawings and instructions, click on the link below:

Rock Foundation Drawings & notes.pdf

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