Mounting of poles and foundations Rette produkt Til rette opgave 12/04/2018
Burying and mounting poles General When mounting poles, the door of the pole must always match the specific pole, with which it was produced. This goes especially for conical poles where a number is found in both pole and door that indicates the affiliation. Be aware that it can be necessary to have isolation material between the foot of the pool and the bolts for poles with foundations. This is due to risk of galvanic corrosion caused by a big discrepancy in anodic value. It s recommended that poles for burying are accompanied by cable sleeve cuffs if no cable tubing is added. Poles with foot must have, as specified in EN 40, oversized washer acc. to ISO 7093. Foundation bolts for these poles should be fastened with a torque wrench acc. to size, steel type and eventual lubricant. Surface treatment Steel poles normally have 60µ of galvanization acc. to EN 1461. Winged foundations are made in alu-zinc which normally have 20-25µ alu-zinc corresponding to 120-150µ heat galvanization. Aluminum poles normally have 20-25µ anodizing. Mounting height In some cases, it can be necessary or an advantageous to change the depth of the hole. The door should as a base always be minimum 300 mm above terrain. Otherwise there is distinguished between 3 situations as specified below. Bolts over terrain, with the foot of the pole in the level of the terrain, makes maintenance easy. Density of soil Foundations placed 200mm under terrain. pole itself be visible. Furthermore the extra depth increases the stability of the pole. Placement of the pole 500 mm over terrain is sometimes used in parking spaces to protect the pole from collision. Here it s important to calculate the pole for a foundation going 500mm above terrain. The maximum deviation allowed is +20 mm. Be aware that security poles must be mounted specifically in relation to the soil. Loose soil Compressed soil Placement of the pole 200 mm under terrain is the aesthetic solution. 200 mm is enough to hide the foot of the pole and bolts, thus letting only the the
Mounting and placement Soil Poles are either for burying or foundation. Ready made foundations and poles for burying goes under the category of pile foundation. These derive their strength from the surrounding soil. It s therefore very important to guarantee the quality of the soil before the pole is mounted. Soil is usually classified as clay, silt and sand soils. The type of soil is determined by the grain size. Sand soil has a large grain size followed by silt and clay has the smallest. Each type of soil acts differently and it can thus be difficult to determine the bearing capacity of the soil. At Daintra we use stable gravel as standard soil. Burying and compression For burying poles, it s recommended that the hole dug is wider than 3 times the diameter of the largest width of the foundation. This ensures that the soil used as filler is responsible for the bearing capacity of the foundation. When mounting a pole in slanted terrain, it s recommended that a shoulder for the foundation is built with the depth of the foundation as a minimum radius. Before the foundation is placed a compressed layer of soil is made in the bottom of the hole. This can be done with stable gravel. The hole is adjusted to the burying mark on the pole for buried poles or the foundation. The compression is carried out acc. to the Eurocode. Typically, the soil is compressed in layers of 100-200 mm using the appropriate methods such that the expected bearing capacity is acquired. Soil type Age Cu ϕ c' Peat Pg 10-200 25-35 0 Gyttja Pg 5-100 25-35 0 Clay Pg 10-100 25-30 0 Sand Pg - 33-39 0 Clay Sg 20-100 25-30 0 Melt w. clay Gc 100-500 25-30 10 Met w. sand Gc - 36-42 0 Boulder clay Gc 50-1500 30-36 0-20 Moraine sand Gc - 38-45 0 Cu/c undrained/effective cohesion, ϕ friction angle, Pg post glacial, Sg late glacial, Gc glacial Stepped poles are adjusted with a bubble level either placed on the foot or the pole. For conical poles place a bubble level on the foot. To check conical poles, a block corresponding to the conicity of the pole is placed at 2 meters. Here, a bubble level can be placed for measuring. For poles placed in environments with damaging vibrations, a vibration dampener can be used. The pole is mounted directly at the foundation only if the surface is sufficiently even. For high poles and poles in risk of big vibration, any gap between the foot and the foundation should be filled with non shrinking concrete mortar. Areas of risk Be aware of the soil conditions. High groundwater reduces bearing capacity. Peat and other soils with high content of organic materials have high risk of displacement. The water content in clay has a big impact, since the clay can either become liquid or lose its cohesive properties. Mounting in frozen soil can result in displacements when heated. Casting of concrete foundation Foundation bolts are placed in a casting template, and then lowered into the wet concrete. The casting template rests on the concrete surface until the hardening has completed. Be aware that it takes the concrete 21 days to harden. Concrete quality: C25/30 or better. Reinforcement of the concrete has to be calculated. Mounting The casting template is removed and the nuts are fastened and leveled. Then the pole is mounted with washer and nuts. Bottom nut is placed 10 mm above the foundation. The foot must supported with concrete if the distance is more than 20 mm from nut to foundation. To minimize the risk of settlements in the soil it s recommended that the foundation is filled inside. For this, it s not needed to compress the soil. Notice that the wrong choice of compression in some cases could be harmful for the bearing capacity of the soil. Drain There must always be a drain for the pole. If the space between the foot and the foundation is full of concrete mortar a drain must be made to avoid water collection. This also goes for the bottom fill if it s made of concrete. Mounting and stabilization of pole When mounting cylindrical poles a bubble level is placed on the foot* or the pole for measurement. *Foundation placed in height of terrain
Steel foundations STEP 1 Before burying, check that the pole and foundation fit together. After, the foundation is buried according to aforementioned considerations, see ( Mounting and placement section). STEP 2 When mounting the foundation, the top nut and disc is removed. The nuts are adjusted such that the fitting plate is level. The pole is then mounted in level based on the buried foundation. Vibration dampeners can be attached between the pole foot and foundation plate. Remember isolation tubing on bolts for aluminum poles. STEP 3 Keep one nut of distance between the two bottom nuts for eventual fine tuning of the pole s inclination. Nuts are tightened with a torque wrench acc. to foundation specifications. Protection caps are attached to the bolts to secure a long life span.
Concrete foundations STEP 1 Before burying it is checked that the pole and foundation fits together. After, the foundation is buried according to aforementioned considerations, see ( Mounting and placement section). STEP 2 When mounting the foundation the top nut and disc is removed. The nuts are adjusted such that they are level. The pole is then mounted in level based on the buried foundation. Vibration dampeners can be attached between the pole foot and the bottom foundation nuts and discs. Remember isolation tubing on bolts for aluminum poles. STEP 3 Keep one nut of distance between the bottom nuts and the foundation for eventual fine tuning of the pole s inclination. Nuts are tightened with a torque wrench acc. to foundation specifications. Protection caps are attached to the bolts to secure a long life span.
Wing foundations STEP 1 Before burying it is checked that the pole and foundations fit together. Then the digging is done with attention to the potential risks. (see risks under Mounting and placement ). STEP 2 If two sets of wings are attached, they are to be placed over and under the cable exit and are turned 90 degrees in relation to each other. One in the bottom as far down as possible. One in the top 100 mm under the surface of the terrain. If only one set of wings, it s placed 100 mm under the terrain. STEP 3 The wings are attached with 4xM5 bolts and nuts. See accompanying bolt bag for size check. Can also be had with 2xM10 bolts. The pole is leveled in the dug out hole and the filler is compressed ( Mounting and placement ) Top/bottom wing foundation can also be replaced with concrete, universal or ring foundations.
Maintenenace General maintenance Movable parts by the door are lubricated once per year. Every fifth year it s recommended to conduct a visual inspection of the pole and its foundation. If necessary, the bolts and lock nuts are tightened. Galvanized surfaces If galvanized surfaces are damaged they must be repaired acc. to DS 1461 with paint containing zinc. Painted surfaces It s recommended to regularly wash/rinse painted surfaces of road salt and dirt. To prolong the durability wash with detergent containing wax. Hereafter a good wax is used for final treatment. This procedure is recommended to be done at least once a year. Damages are to be repaired as soon as possible after the damage is done. Thermoplastic surfaces Can be washed with environmentally friendly detergents. Scratches and cracks can be corrected with heat or repaired with thermoplastic material, which is applied with heat. Treatment of foundation bolts Foundation bolts must be lubricated with grease before mounting the pole. Hereafter it s recommended to use grease filled protection caps, in order to allow for easier tightening of the bolts later on. Retightening of the bolts should happen for the first time after 2-3 years, then every fifth year. Black foundation bolts can, in cases of corrosive environments, be lubricated with paint containing zinc. Galvanized or stainless bolts can also be ordered. In very corrosive environments or where further protection is desired, the bottom of the pole can get a root treatment until 200mm above terrain. The foot of the pole and bolts are treated with a C5 treatment. Protection caps for foundation bolts: Delivered in sets of 4 pcs. for i.a.: M20 bolts El. nr. 53.10.730.088 M24 bolts El. nr. 53.10.730.090 M27 bolts El. nr. 53.10.730.092 M33 bolts El. nr. 53.10.730.094 M39 bolts El. nr. 53.10.730.098 Anodized surfaces Anodized aluminum surfaces need a certain maintenance. The coating effectively protects against corrosion, wear and tear, and keeps the soil from depositing on the surface. In very polluted environments, such as industrial areas, it is necessary to periodically clean the poles to maintain their lifespan. In practice the frequency with which the poles are cleaned depends on how aggressive the environment is. It s best to clean with a neutral and synthetic detergent applied to a cloth or soft brush. Then the poles are to be washed with water. Hardened dirt can be removed with a light grinding detergent or shed fiber with neutral polishing powder. Always avoid sodium, bases and acids.
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