To safely ca∑₽αrry larger turbines at∏∏  higher hub heights, careful considera∑∑÷tion must be given to the foundation d‌↕esign and system componentsβ£↓>. A proper geotechnical evaluation of↔↕ the soils must occur a•∑↓→fter all of the structural lo​β× ads carrying the tower and n₩α♣₩acelle components are evaluated. Witφ≠₽₹h this information, the foundation→$★₹ designer is able to determine the w↕✘₹ idth and depth of the concrete foun☆♠&©dation.

    A vital component•₹ to the foundation system is the tower♣'≠± anchor bolt. These anchor bolts aβ≥πσre responsible for keeping the tower §★and nacelle in equilibrium. The ancho∏≤∞₩r bolts are installed <≠✔♠during the foundation forming procφ™∑ess in a large ring pattern ¥♣‌¥with a matching inner and ou>↔β♣ter circle of anchor b♠✔olts symmetrically arou↕↓↓σnd the foundation.

    Typically, between 140>& and 200 anchor bolts are in ea®©α↕ch foundation design. A $π♣thick steel embedment ring cont¶∞≤aining holes for the tower anchor ♦☆±bolts is placed near the bottom of the∞→ foundation pour, and a☆∏™ template ring – ostensi​€✔•bly, a thinner steel ring with matchin<​Ωg holes – is placed at th" ₽e top of the foundatio©‌σn pour. Each anchor bolt is™∏ fitted with PVC sleeves running∑≠≥  between the steel rings s•‍<$o they are flush against₹← each ring surface in oβ"φrder to keep the anchor bo$ lts de-bonded duringσ‍$™ the foundation pouring operation.

    A heavy ​÷£©pattern hex nut and washer ar≥αe underneath the embedment r ©☆ ing and similarly placed on the to↔&€"wer base plate. (Prior to placing α the tower base plate, the ≈← temporary template ring is removed a™•fter the concrete pour.) It s☆ hould also be noted t↓≥§✔he tower base section is™® shimmed into position above the to∏↑p of the pedestal foun'<♣dation pour, and the voided area beσ♣tween is filled with a high-strength©∑ epoxy grout to complete the gro★÷ut pad.

Once the grout pad is cured, all of←'↔ the tower anchor bolts are pr±≠™e-tensioned to a load ×₹<specified by the foundat∑®ion designer and locked off ¶™by torquing the top hex φ≈>‌nuts to remove the stretch crea ↑ted. The pre-tensioning process™> is typically achiev∞₽≤‍ed by using small-diameter, compact, hi∞£↓'gh-psi capacity calibrated≤π< tensioners. This elas€₹™tic stretch created by tensioning un∞§der load is permanently transferred t★εo the anchor bolt by torquing the nut★  prior to removing pressure from the te∞&∑nsioning jack.

After pre-tensioning t₩÷φhe tower anchor bolts in a predetermine&≤₽→d selected pattern across theλ↔★' foundation, the ring pattern ₹₩✘εof the anchor bolts is placed into ←•§compression. Therefore, the equ &∞εilibrium is maintained β£ ∏as varying load cycles ∑≈¶£are continuously placed on ≥©the foundation. Designers speci§•fy an anchor bolt lock-off prδ↑e-tensioning load to be at a level wherλσe the maximum external desig•←♠n load that is placed on the foundatioσ•αn is never reached.

Pre-tensioning prevents t≤$he anchor bolts from stre§ "tching and relaxing, which can l‍ Ωead to long-term fatigue, a☆'nd also mitigates spa♣π¥lling or cracking of the conc$∞±×rete from tensile stresses.

The normal practice is for the fou✔γ✔♥ndation designer to specify a lock-off ÷&σ&load that takes into consideration★₹ in-service design loads and, in additi∏↑↕δon, losses such as na¥÷tural relaxation loss in the steel (g₩♥enerally averages 2% λ∑★∏max) and slight creep losses♦₹$ in the foundation itself under load. C©∏♣reep refers to the sl∞≤ight movement over time toφσσ♣ the concrete – and, to a less₹₩™er extent, the steel tower base as a r≈♠®esult of being under the$€ pre-tension load. Movement resulting fδ $rom the so-called creep results in♦α a loss of direct pre-tensiβ≠✔on load.

Anchor Bolt/ Anchor Cage ♣γ♠γFor Wind Turbine Foundation  &n←​bsp;       &©§≠nbsp;         σ ≥φ      ≈®π      

We will continually improves and ex‍>∑¥pands the quantity and quality δαΩof our product which exactly meet cu∑™stomers need. We do whatever it t♠★β$akes to make our clients happy.>₽¥
We will develop long-t♥×erm commercial and te≥'chnical partnerships with•♥ customers. And we are c€♦<≈ommitted to continual quality i'♦mprovement of all internalγ↕☆σ processes. The success of   our quality program is affirmed  ₹by our strong customer retentio→→n rate.

Contact infor@aqjiuxing.net ≈πβ<for a free quote, we will r≥♥eply within one working day.