Wind Tower Foundation Anchor Cage ASTM A615 Gr 75 Pre-Assembled Threaded Bar Cage

Product Description

WIND TOWER FOUNDATION ANCHOR CAGE ASTM A615 GR 75 PRE-ASSEMBLED THREADED BAR CAGE


Description:
                                                                                                 
With increased demand for greater output from wind energy projects, the industry is increasingly looking to maximize output from each wind turbine. Over the years, wind power has become competitive with traditional forms of non-renewable energy because advancements in generator technology allow larger and heavier generators to produce a higher-megawatt output than ever before. These newer, advanced turbines are also carried on towers with higher hub heights to capture higher wind speeds. With this comes the requirement for tower anchor bolts to carry higher tensile load capacities.

 To safely carry larger turbines at higher hub heights, careful consideration must be given to the foundation design and system components. A proper geotechnical evaluation of the soils must occur after all of the structural loads carrying the tower and nacelle components are evaluated. With this information, the foundation designer is able to determine the width and depth of the concrete foundation.

     A vital component to the foundation system is the tower anchor bolt. These anchor bolts are responsible for keeping the tower and nacelle in equilibrium. The anchor bolts are installed during the foundation forming process in a large ring pattern with a matching inner and outer circle of anchor bolts symmetrically around the foundation.

     Typically, between 140 and 200 anchor bolts are in each foundation design. A thick steel embedment ring containing holes for the tower anchor bolts is placed near the bottom of the foundation pour, and a template ring - ostensibly, a thinner steel ring with matching holes - is placed at the top of the foundation pour. Each anchor bolt is fitted with PVC sleeves running between the steel rings so they are flush against each ring surface in order to keep the anchor bolts de-bonded during the foundation pouring operation.

A heavy pattern hex nut and washer are underneath the embedment ring and similarly placed on the tower base plate. (Prior to placing the tower base plate, the temporary template ring is removed after the concrete pour.) It should also be noted the tower base section is shimmed into position above the top of the pedestal foundation pour, and the voided area between is filled with a high-strength epoxy grout to complete the grout pad.

Once the grout pad is cured, all of the tower anchor bolts are pre-tensioned to a load specified by the foundation designer and locked off by torquing the top hex nuts to remove the stretch created. The pre-tensioning process is typically achieved by using small-diameter, compact, high-psi capacity calibrated tensioners. This elastic stretch created by tensioning under load is permanently transferred to the anchor bolt by torquing the nut prior to removing pressure from the tensioning jack.

After pre-tensioning the tower anchor bolts in a predetermined selected pattern across the foundation, the ring pattern of the anchor bolts is placed into compression. Therefore, the equilibrium is maintained as varying load cycles are continuously placed on the foundation. Designers specify an anchor bolt lock-off pre-tensioning load to be at a level where the maximum external design load that is placed on the foundation is never reached.

Pre-tensioning prevents the anchor bolts from stretching and relaxing, which can lead to long-term fatigue, and also mitigates spalling or cracking of the concrete from tensile stresses.

The normal practice is for the foundation designer to specify a lock-off load that takes into consideration in-service design loads and, in addition, losses such as natural relaxation loss in the steel (generally averages 2% max) and slight creep losses in the foundation itself under load. Creep refers to the slight movement over time to the concrete - and, to a lesser extent, the steel tower base as a result of being under the pre-tension load. Movement resulting from the so-called creep results in a loss of direct pre-tension load.
        

Technical parameter:
 

Anchor bolt Grade	Nut Grade	Washer	Size	Impact release	Length (mm)
8.8	8	35-45 HRC	M20-M64	65	10000 MAX
9.8	9			55
10.9	10			50
12.9	12			40

Grade	Rm/Mpa	Rp0.2/Mpa	A%	Z%	-40ºCAkv2/J	Hardness
10.9	≥1040	≥940	≥9	≥48	≥50	HRC32-39
8.8	≥830	≥660	≥12	≥52	≥70	HRC23-34

About us
Powerchina Henan Electric Power Equipment Co., Ltd.

• POWERCHINA Henan Electric Power Equipment Co., Ltd. is a subsidiary company of Power Construction Cooperation of China (POWERCHINA) FORTUNE GLOBAL 500
• Professional customer service, product development, technical Support and after Sale Service.
• POWERCHINA Henan Electric Power Equipment Co., Ltd, covering an area of 84000 square meters, was established in 1958
• POWERCHINA Henan Electric Power Equipment Co., Ltd has a total of more than 426 employees, including more than 128 engineers and technicians.

History
POWERCHINA Henan Electric Power Equipment Co., Ltd. covering an area of 84000 square meters was established in 1958 under the name of Luohe Iron Industry Association, during these period, the name of the company changed several times as follows: Luohe Iron Industry Association in 1965, Luohe Electric Equipment Material Factory in 1971, and was placed under the administration of the Electric Power Industry Bureau of Henan in 1976, Henan Electric Equipment Material Company in 2010 with the supervision of State Grid Cooperation of China, after reorganization, become subsidiary company of Power Construction Cooperation of China(POWERCHINA) in September 2011. In 2018, the company name has changed to POWERCHINA Henan Electric Power Equipment Co., Ltd. Presently, the company has a total of more than 426 employees, including more than 128 engineers and technicians, and its fixed asset reached more than 100 million Yuan.

Service
We provide the following services:
Product development and production
Professional customer service
Technical Support
Reliable warehousing and logistics
After-Sale Service and warranty commitmentsOEM&ODM
We have many oversea projects, which have made us professional in OEM and ODM.


Production line
Our company has 440 sets of production equipment and experimental equipment, including low-pressure casting machines, 800-ton die-casting machines, CNC machining centers, 1000-ton servo direct-drive electric screw presses, 300T (200T) horizontal tensile testing machines, 100T servo universal testing machines, magnetic particle flaw detection machines, pendulum impact testing machines that can meet the requirements of - 40 ºC, spectral analyzers, etc., as well as forging hardware, anchor bolts, nuts, segment bolts, dacromet 6 fully automatic production lines including photovoltaic support.


R&D Center
Our R&D Center owes 300t horizontal tension machine, 300t horizontal tension machine, Magnetic particle flaw detector, Magnetic particle flaw detector, Magnetic particle flaw detector, Spectrum analyzer, Coating testing machine and so on
Our Team
We are member of the National Overhead line Standardization Committee and China Electric council Power Equipment Standardization Committee,Participated in the formulation of DL/T 764-2014 DL/T 1343-2014 DL/T284-2012 and other professional standards,At the same time, assisted the State Grid Corporation of China to formulate the general design standard of 1000kV and 800kV transmission and distribution line fittings.
We are also a state-level high-tech enterprise, a provincial enterprise technology center, a Research center of Henan Energy-saving electric power fittings Engineering technology, an innovative pilot enterprise of Henan Province, and an intellectual property advantage enterprise of Luohe City.