Steel anchor bolt short

by:DEFUS     2020-06-20
Anchor bolt is an important part of a connected the upper structure and foundation, if buried deviation is too big, will lead to excessive stress, affect the normal use and service life of the structure, once appear big deviation phenomenon, should be carefully adjusted to correct. Processing method of choice, should according to the bolt diameter size and determine the deviation, should also consider structure types, construction site conditions, factors such as select, so steel anchor bolt short? Here are several kinds of steel structure of anchor bolt deviation remedial measures. ( 1) Anchor bolt plane position deviation handling when bolt center and design the centerline deviation in less than 10 mm, can adjust the column foot bolt hole position or evade ( Cut) Hole to adjust, but be especially careful, avoid damage to the base. When the bolt diameter within 36 mm, deviation distance less than 1. 5 d, generally USES the hot bending bolt method processing. Can be in the root of a deep - 150 200 mm grooves, with oxygen acetylene torch roasted root of bolt, bolt a s-shaped bend ( Figure 1 a) , application of one-side when hot bending, bending part should be buried in the concrete, to prevent the corner stress concentration, because the anchor bolt bending or deformation will make the working stress of bolt times larger than normal. Heating temperature should be 700 - Within the range of 800 ℃, and water cooling should be avoided, in case of bolt brittle. If the bolt diameter equal to or greater than 36 mm, also can use hot bending, but need to add welding steel plate in bending parts or steel anchor solid, such as its length is not less than S bend two tangent point distance ( Figure 2 b) And calculating the weld length, make the bolt straight and tensile strength. Very local bolt off ( Greater than 1. 5 d) , can be used to transition method of steel framework that bolt cut first, add welding channel steel frame, then add new bolt welding on channel steel, channel steel welds are to be calculated. Set the new bolt through channel steel or steel and original buried under the deflection in the basis of bolt welded together, to deliver the upper structure on the horizontal and vertical force. Frame design should guarantee the enough strength and stiffness, makes it a reliable overall. Local bolt deviation is too big, can't install the upper structure, or because of drawing size error, embedded anchor bolts location, elevation does not accord with design drawings, or column foot processing error is too large, need to have the embedded anchor bolts replaced, also buried the new bolt. The available drill out in situ bolt or for in situ bolt truncation, near the bolt hole, back in the hole furnish chemical bolts. ( 2) Anchor bolt elevation deviation handling local elevation deviation for bolt - 10 ~ 30 mm, but installed column foot still can guarantee the thread has 2 when the length of the nut, don't do processing, or tighten nut nut and plate and column foot after welding, prevent loose nut; Thread is high, can add the steel plate to adjust. If bolt elevation deviation is greater than the - 10 ~ 30 mm to meet the installation requirements, can adopt the method of extension bolts for processing. Bolt first cut to the concrete around the concave hole, used with the diameter of the bolt, downhill mouth welded butt ( Figure 2 a) , or butt in on both sides of the welding article to help again after reinforcement ( Figure 2 b) Article, but help should not be revealing short column surface leveling layer, so that Yu Gangzhu installation. When the bolt diameter within 36 mm for repair welding of 2 root reinforcement; Bolt diameter greater than 36 mm weld article 3 root help steel ( Figure 2 c) Article, additional help steel area should not be less than the original bolt cross-sectional area 1. Three times, nor may it use less than 16 mm steel, 2 of each general weld length fluctuation. 5d( D for the bolt diameter) 。 Or it can be compared to the original bolt diameter increased double bolt, processed into the thread, set in the original bolt, also can add screw sleeve or welding on casing in the new bolt. This kind of extension method is more accurate, but more work, and pay attention to the new and sleeve height can not short column above the leveling layer, otherwise it will affect the installation of the steel column. If the bolt design elevation above a lot of, can put nut into the upper thread after the truncation, keeping appropriate height, and nuts along the screw thread screw up and down several times, in order to make sure the thread to open. All bolts after review calibration, if in a short period of time without the installation of the upper structure, shall be coated with solid butter in the thread, in plastic package tied with wire. Above is the small make up today's introduction about the content of the steel anchor bolt short to do, I hope to be of help.
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