How to handle quality issues in grid construction

How to handle quality issues in grid construction

1. The treatment of incomplete welds is a common occurrence in some engineering projects where the welds at the steel pipe and cone head or sealing plate are not full. Especially for some large pipe diameter and thick wall members, multiple welding operations may be required to obtain wide and thick welds. At this time, slight negligence by the welder can easily cause incomplete welds. If a ruler is used to lean against the weld seam, there may be depressions in the weld seam at the junction of the welding rod, and there may also be large continuous depressions. This type of rod has a large force and is far from the requirements of the welding specifications, requiring repair welding. Repair welding work is best carried out before installation in the factory or construction site. It is also feasible to operate the installed grid under the action of its own weight. For the grid structure with a fully loaded roof, appropriate support or segmented welding at intervals is necessary to avoid the high temperature state at the full cross-section of the members, as the steel will lose some of its load-bearing capacity at high temperatures.

2. Treatment method for collision of members at ball nodes. If the steel balls are too small during the installation of the grid, it may easily cause the members to collide and hinder the installation work. Correspondingly, in the construction drawings of large and special shaped grid structures, there are bolt balls with a diameter greater than 100, that is, steel balls that are too large. Due to various factors such as market, processing, and on-site installation, the installation work is ultimately hindered. The following method can be used to solve the problem of small steel balls that can easily cause collisions between rods. When conditions are convenient, large balls and corresponding rods can be replaced. Otherwise, burn off a portion of the cone head and rod from one of the colliding rods, and then simulate a steel plate 2-4mm thicker than the pipe wall for repair welding. The opening edges of the cone head and the rod, as well as the steel plate for repair welding, should be beveled (using a handheld grinding wheel). After repair welding, use a handheld grinding wheel to flatten, remove rust, and apply two coats of anti rust primer. The above processing method should follow the following principle, that is, to check the force status of each rod in the electronic calculation book. [2]

3. Treatment method for insufficient depth of high-strength bolts into the bolt ball. The insufficient depth of high-strength bolts into the bolt ball is mainly due to the unreasonable construction sequence, where the upper chord is tightened first, and the web is tightened against the bolt ball, causing the bolt to not move. Treatment method: Strictly follow the construction process, and operators can judge based on the number of threaded turns and use a torque wrench to check.