Pay attention to these problems, the quality of steel structure construction has been greatly improved

Because of its own advantages, steel structure is widely used in modern buildings such as bridges, industrial plants, and high-rise buildings. In the process of a large number of engineering construction, steel structure engineering has also exposed many quality problems.

1. Some problems and solutions in the construction process of steel structure engineering

1. The production of components

The plates used for portal steel frames are very thin, as thin as 4 mm. The cutting method of multi-thin plate should be selected and avoid using flame cutting, which will cause great wave deformation on the edge of the plate. At present, most manufacturers of H-beam welding use submerged arc automatic welding or semi-automatic welding, if the control is not good, welding deformation should occur, so that the components are bent or twisted.

2. Column foot installation problem

(1) Embedded parts (anchor) problem phenomenon: overall or layout shift; The elevation is wrong; The fastener is not protected. Directly cause the bolt hole of the steel column bottom plate to be out of position, resulting in insufficient wire buckle length.

Measures: The steel structure construction unit cooperates with the civil construction unit to complete the embedded parts work, and the relevant dimensions must be reviewed and fixed firmly before the concrete is poured.

(2) The phenomenon that the anchor is not vertical: the horizontality, the bottom plate of the frame column is poor, the anchor is not vertical, and the horizontal error of the embedded anchor after foundation construction is large. After installation, the column is not in a straight line, and it is crooked, making the appearance of the house ugly, bringing errors to the installation of steel columns, and the structural force is affected, which does not meet the requirements of the construction acceptance specifications.

Measures: The anchor installation should insist on leveling the bottom plate with the lower adjustment bolt first, and then fill it with secondary grout with non-shrinkage mortar, and this method is used for construction abroad. During anchor construction, fixed anchors such as thick steel bars or angle steel can be used to weld into cages to improve support, or take other effective measures to avoid the anchor shifting when pouring foundation concrete.

(3) Anchor connection problem phenomenon: the anchor bolt of the column foot is not tightened, and the pad is not welded with the bottom plate; Some anchors with 2~3 silk buckles are not exposed.

Measures: welding bolts and nuts should be taken; On the outside of the chemical anchor, the fireproof coating and heat insulation treatment should be thickened to prevent the anchoring performance from being affected by fire; Basic settlement observation data should be supplemented.

3. Connection problems

High-strength bolted connection

1) The bolt equipment surface does not meet the requirements,

resulting in the bolt is not easy to install, or the degree of bolt tightening does not meet the design requirements.

Cause analysis:

(1) There are impurities such as floating rust and oil on the surface, and there are burrs and welding tumors in the bolt holes.

(2) Although the bolt mounting surface is treated, there are still defects.

Measures:

(1) The surface of high-strength bolts is rusty, oily and bolt holes should be cleaned up one by one; It must be treated with anti-rust before use; Bolts should be kept and issued by a special person.

(2) The treatment of the assembly surface should take into account the construction and installation order, prevent repeated progress, and try to deal with it before hoisting.

2) The bolt wire buckle is damaged, and the screw cannot be screwed into the nut freely, which affects the assembly of the bolt.

Several

problems that should be paid attention to in the construction of steel structure engineering

1. The safety foreman is set up at the steel structure engineering construction site to implement and manage on-site safety measures, and to carry out unified management of on-site construction personnel, on-site machinery and equipment and on-site electricity consumption. Personnel involved in the construction must be trained and certified. Personnel entering the construction site must wear safety helmets and non-slip shoes, electricians and electrical welders should wear insulating shoes, and safety belts must be fastened when working at height.

2. The tools, tools and equipment used should be inspected before operation, and the safety devices are complete and effective.

3. The operating surface should have a reliable platform, protective body, and operate after inspection. The component lashing method is correct, there should be anti-slip measures at the lifting point, and the tools and materials used in high work should be placed in a safe place, and it is forbidden to place them casually.

4. When lifting steel structural parts, lift or descend smoothly to avoid emergency braking or impact. Dedicated command, the signal is clear, loud and clear, and illegal operation is strictly prohibited. After the installation of the component, its quality must be checked, and it can be shackled only after it is indeed safe and reliable. Every day the work must reach a safe part before it can be completed.

5. The mechanical and electrical equipment at the steel structure engineering construction site should have reliable rainproof measures. Electrical operation must be carried out by professionals, and non-professional operation is strictly prohibited. The welding machine uses strict safety operation procedures, the primary line shall not exceed 2 meters, and the secondary line shall not be broken and exposed.

6. Steel structure engineering construction to do a good job of safe electricity, all electrical equipment dismantling and on-site lighting are by professional electricians, the power tools used must be installed leakage protectors.

7. The construction of steel structure engineering focuses on high-altitude operations, drinking and making trouble during work are strictly prohibited, and hand-held tools should be tied to safety lanyards to avoid straight vertical cross operations.

8. Steel structure construction should do a good job in fire prevention, and all operations should be used correctly according to regulations.

9. When installing the steel structure roof, the safety net should be arranged and the guardrail should be set.

10. The steel structure engineering construction adheres to the pre-shift safety meeting system, and the work arrangement and safety precautions of the day are disclosed.