Common problems encountered in the construction of steel structure engineering and their solutions

　Many of our construction is now built by steel structure engineering, steel structure by virtue of its many advantages, in Bridges, industrial plants, high-rise construction and other modern construction has been widely used. Steel structure is mainly composed of steel beams, columns, trusses and other components made of section steel and steel plate. In the process of a large number of engineering construction, steel structure engineering has also exposed many quality problems.

1, the production of components

The panels used for the portal steel frame are very thin, with the thinnest available up to 4mm. Cutting mode should be selected for blanking multiple thin plates to prevent flame cutting. As a result of flame cutting will make the edge of a large wave deformation. Now H beam welding most manufacturers choose submerged arc automatic welding or semi-automatic welding. If the control is not good, welding deformation should occur, so that the component bending or distortion.

2. The problem of column foot device

(1) Embedded parts (anchor) problem phenomenon: overall or layout offset; Wrong elevation; No protective measures have been taken for the silk buckle. Directly cause the steel column bottom bolt hole misalignment, resulting in the length of the screw buckle is not enough.

Measures: steel structure construction units cooperate with civil construction units to complete the embedded parts work, concrete pouring and ramming before. It is necessary to check the relevant size and fixed firmly.

(2) The anchor bolt is not straight: the levelness of the bottom plate of the frame column is poor, the anchor bolt is not straight, and the horizontal error of the embedded anchor bolt is large after the foundation construction. After the column installation is not in a straight line, disorderly, so that the appearance of the house is very ugly, to the steel column installation error, structural stress is affected, does not meet the requirements of the construction acceptance code.

Measures: anchor bolt device should insist on leveling the bottom plate with lower adjusting bolt first, and then filling it with non-shortening mortar secondary grouting, foreign construction method. Therefore, when the anchor bolt is constructed, the steel bar or Angle steel can be selected to fix the anchor bolt. Weld into a cage, perfect the support, or adopt some other effective measure to prevent the anchor bolt from moving one place when watering the concrete in the foundation.

(3) The anchor bolt connection problem phenomenon: the anchor bolt of the column foot is not tightened, and the backing plate is not welded with the bottom plate; Some anchor bolts with 2 ~ 3 screw buckles are not exposed.

Measures: welding bolt and nut should be adopted; Outside the chemical anchor, fire retardant coating and heat insulation should be thickened to prevent fire from affecting the anchoring function; The observation material of foundation settlement should be measured.

3. Connection problems

1) The bolt equipment surface does not meet the requirements, resulting in the bolt is not good device, perhaps the degree of bolt fastening does not meet the design requirements.

Cause analysis: the appearance of floating rust, oil and other impurities, bolt hole has burr, welding tumor. The bolt assembly surface is still defective after treatment.

Solution: high strength bolt appearance floating rust, oil and bolt hole defects, should be cleaned one by one. Before use, it is necessary to be treated with rust prevention, so that the bolts used in assembly shall not be used in formal assembly. Bolts should be kept and issued by special personnel. The installation surface should be dealt with in consideration of the sequence of construction devices to prevent repetition and be dealt with as far as possible before hoisting.

2) Bolt screw damage, screw can not freely screw into the nut, affecting the installation of bolts.

Cause analysis: silk buckle serious corrosion.

Solution: bolts should be selected before use, and pre-matched after cleaning and removing rust. Bolts damaged by the screw can not be used as temporary bolts, and it is strictly prohibited to force into the screw hole. Pre-selected bolt assembly should be stored according to the sleeve, do not exchange when using.