Three failure modes of steel building construction

The steel structure itself has a certain degree of seismic capacity, but when encountering a strong earthquake, it is still unavoidable to cause the damage of the steel structure. The failure modes of steel structure buildings mainly include joint failure, support connection failure and structural collapse failure.

steel building construction

1、 Destruction of nodes

Most of the joint failures are concentrated in the rigid joints of beams and columns. The cracks on the lower flange of the beam account for the main part, and most of the cracks originate from the middle of the weld. The main causes of damage are:

  1. The impact toughness of the weld after welding is low, and the weld generally has certain defects, especially the discontinuity of the weld in the middle of the lower flange because the web hinders the inspection and connection.
  2. The existence of “artificial” cracks caused by the lining plate and run on plate at the groove weld at the flange end. The stress concentration coefficient at the crack tip under the action of vertical force exceeds the critical value. As a result, the artificial joint continues to expand, causing unstable fracture.
  3. When the beam end passes through the edge of the hole, stress concentration is easy to occur, causing cracks and extending horizontally.
  4. Because the upper flange has the strengthening effect of floor slab and no web to prevent welding, the upper flange is generally rarely damaged.
steel building construction

2、 Failure of support connection

As the main lateral force resisting member of the whole structure, the support of steel structure mainly refers to horizontal seismic action, so when an earthquake occurs, the support will work as the main force bearing member. If the support of a layer is damaged, the layer will become a weak layer, which will have serious consequences. The main failure forms of bolt connection support are the fracture of the weakened part of the support section, the shear slip failure of the bolt hole of the support rod and the shear slip failure of the end of the gusset plate; The main failure form of welded support is the failure of weld.

3、 Collapse and damage of structure

Structural collapse is the main source of seismic damage of steel structure buildings. Through the study of the damage of steel structures in previous earthquakes, it is found that the out of plane bending instability of steel is an important reason for the collapse of steel structure buildings. If the deflection of the vertical and horizontal supports in the design of the structure will cause the distance between the stiffness center and the mass center to be too large, it will cause the structure to produce a large torsional effect in the earthquake, make the steel column exceed its bearing capacity, and cause the collapse of the steel structure building. It can be seen that the regular symmetrical structure plays a great role in improving the seismic performance of the structure.

steel building construction company

steel building construction company

SGSS has been producing steel structures for industrial buildings since 2001. The projects are all over Shandong, China. The main building types include steel structure workshops, warehouses, and agricultural and breeding buildings. Since 2018, SGSS products have been expanded, involving civil buildings, various types of housing, and temporary buildings.

Leave a Comment

Your email address will not be published. Required fields are marked *