At around 3 pm on February 21, 2022, a steel structure corridor connecting Building B and Building G in Dongguan Expo Plaza occurred. Some vehicles were covered by the collapsed corridor, and no casualties were found.
After investigation, the Expo Plaza project was originally developed by Dongguan ×sheng Company and designed by China × West Engineering Design Company. The project covers an area of 100,963 square meters and has a total construction area of 205,650 square meters. The commercial area is about 170,000 square meters, divided into 8 large blocks, each with 3 to 4 floors. One block (G zone) is arranged in the center of the land, and the remaining seven blocks are arranged around. The project has been completed for 17 years.
At the beginning of the design, each commercial building was 10 to 20 meters away for people and vehicles to pass through, but there were wind and rain corridors connected to each floor. No matter which direction the passenger flow entered, it could avoid the influence of the wind, rain and sun and enter any corner.
The location of the corridor occurred (in the red circle in the picture)
Before the collapse of the corridor connecting Area B and Area G collapse
With the continuous improvement of building functions and the increasing richness of building shapes, in order to meet the connection, traffic functions and usage requirements between various parts of the building and create architectural effects, corridors have often been set up between various parts of the building in recent years. Steel structures have the advantages of strong plastic toughness, large span, high strength, relatively light weight, fast manufacturing and installation construction, and novel architectural effects, so steel structures are often used in corridor design.
Incident Corridor
The most important part in design of the entire corridor structure is the support connection form between the two ends and the main structure. If the design and handling are improper, the overall security of the structure will be seriously affected.
Connecting corridor and the main structure will have a spatial coupling effect, and the two are directly connected by support. If the support form is not selected properly, under the action of earthquakes, the steel connecting corridor will be subject to the interaction force transmitted from the main structure. If the steel corridor and the main structure are coupled, the steel corridor and the connecting nodes are easily destroyed. The connection methods of
incident corridor
corridor are generally divided into two categories: flexible connection and rigid connection . Among them: ① Flexible connection means that by setting up a movable support, the constraints between the main structure and the corridor in a certain direction can be released, so that the main structure does not have a coupling effect in this direction. ② The connection between the corridor and the main structure does not release any constraints is a rigid connection, so bending moment, shear force and axial force in all directions can be transmitted through the corridor. Generally speaking, determining the connection method of the corridor is the key. As for which method is used, it should be determined comprehensively based on factors such as span, stiffness, and vertical position.
Incident Corridor
Corridor
There are many flexible connection methods, such as:
① One end is fixed and the other end is sliding. Among them, the steel columns of the main structure are rigidly connected to the upper and lower chords of the corridor.
② One end is fixed and one-way sliding support is fixed. beef legs is arranged on the main structure, the fixed hinge support is arranged on the beef legs, and the fixed hinge support is connected to one end of the corridor, thereby achieving the effect of hinge connection at one end. This method can effectively solve the problem of the deformation of buildings on both sides of the two sides of the building and reduce the seismic coupling effect caused by corridors on both sides of the buildings. In this connection, the bearings often use seismic-resistant finished spherical steel bearings, and welded connections between the corridor and the bearing, and the bearing and the main body embedded parts.
③ The connection methods on both sides of one end of the corridor are articulated and bidirectional sliding respectively, and the other end is one-way sliding and bidirectional sliding respectively.
video data of the site is speculated that the side connecting the steel corridor to Building B Haiya Department Store main structure is more like a fixed connection, while the connection form with Building G Tianyuan Cyberport is unknown.
The connection between steel corridor and Building B is disconnected
The connection between steel corridor and Building B is disconnected
The connection between steel corridor and Building G is disconnected (left side in the picture)
This steel truss corridor that collapsed as a whole is allowed to pass by both upper and lower floors, but the support on site falls off and the deformation of the corridor structure is not obvious. It is speculated that the entire steel corridor collapsed after the bearing is damaged and instable. As for the specific cause of the accident, whether the support is loose, rust and damage, or other reasons, it remains to be investigated and analyzed professionally. A 2016 news published online by
pointed out that there are fire hazards in the corridor in Area G of Expo Plaza.
