Many construction companies and purchasers often wonder during project construction: “In which scenarios are seismic supports required?” and “Do all buildings need them?” In reality, seismic support installation is not a one-size-fits-all solution. Specific regulatory requirements exist based on factors such as building type, mechanical/electrical system type, and seismic design intensity. This article details core scenarios requiring seismic support installation according to national seismic codes, helping you mitigate compliance risks and ensure project standards are met.
I. Clarifying the Core Basis for Seismic Support Installation
According to the “Code for Seismic Design of Building Mechanical and Electrical Engineering” (GB 50981-2014), seismic support installation must satisfy two core conditions: First, the seismic fortification intensity of the building’s location must be ≥6 degrees (most regions in China have fortification intensities of 6-8 degrees); Second, the building’s mechanical and electrical systems must fall under the category of “requiring seismic protection.” Both conditions are indispensable.
Simply put: If the seismic fortification intensity of the building’s location is ≥6 degrees and it contains mechanical and electrical systems (pipes, ducts, cable trays, etc.), seismic support brackets must be installed according to the code; If the seismic design intensity is <6, installation may be voluntary based on project requirements.
II. Five Core Scenarios Requiring Mandatory Seismic Support Installation
Scenario 1: Building MEP Piping Systems (Top Priority)
The following piping systems must install seismic supports regardless of pipe diameter:
- Fire Protection Piping: Including fire hydrant piping, sprinkler piping, and fire curtain piping. As life-saving systems, damage during earthquakes would render fire suppression ineffective, making installation mandatory.
- Water Supply and Drainage Piping: Water supply and drainage pipes with diameters ≥ DN65, especially those in high-rise buildings and underground utility tunnels, require seismic support installation.
- Gas Piping: Pipelines conveying natural gas or liquefied petroleum gas (LPG) must be equipped with seismic supports and compatible seismic connectors, as leaks during earthquakes can easily trigger explosions.
- HVAC Ductwork: Central air conditioning ducts, chilled water pipes, and condensate drain pipes. Ducts with diameters ≥1200mm and water pipes with diameters ≥DN100 require seismic support installation.
Scenario 2: Cable Trays and Power Distribution Systems
Power distribution equipment including cable trays, bus ducts, and distribution boxes must be installed with seismic supports:
- Cable Trays: Trays with width ≥600mm, ≥2 tiers, or installed at heights ≥4m require seismic supports to prevent falling and circuit damage during earthquakes.
- Bus ducts: All bus ducts installed on the building’s main structure must be fitted with seismic supports to ensure power supply system stability.
- Distribution Boxes: Distribution boxes and cabinets weighing ≥100kg must be secured with seismic supports fixed to beams or columns to prevent tipping during earthquakes.
Scenario 3: Underground Utility Tunnels, Subways, and Tunnel Projects
Underground utility tunnels, subways, and tunnels are designated as key seismic protection zones. All mechanical and electrical systems (pipes, ducts, cable trays, communication lines) must be equipped with seismic supports. The seismic resistance level must be one grade higher than that of ordinary buildings to ensure the safety of underground structures.
Scenario 4: Public Buildings and Industrial Plants
- Public Buildings: In high-occupancy facilities such as hospitals, schools, shopping malls, office buildings, and convention centers, all mechanical and electrical systems must be equipped with seismic supports according to regulations to safeguard human life.
- Industrial Plants: Chemical, pharmaceutical, power generation, metallurgical, and other industrial facilities handling flammable, explosive, toxic, or hazardous media must install seismic supports on pipelines to prevent leaks and mitigate safety incidents.
Scenario 5: High-Rise Buildings (≥10 stories)
In high-rise buildings of 10 stories or more, the risk of displacement for mechanical and electrical equipment is significantly higher due to greater horizontal sway during earthquakes. All pipelines with diameters ≥DN50, ductwork with widths ≥500mm, and all cable trays must be equipped with seismic supports.