Understanding Seismic Support Systems for MEP Installations

Seismic supports serve as essential components in buildings. They restrict the displacement of mechanical, electrical, and plumbing (MEP) installations during earthquakes. These supports help control vibration, stabilize equipment, and safely transfer loads to the building’s structural elements.

In the event of a destructive natural disaster, seismic supports significantly reduce damage, prevent large-scale economic loss and casualties, and help minimize secondary disasters such as fires, system collapses, or equipment failures.

Types of Seismic Bracing Systems

Depending on their function and application, seismic bracing systems can be categorized into several types:

1. Lateral Seismic Bracing

A bracing system where the diagonal brace runs parallel to the cross-section of the pipe.

2. Longitudinal Seismic Bracing

A bracing system where the diagonal brace runs parallel to the longitudinal section of the pipe.

3. Single-Pipe Bracing

A system composed of one load-bearing hanger and one diagonal seismic brace, designed for single-pipe installations.

4. Portal-Frame Bracing

A bracing structure consisting of two or more load-bearing hangers, a crossbeam, and diagonal braces. This is commonly used for multiple pipes or larger equipment.

5. Integrated Seismic Bracing

Systems designed for complex installations, including rectangular duct bracing and multi-system integrated bracing assemblies.

Materials and Installation

A typical seismic bracing system consists of prefabricated strut channels, pipe clamps, and various connectors assembled according to design specifications. Compared with traditional braces, seismic bracing systems offer easier, more standardized installation and superior structural performance.

Application Requirements

Seismic supports are commonly used in HVAC, ventilation, fire protection, electrical, and plumbing systems. The following conditions typically require the use of seismic bracing:

For HVAC and Ventilation Ducts:

• Circular ducts with a diameter ≥ 0.7 m

• Rectangular ducts with a cross-sectional area ≥ 0.38 m²

For MEP Systems in Large Indoor Projects:

Seismic bracing is recommended for:

• Equipment, ducts, cable trays, and pipelines requiring integrated layout and support

• Suspended pipes with hanger rods shorter than 300 mm

• Smoke-exhaust ducts and related components, including:

  • Smoke exhaust systems

  • Fire-supplementary air systems

  • Positive-pressure air supply systems for fire refuge areas

  • Associated pipelines and ventilation equipment

Equipment Requirements:

1. Seismic bracing must support suspended HVAC units and fans that exert a gravity load exceeding 1.8 kN.

2. Rectangular ducts with a cross-sectional area > 0.38 m² or round ducts with a diameter > 0.7 m must use seismic bracing systems.