Requirements for wind-resistant design grades
Basic wind pressure values
According to GB50009 “Building Structure Load Code”, silo should determine basic wind pressure (≥0.35kN/m²) based on a 50-year recurrence period, and coastal areas or tall silos need to consider a 100-year recurrence period. Wind load calculations require the addition of height variation coefficients (1.0-2.5) and body coefficients (0.7 for circular silos).
Wind-resistant stability measures
Structural verification must meet the horizontal displacement limit (H/500) specified in GB50077 “Design Code for Reinforced Concrete Silo”
Set up circumferential stiffening ribs (spacing ≤6m) to resist wind-induced vibration
For silo with a height of more than 30m, it is recommended to conduct wind tunnel tests
Seismic design standards
Fortification classification basis
According to GB50191 “Seismic Design Code for Structures”, silo belong to Class B seismic fortification structures, and the seismic level should be increased by one degree (7-degree area is fortified according to 8 degrees).
Key points of earthquake-resistant calculation
Use the vibration mode decomposition response spectrum method to calculate horizontal earthquake effects
Consider the dynamic pressure of materials (calculated according to JB/T13029 standard)
The weak layer verification must meet the displacement angle limit (1/100) that does not collapse in a large earthquake
Structural reinforcement measures
The reinforcement ratio of the warehouse wall is not less than 0.3%
Set up earthquake-resistant joints (width ≥ 100mm)
The foundation uses raft or pile foundation to avoid uneven settlement
Comprehensive protection recommendations
Wind-seismic coupling analysis
For silo in earthquake-prone areas, engineers recommend using the time history analysis method to verify the wind-seismic combined working condition (1.0 dead load + 0.6 live load + 0.28 wind load + 0.5 earthquake action).
Monitoring and maintenance requirements
Install a tilt monitoring system (accuracy 0.01°) and conduct structural state detection every 5 years, focusing on the development of cracks at the connection nodes between the ring beam and the warehouse wall.
