Skip to main content
This section explains how Clariti calculates anchor channel capacity according to EN 1992-4. Understanding the methodology helps you interpret results and make informed design decisions.

Supported Products

Clariti supports the following cast-in anchor channel systems: All calculations use certified values from ETA-25/0222.

Design Philosophy

Clariti follows the limit state design approach of EN 1992-4:
Where:
  • NEd = Factored design load (input by you)
  • NRd = Design resistance (calculated by Clariti)
The utilization ratio is:
A utilization ≤ 100% means the design is adequate for that failure mode.

Calculation Flow

For each connection, Clariti performs these steps:
  1. Validate inputs — Check bolt positions against constraints and verify channel/bolt compatibility
  2. Calculate influence length — Determine which anchors are affected by each load
  3. Distribute forces to anchors — Calculate how loads transfer to individual anchors
  4. Find worst-case loading — Identify the critical bolt position that maximises anchor forces
  5. Calculate resistances — Determine characteristic resistances (NRk, VRk) for each failure mode
  6. Apply safety factors — Convert to design resistances (NRd = NRk / γM)
  7. Calculate utilization — Compare demand to capacity (β = NEd / NRd)
  8. Check interaction — For combined loading, verify interaction equation
  9. Report results — Identify governing failure mode (highest utilization)

Failure Modes

Anchor channels can fail in multiple ways. Clariti checks all applicable failure modes per EN 1992-4 Table 7.4 and reports the governing one (highest utilization).

Tension Failure Modes

Per EN 1992-4:2018, anchor channels under tension must be verified against both steel and concrete failure modes.

Steel Failure Modes (Tension)

Concrete Failure Modes (Tension)

Shear Failure Modes

Per EN 1992-4:2018, anchor channels under shear must be verified against both steel and concrete failure modes.

Steel Failure Modes (Shear)

Concrete Failure Modes (Shear)

Combined Loading

When both tension and shear act simultaneously, Clariti checks interaction using EN 1992-4 equations. The combined utilization must also be ≤ 100%.

Partial Safety Factors

Material partial factors from ETA-25/0222:
Clariti uses product-specific γM values from the ETA where available, which may differ from generic EN 1992-4 values.

Transparency

Every calculation in Clariti can be expanded to show:
  1. Reference — EN 1992-4 clause number
  2. Equation — The formula being applied
  3. Inputs — All values used with sources
  4. Factors — Each ψ and γ factor with justification
  5. Result — Step-by-step evaluation
This transparency allows you to:
  • Verify calculations manually
  • Understand why capacity is limited
  • Explain results to checkers and approvers
  • Learn the EN 1992-4 methodology

Further Reading