10.  Anchor Spacing and Edge Distance

 

DEFINITIONS

 

Anchor capacities are reduced when installation is close to an edge or adjacent anchor. The reduction is calculated based on distances referred to as the Critical and Minimum Edge Distance and Spacing. The percentage of reduction is different for each anchor type and the load condition (tension or shear). Defined below are the terms and factors used in determination of the effect of edge(s) and anchor spacing. The following pages outline when and how to calculate the effect of edge(s) and anchor spacing(s).

 

The product specific values for Critical & Minimum Edge Distance & Spacing and their corresponding Load Factors are in ICBO, ES Reports Nos. 1372, 4285 and 5308. Table 3 of Report No. 5308 (Epcon Granite 5) lists minimum edge and spacing distances. These values are actually critical values as defined below. The anchor system achieves 100% capacity at these distances. Closer edge and spacings were not tested. (i.e. - reduction factors for Granite 5 are not available.)

 

 

 

 

 

 

 

 

EDGE DISTANCE  (Between Critical and Minimum Edge Distances The Load Factor is Determined By Interpolation.  Anchor Capacity is Reduced.)

 

 

Note:  Complete cone - 100% anchor capacity.

Critical Edge Distance (mPcrit or mVcrit)

 

 

Note:  Cone reduced by closeness to edge - reduced capacity determined by testing.  Capacity varies from 20% to 90% of the maximum value depending on the anchor and load type.

Minimum Edge Distance (mPmin or mVmin)

 

SPACING  (Between Critical and Minimum Spacings The Load Factor is Determined By Interpolation.  Anchor Capacity is Reduced.)

 

 

Note:  No cone overlap from adjacent anchor - 100% anchor capacity.

         Critical Spacing (sPcrit or sVcrit)

 

 

Note:  Cone overlap from adjacent anchor - reduced capacity determined by testing. Capacity varies from 40% to 95% of maximum value depending on the anchor and load type.

 

Minimum Spacing (sPmin or sVmin)

 

 

CRITERIA FOR DETERMINATION OF LOAD REDUCTION FACTORS

 

 

Tension and Shear Load Factors for edge and spacing are determined based on how the anchor location relates to the Critical and Minimum Edge Distance and Anchor Spacing.  Listed below is the relationship of anchor location to Anchor Capacity and Load Factors.

 

 

 

 

 

 

EDGE AND SPACING CONFIGURATION

 

l  Design Anchor – is the anchor for which a reduced load capacity is being determined.  The anchor’s capacity is reduced by its closeness to an edge(s) or Influence Anchor(s).

 

    ¡ Influence Anchor – is an anchor that reduces the capacity of the Design Anchor as a result of it being spaced closer than mcrit.