Methods to Determine Drag Embedment Anchor Capacity 

 1. Method of Cole and Beck (1964) 



- Verfied procedures relating anchor capacity to soil engineering 

 properties not available. 



- Available procedure dated to Leahy and Farrin (1955) is reasonable 

 provided anchor test data available 



Anchor capacity relates to anchor wt as follows: 

 F = C W ^ 



Where F = Short-term holding capacity (lbs) 

 W = Anchor wt in air (lbs) 

 C,b = Empirical soil constants, dimensionless 



- Relationship plots as a 

 straight line on log-log 

 plot, C is the intercept, 

 b is the slope. 



- Results valid for that 

 anchor, mooring line type, 

 soil type. 



OPTIONAL-PROCEDURE 



- Perform single test, use 



b = 0.75 to calculate C. 



- Extent of extrapolation of 

 this procedure questionable. 



- Theoretical limit for b is 

 2/3, where steel stress is 

 controlling factor. Refer to 

 Valent et al., 1979. 



- Use verified manufacturer 

 data to calculate C for 



b - 0.75. 



2. Prototype Data 



1000 10,000 



ANCHOR WEIGHT • IB 



- Refer to manufacturers for data; data often based on small 

 anchor tests at unlimited drag (request details of tests). 



- Data valid for specific test conditions; anchor performance 

 very sensitive to conditions (use data with caution for other 

 conditions). 



3. Full-Scale Pull Test 



Most accurate/costly. 



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