rock were not considered. 



3. Considerable research on short-term capacity in cohesive and 

 cohesionless soils has been accomplished. Procedures for predicting 

 this capacity based on empirical results appear to be relatively far 

 advanced and accurate. 



4. Holding capacities under long-term repeated and long-term 

 static loading conditions are not well understood at present. It is 

 necessary to combine work from other areas with a small amount of 

 directly applicable research to yield approximate, immediate use re- 

 sults. 



5. Given these limitations, the procedures of this report are 

 recommended for use at the present time. Additional research is 

 strongly recommended. 



RECOMMENDATIONS FOR FURTHER RESEARCH 



1. The holding capacity of embedment anchors under static and 

 repeated long-term loading is poorly understood at present. Of these 

 two, static long-term is the less complex and, therefore, should be 

 investigated first. Since cohesive soils are more common and also 

 more susceptible to long-term effects, they should be investigated in 

 greatest detail. 



2. The central element in researching long-term static capacities 

 in cohesive soils should be the small to medium scale laboratory model 

 test. It is relatively economical, can be well controlled, and a large 

 number of parameters can be measured. The following types of experiments 

 are recommended : 



(a) Several cohesive soils, each at several densities, should 

 be investigated. 



(b) Several fluke sizes and embedment depths should be used. 



(c) The soils themselves should be tested extensively to deter- 

 mine undrained strength, drained strength, and creep strength. 



(d) Short-term holding capacities should be determined first; 

 and then loads a given percentage of the short-term loads should be 

 applied and the time to breakout measured. 



(e) Upward anchor movement and pore pressures at several points 

 in the soil should be measured. 



3. Analytical research, possibly using finite element computer 

 programming, should be performed so that improved theoretical predictions 

 of stress distributions and failure loads can be made. These should be 

 compared with the results of the model tests and modified if necessary 



to comply with the empirical data. 



4. When an adequate prediction technique has been developed, it 

 should be tested with a limited number of well monitored, long-term 

 static load, full scale, field tests. 



5. When long-term static holding capacity is sufficiently well 



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