3. Improved various behavioral aspects that yield low load carrying 

 capacity, and maintained or enhanced various behavioral aspects 

 that yield relatively high load carrying capacity similar to 

 those in comparable terrigenous soils. 



4. Developed practical systems that were practical, achievable and 

 involved minimal risk and development. 



5. Applied feasible, proven techniques, that were successful else- 

 where. 



Installing and loading piles in calcareous sediments will introduce 

 varying degrees of grain crushing and volumetric contractions near the 

 pile. The extent of grain crushing and volumetric contraction depends 

 on the piling system, installation method, characteristics of calcareous 

 sediments, state of stress, loading characteristics, and other factors. 

 After examining the key behavioral aspects, it was clear that any improved 

 piling system must incorporate one or a combination of the following 

 features: 



1. Must increase the effective lateral stress on pile shaft. 



2. Must force the pile to transfer load to the zone of soils where 

 degradation due to grain crushing is minimal. 



3. Should have an enlarged base area. 



4. Should eliminate or reduce the effect of grain crushing and 

 associated volumetric contraction as well as soil arching. 



5. Should increase contact area between pile and sediments. 



Numerous variations of piling systems exist that can incorporate 

 one or a combination of the above features. Most of the conventional 

 piling systems (except driven piles) do incorporate some of these fea- 

 tures. These features are costly and are out of the scope of this con- 

 ceptual development work. 



The following improved piling systems were conceptually developed 

 following the approaches and principles described in previous sections: 



• Backfilled piles (BP) 



• Vibratory installed backfilled piles (VBP) 



• Pressurized piles (PP) 



• Backfilled and pressurized piles (BPP) 



• Piles with enlarged tips (PET) 



• Modified drilled and grouted piles (MDGP) 



• Keyed-in piles (KIP) 



• Drilled and screwed piles (DSP) 



• Other potential piling systems 



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