The screw-in, jack-in, and single vibratory driver systems are 

 estimated to be equivalent in versatility for use in a foundation re- 

 quiring more than the minimum number of piles. The multiple vibratory 

 system is rated as essentially unadaptable because of the excessive 

 weight of additional drivers. The screw-in and jack-in systems are 

 rated equivalent in versatility related to varying installation plan 

 dimensions. The screw-in system can be readily adapted for varying 

 foundation sizes and shapes; i.e., triangular, square, rectangular, 

 circular, etc. The jack-in system must retain its basic circular 

 shape (i.e., the vertexes of the regular pentagon lie on a circle) for 

 best efficiency but the dimensions can be varied with no loss in effi- 

 ciency. The vibratory driver systems are judged to be less adaptable 

 to changes in foundation size and shape. 



The screw-in system is estimated to require the least development. 

 Nearly all of the components are easily within the state-of-the-art 

 and industry experience with submerged pipeline and electric utility 

 line anchoring provides sufficient guidelines for expeditious develop- 

 ment. The jack-in system would not require much component development 

 but would require more testing to prove the concept. The vibratory 

 systems would require both component development and rather extensive 

 testing. 



The overall complexity of each system was evaluated by first 

 determining the mechanical and control functions for the operation of 

 each system. The complexity of each function was appraised as either 

 simple or complex, and was assigned a numerical rating of 1 or 2, 

 respectively. The ratings for each system were summed, and the aggre- 

 gate number for each system was taken as a measure of the system 

 complexity. The screw-in, jack-in and multiple vibratory driver systems 

 are judged to be relatively simple systems, and the single vibratory 

 driver systems is judged to be quite complex. 



Finally, the last line in Table 4 summarizes the overall effec- 

 tiveness of each system. It is evident that the screw-in system rates 

 the highest, closely followed by the jack-in system. The two vibratory 

 driver systems are rated considerably lower. The screw-in system was 

 chosen for preliminary design. 



PRELIMINARY DESIGN OF PILOT -MODEL EMPLACEMENT SYSTEM 



General 



For the preliminary design of the pilot-model emplacement system, 

 the shape and the overall plan dimensions could be chosen arbitrarily 

 because the use of a pile foundation/anchorage is not limited to 

 installations of a certain class or size range. It was decided to 



13 



