SLURRY PERFORMANCE IN DRILLED SHAFT CONSTRUCTION. FINAL REPORT

This research involved extensive and systematic laboratory studies on the Florigel H-Y clay slurry and the Super Mud polymer slurry to achieve the following objectives: 1) To determine the proper slurry preparation method to achieve the desired slurry density/viscosity; 2) To investigate the flow characteristics of the slurries; 3) To study the effect of pH on the rheological properties of the slurries; 4) To design a full scale settling column and use it to study the settling characteristics of cuttings in the slurries; 5) To examine the current available slurry specifications based on the results obtained from the above studies and to make any recommendations, if warranted; and 6) To attempt to use centrifuge modeling technique to study the integrity of a slurry-filled hole. The results of this research are presented in this report which contains the following: (a) a review of pertinent literature; (b) laboratory studies on the various factors that affect the rheological properties of both slurries; (c) the design of a unique, 20-ft (6.096 m) settling column; (d) settling tests of sands in slurries using both sedimentation cylinders and the settling column; (e) centrifuge modeling tests of slurry-filled holes; and (f) conclusions and recommendations made possible by this research.