Document Type
Thesis
Date of Award
9-30-1985
Degree Name
Master of Science in Civil Engineering - (M.S.)
Department
Civil and Environmental Engineering
First Advisor
John R. Schuring
Second Advisor
Dorairaja Raghu
Third Advisor
R. John Craig
Abstract
The geotechical construction problem of rock fracturing caused by pile driving is investigated using a laboratory model. One inch diameter closed bottom steel pipes were driven into a simulated rock mass consisting of masonry bricks having an average compressive strength 3,200 psi. Both single pile and five pile model groups were tested. The single pile tests indicated that a threshold of penetration behavior occurred at a theorical hammer energy of 100 ft-lb and this was used for the group tests. Penetration rates were measured using an optical level.
Piles in the five pile model group were initially driven to a penetration resistance of 9 blows/ 1/8 inch. The piles were then redriven in the original order to the same penetration resistance. All piles in the group exhibited a definite relaxation upon redriving which is attributed to mechanical disturbance of the rock mass beneath previously driven piles. Progressive fracturing and slight heaving of the rock mass were observed.
Comparison is made between model test data and actual field driving data from a project where rock fracturing occurred. The similarity of behavior indicate that the model does simulate the field problem of rock fracturing. Recommendations are made for future model testing.
Recommended Citation
Lee, Dai-Heyng, "Model experiment of rock fracturing caused by driving piles" (1985). Theses. 3448.
https://digitalcommons.njit.edu/theses/3448
