Document Type
Thesis
Date of Award
5-31-1986
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 purpose of this thesis was to investigate the loss of load capacity of relaxed pile groups driven into weak bedrock. This was accomplished in the laboratory using a dynamic driving apparatus equipped with a static load testing system. The static load testing system applied loads hydraulically, and the load settlement behavior was monitored using an electronic load cell and a linear variable differential transducer (LVDT).
Tests were performed using 1" diameter steel pipe piles driven in a five pile group pattern at spacings of two diameters and four diameters. Piles were driven into a simulated rock mass consisting of clay masonry bricks.
The primary factor which determined the degree of relaxation was the depth to which a pile penetrated relative to the other piles in the group. When piles penetrated less than the average penetration of the group, a greater amount of relaxation was observed. Conversely, piles which penetrated deeper than the average of the group experienced less relaxation. This trend was confirmed with both redrive tests and static load tests.
Pile spacing was also found to affect relaxation in general. The degree of pile relaxation decreased as the pile spacing increased. Some amount of random behavior was observed between tests. This was attributed to rock mass variability, driving system characteristics, and the influence of multiple load testing. Suggestions are made for future study of the phenomenon.
Recommended Citation
Caruso, Daniel Walter, "Modelling of pile load tests in weak rock" (1986). Theses. 3136.
https://digitalcommons.njit.edu/theses/3136
