2026-09-23T06:59:26Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/22037 2023-07-10 col_2142_5131 col_2142_14770 com_2142_5130 com_2142_3518 com_2142_234

The use of CPT for calculating axial capacity of drilled shafts text Long, James H. Alsamman, Omar Mohammed 2011-05-07T13:26:57Z 2011-05-07T13:26:57Z 10000-01-01 1995 The use of drilled shafts has increased significantly in the last two decades due to their ability to carry large loads economically. Current methods for calculating axial capacity of drilled shafts rely heavily on static methods. The cone penetration test is a simple, fast, and economical test that provides a continuous measurement of in-situ soil resistance with depth. The objectives of this thesis are (1) to evaluate the cone penetrometer as an alternative for calculating axial capacity of drilled shafts, (2) to evaluate available CPT methods, and (3) to develop procedures that rely on CPT resistance to calculate side and tip capacity of drilled shafts. A database of 95 full-scale drilled shaft load tests has been collected for this study. The database consists of 48 load tests in cohesionless soils, 16 load tests in cohesive soils, and 31 load tests in mixed soils. Five cone methods are evaluated: Schmertmann method, modified Schmertmann method, LPC method, Meyerhof method, and Gwizdala method. The Reese and O'Neill method is also evaluated for shafts in cohesive soils (using current database), for shafts in cohesionless soils (using q$\sb{\rm c}$/N conversions), and in mixed soils (using Reese and O'Neill database). The influence of geometry (L/B ratio, diameter, length, expanded base), construction procedure, type of bearing layer, and cone type on predicted capacity has been assessed. The study resulted in improved CPT design procedures that correlate q$\sb{\rm c}$ of the cone to q$\sb{\rm b}$ and f$\sb{\rm s}$ of a drilled shaft. Design curves are given for mechanical and electric cones. The database was used to evaluate the proposed method and other design procedures studied. The average ratio of predicted to measured capacity Q$\sb{\rm p}$/Q$\sb{\rm m}$ for the proposed method was approximately equal to one for all soil categories. The scatter exhibited in prediction results was lower than that in other CPT methods analyzed. The proposed method predicted capacity with more accuracy (average Q$\sb{\rm p}$/Q$\sb{\rm m}$ closer to 1.0) but with similar scatter to Reese and O'Neill method for shafts in cohesive soils and shafts in mixed soils. For shafts in cohesionless soils, the proposed method predicted capacity closer to measured and exhibited less scatter than the Reese and O'Neill method. Made available in DSpace on 2011-05-07T13:26:57Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9543515.pdf: 9082921 bytes, checksum: abc12afb0708c957a6a65ffae351aed6 (MD5) Previous issue date: 1995 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:54:53Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:25:33-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9543515 (UMI)AAI9543515 http://hdl.handle.net/2142/22037 eng Copyright 1995 Alsamman, Omar Mohammed Engineering, Civil Engineering, Civil Engineering, Civil University of Illinois at Urbana-Champaign Dissertation Ph.D.