Details:

Creators:
McVay, Michael C. ; Klammler, Harald ; Tran, Khiem ; Faraone, Michael ; Dodge, Nathan ; ... More +
McVay, Michael C. ; Klammler, Harald ; Tran, Khiem ; Faraone, Michael ; Dodge, Nathan ; Vera, Nilses ; Yuan, Le Less -
Corporate Creators:
University of Florida. Dept. of Civil and Coastal Engineering
Subject/TRT Terms:
[+]
Bridge Foundations Data Collection Genetic Algorithms Limestone Load Tests Piles (Supports) Prestressed Concrete Skin Resistance Strain Gages
Publication/ Report Number:
BDK75-977-68
Resource Type:
Tech Report
Geographical Coverage:
Florida
Corporate Publisher:
Florida. Dept. of Transportation
Abstract:
The work focused on the improvement of FB-DEEP’s prediction of skin and tip resistance of concrete

piles and drilled shafts in Florida. For the work, data from 19 concrete pile sites and 18 drilled shaft sites were

collected. This included 458 standard penetration test, SPT, borings on the pile sites and 815 borings on the

drilled shaft sites. A total of 64 static pile load tests and 66 drilled shaft tests were acquired. For the piles, 48

tests reached Davisson Capacity, of which 28 had separation of skin and tip resistance. All of the drilled shafts

were instrumented with strain gauges from which unit skin transfer (T–Z) was assessed for Florida limestone.

All of the data were uploaded into the FDOT online database based on position (i.e., station + offset, or GPS).

In the case of piles, the data (e.g., boring vs. measured skin friction) were analyzed with a genetic

program (GP) algorithm to construct equations for unit skin friction and tip resistance based on soil type (USCS)

and SPT N values. The resulting GP skin friction curves were found to be similar to FB-DEEP; the tip resistance

curves had higher unit tip resistance vs. blow count values, as well as being only averaged 4 diameters/widths

beneath the piles. In addition, the practice of setting SPT N to zero for N< 5 was found to be conservative, and

the use of N=5 for N< 5 is recommended. For both current FB-DEEP and GP curves, load resistance factor

design, LRFD , were obtained for borings within 100 ft. In the case of borings outside this distance or for sitespecific

conditions, method error (CVm) for FB-DEEP and the GP curves is presented from which LRFD  may

be found.

In the case of drilled shaft, the GP algorithm a developed normalized unit skin friction vs. displacement

curve for limestone, which were similar to Kim (2001). In the case of ultimate skin friction in limestone, the

GP algorithm was used to validate the FDOT relationship between unit skin friction and rock strength

(unconfined compression, split tension).


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:76cd7a3cfdf914efe56356210a41bbaf2b21b06efe91d5bfef851eab3ccd06e2
Download URL:
https://rosap.ntl.bts.gov/view/dot/27185/dot_27185_DS1.pdf
File Type:

Supporting Files

• No Additional Files

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