LTRC Rearch Project
C a
p s u l e
98-3GT
October 1998 Evaluation of Bearing Capacity of Piles from Cone Penetration Test
Problem
Due to the soft nature of soil deposits in
the state of Louisiana, pile foundations
are ud by the Louisiana Department of
Transportation and Development (DOTD)
to support highway bridges and other
transportation infrastructure.
In the design of pile foundations, the
number and size of piles are generally
determined bad on the v六年级数学手抄报
alue of the
bearing capacity.
Therefore, in order to design pile founda-
tions with optimum safety and minimum
construction cost, the pile bearing capaci-
ty must be estimated within an accept-
able margin of acc婴儿高烧
uracy and reliabili-
ty.
The cone penetration test (CPT) is
among the popular in situ tests con-
ducted by DOTD. Three cone trucks
operate on DOTD projects. Two vehi-
cles are managed by LTRC. Both the
DOTD and LTRC 20-ton cone trucks
are reaching ten years of rvice.
Cone penetration tests can provide
valuable and continuous information
regarding the soil strength with depth.
Becau cone penetration tests can be
taken much faster and economically Starting date:5/15/98
Duration:18 months
Completion date: 11/15/99
Funding:State/Federal
Principal Investigator:
Hani Titi, Ph.D.
LTRC
Co-principal Investigator:
Murad Abu-Farsakh,Ph.D.
LTRC
LTRC Contacts:
Administrative:
Harold "Skip" Paul, P.E.
Assoc. Director, Rearch
(225)767-9102
Technical:
Mark Morvant, P.E.
Rearch Manager
(225)767-9124
LTRC
Louisiana Transportation
Rearch Center
Sponsored jointly by the
Louisiana Department of
Transportation and Development
and
Louisiana State University
4101 Gourrier Avenue
Baton Rouge, LA 70808-4443
The LTRC electronic cone penetrometer truck to be ud in the evaluation of the bearing
capacity of piles.
than standard soil borings, the actual site characteristics will be available to the design engineer for each par-ticular pile bent location. This will make a pile design method that can u the CPT data more accurately for the evaluation of pile bearing capaci-ty. To be reliable for Louisiana soils, particularly silts and clays, the appro-priate design method must be corre-lated with pile load tests.
The existing data acquisition systems are approaching obsolescence due primarily to the MS-DOS b
ad applications required to operate the systems. The cost of repairing older hardware, in particular computers, ris becau of the diff检讨书800
iculty in locating parts that are not being man-ufactured anymore. Theref企业规章制度
ore, the data acquisition system and software needs to be updated to take advan-tage of newly available technologies. Objectives
The objectives of this rearch are as follows:
1.)Collect a suitable number of
pile load test reports which
ha植树标语
s CPT data from DOTD
files
2.)Conduct a comprehensive lit-
erature review to investigate
and evaluate methods of esti-
mating bearing capacity of
pile fou额头窄的人命运
ndations using cone
penetration test data 3.)Identify the most reliable
interpretation methods bad
on their suitability for poten-
tial application to different
soil types in Louisiana soils
4.)Identify (and improve, if
required) a design method
for implementation in the
design and analysis of bear-
ing capacity of pile founda-
tions using the CPT test
results
5.)Identify/develop software
solutions for the interpreta-
tion of pile capacity and soil
characterization using the
CPT test results
6.)Conduc目录怎么弄
t a verification
scheme using other pile and
cone data to evaluate the
capabilities of the method
7.)Upgrade the data acquisition
systems on the LTRC and
DO英语签名
TD cone trucks.
Description
The precast, prestresd concrete and
steel pipe piles are the most common
piles currently ud in DOTD pro-
jects. DOTD spent about $19 mil-
lion on driven piles in 1995. A reli-
able design and analysis method
needs to be identified to estimate the
bearing capacity of the piles using
the cone penetration test data.
The availability of cone penetration
test systems at DOTD will make
such a method easy to implement in
t土鸡怎么做好吃
he design and analysis of piles.
Moreover, a small percentage cost
reduction on expensive piling pro-
jects will result in significant finan-
cial savings.
This method will increa the confi-
dence in pile design and will reduce
the uncertainties and personal judge-
ments associated with design and
analysis of pile foundations.
Implementation Potential
The goal of this rearch is to u the
cone penetration test data to evaluate
and improve the available interpreta-
tion methods ud to estimate the
bearing capacity of pile foundations
installed in Louisiana soils. An
attempt will be made to establish
empirical but databad correlations
between the CPT data and pile
capacity components.
n October 1998LTRC Project Capsule
