Page 1 of 4
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 827
Non-Dimensional Solutions For Vertical Piles Subjected To Lateral Loads
M. PURUSOTHAMAN
DEPARTMENT OF CIVIL ENGINEERING
PRIST (Deemed to be University), THANJAVUR
ABSTRACT
The research on damages of structures that are supported by deep foundations has been quite
intensive in the past decade. Kinematic interaction in soil-pile interaction is evaluated based on
the p-y curve approach. Existing p-y curves have considered the effects of relative density on
soil-pile interaction in sandy soil. The roughness influence of the surface wall pile on p-y curves
has not been emphasized sufficiently. The presented study was performed to develop a series of
p-y curves for single piles through comprehensive experimental investigations.
Modificationfactors were studied, namely, the effects of relative density and roughness of the
wall surface of pile. The model tests were subjected to lateral load in Johor Bahru sand. The new
p-y curves were evaluated based on the experimental data and were compared to the existing p- ycurves. The soil-pile reaction for various relative density (from 30% to 75%) was increased in
the range of 40–95% for a smooth pile at a small displacement and 90% at a large displacement.
INRODUCTION
Piles are always required to be designed to
with stand the lateral loads in addition to the
compression and tension loads. Lateral
capacity of these piles depends on the
properties ofsoil. Pile behaves as a
transversely loaded beam in case of lateral
loads and they transferlateral load to
surrounding soil by means of lateral
resistance of the soil. Pile shiftshorizontally
in response to applied load which results in
bending, rotation or translation ofpile. Based
on fixity of pile head laterally loaded piles
are classified as fixed head pile andfree head
pile according to whether the top portion of
the pile is fixed or not. And based onthe
mode of functioning it is classified as
friction piles and end bearing piles. Friction
pilestransfer the load through skin friction
between the embedded surface of the pile
Page 2 of 4
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 828
andsurrounding soil. And the end
bearingpiles transmit the loads through their
bottom tipsresting on a hard stratum.
LOAD TRANSFER MECHANISMS OF
LATERALLY LOADED PILE:
In the lateral loads, piles behave as
transversely loaded beams. They transfer
lateral load to the surrounding soil mass by
using the lateral resistance of soil. When a
pile is loaded laterally, a part or whole of the
pile tries to shift horizontally in the direction
of the applied load, causing bending,
rotation or translation of the pile. The pile
presses against the soil in front of it (the soil
mass lying in the direction of the applied
load), generating compressive and shear
stresses and strains in the soil that offers
resistance to the pile movement. The
EXPERIMENTAL WORK
IS 2911 (Part 1/Sec 2)-2010 Approach
The behaviour of laterally loaded piles was
analysed based on IS 2911. The IS approach
always gives an approximate solution
because of the complexity involved in many
problems.
The first step was to determine whether the
pile behaved as a short rigid unit or as an
infinitely long flexible member. This was
done by calculating the stiffness factor, T for
a particular combination of pile and soil.
Having calculated the stiffness factor, the
criteria forbehaviour as a short rigid pile or
as a long elastic pile are related to the
embedded length L ofthe pile. The depth
from the ground surface to the point of
virtual fixity was then calculatedand used in
the conventional elastic analysis for
estimating lateral deflection and bending
moment. The lateral soil resistance for
granular soils and normally consolidated
clay which have varying soil modulus was
analysed according to the modulus of
subgrade reaction for which the
recommended values are given in IS 2911as
shown in Tables.
The critical review of the literature
presented in the previous chapter reveals the
limitations ofthe experimental studies
carried out so far in the field and laboratory
to investigate the lateralresponse of single
piles and pile groups. Hence, in the present
study, a comprehensiveexperimental
investigation has been undertaken to
understand the response of single piles and
pile groups in sand, gravelly sand and clay
under static lateral loads. This chapter
Page 3 of 4
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 829
describesthe details of materials used,
scaling law adopted to select the model pile
and the experimental setup. The soil bed
preparation and test procedures adopted in
the present studyare also discussed. Finally
the scheme of test programmecomprising of
several series of experiments is given at the
end.
RESULTS AND DISCUSSION
Lateral loads on piles occur due to earth
pressure, wave action, impact of barges and
berthing ships, wind force, earthquake,
operating machineries, etc. Pile foundations
for harbor structures and bridges extend
deep into sand beds. Static lateral load tests
are carried out in the present study on model
single pile and pile groups embedded in dry
sand to investigate the effects of spacing,
size of pile group and relative density of
sand. This chapter discusses the results of
experimental studies carried out on model
piles in sand subjected to staticlateral loads.
The results are presented and analysed in
terms of load deflection behaviour.
LOAD-DEFLECTION BEHAVIOUR OF
SINGLE PILE
load-deflection curves of single pile having
L/D ratios of 12, 20 and 26embedded in
sand with Dr of 50% and subjected to static
lateral loading. This indicatesnonlinear
behaviour of piles under lateral loading and
the rate of increase in deflectionincreases
significantly after 3.2 mm (0.1D) of pile- head deflection. It can be seen that for any
given load level, long pile (L/D of 26)
deflect significantly lessthan short pile (L/D
of 12) due to flexible behaviour of piles. As
per Broms (1964), ultimatelateral capacity is
the load corresponding to a deflection of
20% of pile diameter. The criteriabased on
deflection is well established and
recommended by many previous researchers
(Poulos et al. 1980, Rao et al. 1996, Rollins
et al. 1998, Ilyas et al. 2004,
Chandrasekaran etal. 2010a) for comparison
of pile group behaviour with that of the
single pile. In the presentstudy, lateral
capacity of pile is obtained as per Brom’s
criteria and is found to be 46 N, 52 Nand 55
N corresponding to L/D ratios of 12, 20 and
26 respectively. The increase in
lateralcapacity with embedment length is
due to the increase in the zone of passive
resistance.
