Geo-Environmental Engineering 2017
Seoul National UniversitySeoul, Korea
May 19-20, 2017

DEVELOPMENT OF PULLING-OUT OF EXISTING PILES AND
INFLUENCE OF THE PULLING-OUT HOLES ON
SURROUNDING GROUND
Kazuki Nosho1, Shinya Inazumi2, Shuichi Kuwahara3, Shinichi Hamaguchi4
1

Akashi College, National Institute of Technology, Hyogo, Japan2
Shibaura Institute of Technology, Tokyo, Japan
3
Marushin Co., Ltd., Hyogo, Japan
4
Yokohama Wright Industries Co., Ltd., Kanagawa, Japan

Abstract: The teardowns of social infrastructures including the civil structures have been increasing
because of aging them constructed in a period of high economic growth and decrease in their utilization
with a population decrease, in recent years. The number of pulling-out existed pile foundations has been
becoming a lot more than that of newly installing pile foundations. However, after pulling-out a pilefoundation, mechanical characteristics of surrounding grounds is concerned due to existence of theformed pulling-out hole. There are no regulations yet on fillers injected into a pulling-out hole, and theinfluence by which the strength of the fillers gives it to the surrounding grounds is not also elucidated.
This study considers the influence by which a pulling-out hole of a pile foundation gives it to static anddynamic characteristics of surrounding grounds by using two-dimensional dynamic finite element analysis. The special qualities required for fillers injected into a pulling-out hole are also clarified in thisstudy.
Keywords: Pile Foundation, Pulling-out Method, Pulling-out hole, Finite Element Method

environmental problems. The pull-out method
has been widely used from this thing. However,there are also problems in the pull-out method.
The pulling-out hole is formed when pulling out
the existed pile. If the pulling-out hole is left,
the collapse of the empty drilling part of theearth and sand, and there is a possibility that thesubsidence of the ground surface by the gap
widening in the ground occurs. Therefore, it isnecessary to fill the pulling-out hole byinjection of the fillers. About fillers,conventionally, in many cases to construction
in mountain sand and recycled sand fromconstruction it is easy and inexpensive. But, by
cannot ensure a reliable filling and stablestrength, in recent years the flow of processing
soil and cement-bentonite use has increased.
However, there are no regulations yet on fillers
injected into a pulling-out hole, and theinfluence by which the strength of the fillers

1. Introduction
In Japan, many of the city located in the soft
ground, there are many structures using a pilefoundation. Therefore, to achieve a new land
utilization at the place where existed structures
are present, it is necessary to remove existed
pile supported the structure as well as existed
structures for construction of a new structure.
Further, existed piles and concrete husk become
industrial waste, be left of these industrial waste
in the ground is a very difficult problem. Inaddition, it is seen troubles many as "hidden
defect" in the sale of land transactions.
Accordingly, it can be said that the removal ofexisted pile is essential.
The removal method of existed pile, there isa pull-out method and crushing removal
method, and the like. But the crushing removal
method are having such as vibration, noise and1

Geo-Environmental Engineering 2017
Seoul National UniversitySeoul, Korea
May 19-20, 2017

gives it to the surrounding grounds is not also
elucidated.
This study considers the influence by whicha pulling-out hole of a pile foundation gives it
to static characteristics of surrounding grounds
by using two-dimensional static finite element
analysis. The special qualities required forfillers injected into a pulling-out hole are also
clarified in this study.

Clay layer(N value=4)

19 m

Gravel layer(N value=50)6mpulling-out hole=1m

20 m

25 m

50 m

Figure 2 Sectional view

2. STUDY SUMMARY ABOUT THE
STATIC BEHAVIOR OF THE PULLING-OUT HOLE AND THE ORIGINAL GROUND

50m

Gravel layer

6m

25m

Clay layer

19m

20 m

Describe the study content to ① ~ ④ (Fig. 1).
① To select the study cross-section.
② To create the analysis model, based on theselected cross-section in the ①. And theanalysis area to mesh division.
③ To select an analysis constant. To set the application configuration model and material
parameters in the initial stress analysis.
④ Perform the initial stress analysis. Analysis
technique is a total stress analysis. In thisstudy, HD model for the ground material andelastic model for the hollow portion has been
applied.

Figure 3 Analysis model

3. ON THE STATIC BEHAVIOR OF
THE PULL-OUT HOLE AND THE
ORIGINAL GROUND, ANALYSISMODEL AND INPUT GROUND MOTION WAVEFORM
3.1 Analysis model
In the analysis, the analysis cross-section has
a two-layer, upper layer part is clay layer as soft
strata, which N value is about 2. And underlayer part is gravel layer as strong formations
serving as a support layer, which N value isabout 50. The width of the analysis crosssection is set to 50m, the thickness of the clay
layer is 19m, the thickness of the gravel layer is
6m, and the total depth of the cross section is25m. About pulling-out holes, the number isone, pore diameter is 1m, depth is 20m, andembedment depth into the gravel layer is the 1m.
For mesh division, improve the accuracy ofanalysis by finer mesh spacing near the pullingout hole. Also, even when filled with pullingout holes, it is finer mesh in order to examine
the behavior of the filling portion of the pullingout hole. As a boundary condition, the bottom
was fixed fulcrum, and the lateral boundary isthe equal displacement boundary. When themoving node on the side of the left side, nodeof the other side to the displacement is the same
movement as the node on the side of the left.

Figure 1 Analysis procedure2

Geo-Environmental Engineering 2017
Seoul National University
Seoul, Korea
May 19-20, 2017

Therefore, it is possible to express that stratum
has spread to the left and right.
In the analysis, filler material is fluidization
treated soil. The analysis cross-sectional viewof the ground shown in Figure 2. Also shown asimilar analysis model in Figure 3. In the figure
at the time of filling material injection in Figure
3, portion surrounded by a red frame is apulling-out hole portion.

Table 3 Elastic model parameters
quEParameters2(N/mm ) (kN/m2)

Pullingout holes(filler)

3.2 Constitutive law and material parameters
Parameters in the clay layer and gravel
layer used for the analysis and soil parameters in the pulling-out hole are shown in Table 1. In this analysis, using a fluidizing
processing soil that many of the experimental value. In addition, it analyzes in ten
fillers with different elastic modulus andPoisson's ratio of the fluidizing process soil
in order to examine the effect of filler
strength has on the ground. From having asmall strength, the filler 1, filler 2, …, filler
10. Parameters used in the analysis is to determine the anamnestic literature reference.
Claylayer

Gravellayer

Pullingout holes(filler)𝛾𝑡(kN/m3)

152115𝛾𝑤(kN/m3)
Constitutive
lawHD
model

Table 2 HD model parameters
Parameters
Clay layer

0.1

15700

0.479

②0.2

31400

0.476

③0.3

47100

0.472

④0.462800

0.468⑤0.578500

0.464

⑥0.6

94200

0.460

⑦0.7109900

0.456

⑧0.8

1256000.452⑨0.9141300

0.448⑩1.0157000

0.444

4. ANALYSIS RESULTS AND STUDYON THE DYNAMIC BEHAVIOR OF
THE PULLING-OUT HOLE AND
THE ORIGINAL GROUND
In this study, to compare the ten types ofground used deferent filler, in the static analysis.
The results are shown in the following.

9.8HDmodel①

γt represent unit volume weight of the soil.
γw represent unit volume weight of water. G0represent initial shear stiffness. σ’m represent initial average active confining pressure. ν represent Poisson's ratio. c represent adhesive force.
φ represent internal friction angle. qu compressive strength. E represent elastic coefficient.

Table 1 Element parameters
Parametersν

4.1 Results of the analysis
Elasticmodel

Figure 4 and 5 show the results about theeffect of 10 types of fillers with different
strength on the surrounding ground by thisstudy. Figure 4 is maximum subsidence amountin analysis section when each filler withdifferent strength is used. Figure 5 is the graphcomparing maximum subsidence amount at
each depth when each filler with different
strength is used.

Gravel layer

𝐺0 (kPa)26985.77

173722.74′𝜎𝑚(kPa)

67.5

201

ν (-)

0.45

0.40c (kPa)

19.6

04.2 Study on the results of the analysis

φ (°)

042

From Figure 4, the maximum subsidence isthe largest in the filler central portion in the caseof the strength of the filler is 0.1N/mm2, 0.2
N/mm2. So that, it can be said that thesurrounding ground subsids into the filler partin the existing pile pull out hole, it is because of3Geo-Environmental Engineering 2017
Seoul National University
Seoul, Korea
May 19-20, 2017

Horizontal distance (m)Horizontal distance (m)
水平距離(m)-30-20-10010

Y=25m
2030

subsidence(m)maximum
最大沈下量(m)-2.00E-03

-30

Y=20m
Y=19m
Y=15m
Y=10m

-4.00E-03

Y=5m
Y=0m

-6.00E-03

水平距離(m)

0.00E+00

subsidence(m)maximum
最大沈下量(m)0.00E+00-8.00E-03-1.00E-02-1.20E-02-20-10

0

Y=25m
2030

Y=20m
Y=19m

-2.00E-03

Y=15m
Y=10m

-4.00E-03

Y=5m-6.00E-03

Y=0m-8.00E-03-1.00E-02-1.20E-02-1.40E-02-1.40E-02

qu=0.1

qu=0.2
Horizontal distance (m)

水平距離(m)subsidence(m)maximum
最大沈下量(m)-30-20-100102030-2.00E-03-4.00E-03-6.00E-03

Y=25m
Y=20m
Y=19m
Y=15m
Y=10m
Y=5m
Y=0m

水平距離(m)

0.00E+00-30

subsidence(m)maximum
最大沈下量(m)Horizontal distance (m)0.00E+00-8.00E-03-1.00E-02-1.20E-02-20-1002030

Y=20m
Y=19m

-2.00E-03

Y=15m-4.00E-03

Y=10m
Y=5m

-6.00E-03

Y=0m-8.00E-03-1.00E-02-1.20E-02

qu=0.3

qu=0.4

Horizontal distance (m)
水平距離(m)Horizontal distance (m)Y=25m

0.00E+00-100102030-2.00E-03

Y=19m
Y=15m

最大沈下量(m)Y=10m-4.00E-03

Y=5m-6.00E-03

Y=0m-8.00E-03-1.00E-02-1.20E-02-30

maximumsubsidence(m)
最大沈下量(m)-20

水平距離(m)

0.00E+00

Y=20m
-30

-20

-100

10

Y=25m

2030

Y=20m
Y=19m

-2.00E-03

Y=15m-4.00E-03

Y=10m

Y=5m
-6.00E-03

Y=0m-8.00E-03-1.00E-02-1.20E-02-1.40E-02-1.40E-02

qu=0.5qu=0.6

Horizontal
distance (m)
水平距離(m)-30-20-100-2.00E-03

10

Y=25m
2030

Y=19m

Y=15m
Y=10m-4.00E-03

Y=5m-6.00E-03

Y=0m-8.00E-03-1.00E-02-1.20E-02-1.40E-02

Horizontal
distance (m)
水平距離(m)

0.00E+00

Y=20m

-30

subsidence(m)maximum
最大沈下量(m)0.00E+00

subsidence(m)maximum
最大沈下量(m)Y=25m

10-1.40E-02-1.40E-02

maximum subsidence(m)10-20-100-2.00E-03

30

Y=20m
Y=19m
Y=10m
Y=5m-6.00E-03

Y=0m-8.00E-03-1.00E-02-1.20E-02

qu=0.8420

Y=15m-4.00E-03-1.40E-02

qu=0.7

10Y=25m

Geo-Environmental Engineering 2017
Seoul National University
Seoul, Korea
May 19-20, 2017

-30

-20

-100

10

Y=25m
20subsidence(m)maximum
最大沈下量(m)subsidence(m)maximum
最大沈下量(m)Horizontal distance (m)Horizontal distance (m)
水平距離(m)

0.00E+00

Y=20m

30

Y=19m

-2.00E-03

Y=15m-4.00E-03

Y=10m
Y=5m

-6.00E-03

Y=0m-8.00E-03-1.00E-02

水平距離(m)

0.00E+00-30-20-100

Y=25m

1020

Y=20m

30

Y=19m

-2.00E-03

Y=15m

Y=10m

-4.00E-03

Y=5m
Y=0m

-6.00E-03-8.00E-03-1.00E-02-1.20E-02-1.20E-02-1.40E-02-1.40E-02

qu=0.9qu=1.0Figure 4 Maximum subsidence amount when each filler with different strength is used
Horizontal distance (m)-20-100

qu=0.2102030-1.74E-03

qu=0.8-1.76E-03-25

qu=0.4
qu=0.6qu=1.0-1.78E-03-1.80E-03-1.82E-03-1.84E-03-1.86E-03-1.88E-03

水平距離(m)-2.00E-03

subsidence(m)maximum
最大沈下量(m)-30

subsidence(m)maximum
最大沈下量(m)Horizontal distance (m)

水平距離(m)-1.72E-03-15-52030-2.30E-03-2.40E-03-2.50E-03

Y=19m

Horizontal distance (m)

水平距離(m)subsidence(m)maximum
最大沈下量(m)-30-20-10010

qu=0.22030-5.40E-03

qu=0.4

qu=0.6
qu=0.8-5.50E-03

qu=1.0-5.60E-03-5.70E-03-5.80E-03-5.90E-03

Horizontal distance (m)
水平距離(m)-8.30E-03

subsidence(m)maximum
最大沈下量(m)-5.30E-03-8.40E-03 -30-20-1010

qu=0.2
qu=0.4-8.50E-03

qu=0.6-8.60E-03

qu=0.8-8.70E-03

qu=1.0-8.80E-03-8.90E-03-9.00E-03-9.10E-03-9.20E-03

Y=15m

Y=10m

Horizontal
distance (m)
水平距離(m)qu=0.2-20-100102030

Horizontal distance (m)
水平距離（m）-1.08E-02

qu=0.4

subsidence(m)maximum
最大沈下量(m)-1.00E-02-30

0-9.30E-03-6.00E-03

maximum
subsidence(m)
最大沈下量(m)25-2.20E-03

Y=20m-1.04E-02

15-2.60E-03-1.90E-03-1.02E-02

5-2.10E-03

qu=0.2
qu=0.4
qu=0.6
qu=0.8qu=1.0qu=0.6
qu=0.8qu=1.0-1.06E-02-1.08E-02-1.10E-02-1.12E-02-1.14E-02-30-1.10E-02-20-1001020

qu=0.230

qu=0.4
qu=0.6
qu=0.8-1.12E-02

qu=1.0-1.14E-02-1.16E-02-1.18E-02-1.20E-02

Y=5m
Y=0mFigure 5 The graph comparing maximum subsidence amount at each depth when each filler with different strengthis used5

Geo-Environmental Engineering 2017
Seoul National University
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May 19-20, 2017

insufficient strength of filler. In the case of thestrength of the filler is 0.4N/mm2, the maximum
subsidence is the smallest in the filling material
the central part. So that, it can be said thatsurrounding ground subsides, because the filler
strength is higher than the strength of thesurrounding ground. In the case of the strengthof the filler is 0.3N/mm2, the maximum
subsidence amount is almost evenly occurring,and it shows the behavior closest to the field
panel than other fillers in this study. It isbecause of the strength of the filler is closest to
the strength of the surrounding ground.
Furthermore, Figure 5 shows that themaximum subsidence amount is larger as thestrength of the filler is higher in the position of
the depth of 20m from the ground surface.
However, the maximum subsidence amount issmaller as the strength of the filler is higher atthe place other than filler part. The maximum
subsidence amount is larger as the strength of
the filler is lower in the filler part, and themaximum subsidence amount is about the samein the other horizontal position, which is in theposition of the depth of 19m from the groundsurface. In the position of the depth of 15m,10m, and 0m from the ground surface, themaximum subsidence amount is smaller as thestrength of the filler is higher at the place otherthan filler part, the maximum subsidence
amount is smaller as the strength of the filler islower after the distance from the center isaround ± 12m. It is because of the relationshipbetween strength of filler and strength ofsurrounding ground. Moreover, it is presumed
that it is subsided toward the center of theanalysis section from result of the maximum
subsidence amount is smaller as the strength of
the filler is lower after the distance from thecenter is around ± 12m.
From the above, in this study’s analysis
section, the strength of the filler to the pullingout hole of existing pile is 0.3 N/mm² or more.
It is because of that there is no subsiding toward
the filler part.

is lower than the strength of the surrounding
ground, the surrounding ground subsided
towards the filler part. So it is conceivable thatit suffices for the filler to the pulling-out hole tosatisfy the minimum strength according to eachground condition.
As this study’s future work is that it isnecessary to examine the influence of thisanalysis compared with this analysis result
when changing ground conditions.

References
Takao M. (2011). Leaving the foundation pile, backfilling denied
the defects of ground support force of the part, agent ofaccountability violation was also negative case, RETIO, No.82,(pp 166-167).
Yasushi F, Futa N, Yasushi U, Keisuke T. (2014). Study on theYoung's modulus of the fluidized processing soil. Summariesof technical papers of annual meeting Architectural Institute ofJapan, (pp 591-592).
Yasushi F. (2011). Deformation properties of the backfill
material which has a fluidity and self-hardening, Town Valueup Management report, No.37, (pp 41-44).
MLIT. (2014). Public building construction standard
specification (Building work) 2013 Edition. MLIT.
Marushin Co., Ltd. (2016). About the pegging chucking method”,Retrieved February 22, 2016, from http://marushinn.jp/about_chacking.html.

5. Conclusions
In this study, the influence of the pulling-out
holes on surrounding ground was evaluated by
two-dimensional static FEM analysis fordevelopment of pulling-out of existing piles.
From this, it was founded that if the strength of
the filler to the pulling-out hole of existing pile6