2016 6th International Annual Engineering Seminar (!nAES), Yogyakarta, Indonesia
Banjarnegara Landslide and Mudflow
Rheological parameters and numerical simulation using Bingham's model
Nadya Amartiawati
Department of Civil Engineering
Parahyangan Catholic University
Bandung, Indonesia
[email protected]
Budijanto Widjaja
Department of Civil Engineering
Parahyangan Catholic University
Bandung, Indonesia
geotek gw@gmail. com
Stella Marcelina Budi Naba
Department of Civil Engineering
Parahyangan Catholic University
Bandung, indonesia
stellanaba@gmai I. com
Abstract- A mas.liiYC mass movement occurred in Jemblung
Village, Karangkobar District) Central Jaya on 12 De(cmber
2014. Its probable cause was a high-intensity rainfall that
bap(lened before the monment. Act;ordingly, this study intends
to provide soil and rheological parameters to develop a numerical
simulation. The rheological approach used in the calculation is
Bingham's model. A numerical simulation is subsequently
conducted using tbe derived parameters. Result is then COillJ)ared
with the transportation time obtained from interYiews with
residents to validate it with evidence from actual e"Xpcrience, The
actual transportation time and the time obtained from the
numerical simulntion are sufficiently close, lienee, the dntabase
for soil rheological par.1meters f{)r hmdslidc and mudftow is
presented for future references.
II. SOIL AND RHEOLOGlCAL PARAMETERS
Table I presents the result of the basic parameters of the
soil in the west side of the study area, The soil is silted and
exhibits high plasticity. It is in a viscous liquid state~ with the
natural water content (w) higher than the liquid limit (LI.).
There are 6 (six) samples taken in this area. Table I shows the
average value of basic soil parameters of the site. For the soil
in the east side of the study art::a, w is approximately 50%. The
average LL is 64, and the plastic limit is 40.
Keywords-land.vlide; mudjlow; rheo/Qgical; Binglwm
I.
INTRODUCTION
On 12 December 20 14, after heavy rainfall of
approxirnately l 00 mm/day occurred for two consecutive
days, a huge mass movement happened in Jemblung Village,
Karangkobar District, Central Java (Fig. I). A mass of soil
moved down !rom the side of Telagalele Mountain (source
area) [1]. Interestingly, this incident was divided into two
types of mass movement. The first movement was the huge
mudflow toward the west; then, several minutes later, a
landslide (the second movement) continued ftom the source
area and moved toward the east (Fig. 2).
This study aims to serve as a guideline on how appropriate
soil parameters can be obtained for a similar case study. The
soil parameters include basic parameters from the
conventional standard laboratory test and advance parameters
for obtaining rheological parameters. Then, a numerical
simulation is conducted, and the result is compared with the
actual case.
Fig. ! . Location of Jcmblung Village.
TABLE I.
""'-
RASIC PARAMETERS OF THE SOJL IN THE WEST SIDE
OF THE STUDY AREA
--·-
Liquid
Soil
Limit
Sample
(LL)
-·
P!ttstic
Pltutici(v
Specific
Limit
lntlex
Gravity
(PL)
(PI)
(G,)
40.32
24.51
2.74
Jcmb!u
ng
LY.i)lagc
64.83
Water
Content
w
(%)
70104
soildassific
ation
(USCS)
Mll
2016 6th International Annual Engineering Seminar {!nAES), Yogyakarta, Indonesia
TABLE Il.
Fig. 2. Situation in the area approximately 2 weeks after the
had occurred (28 December 2014).
ma~,
movement
Rheological parameters were identified via the flow box
test. The procedures for this test are described in detail in [2]
and (3]. Fig. 3 presents a comparison between the viscosities
of kaolin and the soil in Jemblung Village. As shown in the
figure, soil can be divided into tvvo states, namely, plastic (w
is lower than LL) and viscous liquid (w is higher than LL).
When soil is in plastic state, its gradient is steeper than that in
viscous liquid state. Viscosity ranges from 0.7 Pa•s to 100
Pa•s in plastic state and from 0.12 Pa•s to 0.7 Pa•s in viscous
liquid state.
Table II indicates that the yield stress is within the range of
1.41 kPa to 14.45 kPa. An increase in w is followed by a
decrease in yield stress. ln this case, yield stress is assumed to
be similar to the undrained cohesion, which is derived from
the results of the fall cone penetrometer test.
in the west side of the study area, the soil is mostly in a
viscous liquid state. By contrast, the soil in the east side is in
a plastic state. l. fence, the authors use the w mnge that is lower
and higher than LL (w 41%~79%).
HX>C , - - -
RH.ATtONS!lJP BETWEEN WATVR CONTENT A'lD YIELD
STRESS
Water Content, w ( 1%)
Yield Stress,1j {kPa)
4L75
14.45
52.32
9.i2
56.51
7.13
61.20
329
69.i9
1.63
72.99
1.46
78 73
1.41
IlL NUMERICAL SiMULATION
For the numerical simulation, we adopt the assumption of
Bingham's model, whlch states that a mass movement will
move/flow using a single viscosity value. J. :lence, the viscosity
in this case may be assumed to be the lower shear resistance
from the soil to the movement/flow. A child playing on a slide
provides a good analogy. The child can move down because
the shear resistance occurring on the slide is smaller than that
occurring on tlte cloth of the child.
Bingham's model is a simple rheological model with two
parameters, namely~ yield stress and viscosity. These
parameters are obtained from the shear stress versus the shear
strain rate curve (called the consistency curve). Yield stress is
observed when no movement occurs. By contrast, t1ow is
governed hy its viscosity when movement occurs. Viscosity is
derived as a line gradient from a latter curve. Using another
soil sample from Sidoarjo mud, soH in the viscous state has a
tendency that Hingham model is relatively close to HerschdBulk!ey model [6].
The numerical simulation used FL0-2D soflware, which
applies Bingham's model to simulate mass movement. For the
current case study, two simulations are generated, namely, for
plastic and viscous liquid states. Table Ill lists the parameters
used in the simulation.
100
~
!
TABLE Ill.
"
-~•
~
Scenario
w
>
Soil State
PARAMETf::RS H)R Tl II: SIMULATION
Water
Content, w
···-·
(%}
Yield Stress,
1Y (kPa)
Viscosity. TJ
(Pa•s)
1---·i
Plastic
57
7.I
3.7
~2
Viscous liquid
73
1.5
0.2
-·IV. RESULTS AND DISCUSSiON
c
1.S
Liquidity Index (l!}
Fig. 3. Comparison of the viscosities of kaolin and Jemblung Village soil.
2.5
Pig. 4 presents the simulation result for the west side in a
viscous liquid state, which is obtained at a simulation time of
4 min and 30 s. This result shows that all of the soil flow ftom
the source area (point I) from Telagalele Mountain through
point 2,3, and 4 to end of the deposition area (point 5). A
small island-like formation occurs between points I and 2. Iu
this position, soil moves Independently in the west and east
2016 6th International Annual Engineering Seminar (lnAES), Yogyakarta, Indonesia
sides. The soil in the west side is in a viscous liquid state,
whereas that in the east side is in a plastic state.
According to [4] and [5], the mass movements in the west
side and the east side can be classified as mudflow and
landslide, respectively.
in Table IV, the transportation time for the mudflow is
approximately 4 min 30 s, with an average flow depth of 4.6
m, and a velocity ranging from 1.5 m/s to 4.4 m/s, The
landslide has a slower transportation time because of its higher
viscosity compared with the mudflow.
TABLEJV.
Scenario 1
Landslide
Scenario 2
Mudflow
Transportation Time
6 m1nutes
4 min 30 seconds
Average Flow depth (m)
3.8-8,6
4,6
Average Velocity (mts)
2,6-3,9
1.5-4.4
Description
Fig. 4. Simulation 2 for the viscous liquid state.
SIMULATION RESULTS
The viscosity used in this case study has a single value, as
mentioned previously. Then, the value obtained from
Bingham's model can be used to estimate the behavior of
landslide and mudflow.
V. CONCLUSIONS
Although Bingham's model is a simple rheological model,
the results show that the influence area from the numerical
simulation is sufficiently close 1o the actual event This case
study in Banjarnegara further shows that the rheological
parameters derived via the flow box and tall cone
penetrometer tests are suitable inputs for simulation. The
viscosity derived from the flow box test is reasonable
compared with the resu Its obtained by other scholars,
Through the numerical simulation using FL0-2D,
mudtlow and landslide can be modeled and compared with an
actual case, namely, the Banjarnergara mass movement The
prediction of transportation time tfom the source area to the
impact area is close to the evidence time.
Fig. 5. Combination of simulation I and 2 at a simulation time of 15 min.
Disturbed soil samples are collected from the study area.
These samples are used to detennine the physical properties of
soiL Then, we assume that mudflow will move on the soH
surface using a classification scheme from [4, 7]. No erosion
occurs during transportation based on this assumption. Hence,
only the soil at the surface will move. This assumption is one
of the shortcomings of this simulation.
I Iowever, using the evidence time for the study area, the
estimation time (for the simulation results from the source area
to the end of the deposition area) is sufficiently close to the
actual transportation time as reported by the residents in the
impact area who have been interviewed for the study.
Transportation time is defined as the time it takes to reach
the first point in the plan area ·from the source area. As shown
Hence1 this study successfully detern1ines soil parameters
using Bingham's modeL Furthermore, a numerical simulation
that uses the same model is presented and compared with the
actual case. However, the method exhibits several
shortcomings, such as using a constant viscosity value and not
considering erosion during mass transportation.
References
[I]
S.B. Naba, N. Amartiawali, and B. Widjaja, "Landslide and mudtlow:
behaviour and simulation," International Student Conference on
Advanced Science and Technology. ITS and Kumamoto University.
Surabaya, 2015.
(2]
SJ·LH. Lee and B. Widjaja, "Phase concept for mudtlow based on the
inHucncc of viscosity," Soils and Foundations, vo\53, no. I, pp. 77-90,
20!3.
f3]
B. Widjaja dan SJI.H. Lee, ''Flow box test for viscosity of soils in
plastic and viscous liquid state/' Soils and Foundations, vol. 53, no. l,
pp. 35-46,2013.
2016 6th International Annual Engineering Seminar (lnAES), Yogyakarta, Indonesia
[4'1
0. Hungr, S.G. Evans, M.J. Bovis, and lN. Hutchinson, "A review of
the classification of landslides of the flow type," Environ. and Eng.
Geoscience, vol. VII, no. 3, pp. 221~238, 200L
[5'1
J.S. O'Brien and P.Y. Julien. "Laboratory analysis of nmdflow
properties," J. HydmuL Eng., vol. 114, no. 8, pp. 877-887, 1988.
(6]
Anthony (2016), "Pcrbandingan pencntuan nilai viskosita..<; lumpur
Sidoarjo dengan How box test mcnggunakan model Bingham dan
Hcrschel~Bulk!cy,"
thesis
(in
Indonesia),
Universitas
Katolik
Parahyangan
[71
USGS
(2010),
"Diffen;mcc
lx:twx.,-cn
slide
and
<http://www. pro nmcdia.sl! picture/lands lidc:s-and-nmd-
flows/0088784198!> {Fch. 22, 2011).
t1ow,"
2010
+IEEE
A.cbtandn!!J Tcchn>:>logy
fur Humanity
E
This is to certify that
Budijanto Widjaja
Presenter
Has contributed in
Tlie 6'11 Internationa[ Annua[ Engineering Seminar (InAES) 2016
on 1 - 3 August, 2016
at Eas!)Jarc Rote{, Yogyakarta, Indonesia
Jointly organized by :
Faculty of Engineering, Universitas Gadjah Mada, Universiti Tun Hussein Onn Malaysia (UTHM)
and Universitas Muhammadiyah Surakarta (UMS)
Dean of tbe Faculty qf Engineering
.J.Jnlv~mtas GadJah Mada
.
{
;.
~~
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Prof. lr~~~ulyono, M.Eng., D.Eng.
_-
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General Chair, lnAES 2016
muTHM
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