AN INTEGRATED MODEL SIMULATING THE INITIATION
AND MOTION OF EARTHQUAKE AND RAIN INDUCEDLANDSLIDE IN PAKISTAN
Presented at:

UNESCO-JASTIP Joint Symposium on IntraRegional Water Security and DisasterManagementAffiliation
Disaster Prevention Research Institute(DPRI), Kyoto University, Kyoto, Japan.
Dr. Saima Riaz
Prof. Kaoru Takara
Prof. Kyoji Sassa

Sequence of Presentation
 Introduction/Background of study
 Objectives

 Site investigation and soil sampling Ring shear test’s results
 Integrated computer simulation model (LS-Rapid)
 Conclusions
 Recent works and ongoing researchAn integrated model simulating the initiation and motionof earthquake and rain induced landslide in Pakistan
Database inventory and Methodology

Completed

Completed

Data collection– Geological maps
– Topographic maps
– Digital elevation models– Field investigation– Soil sampling– Literature review

Laboratory tests using thelandslide ring shear simulator– Undrained stress control test
– Rubber edge friction test
– Pore water pressure control test
– Seismic loading test

On going
Landslide simulation– LS Rapid model

Landslide risk assessment and Data analysis
Failure mechanism

Dynamic analysisReproduce the initiation and motionof landslide by LS Rapid software

Conclusions

Introduction

The study area lies in the NE of Muzaffarabad city,
capital of the state of Azad Jammu and Kashmir,
between the coordinates 34°21ʹ to 34°28ʹ N and73°27ʹ to 73°41ʹ E .



It is the part of “Sub-Himalaya” atectonostratigraphic division of Himalaya.

Himalayan orogeny is the world's youngest active
continental to continental collision.

morpho-PanjgranslidePanjgran landslide

Fig. Geological map of study area

Fig. SPOT image of the epicentral area, Outline shows
the boundary of the Panjgran landslideTwoactivefaults
Kashmir
Boundary Thrust (KBT) and KawaiFault(KF) are running through thearea.

KBT was responsible for thedevastating
2005
Kashmir
Earthquake. KF joins the Indu
Kohistan Seismic Zone (IKSZ)
which extends up to the Moho
(Khan et al., 2012).

These interformational (KBT) andintraformational (KF) faults haveaffectedthephysicalandmechanical properties of therocks present in the immediate
vicinity forming a 200 m orPanjgran Landslide
sometimes more thick deformedzone.
 The rocks present in these fault zones are highly sheared, folded, weathered and in most parts
are badly crushed to fine materialObjective of Study
The main objectives of the study are:
 To identify different causes of land sliding in the study area,
 To interpret the failure characteristics of deep seated Panjgran

landslide in Neelum valley, Azad Kashmir, and To model and study the initiation mechanism and motion behavior ofearthquake and rain induced landslides by reproduction of landslide
initiation and develop a failure surface in the laboratory using theLandslide Ring shear simulator.

CausesNatural causes
 Heavy Rainfall

Average annual precipitation 1511 millimeters.



Heavy rainfall events especially in July and August Seismic Activities
Collapse of steep rock walls

Coseismal mass movements

 Steep topography and Soil ErosionOriginal slopes of area are steep and prone to mass movement

Site investigation and soil samplingThe Panjgran landslide is located inthe Neelum Valley area 35 km awayfrom the Muzaffarabad city. It is anoldmass movement of the area which wasreactivated in the 2005 Kashmir
earthquake.

Panjkot ridge (34° 25′ 47′′ N; 73° 37′12′′ E, altitude 1,450m asl) was theinitiated point of this landslide.

The landslide moved towards northeastof the Neelum river. The Neelum riverhadfrequent
undercutandoversteepened the slope in the area.
This was one of the reasons to reduce
the overall stability of the slope.

Lithology of Formation at landslide site
may be described as a series ofalternate
bedsofsandstone,
mudstone, clay stone and shale (cyclicdeposition).

Site investigation and soil samplingFig.(a,b) Geological Cross sections of Panjgran landslide The shale/clay and mudstone is exposed at scarp along the road which has swelling potential. In rainy season,
the argillaceous material, absorbs water and accelerate the movement.
The landslide started at an elevation of 1450m asl from the Panjkot ridge. The length and width of landslide isabout 950m and 650m. The rough estimated average depth of landslide is about 80m. The volume of thelandslide is calculated approximately 6.75 x106 m3.

Existing condition at Panjgran slide

Sample location

Source: Google Earth, Pakistan Forest Institute, Peshawar

Existing condition at Panjgran slideSome Landslides related Issues
 Blockage&DamageofMuzaffarabad-Neelum

Valley&Muzaffarabad-Islamabad main roads.
 Scarcity of medical facilities in Neelum Valley due to blockageof roads.
 Human live losses.
 Damage to houses.
 Damage to infrastructure(bridges, electricity poles, telephonelines etc).
 Damage to Public & Private vehicles.
 Deforestation due to slope failure.

Landslides related Issues
 Water and Air pollution.
 degradation of these natural resources (The debris flowing due to landslides not only caused

human causalities but also polluting the water of Neelum River, which is the only available

drinking source to the valley. The water pollution is posing a serious threat to the local
community’s health and life by spreading of various diseases to the population andenvironmental degradation to the aquatic fauna (water species i.e. fish, crab, fresh water

mussels etc.).
 Debris produced by slopes failure may also increase the sediment load in the river. As entire

AJK is a catchment area of the major reservoir e.g. Mangla, high sediment load can enhance
the silting up of the dams and ultimately can reduce the life of the reservoirs as a long term
hazard.

Test results

#4100

#10

#18 #30#50#100 #200

90
80

Percent Finer By Weight

70
60

50
40

30
20
100100Landslide Ring shear apparatus ICL-2

1010.1
Grain Size (mm)Landslide simulator (photosurface after testing)showing0.01

sliding0.001

Stress conditions of slopes1001200
1000

80

Ru = 0.31
Shear Stress (kPa)Shear Resistance (KPa)

Pore water pressure ratio due to rainfall triggeredlandslides (Ru)

1.5MPa60

1.0MPa400.5MPa

400

800
600
400

202000
2000

4000
6000
Shear Displacement (mm)

8000

0

10000

01000

200400

1000

1400

900

1200
Stresses and pressure (kPa)700600ɸp=43.60

500
400
300

ɸm=42.60

10000

Total normal stress

1000

8000

800
6000
600
4000

400

200

2000

200

100000100

200

300

400 500 600 700
Normal Stress (kPa)

800

900

1000

1200

12000

800

Shear Stress (kPa)

600
800
Normal Stress (kPa)

00100

200

300

400
Time (sec)500600700

Shear displacement (mm)0Test results
600

DL = 3-5mm

DU = 80-100mm

500

Shear Stress (kPa)

400300τss = 250kPa

200

Excess pore water pressure
generated
undershear
displacement which initiated thelandslide failure; DL = 3-5mm.

10001

10100

1000

10000

Shear Displacement (mm)Shear strength reduction in progress of shear displacement

100000Integrated computer simulation model (LS-Rapid)-an example study

Countermeasures in Practice

RCC Retaining Walls along Muzaffarabad-Islamabad Highway

Plantation Projects in MuzaffarabadGabion Retaining Walls near Murree

Stone Masonry Retaining Walls

Countermeasures in PracticeLand sliding Protection Tunnel in Muzaffarabad (Year 2012)

Conclusions/ongoing research
The Panjgran landslide was first activated in 1988 and 1992 floods and was reactivated during the2005 Kashmir earthquake in northern Pakistan causing many causalities and blocked the Neelum
valley road for 60 days. The factors controlling the landside activity includes steep slope, presenceof clayey material, construction of the Neelum road and river under cutting.
 The pore pressure control test for simulating the source area of the landslide suggested that a porepressure ratio of 0.31 could have caused the landslide without an earthquake.
 Excess pore water pressure generated under shear displacement which initiated the landslide failure;
DL = 3-5mm.
 Sliding surface liquefaction behavior observed during tests.
 This study can not only help in reducing the casualties but also in saving millions of dollars of nation
by detailed analysis of the active landslide in landslide prone areas including geological,
geotechnical, hydrological, and topographical data essential for the assessment of landslides. This
research can provide a strong and practical base for the evaluation of risk and vulnerability
assessment of the active landslides and slope failures in study area, and for the secured and costeffective buildings and sustainable infrastructure in landslide prone areas.
 Seismic loading test results and simulation on LS-Rapid software are under process and their data
will be published later.
 By this Project, the author will find an opportunity for long term international collaboration between
Disaster Prevention Research Institute, Kyoto University and University of Engineering andTechnology, Lahore Pakistan which will be beneficial for both countries.
