DPRI, KYOTO UNIV.

First Time Investigation on
Landslides Triggeredgg
byy 12 Mayy2008 Wenchuan Earthquake, China(12-15 June 2008)
Fawu Wang
Research Center on Landslides
Disaster Prevention Research InstituteKyoto University
18 June 2008

From: website of China Geological Survey

Epicenter and aftershock (USGS)Landslide p
points in our investigationsgGeological map

Routes of the 4-dayy investigationsg
Day 1-3

Day 1-4

Day 1-2

Day 1-1

Investigation schedule• 12 June (Day 11-1)
1)
Chengdu – Dujiangyan – Mt. Qingchenghoushan((Hongyangy resort))• 13 June (Day 1-2)
ChChengdu
d – Longmenshan
Lh – Yinchanggou
Yi hresortt• 14 June (Day 1-3)
Chengdu – Qingchuan – Mianyang• 15 June (Day 1-4)
Mianyang – Beichuan – Chengdu

The participants of the investigation

From left:
Dr. C.G. Yan: Kanazawa Univ., Japan / Changan Univ., China
Prof M.
Prof.
M Miyajima: Kanazawa University,University Japan
Prof. Q.G. Cheng: Southwest Jiaotong University, China
Ass. Prof. F.W. Wang: Kyoto University, Japan

Content in Day 1-111• Building failure in Puzhao Temple (普照寺)• Shallow landslide caused damage of a tea
shop in Tai-an Town (泰安鎮)• Large area shallow landslide as a part of
failure of a giant ancient landslide whichdammed the river in Hongyan Resort (紅岩村)Building failure in Puzhao
Temple (普照寺)

Tilted temple name

Damaged situationin the temple
No life loss in this temple

Reparation workin the temple

The fallen head of thestatue was relocatedrelocated.

Damaged pipe

No damage in theold tower

Sled roof

X cracks in the wall

Shallow landslide caused collapse ofa tea shop in Tai-an Town (泰安鎮)

About 4 persons were buried at the landslide toe.

The ridge tiles wereshaken down.

The landslide
reached the centerof the stream.

Front view of the Tai-an
Tai an Town landslideLarge area shallow landslide as a part ofgiant ancient landslide which
failure of a g
dammed the river in Hongyan Resort

47 tourists from Chengdu and 4 local people were buried by thelandslide, when they walked along the road.

Shallow landslides occurred at the both sides of the stream.

Shallow failures also occurred around the small tree in thecenter of the photo when we investigated this site.

The stream passes through a ancient landslide. It isestimated that the ancient landslide has dammed the riverriver.
In this event, shallow landslide occurred in the cut.

Landslide paradise

The Chinese characters means paradise.

Houses damaged in theHongyan Resort. Actually, all
off theth resortt was built
b ilt on ththeancient landslide. It is unusual
to find such wide open area inthe mountains.

The young man waspulled out from adamaged house. His
finger and head wasinjured.
injured

The local people told us the story
when the earthquake occurred. Theyhhope
governmentt can guideid theirth i
rebuilding to avoid further damages.

This step was shown in the video taken
by a Peruvian tourist. The video wasbroadcasted by NHK for many times
times.
The Peruvian tourist left
his tent to local people.

Debris flow came from the rock slide
after a post-earthquake rainfall. Weasked
k d theth local
ll people
l pay attention
tt ti totthe rockslide in rainy days.

A rockslide occurredbehind the Hongyan
Resort.
ResortMt. Qingchengshan,MtQihha
world cultural heritage
was closed to prevent
landslide disaster.

Content in Day 1-2
12• Bridge failure near Longmenshan (龍門山)龍• Large shallow landslide in Sangouchun village(三溝村)• Large scale landslide in Jiufengchun (九峰村)• Slope failure in Yinchanggou Resort (銀場溝)Bridge failure near Longmenshan(龍門山)

The damage of the bridge cut the access to Longmenshan
Town. The active fault was named after the town.

The big stone jammed the road completely.

Shallow failure occurred along the steep terrace.

Large shallow landslide in
Sangouchun village (三溝村)
溝村

4 young men working on a house roof
roof,and an old woman were buried by thelandslide. They had no time to escape.

Another house at the rightside of the landslide

Another house at the left
side of the landslideLunch served by local people(rice, potato and noodle )Asking questions totheh pupils.
ilThey were quite
willing to answer.

Large scale landslide inJiufengchun (九峰村)

A lake formed by the Jiufengchun landslide. The bridge wasdamaged by the earthquake.

The Jiufengchun landslide

The local people said, the landslide was formed in only one minute.
They thought the debris should come from the ground, because it
was formed so sudden
sudden.
More than 60 persons from 17 families, and more than 30 tourists
were buried by the debris.

From the middle looking to the source area, it is estimated that thedistance to the failure in the source area is more than 1km.

The granite debris is quite dry. However, water was found in the middle ofthe debris.
It is estimated that the slide zone can be saturated by the water. For thisreason, the landslide travelled rapidly for long distance.

The landslide toe dammed the stream partially. If the earthquake
occurred in rainy season, the stream should have been fully dammed.

Situation at the landslide toeView from the toe to the source area of the landslide

The boundary was quite dry. Wracks of the houses can be seen.

Slope failure in Yinchanggou Resort (銀場溝)Shallow slides cut the access to the mountain at the bridge.

Shallow landslide partially dammed the stream fromYinchanggou to Longmenshan Town.

Bridge across the stream from Yinchanggou to Longmenshan
Town collapsed .

The small dam was safe in the earthquake.

Thrust fault cutting the road from Yinchanggou toLongmenshan Town

Content in Day 1-3
13• Shiziliang landslide (獅子梁) in QingchuanCounty (青川)• Landslide lake in Qianjin village (前進郷)

Shiziliang landslide in Qingchuan County

There is a long continuous crack in the top of the mountain,mountainthreatening large part of the Qingchuan County.

The cracks

Looking down to the City from the crack

Blue roofs are rescue tents.

Landslide lake in Qianjin Village

The lake was formed by Hongguang Village landslide

Landslide lake in Qianjin Village

Damaged underconstruction building

The lake

Disappeared road to the lake

Landslide lake

（From China Geological Survey)

Content in Day 1-4
14• Damage to Libai’s ceremony house in
Qinglian Town(青蓮),Town(青蓮) Jiangyou City (江油市)• Landslides and active fault in BeichuanCounty (北川県)This small
Thill townt
if famousffor the poet, Li Tai-po.

The Valhalla for the most famous poet, Li Tai-po, in Qinglian Town, Jiangyou City

Light damages in the main building

One of the two memorialstones tilted.
The tilted one was written
by Mr. Deng Xiaoping.

Roof damages
g in theold building.

The wall fell down and hit theyoung poet statue’s head
No damage to the old poet statue

The large tower in Qinglian Town

Damage in the simple fenceDamaged bridge
Shallow slides along the riverfrom Beichuan

The boundary of Beichuan County

Landslides and building collapse become severe in Beichuan County.

Shallow landslide

Deposit fan of debris flowGiant rockfall at Leigu Town

The lady survived from a rapid
landslide (marked by circle). Only
two survivors from the landslide.

The Destroyed Beichuan County

The left slide is Wangjiayan slide, while the right one is Jingjiashan slide.

The Wangjiayan slideThis slide
Thilid occurredd ini weathered
thd mudstone.
d t
It destroyedd t
d theth countyt servicesiincluding Education Bureau, Public Safety Bureau, a jail, a hospital, akindergarten, and so on. Almost no body survived from this slide.

The Wangjiayan slide

The sliding mass of the Wangjiaya slide is almost flat. It is arapid and long-travel landslide.

Another view with two slides

The Jingjiashan slide

The Jingjiashan slide occurred in weathered limestone. It destroyed two schools
at its toe. The young survived from the slide when he jumped out of a motorbike.

The damaged bridge in theCenter of Beichuan County

Strict prohibition for entering

The active fault behind the gate
off Beichuan
B i hCCountyt

Originally, the house was at the same level as the road. The height of one floor isabout 3m, so the uplift of the fault in this position is estimated around 4m.

The active fault behind the gate
off Beichuan
B i hCCountyt

The active fault behind the gate
off Beichuan
B i hCountyCt

The same fault crossed the road in the up branch.

Only helicopter can pass
Beichuan County

Everybody comesoutt off ththe gatet offBeichuan Countyshould acceptdisinfection.

My impression on the landslide
triggered by Wenchuan Earthquake• Lots of shallow slides.
• Most of the slides were rapid. Rapid and long-travel
landslides occurred in mudstone
mudstone, shale,
shale limestone,limestone
granite.
• Because the earthquake is so strong, the difference bystrata is not clear.
• The landslide disasters caused by the combination ofstrong earthquake motion, steep geomorphologicalcondition and fragile strata (by weathering and activecondition,faults).
• It will be extremely worse if the earthquake occurs inrainy season.

Some other photos

The isolated dogs by the damaged bridge

E dlEndlessrescue tentst tJapanese tents

UNHCR tents
Endless rescue trucks
Endless rescue houses

Damaged carsGeologist, do you know what will
happen next time?

The earthquake is nothing for us!