K178+550━එ࣐ᇭ‫ח‬ԕẕԓ䐟

K177+550━එ㲭㓿ᣇ━ẙ᭟ᥑˈᰗ━එࡽ㕈ࠪ⧠ᯠ━එ

Using bridge to instead original road near K178 + 550 landslide

set anti-slide pile(17*24m, DIS 3m), the second creep landslide occur ahead━එ䐟⇥2017.01.11-02.16ᰦ⇥SARᒢ⎹മ

Conclusion-Landslide in Embankments

SAR interferogram (2017.01.11- 2017.02.16 )01.11-01.23

01.23-02.04• Because of climate warming and artificial disturbance, thepermafrost degradation there is serious.
• The water accumulation and distribution again along geologicalsoil interface.
• In some place( impermeable layer beneath), from spring,thawing water form sliding surface and landslide.
• Landslide movement has characteristics of seasonal and annualperiodicity.
• The slip rate and movement of landslides are controlled by boththe thawing process of permafrost and the geological soilinterface condition.

02.04-02.16

3.2䐟แ䗩එ⎾⍱ߠ

Icing in excavation section

3.1.1 Landslide caused by icing
Background

Aufeis on the cutting slope (2010.03)

The cutting slope after excavated (2009.09)

Highway cutting slope(560m):• The highway is Extension Project.
• In 2009 fall, mechanical excavation.
• In Feb.2010, Icing occurrence.

The Location of cutting slope (photo from Google earth)2010.03

2010.04

2010.06

2010.112010.072010.10

Taken by infrared camera

Geological profile of left cutting slope in K161 + 860 section

Geological profile of left cutting slope in K161 + 860 section

MethodMethodMonitoring(2011~2015):

Drilling exploration(2010.07):• At the top of the hill.
• Soil samples was conducted particle
analysis and penetration tests.
• Different soil layer is very important foricing here.

• At the second floor of the slope, near thetoe of the slope, four drilling
borehole(space,40m).
• Soil temperature, water content, porewater pressure for 5 years.

Soil physical indicators in monitoring section of the slope
Layer

Category

Rock types

Thickness (m)Permeability
coefficient (cm / s)1

Quaternary loose layer

silty clay

0.8~1.0

3.84h10-82

Quaternary loose layer

muddy sandstone

2.5~3.0

6.49h10-6

3

Tertiary sandstones

pebbly sandstone

1.0~1.2

2.11h10-5

4

Cretaceous mudstone

mudstone

˚5

2.09h10-8

The position of monitoring borehole on the slope

The cutting slope after excavated (2010.09)

MeasureThe cutting slope after excavated (2010.09)

Results& Discussion

Geological profile of left cutting slope in K161 + 860 section
250

Pore water Pressure(0.8m)

25Groud Temperature(0.4mdepth)

The cutting slope after excavated (2010.09)

2015/4/6

2014/9/18

2014/12/27

2014/3/2

2014/6/10

2013/11/22

2013/5/6

2013/8/14

2013/1/26

Temperature (ć)-52012/10/18

0

2012/4/1

0-50

2012/7/10

5

2011/12/23

1050

2011/6/6

100

2011/9/14

2015

2010/11/18• At the second floor of the slope.
• A ditch was backfilled by gravel (2.0m depth)
and geotextile(1.5m depth).
• Catchment and derangement.

2001502011/2/26

Gravel ditch(W0.8m,D3.5m):

Pore water Pressure (kPa)

Groud Temperature(0.8mdepth)

Signal of icing :Icing is related to soil PWP aroundhere. The signal of it is a sudden
increasing of soil PWP accompanied
by soil temperature dropped to 0
ć.(frozen front)

Icing cycles:Occurrence, bigger, smaller,
disappearance…

Conclusion- Icing

3.3 ߫൏䘰ॆሬ㠤ൠส⊹䱽৺ᐕ〻ሩㆆ
Foundation settlement caused by PF Degradation and Engineering Countermeasures

 Icing here is caused by slope excavation which not only
destroy the balance of underground water, but alsochange the condition of permafrost around here.
 The water accumulation and distribution again along
geological soil interface.
 In some place, in winter, the water out flew pressured byupper frozen front and beneath impermeable layer.
 Using Gravel Ditch on the slope could solve this icing
problem.
 Icing could erosion the slope surface and lead tolandslide in spring.

K161+440ᯝ䶒ⴁ⍻ᆄᐳ㖞ǃൠ䍘ࢆ䶒⽪᜿മ
Monitoring hole layout, geological profile diagram
Gravel pilesettlementCrackĉ-ĉʹ⍻㓯2010.9 ⭥⌅৽╄മ‫ۿ‬ċ-ċʹ⍻㓯2010ǃ2012ǃ2014ǃ2015ǃ2016ᒤ9ᴸ⭥⌅৽╄മ‫˗ۿ‬Č-Čʹ⍻㓯2010ǃ2014ǃ2015ǃ2016 ᒤ9ᴸ⭥⌅৽╄മ‫ۿ‬

ST curve with time

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

4.ཊᒤ߫൏䘰ॆᕅਁⲴ⧟ຳൠ䍘䰞仈⊹䱽䟿˄FP˅ᰕᵏປ൏儈ᓖ P

⊹䱽䟿 FP

161+440ᯝ䶒ѝཞ࠶䳄ᑖ˄T2⛩˅ൠ⑙䲿ᰦ䰤ਈॆᴢ㓯മ

161+440ᯝ䶒ᐖඑ㝊˄T1⛩˅ൠ⑙䲿ᰦ䰤ਈॆᴢ㓯മᰕᵏ

ᰕᵏᯠ䐟ປ൏儈ᓖަԆ⧟ຳൠ䍘䰞仈˄⹄ウ४˅



Vertical displacement –TIMEᰕᵏ







161+440ᯝ䶒ᐖඑ㝊ⴁ⍻⛩൏փㄆੁս〫䲿ᰦ䰤ਈॆᴢ㓯





161+440ᯝ䶒ѝཞ࠶䳄ᑖⴁ⍻⛩൏փㄆੁս〫䲿ᰦ䰤ਈॆᴢ㓯

4.1 ߫൏䘰ॆⲴ䇱ᦞ——≤᮷ൠ䍘ᶑԦਈॆ

Evidence of PF Degradation - Variation of Hydrogeology Condition

4.2 ൠ䊼ਈॆ
Geomorphology changes

4.3 ൠ㺘Ἵ⢙⿽㊫ਈॆ
Changes in surface plant species

Other environmental
geological issues˄ study area ˅4.4ਟ⟳ߠо⑙ᇔ≄փᧂ᭮Combustible ice and greenhouse gas emissions

Thanks for your attention!