Earth Reinforcement Combined with Other Method

- Case History -

Yoshihisa MIYATANational Defense Academy

Japanese Supporting Committee for TC9

1st meeting of TC9 (2002-2005), Nice, September 23, 2002

How to Spread The Application Field?

• One of Current Task of Earth Reinforcement Technique ---

“ How to Spread The Application Field”

• Course of our research ---“ Development of New Ability “

or“ Improvement of Technical Reliability “

Reinforced Soil Wall

Reinforced Embankment

Nailing Reinforced Foundation

Combination with Other Method

Other Geotechnical MethodsSoil Mixing, EPS, and Preloading + Prestressing etc.

NEXT

Reinforced Soil Wall (RSW)Combined with Other Method

Ex.1 RSW with Cement & Short Fiber MixingCement & Short Fiber MixingEx.2 RSW with EPS BlocksEPS BlocksEx.3 RSW with Foam Grass MixingFoam Grass MixingEx.4 RSW with Preloading + PrestressingPreloading + PrestressingEx.5 RSW with Deep Mixing and GroutingDeep Mixing and Grouting

NEXT

Ex.1 RSW with Cement & Fiber Mixing

2.0m

1.0m 2.7m0.7m

6.0m

0.3m

0.8m

GeogridTmax = 35kN/m

Fill materialc = 0 kN/m2

φ= 30 deg

c = 210 kN/m2

φ= 0 deg

Improved soil (soil / cement / short fiber)

From Dr. T.Hirai (Mitsui Chemicals Industrial Products Co. Ltd.)

Ex.1 RSW with Cement & Fiber Mixing

NEXT

RC Slab

RC Slab

Cover soil

Sand

Tie bar

From Mr. T.Konami (Okasan Livic Co. Ltd)

EPS Blocks

Ex.2 RSW with EPS Blocks

NEXT

Ex.2 RSW with EPS Blocks

EPS Blocks

RC slab

Ex.3 RSW with Foam Glass Mixing

Improved soil(recycled foam glass/ soil)φ = 41 degc = 20kN/m2

γt = 1.1 kN/m3

From Mr. T.Konami (Okasan Livic Co. Ltd)

Ex.3 RSW with Foam Glass Mixing

NEXT

Foam Glass

Soil

Tie rods

From Mr. T.Uchimura (Univ. of Tokyo)

Ex.4 RSW with Preloading + Prestressing

NEXT

Ex.4 RSW with Preloading + Prestressing

Ex.5 RSW with Deep Mixing and Grouting

From Dr. N.Kotake (Toyo Construction Co. Ltd)

Deep Mixing Zone

Jet Grouting Zone

Soft Soil

Reinforced soil wall

Ex.5 RSW with Deep Mixing and Grouting

NEXT

Reinforced Embankment (RE)Combined with Other Method

Ex.6 RE with PLPS and DrainagePLPS and DrainageEx.7 RE with Impact AbsorbersImpact Absorbers

NEXT

Ex.6 RE with PLPS + Drainage

From Mr. Y.Yokota (Maeda-Kosen Co. Ltd)

Scale : 40m in height, Fill: cohesive soils

Ex.6 RE with PLPS + Drainage

NEXT

Ex.7 RE with Impact Absorbers

Impact Transmission Bags

Sandy SoilGeogrid

Impact Catch Bags

Protect Matt

From Mr. Y.Yokota (Maeda-Kosen Co. Ltd)

Ex.7 RE with Impact Absorbers

NEXT

Nailing Combined with Other Method

Ex.8 Nailing with Deep MixingDeep MixingEx.9 Nailing with Fiber Reinforced SoilFiber Reinforced SoilEx.10 Nailing with Ring ReinforcementRing Reinforcement

NEXT

DAGSIMφ60㎜

Deep Mixing

Ex.8 Nailing with Deep Mixing

From Mr. Y.Otani (Hirose Co. Ltd)

Ex.8 Nailing with Deep Mixing

NEXT

Ex.9 Nailing with Cement & Fiber Mixing

Deteriorated shotcrete

Void filling

Repeated grouting type anchor

Propylite

( L=3.0m )

From Dr. H.Wada (Raito Kogyo Co. Ltd)

In the middle of constructionBe

fore

con

stru

ctio

nAfter construction

Ex.9 Nailing with Cement & Fiber Mixing

NEXT

Ex.10 Nailing with Ring Reinforcement

From Mr. K.Ogata (Research Institute of Japan Highway Public Co.)

pierStep. 1

Step. 2 Step. 3

Step. 4

Ex.10 Nailing with Ring Reinforcement

NEXT

Reinforced Foundation (RF) Combined with Other Method

Ex.11 RF with PilesPilesEx.12 RF with Deep Mixing

NEXT

Ex.11 RF with Piles

From Mr. T.Konami (Okasan Livic Co. Ltd) Reference/ Jones, Lawson and Ayres(1990): Geotextile reinforced piled embankments, Geotextile, Geomembranes and related products, Den Hoedt (ed.), Balkema, Rotterdam, pp.155-160.

Pile

Sand

SoftClay

Fill Material

Strip type geosynthetics

Ex.11 RF with Piles

NEXT

1.2m

2.0m10.25m

5.5m

2.5m

Soft Clay

Geogrid W = 8m

3.7m5.

0m

6.1m

Ex.12 RF with Deep Mixing

From Dr. T.Hirai (Mitsui Chemicals Industrial Products Co. Ltd.)

Ex.12 RF with Deep Mixing

NEXT

Combination method & ICG 2002

NEXT

Several related papers are included in the conference proceedings.

Some related sessions will be organized.

-- Reinforced Embankment on piles

(chaired by Prof. Jones and Prof. Lawson)

and so on.

SUMMARY

• Earth reinforcement combined with the other method was focused, and 12 case histories were introduced.

• The introduced technique has new ability, however combined techniques are very traditional each other.