1Slide

2

3/16/2014Civil

Work

–

Earthwork

&

Embankments

RailTEC@Illinois

High

Speed

Rail

Engineering

TC

Kao

Conrad

Ruppert,

Jr.

Rail

Transportation

&

Engineering

Center

(RailTEC)

Department

of

Civil

and

Environmental

Engineering

Slide

1

The

Scope

of

the

Earthworks

RailTEC@Illinois

The

ballast

and

the

hydraulically

bonded

layer

of

the

slab

track

are

part

of

the

TRACKWORK

and

not

included

in

the

earthwork

design.

The

EARTHWORKS

Include:????Embankment

(Fill)Cut

SectionRetaining

StructureDrainage

System

(Ditches,

Culverts,

etc.)

23/16/20142Slide

3RailTEC@IllinoisExamples

of

EarthworksSlide

4RailTEC@IllinoisExamples

of

Earthworks

3/16/2014Design

Requirements

RailTEC@IllinoisDrainage,

Drainage,

DrainageDerailment

ConsiderationSettlement

ControlRide

Comfort

Maintenance

Requirements

Slide

5

5

Design

Loads

RailTEC@Illinois

Trackworks

–

5

ton/m2

(49

kN/m2)

on

a

strip

3.5m

wide

and

infinitely

long.

Dynamic

Train

Loads

Seismic

Loads

Slide

6

6

33/16/20144Slide

7RailTEC@IllinoisEarthwork

Supporting

the

Track7Slide

8RailTEC@IllinoisGeneral

Earthwork

Terms3/16/20145Slide

9RailTEC@IllinoisBallastless

Track

EarthworksSlide

10RailTEC@IllinoisSpecific

Design

Considerations

(1)

Geological

&

Geotechnical

Investigation

/

Design–

Local

distribution

of

the

geological

and

structural

elements

of

the

area

(tectonics,

faults,

slope

failures,

pre‐historic

landslides,

potential

liquefaction,

etc.)–

Characteristics

of

nature,

status

and

behavior

of

the

materials

pertaining

to

the

project–

Hydrogeological

characteristics

of

the

different

intercepted

layers3/16/20146Slide

11RailTEC@IllinoisSpecific

Design

Considerations

(2)

Meteorological

Design–

provide

figures

and

statistics

for

use

in

defining

favorable

and

unfavorable

periods

for

carrying

out

the

work,

as

well

as

in

assessing

the

impact

of

climatic

variability

on

the

behavior

and

implementation

of

the

materials

Hydraulic

and

Drainage

Design–

Altitude

of

the

Higher

Water

Level

in

flooding

area–

Type

of

protection

to

install

along

earth

structure

in

order

to

avoid

erosion–

Definition

and

sizing

of

the

culverts

and

drainage

networkSlide

12RailTEC@IllinoisSpecific

Design

Considerations

(3)

Hydro‐geologic

Design–

Identify

the

impact

of

groundwater

on

the

project

and

its

implementation–

Determine

impact

of

the

project

on

groundwater

and

water

resources–

Determine

regulatory

requirements,

including

constraints

in

the

study

phase,

the

work

phase

and

permanent

dispositions

and

compensatory

solutionsPARTICLE

CLASSGRAIN

SIZE

(mm)Clay<

0.002Silt0.002

–0.06Sand0.06

‐2Gravel2

‐60Cobbles60

‐200Boulders>

200

3/16/2014

Geotechnical

Classification

of

Soil

RailTEC@Illinois

Mineral

Soils––––Particle

sizePlasticitySensitivity

to

WaterMineral

Content

Organic

Soils

Mixed

Soils

Slide

13

Geotechnical

Classification

of

Soil

RailTEC@Illinois

Slide

14

7

3/16/2014

Special

Characteristics

(1)

RailTEC@Illinois

Settlement

Control

?

Embankments

vulnerable

to

settlement

?

Could

cause

safety

or

ride

comfort

issuesBearing

capacity

of

embankment

fillElasticity

of

embankmentFrost

susceptibilityMulti‐layer

systemAnalyze

the

whole

system:

track,

track‐bed,

ballast/subballast,

subgrade

and

bedrock

Slide

15

15

Special

Characteristics

(2)

RailTEC@IllinoisResidual

settlementTransition

zonesErosion

protectionWider

shoulder

for

maintenance

activities

once

operations

begin

Pre‐consolidate

as

much

as

possible

Slide

16

16

8

3/16/2014The

Truth

is

?

RailTEC@IllinoisOften

missed

in

quality

controlConsidered

as

low

techMissing

construction

detailUnfavorable

construction

conditionsA

way

to

balance

the

excavation

soil

Slide

17

17

Sub‐Ballast

Layer

Function

RailTEC@Illinois

Intermediate

layer

between

the

ballast

and

the

subgrade

layers.

Ensures

better

distribution

of

loads

Protects

subgrade

layer

against

erosion

and

to

avoid

seepage

into

the

subgrade

layer

Prevents

penetration

of

fine

soil

material

into

the

track

bed,

especially

the

ballast

(WHY?)

Slide

18

18

910

3/16/2014

Sub‐Ballast

Layer

Specifications

RailTEC@Illinois

Well‐graded

crushed

rock

aggregate

Minimum

thickness

for

the

sub‐ballast

shall

be

0.20

m

and

0.50

m

for

the

bearing

base

layer.

Top

surface

shall

have

a

transverse

slope

of

no

less

than

4

%

Slide

19

19

Sub‐Ballast

Thickness

RailTEC@IllinoisThe

total

thickness

(ballast

layer

+

sub‐ballast

layer)

varies

according

to

the:Bearing

capacity

of

the

subgradeLevel

of

frost

protection

required.Type

of

sleeper

and

the

sleeper

spacingTraffic

characteristics

(tonnage

supported,

axle‐load

and

speed)

Slide

203/16/201411Slide

21RailTEC@IllinoisSubgrade

Layer

Consists

of

soil

that

has

been

brought

in(embankment)

or

natural

soil

or

rock

(cut)

Classification:–

QS0:

"Unsuitable"

soils

that

need

removal

orstabilization.–

QS1:

"Poor"

Soils

-

These

soils

may

be

accepted

"as

is",

however,

drainage

must

be

provided.

Soil

improvement

may

be

needed.–

QS2:

"Average"

Soils–

QS3:

"Good"

Soils21Slide

22RailTEC@IllinoisPrepared

Subgrade

Layer

Prepared

subgrade

layer

is

between

the

sub-ballast

and

the

subgrade

Minimize

the

deformation

of

the

earthwork

Prevent

water

that

has

passed

through

thesub-ballast

from

penetrating

into

theearthwork

below

Top

surface

of

prepared

subgrade

layer

shallhave

a

transverse

slope

of

no

less

than

4

%.22Soil

Classification

(Geotechnical

identification)Soil

Quality

Class0‐1:Loose

organic

soils0‐2:Fine

soils

(incorporating

more

than

15%

fines

),

swollen,

moist

and

therefore

not

compatible

(where

enhancement

by

treating

with

binders

is

not

possible

for

technical

or

economic

reasons)0‐3:

Thixotropic

soils

(quick

clay,

for

example)0‐4:

Soluble

materials

(soil

containing

rock

salt

or

gypsum)0‐5:

Polluting

materials

(industrial

waste,

for

example)0‐6:

Mixed

“mineral‐organic”

soilsQS01‐1:Soils

containing

more

than

40%

fines

1‐2:Rocks

highly

susceptible

to

weathering

for

example

:3chalk

with

d<1.7

t/mand

highly

friablemarlsweathered

schistsQS1Quality

ClassSubgrade

or

CutTrack

TypePrepared

SubgradeThicknessQS1Ballasted

Track0.50madded

materialQS2Ballasted

Track0.35madded

materialQS3Ballasted

Track0.30msame

material

as

subgradeQS1,

QS2,

QS3Slab

Track2.00madded

material3/16/201412Slide

23RailTEC@IllinoisThickness

Requirement

for

Prepared

Subgrade

Layer

23Slide

24RailTEC@IllinoisQuality

Class

of

Subgrade

Soil

Classification

(Geotechnical

identification)Soil

Quality

Class1‐3:Soils

comprising

15

to

40%

fines

1‐4:Rocks

moderately

susceptible

to

weatheringfor

example

:3

chalk

with

d<1.7

t/mand

slightly

friableschists1‐5:Soft

rock

(e.g.

dry

Deval6

and

LA

>

33)QS1

2‐1:Well

graded

soils

containing

5

to

15%

fines

2‐2:

Uniform

sands

containing

less

than

5%

fines

(CU6)2‐3:Rock

of

medium

hardness

(e.g.

6

dry

Deval9

and

33

LA

30)QS2

3‐1:

Well

graded

soils

containing

less

than

5%

fines3‐2:

Hard

rock

(e.g.

dry

Deval9

andLA

30)QS33/16/201413Slide

25RailTEC@IllinoisQuality

Class

of

SubgradeSlide

26RailTEC@IllinoisSuitability

of

Soils

for

Re‐Use

Maximize

use

of

materials

from

the

site

and

minimize

need

for

material

from

temporary

or

existing

quarries

and

deposits

outside

the

ROW.

Take

into

account

the

constraints

imposed

by

the

environment

of

the

project.

Minimize

earth

movement

transport

distances.

Substandard

materials

may

be

used

at

locations

where

they

will

not

impact

the

high‐speed

line

operation

in

case

of

slope

failure

or

weathering.3/16/201414Slide

27RailTEC@IllinoisSuitability

of

Soils

for

Re‐Use

Soils

which

cannot

be

re‐used

include

soils

0.1‐0.6,

1.1

(if

medium

or

high

plasticity)

and

1.2;

Soils

which

can

be

re‐used

in

certain

conditionssubject

to

moisture

content,

climatic

conditions,

height

of

embankment,

layer

of

low

quality

fill

protected

by

a

layer

of

higher

quality

material

soils:

1.1

(if

soil

has

a

low

plasticity),

1.3‐1.5,

2.1

and

2.2;

Soils

which

can

always

be

re‐used

2.3,

3.1

and

3.2.Slide

28RailTEC@IllinoisHydrological

Conditions

(Drainage)Good:

Top

of

the

subgrade

exists

above

groundwater

table

(the

highest

level

of

the

groundwater

table

is

more

than

1.50

m

below

the

top

of

the

sub‐ballast

layer

in

an

unfavorable

climatic

season);

Subgrade

is

free

of

harmful

transverse,

longitudinal,

or

vertical

natural

percolation;

Rainwater

is

properly

evacuated

from

the

top

of

subgrade

and

the

longitudinal

and

transverse

drainage

networks

are

operational.POOR

DRAINAGE

conditions

ARE

NOT

allowed

in

design!1530DrainagematerialHigh

water

levelSlide

30

3/16/2014

Drainage

Layer

under

Embankment

in

Wet

Location

RailTEC@IllinoisDrainagematerial

0.20

m

Cleaning

Slide

29

Drainage

Layer

under

Embankment

in

Flood

Plain

RailTEC@Illinois

0.50

m3/16/201416Slide

31RailTEC

@

IllinoisTransition

to

StructuresSlide

32RailTEC

@

IllinoisEmbankment

Over

Bo