Three Dimensional Numerical Simulations of Residential ... · Three Dimensional Numerical Simulations of Residential Buildings on ... Coupled consolidation theory for saturated and

Three Dimensional Numerical Simulations ofThree Dimensional Numerical Simulations ofResidential Buildings on Expansive SoilsResidential Buildings on Expansive Soils

Department of Civil Engineering Department of Civil Engineering

Texas A&M UniversityTexas A&M University

ByBy

Robert L. Lytton, Xiong Zhang and Rifat BulutRobert L. Lytton, Xiong Zhang and Rifat Bulut

OUTLINEOUTLINE

• INTRODUCTION

• MODELS NEEDED FOR SIMULATION

• LABORATORY TESTS

• VERIFICATION OF THE PROPOSED METHOD

• NUMERICAL SIMULATIONS OF RESIDENTIAL

BUILDINGS ON EXPANSIVE SOILS

• CONCLUSIONS

FACTORS INFLUENCING THE VOLUME OF FACTORS INFLUENCING THE VOLUME OF EXPANSIVE SOILS EXPANSIVE SOILS

WATER

MECHANICAL STRESS MATRIC SUCTION

TYPICAL DAMAGE CAUSED BY EXPANSIVE SOILSTYPICAL DAMAGE CAUSED BY EXPANSIVE SOILS

SUMMERSUMMER WINTERWINTER

swellswell

No change

* MODIFIED FROM WRAY (1995)

DAMAGE MODES FOR SLAB ON EXPANSIVE SOILSDAMAGE MODES FOR SLAB ON EXPANSIVE SOILS

∆

∆

ym

ym

em

em

Edge Moisture Distance

Perimeter Load

Perimeter Load

Uniform Load

Perimeter Load

Perimeter Load

Uniform Load

Slab Length

Slab Length

Initial Ground Surface

Initial Ground Surface

(a) Center lift (or Edge drop) case

(b) Edge lift (or Center drop) case

Ground Surface If Slab Has No Weight

Ground Surface If Slab Has No Weight

SIGNIFICANCE OF THE RESEARCHSIGNIFICANCE OF THE RESEARCH

1. JONES AND HOLTZ (1973): $2.2 BILLION/YEAR

2. KROHN AND SLOSSON (1980): $7.0 BILLION/YEAR

3. JONES AND JONES (1987): $9.0 BILLION/YEAR---MORE

THAN TWICE THE COMBINED DAMAGE FROM

EARTHQUAKE, FLOODS, TORNADOS AND HURRICANES

4. WRAY (1989): 8,470 RESIDENTIAL FOUNDATION

FAILURES IN ONLY ONE YEAR IN DALLAS COUNTY,

TEXAS, 98% OF WHICH OCCURRED IN EXPANSIVE

SOILS

MODELS NEEDED FOR THE SIMULATIONSMODELS NEEDED FOR THE SIMULATIONS

∆

∆

y m

y m

e m

e m

E d g e M o i s t u r eD i s t a n c e

P e r i m e t e rL o a d

P e r i m e t e r L o a d

U n i f o r m L o a d



U n i f o r m L o a d

S l a b L e n g t h

S l a b L e n g t h

I n i t i a l G r o u n d S u r f a c e

I n i t i a l G r o u n d S u r f a c e

( a ) C e n t e r l i f t ( o r E d g e d r o p ) c a s e

( b ) E d g e l i f t ( o r C e n t e r d r o p ) c a s e

4. Shell elements for walls 3. Soil-structure interaction 2. Evaporation & transpiration

1. Coupled consolidation theory for saturated and unsaturated soils

5. Damages in the walls

MODELS NEEDED FOR THE SIMULATIONSMODELS NEEDED FOR THE SIMULATIONS

• COUPLED HYDRO-MECHANICAL STRESS ANALYSIS

-----VOLUME CHANGE OF EXPANSIVE SOILS

• ESTIMATION OF EVAPOTRANSPIRATION AND INFILTRATION

-----INFLUENCE OF WEATHER AND VEGETATION (WATERING)

• SOIL-STRUCTURE INTERACTION

-------SHEAR, SLIP AND SEPARATION BETWEEN SOIL AND SLAB

• SIMULATION OF SLABS AND WALLS

-------MOMENTS AND STRESSES IN THE WALL AND SLAB

• CRACKING MODEL

--------DAMAGES TO THE STRUCTURE

GOVERNING DIFFERENTIAL EQUATIONSGOVERNING DIFFERENTIAL EQUATIONS

( ) ( ) 01 2

( ) ( ) 01 2

( ) ( ) 01 2

( 1)

yxx a zx a w

xy y a zy a w

yzxz z a a w

w w w

u u uE Xx y z x

u u uE Yx y z y

u u uE Zx y z y

u u u dk k kx x y y z z dt

τσ τ αν

τ σ τ αν

ττ σ αν

θ

∂∂ − ∂ ∂ −+ + − + =

∂ ∂ ∂ − ∂

∂ ∂ − ∂ ∂ −+ + − + =

∂ ∂ ∂ − ∂

∂∂ ∂ − ∂ −+ + − + =

∂ ∂ ∂ − ∂

⎡ ⎤∂ ∂ ∂∂ ∂ ∂⎡ ⎤ ⎡ ⎤+ + + =⎢ ⎥⎢ ⎥ ⎢ ⎥∂ ∂ ∂ ∂ ∂ ∂⎣ ⎦ ⎣ ⎦⎣ ⎦

1 2

1 2

MATERIAL PARAMETERS NEEDED: E, , , , an

( ) ( )

d

K

a w w wm

w

au w

w

u ad u d u u

m

dm m

dd t dtd

m

tσθ

ν

θ

α

σ−=+

=− −

+

LABORATORY TESTS NEEDED (I)

METHOD PROPOSED BY XIONG ZHANGMETHOD PROPOSED BY XIONG ZHANG

•• ONE DIMENSIONAL CONSOLIDATION TESTONE DIMENSIONAL CONSOLIDATION TEST

•• FREE SWELLFREE SWELL--SHRINK TEST SHRINK TEST

•• SUCTION TESTS SUCTION TESTS

(PRESSURE PLATE & SALT CONCENTRATION TESTS)(PRESSURE PLATE & SALT CONCENTRATION TESTS)

•• SPECIFIC GRAVITY TESTSPECIFIC GRAVITY TEST

CONSTITUTE SURFACES OF UNSATURATED SOILS

S vs. (σ m

-u a) Curve

S vs. (ua-uw) Curve

e vs. (ua-uw) Curve

e vs. (

σ m-u a)

Curve

w vs. (σ m

-u a) Curve

w vs. (ua-uw) Curve

LABORATORY TESTS NEEDED (II)

METHOD PROPOSED BY PTI MANUALMETHOD PROPOSED BY PTI MANUAL

•• ATTERBERG LIMITSATTERBERG LIMITS

LIQUID LIMITLIQUID LIMIT

PLASTIC LIMITPLASTIC LIMIT

•• HYDROMETER TEST HYDROMETER TEST

%%--No.200No.200

%%--2 MICRONS2 MICRONS

VOID RATIO CONSTITUTIVE SURFACEVOID RATIO CONSTITUTIVE SURFACEOF A SOIL AT ARLINGTON, TEXASOF A SOIL AT ARLINGTON, TEXAS

00.6

1.21.8

2.43

0

1.2

2.4

3.6

4.8

60.000.100.20

0.30

0.40

0.50

0.60

0.70

Void Ratio e

Mechanical Stress

log 10 ( σ m-u a ) (kPa)

Matric Suctionlog 10 ( u a -u w ) (kPa)

0.60-0.70

0.50-0.60

0.40-0.50

0.30-0.40

0.20-0.30

0.10-0.20

0.00-0.10

0.3870.492 0.456ln 1 3.6240.422ln -1 +2.640-0.299( 0.195)

( ) ( )MATHMATICAL EXPRESSION: 1

1010

v a a w

ee

u u uσ⎛ ⎞ ⎛ ⎞⎛ ⎞ ⎛ ⎞− +⎜ ⎟ ⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟− ⎝ ⎠⎝ ⎠⎝ ⎠⎝ ⎠

− −+ =

WATER CONTENT CONSTITUTIVE SURFACE WATER CONTENT CONSTITUTIVE SURFACE OF A SOIL AT ARLINGTON, TEXASOF A SOIL AT ARLINGTON, TEXAS

00.6

1.21.8

2.43

0

1.2

2.4

3.6

4.8

60.00

0.05

0.10

0.15

0.20

0.25

0.30

Water Content w

Mechanical Stress log 10 ( σ m-u a )

(kPa)


0.25-0.30

0.20-0.25

0.15-0.20

0.10-0.15

0.05-0.10

0.00-0.05

0.186 0.2860.422ln -1 +2.640 0.672ln -1 +4.386( 0.0737) ( 0.0263)

MATHEMATICAL EXPRESSION: 1

10 10

v a a w

w w

u u uσ⎛ ⎞ ⎛ ⎞⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟− +⎝ ⎠ ⎝ ⎠⎝ ⎠ ⎝ ⎠

− −+ =

DEGREE OF SATURATION CONSTITUTIVE DEGREE OF SATURATION CONSTITUTIVE SURFACE OF A SOIL AT ARLINGTON, TEXASSURFACE OF A SOIL AT ARLINGTON, TEXAS

00.6

1.21.8

2.43

0

1.2

2.4

3.6

4.8

6

0.00

0.20

0.40

0.60

0.80

1.00

Degree of SaturationS

Mechanical Stress log 10 ( σ m-u a )

(kPa)


0.80-1.000.60-0.800.40-0.600.20-0.400.00-0.20

MATERIAL PARAMETERS (I)YOUNG’S MODULUS SURFACE *

0 0.6 1.2 1.82.4 3

0

1.8

3.6

5.4

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

YOUNG’S MODULUS

(kPa)

Mechanical Stress (σm-ua) log(kPa)

Mat

ric S

uctio

n (u

a-u w

) log

(kPa

)

5.00E+00-6.00E+00

4.00E+00-5.00E+00

3.00E+00-4.00E+00

2.00E+00-3.00E+00

1

Young's Modulus:3(1 2 ) sE

mµ−

=

* RELATED TO THE MEAN PRINCIPAL STRESS COMPRESSION INDEX γσ IN THE PTI MANUAL

MATERIAL PARAMETERS (II)COEFFICIENT OF EXPANSION SURFACE *

00.6

1.21.8

2.43

0

1.2

2.4

3.6

4.8 6

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

Expansion

Coefficient α

(1/kPa)

Mechanica

l Stre

ss (σ m

-u a)

Matric Suction (ua-uw)

-5.00E+00--4.00E+00

-6.00E+00--5.00E+00

-7.00E+00--6.00E+00

-8.00E+00--7.00E+00

-9.00E+00--8.00E+00

-1.00E+01--9.00E+00

2

Coefficient of Expansi

on:

3

smα =

* RELATED TO THE SUCTION COMPRESSION INDEX γh IN THE PTI MANUAL

MATERIAL PARAMETERS (III)SPECIFIC WATER CAPACITY SURFACE *

00.6

1.21.8

2.43

0

1.2

2.4

3.6

4.8

61.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

Cw

Mec

hanic

al Str

ess (σ

m-u a)

log( k

Pa)

Matric Suction (ua-uw) log(kPa)

-4.00E+00--3.00E+00

-5.00E+00--4.00E+00

-6.00E+00--5.00E+00

-7.00E+00--6.00E+00

-8.00E+00--7.00E+00

2

2

Specific W ater Capacity: ( )

( )

d w a w

w

wu w

w

a

d

d m d u C d u u

m

u

Cρ

θ ρ −−

=

= =

* RELATED TO S VALUE IN THE PTI MANUAL

MATERIAL PARAMETERS (IV)WATER GENERATION PARAMETER SURFACE*

0

0.9

1.8

2.7

0

1.2

2.4

3.6

4.8

61.00E-09

1.00E-08

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

-M1w

Mec

hanic

al Str

ess

Matric suction

-4.00E+00--3.00E+00

-5.00E+00--4.00E+00

-6.00E+00--5.00E+00

-7.00E+00--6.00E+00

-8.00E+00--7.00E+00

-9.00E+00--8.00E+00

* THE ABILITY OF THE MEAN MECHANICAL STRESS TO SQUEEZE WATER OF THE SOIL

MATERIAL PARAMETERS (V)COEFFICIENT OF PERMEABILITY SURFACE*

00.6

1.21.8

2.43

01.2

2.43.6

4.86

1.E-16

1.E-15

1.E-14

1.E-13

1.E-12

1.E-11

1.E-10

1.E-09

Permeability (m/s)

Mehcanical Stresslog (kPa) Matric Suction log (kPa)

-10--9-11--10-12--11-13--12-14--13-15--14-16--15

* RELATED TO THE DIFFUSION COEFFICIENT α IN THE PTI MANUAL

MEASURING DIFFUSION COEFFICIENTSAMPLE PARAPRATION & EQUIPMENT SETUP

BACKCALCULATING DIFFUSION COEFFICIENT

DIFFUSION COEFFICIENT FOR BHC 2

3

3.5

4

4.5

5

5.5

6

100 1000 10000 100000

Drying Time (minutes)

Suct

ion

(pF)

L = 15.93 cm

x = 14.23cm

ua = 5.91 pF

u0 = 5.91 pF

he = 0.54 cm-1

α = 0.001cm2/min

MATERIAL PARAMETERS (VI)DETERMINATION OF DIFFUSION COEFFICIENT

0

2

4

6

8

10

12

140.1 1 10 100

Diffusion Coefficient, α (10-5 cm2/s)

0

2

4

6

8

10

12

142.5 3 3.5 4 4.5 5

Dep

th (f

t)

Initial Suction (pF)

SUCTION PROFILE(Fort Worth IH 820)

MEASURED DIFFUSION COEFFICIENT

2

2

9000.408 ( ) ( ) 2730 ( 1 0 .34 )

asR G u e en TE T uγ

γ∆ − + −+= ∆ + +

H

Evapotranspiration

FACTORS INFLUENCING EVAPOTRANSPIRATIONFACTORS INFLUENCING EVAPOTRANSPIRATION

EVAPOTRANSPIRATION PROCESSEVAPOTRANSPIRATION PROCESS

• TWO PROCESSES

1. VAPORIZATION OF WATER

2. VAPOR REMOVAL

• SEVEN INFLUENCING FACTORS1. SOLAR RADIATION

2. RELATIVE HUMIDITY

3. WIND SPEED

4. RAINFALL

5. VEGETATION TYPES

6. SOIL PERMEABILITY

7. SOIL WATER CONTENT

ESTIMATION OF EVAPOTRANSPIRATIONESTIMATION OF EVAPOTRANSPIRATION

• CURRENTAVAILABLE METHODS

1).THE TEMPERATURE METHODS

(THORNTHWAITE, MCCLOUD, MBC)

2).THE RADIATION METHODS

(MMBC, HARG, TURC)

3).THE COMBINATION METHODS

( FAO 56 PM, ASCE2000 PM)

• THE FAO 56 PENMAN-MONTEITH METHOD

1). AN INTERNATIONAL STANDARD, GLOBALLY VALID

2). CAN USE DAILY OR HOURLY WEATHER DATA

3). METHOD FOR ESTIMATING MISSING DATA AVAILABLE

POTENTIAL VS. ACTUAL EVAPOTRANSPIRATIONPOTENTIAL VS. ACTUAL EVAPOTRANSPIRATION

0

0.2

0.4

0.6

0.8

1

1.2

1 10 100 1000 10000 100000 1000000

Matric Suction (kPa)

Wat

er st

ress

coe

ffici

ent K

s

0.00

0.20

0.40

0.60

0.80

1.00

0.0 RAW TAW

θFC θt θWP

RAW

TAW

Dr (mm)

θ : volumetric water content

Ks

( ) ( )( )

( )

2

02

0

0

0

The FAO 56 Penman-Montieth Method

9000.408273

1 0.34

ETc = Kc ET

ETc adjusted = Ks Kc ET

ET =reference evapotranspiration (mm/day)ETc=crop evapotranspiration (mm/day)ETc adj=a

n s aR G u e eTET

u

γ

γ

∆ − + −+=

∆ + +

× ×

ctual evapotranspiration (mm/day)Kc=crop coefficient (dimensionless)Ks=water stress coefficient(dimensionless)

SOIL WATER BALANCESOIL WATER BALANCE

TAW=the total available soil water in the root zone (mm)RAW= the readily available soil water in the root zone (mm)

FOUNDATION MODELS (I)FOUNDATION MODELS (I)

• WINKLER FOUNDATION MODELASSUMPTION: THE FOUNDATION IS CONSIDERED AS A NUMBER OF CLOSELY SPACED, VERTICAL, INDEPENDENT, LINEAR ELASTIC SPRINGS PROVIDING VERTICAL REACTION ONLY.DRAWBACK: SHEAR DEFORMATION CAN NOT BE SIMULATED.

ELASTIC HALF SPACE FOUNDATIONASSUMPTION: THE SOIL IS CONSIDERED AS AN ELASTIC, ISOTROPIC, AND HOMOGENEOUS SEMI-INFINITE CONTINUUM WITH E AND vDRAWBACKS: (1). SEPARATION AND FRICTION BETWEEN THE SLAB AND THE FOUNDATION ARE NOT EASY TO SIMULATE.

(2) NOT EASY TO DETERMINE E AND vFOR MULTILAYERS

WINKLER FOUNDATION

ELASTIC HALF SPACE

1. NORMAL BEHAVIOR : “HARD CONTACT”P=0 for h>0 (OPEN),AND h=0 for P>0 (CLOSED)

2. TANGENTIAL BEHAVIOR: COULOMB FRICTION MODEL THE EQUIVALENT FRICTIONAL STRESS

τeq=(τx2+τy

2)1/2

THE CRITICAL STRESS *τcritical=µ P

WHERE, P=CONTACT PRESSUREIF , NO RELATIVE MOTION

* ALTERNATIVELY, τcritical =(σ-ua)tgφ’+(ua-uw)tgφ’’+C

SOIL STRUCTURE INTERACTION (II)SOIL STRUCTURE INTERACTION (II)--CONTACT ELEMENTCONTACT ELEMENT

x, u

y, v

e o

m

j

r

i l/2l/2

eq criticalτ τ≤

Slab

Soil

FRICTION COEFFICIENTS AFTER SLIPPINGFRICTION COEFFICIENTS AFTER SLIPPING

( ) 4

IF , THEN

=the kinetic friction coefficient =the static friction coeffic

0.1 0

ient=a user-defined decay coefficient, and

= the slip

.

ra

4c eq eqdk s k

k

s

c

eq crit

eq

ical

e e

d

γ γµ µ µ µµµ

τ τ

γ

• •− −

•

= − − = +

>

te (see Oden, J. T. and J. A. C. Martins, 1985).

KIRCHHOFFKIRCHHOFF PLATE THEORY (PURE BENDING)PLATE THEORY (PURE BENDING)

• STRAIGHT LINES PERPENDICULAR TO THE MID-SURFACE BEFORE

DEFORMATION, REMAIN STRAIGHT AFTER DEFORMATION.

• THE TRANSVERSE NORMALS DO NOT EXPERIENCE ELONGATION.

• THE TRANSVERSE NORMALS ROTATE SUCH THAT THEY REMAIN

PERPENDICULAR TO THE MID-SURFACE AFTER DEFORMATION.

y

b a

h/2

h

z

x

O

0 0 0

0, 0, 0

0, 0, ( , )

z yz z

z z z

w w v u wz y z z x

u v w w x y

ε γ ε

= = =

∂ ∂ ∂ ∂ ∂= = = + = = + =

∂ ∂ ∂ ∂ ∂= = =

MINDLIN PLATE THEORYMINDLIN PLATE THEORY

• STRAIGHT LINES PERPENDICULAR TO THE MID-SURFACE BEFORE

DEFORMATION, REMAIN STRAIGHT AFTER DEFORMATION.

• THE TRANSVERSE NORMALS DO NOT EXPERIENCE ELONGATION.

• THE TRANSVERSE NORMALS ROTATE SUCH THAT THEY REMAIN

PERPENDICULAR TO THE MID-SURFACE AFTER DEFORMATION.

y

b a

h/2

h

z

x

O

0, 0, 0z yz xzw w v u wz y z z x

ε γ γ∂ ∂ ∂ ∂ ∂= = = + ≠ = + ≠

∂ ∂ ∂ ∂ ∂

0 0 00, 0, ( , )z z zu v w w x y= = == = =

• THE TRANSVERSE NORMALS REMAIN STRAIGHT AFTER DEFORMATION AND THE LENGTH REMAIN UNCHANGED.

• ADVANTAGES:

1. 5 DEGREES OF FREEDOM, CAN SIMULATE PLATE BENDING WITH

SHEAR DEFORMATION AND PLATE STRETCHING

2. NEGLECT THE STRAIN ENERGY CAUSED BY σZ, MORE ACCURATE.

3. THE MID-SURFACE CAN BE ARBITRARY

4. SHEAR LOCKING CAN BE SOLVED TO ANALYZE THIN SHELL.

GENERAL SHELL ELEMENTGENERAL SHELL ELEMENT

ξ

ζ η

1

2

3

4

5

6

78

SOILSOIL--STRUCTURE MOISTURE VARIATION SIMULATIONSSTRUCTURE MOISTURE VARIATION SIMULATIONS

( )

Concrete:0

3 Contact Element :

0=0

v T

A B

Bd dTBd

kq k T T

σ

αε ε ε σ α

σ

== + = +

=

=

= −

Soil

FLUX BOUNDARY CONDITION:

AD and BC: qx=0

AB: ua-uw=10kPa

DG and CH: qy=ETP-Rainfall (Bare soil) or

S=(ETP-Rainfall )/dgrass (Grass) or

S=ETP/dtree (Tree)

GH: qy=0 *

MECHANICAL BOUNDARY CONDITION:AD and BC: u=0AB : u=v=0 DG and CH: None Typical Environment around a HouseGH : (Contact element)

* It is realized by thermal behavior of contact element

BOUNDARY CONDITIONSBOUNDARY CONDITIONS

MATERIAL PROPERTIES FOR STRUCTUREMATERIAL PROPERTIES FOR STRUCTURE

Mechanical Behavior:Linearly elastic concrete

Thermal Behavior:

No Expansion

No Heat Generation

Boundary Condition:

Zero Initial Condition

Load:

Gravity

VERIFICATIONVERIFICATION--PLAN VIEW OF THE SITEPLAN VIEW OF THE SITE

Boring date

# 1 : 06/24/99# 2 : 07/13/99# 3 : 10/25/99 # 4 : 02/11/00 # 5 : 05/11/00 # 6 : 08/11/00 # 7 : 11/17/00# 8 : 03/13/01# 9 : 07/15/01

BM1

BM2

W2 RF2

W1

RF13m

2m 2m

0.6m

Boringlocation

Boringorder

..0.61m

0.67m

1 - deep.

0.67m

B/W1/7 redrill - deep

0.67m

.

...

. ..1

2 34

5 6

7

.

.

8

9

.

...

. ..1

2 34

5 6

7

.

.

8

9

.

...

. ..1

2 34

5 6

7

.

.

8

9

.

...

. ..1

2 34

5 6

7

.

.

8

9

NorthSite in Arlington,Texas

Daily MeanTemperature of Arlington, Texas

0

20

40

60

80

100

08/0

1/99

10/0

1/99

12/0

1/99

02/0

1/00

04/0

1/00

06/0

1/00

08/0

1/00

10/0

1/00

12/0

1/00

02/0

1/01

04/0

1/01

06/0

1/01

08/0

1/01

10/0

1/01

(oF)

Daily Mean Relative Humidity of Arlington, Texas

0

20

40

60

80

100

08/0

1/99

10/0

1/99

12/0

1/99

02/0

1/00

04/0

1/00

06/0

1/00

08/0

1/00

10/0

1/00

12/0

1/00

02/0

1/01

04/0

1/01

06/0

1/01

08/0

1/01

10/0

1/01

(%)

Daily Mean Wind Speed of Arlington, Texas

0

2

4

6

8

10

08/0

1/99

10/0

1/99

12/0

1/99

02/0

1/00

04/0

1/00

06/0

1/00

08/0

1/00

10/0

1/00

12/0

1/00

02/0

1/01

04/0

1/01

06/0

1/01

08/0

1/01

10/0

1/01

(m/s

)

Daily Acumulative Rainfall of Arlington, Texas

0

20

40

60

80

100

08/0

1/99

10/0

1/99

12/0

1/99

02/0

1/00

04/0

1/00

06/0

1/00

08/0

1/00

10/0

1/00

12/0

1/00

02/0

1/01

04/0

1/01

06/0

1/01

08/0

1/01

10/0

1/01

(mm

/day

)

ENVIRONMENTAL FACTORS AT ARLINGTON

FOOTING MOVEMENT OVER TWO YEARSFOOTING MOVEMENT OVER TWO YEARS

08/1

/199

9

09/1

/199

9

10/1

/199

9

11/1

/199

9

12/1

/199

9

01/1

/200

0

02/1

/200

0

03/1

/200

0

04/1

/200

0

05/1

/200

0

06/1

/200

0

07/1

/200

0

08/1

/200

0

09/1

/200

0

10/1

/200

0

11/1

/200

0

12/1

/200

0

01/1

/200

1

02/1

/200

1

03/1

/200

1

04/1

/200

1

05/1

/200

1

06/1

/200

1

07/1

/200

1

08/1

/200

1

09/1

/200

1

40

30

20

10

0

-10

-20

-30

-40

-50

-60

Dis

plac

emen

t, m

m

Date

RF1RF2

W1W2

sum

mer

fall

win

ter

spri

ng

sum

mer

fall

win

ter

spri

ng

sum

mer

Weather of Arlington,Texas

-200

20406080

100

08/0

1/99

09/3

0/99

11/2

9/99

01/2

8/00

03/2

8/00

05/2

7/00

07/2

6/00

09/2

4/00

11/2

3/00

01/2

2/01

03/2

3/01

05/2

2/01

07/2

1/01

09/1

9/01

11/1

8/01

ET a

nd R

ainf

all (

mm Rainfall ETP

Comparison Between Predicted and Measured Movements

-50

-40

-30

-20

-10

0

10

20

30

40

08/0

1/99

09/3

0/99

11/2

9/99

01/2

8/00

03/2

8/00

05/2

7/00

07/2

6/00

09/2

4/00

11/2

3/00

01/2

2/01

03/2

3/01

05/2

2/01

07/2

1/01

09/1

9/01

11/1

8/01

Mov

emen

ts (m

m)

RF1 Movements RF2 MovementsW1 Movements W2 MovementsPredicted movements

RESIDENTIAL BUILDING ON EXPANSIVE SOILSRESIDENTIAL BUILDING ON EXPANSIVE SOILSAN EXAMPLE FOR CENTER LIFT CASEAN EXAMPLE FOR CENTER LIFT CASE

16 m 16 m

8 m

8 m

DETERMINATION OF SLAB DIMENSIONDETERMINATION OF SLAB DIMENSION

WALLS:EXTERIOR: BRICK INTERIOR: STUD AND DRYWALL

SLAB: FROM PTI MANUAL APPENDIX A.4 FOR AUSTIN, TEXAS;STIFFENING BEAMS: 12”X34” @15ft SPACING

EQUIVALENT SLAB WITH UNIFORM THICKNESS:400mm (SAME MOMENT OF INERTIA AS ABOVE)

CENTER LIFT CASECENTER LIFT CASE

100m

m.

1600

0mm

.

8000

mm

.80

00m

m.

6000

mm

.

3000

mm

.

400m

m.

914m

m.

4800

0mm

16000mm.8000mm.8000mm.

1600

0mm

.

8000

mm

.80

00m

m.

6000

mm

.

6000mm.3000

mm

.

5000mm.

FLOOR PLAN OF THE BUILDINGFLOOR PLAN OF THE BUILDING

DEFORMATION OF THE SOIL AND THE SLAB DEFORMATION OF THE SOIL AND THE SLAB

* THIS PICTURE IS TAKEN FROM A MOVIE. A COMPLETE COPY OF THE MOVIE IS AVAILABLE FROM R. L. Lytton ( [email protected] )

DEFLECTION AND SEPERATION AT THE EDGE DEFLECTION AND SEPERATION AT THE EDGE OF THE SLABOF THE SLAB

0.040.060.080.100.120.140.16

-12 -8 -4 0 4 8 12

Distance Frome the Center of the House (m)

Disp

lace

men

t (m

)

Ground surface

Upper envelope

Lower envelope

Shell


SEPARATION BETWEEN THE SLAB AND SEPARATION BETWEEN THE SLAB AND THE GROUND SOILS THE GROUND SOILS


CONTACT PRESSURE BETWEEN THE SLAB AND CONTACT PRESSURE BETWEEN THE SLAB AND THE GROUND SOILSTHE GROUND SOILS


SHEAR FORCE ALONG X DIRECTIONSHEAR FORCE ALONG X DIRECTION


SHEAR FORCE ALONG Y DIRECTIONSHEAR FORCE ALONG Y DIRECTION


RELATIVE SLIP ALONG X DIRECTION RELATIVE SLIP ALONG X DIRECTION


RELATIVE SLIP ALONG Y DIRECTION RELATIVE SLIP ALONG Y DIRECTION

* THIS PICTURE IS TAKEN FROM A MOVIE. A COMPLETE COPY OF THE MOVIE IS AVAILABLE FORM R. L. Lytton ( [email protected] )

MATRIC SUCTION IN THE SOILMATRIC SUCTION IN THE SOIL


VON MISES STRESSES IN THE STRUCTRE VON MISES STRESSES IN THE STRUCTRE


RESIDENCE USED IN THE SIMULATIONRESIDENCE USED IN THE SIMULATIONEDGE LIFT CASEEDGE LIFT CASE

Tree Root ZoneDtree=2.0 m

slabwall

slab

6 m 6 m2.0 m

16 m 16 m

8 m

8 m

0.4 m

16 m

8 m

16 m

8 m

3.5 m

wall

Tree

Grass Root ZoneDgrass=0.47m

1 st Soil Layer

2nd Soil Layer

48 m 48 m

6.0 m

EDGE LIFT CASEEDGE LIFT CASE

100m

m.

1600

0mm

.

8000

mm

.80

00m

m.

6000

mm

.

5000

mm

.

400m

m.

914m

m.

4800

0mm

FLOOR PLAN OF THE BUILDINGFLOOR PLAN OF THE BUILDING

1600

0mm

.

8000

mm

.80

00m

m.

6000

mm

.

5000

mm

.

DEFORMATION OF THE SOIL AND THE SLAB DEFORMATION OF THE SOIL AND THE SLAB


0.040.060.080.100.120.140.16

-12 -8 -4 0 4 8 12

Distance Frome the Center of the House (m)

Disp

lace

men

t (m

)

Ground surface

Upper envelope

Lower envelope

Shell

DEFLECTION AND SEPERATION AT THE EDGE DEFLECTION AND SEPERATION AT THE EDGE OF THE SLABOF THE SLAB


SEPARATION BETWEEN THE SLAB AND SEPARATION BETWEEN THE SLAB AND THE GROUND SOILS THE GROUND SOILS


CONTACT PRESSURE BETWEEN THE SLAB AND CONTACT PRESSURE BETWEEN THE SLAB AND THE GROUND SOILSTHE GROUND SOILS


SHEAR FORCE ALONG X DIRECTIONSHEAR FORCE ALONG X DIRECTION


SHEAR FORCE ALONG Y DIRECTIONSHEAR FORCE ALONG Y DIRECTION


RELATIVE SLIP ALONG X DIRECTION RELATIVE SLIP ALONG X DIRECTION


RELATIVE SLIP ALONG Y DIRECTION RELATIVE SLIP ALONG Y DIRECTION


MATRIC SUCTION IN THE SOILMATRIC SUCTION IN THE SOIL


VON MISES STRESSES IN THE STRUCTRE VON MISES STRESSES IN THE STRUCTRE


CONCLUSIONSCONCLUSIONS

READILY AVAILABLE HISTORIC WEATHER DATA SUCH READILY AVAILABLE HISTORIC WEATHER DATA SUCH AS DAILY TEMPERATURE, SOLAR RADIATION, AS DAILY TEMPERATURE, SOLAR RADIATION, RELATIVE HUMIDITY, WIND SPEED AND RAINFALL AS RELATIVE HUMIDITY, WIND SPEED AND RAINFALL AS INPUT;INPUT;

DIFFERENT SIMULATION METHODS FOR DIFFERENT DIFFERENT SIMULATION METHODS FOR DIFFERENT BOUNDARY CONDITIONS SUCH AS TREE, GRASS, AND BOUNDARY CONDITIONS SUCH AS TREE, GRASS, AND BARE SOILS;BARE SOILS;

THE COUPLED HYDROTHE COUPLED HYDRO--MECHANICAL STRESS MECHANICAL STRESS ANALYSIS ARE USED TO SIMULATE THE VOLUME ANALYSIS ARE USED TO SIMULATE THE VOLUME CHANGE OF EXPANSIVE SOILS;CHANGE OF EXPANSIVE SOILS;

CONCLUSIONSCONCLUSIONS

““PSEUDO MOISTURE VARIATION SIMULATIONPSEUDO MOISTURE VARIATION SIMULATION””

TECHNIQUE IS USED TO SIMULATE THE BEHAVIOR OF TECHNIQUE IS USED TO SIMULATE THE BEHAVIOR OF

SLAB AND GROUND SOILS IN ONE PROGRAMSLAB AND GROUND SOILS IN ONE PROGRAM

CONTACT (JOINTED) ELEMENTS ARE USED TO CONTACT (JOINTED) ELEMENTS ARE USED TO

SIMULATE THE SOILSIMULATE THE SOIL--STRUCTURE INTERACTION;STRUCTURE INTERACTION;

GENERAL SHELL ELEMENTS ARE USED TO ANALYZE GENERAL SHELL ELEMENTS ARE USED TO ANALYZE

THE STRUCTURE BEHAVIORS; THE STRUCTURE BEHAVIORS;

MOMENTMOMENT--CURVATURE CURVES FOR CONCRETE CROSS CURVATURE CURVES FOR CONCRETE CROSS

SECTIONS WITH BONDED AND UNBONDED SECTIONS WITH BONDED AND UNBONDED

REINFORCING IS PROPOSED TO SIMULATE DAMAGE TO REINFORCING IS PROPOSED TO SIMULATE DAMAGE TO

THE STRUCTURE.THE STRUCTURE.

COMMENTS/ QUESTIONSCOMMENTS/ QUESTIONS

………………THANK YOUTHANK YOU

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