Lab 4 soil

LEBANESE AMERICAN UNIVERSITYBYBLOS CAMPUS

SCHOOL OF ENGINEERING

DEPARTMENT OF CIVIL ENGINEERING

FALL 2012

CIE 445-SOIL MECHANICS LAB

Instructor: Hussein Annan

Specific Gravity and Relative DensityPREPARED BY:

Chadi Fawaz

Mazen Haidar

Moufid Said

Mustafa Saab

Jihad Milan

DUE DATE: 29 OCTOBER 2012

TABLE OF CONTENTS

Specific Gravity............................................................................................................................................................4

Equipment Needed......................................................................................................................................................4

Procedure....................................................................................................................................................................4

Minimum Dry Density..............................................................................................................................................4

Tube Method.......................................................................................................................................................4

Funnel Method.....................................................................................................................................................5

Maximum Dry Density..............................................................................................................................................5

Data Collected..............................................................................................................................................................6

Determination of Minimum Dry Unit Weight:.........................................................................................................6

Determination of MaximumDry Unit Weight:..........................................................................................................7

sPECIFIC GRAVITY.....................................................................................................................................................7

Calculations & Results..................................................................................................................................................8

Determination of Minimum Dry Unit Weight:.........................................................................................................8

Determination of Maximum Dry Unit Weight:.......................................................................................................10

Maximum void ratio emax ...................................................................................................................................11

Discussion..................................................................................................................................................................12

References.................................................................................................................................................................13

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LIST OF TABLES

Table 1: Mold Dimensions............................................................................................................................................6

Table 2: Minimum Dry Unit Weight – Tube Method....................................................................................................6

Table 3: Minimum Dry Unit Weight – Funnel Method.................................................................................................6

Table 4: Mold dimensions for maximum unit weight...................................................................................................7

Table 5: Maximum Dry unit weight- vibratory table method.......................................................................................7

Table 6: Volume calculation.........................................................................................................................................8

Table 7: Minimum Dry Unit Weight – Tube Method....................................................................................................8

Table 8: Minimum Dry Unit Weight – Funnel Method.................................................................................................9

Table 9: Mold Dimensions..........................................................................................................................................10

Table 10: Maximum Dry Unit Weight – Vibratory Table Method...............................................................................10

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SPECIFIC GRAVITY

This experiment is performed to determine dry density and wet density of a granular soil.

EQUIPMENT NEEDED

- Metal mold- Balance- Filling devices (bottle)- Spatula

PROCEDURE

DRY DENSITY

1. Calculate the volume of the mold by measuring inner diameter and height.2. Weigh mass of empty mold excluding collar.3. Place the collar on top.4. Place tube vertically in the center of the mold.5. Fill the tube with the sand employing a scoop. Add sand in slow manner to prevent

compaction.6. Remove the tube from the mold raising it vertically (and slowly), allowing the soil to

overfill the mold.7. Carefully remove the collar and screen off the top of the mold the excess soil using a

ruler.8. Measure and record the mass of the mold full of sand. (Make sure to clean all sand

residues on the mold)9. Calculate dry density, unit weight and void ratio of the sand.

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DRY DENSITY

1. Measure the volume of the mold (get diameter and height).2. Record mass of the empty mold without collar.3. Place the collar on top.4. Place the soil in the mold in three equal layers.5. Place the first layer of sand inside the mold. The height of the lift is such that the 3rd

layer should exceed the height of the mold by 0.25 in almost.6. Place the deadweight on the sand – fix the mold on the vibrating table. Vibrate for 3

minutes. 7. Remove the deadweight. Place 2nd and 3rd layers an repeat step 6.8. Remove deadweight after 3rd layer being vibrated. Screen off excess soil.9. Measure the mass of the mold full of sand.

DATA COLLECTED

DETERMINATION OF MINIMUM DRY UNIT WEIGHT:

Mold Dimensions1 2 3 Avg

Height (m) 0.116 0.116 0.116 0.116Internal Diameter (m) 0.1 0.1 0.1 0.1

Table 1: Mold Dimensions

Minimum Dry Unit Weight – Tube Method:

Description Symbol Trial-1 Trial-2 Trial-3 Unit

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Mass of mold without collar

Mm 4184.91 4184.91 4184.91 g

Mass of mold with dry soil

Mms 5620.75 5646.75 5630 g

Mass of dry soil Ms 1435.84 1461.84 1445.09 gWeight of dry soil

Ws 14.086×10-3 14.341×10-3 14.176×10-3 kN

Table 2: Dry Unit Weight

DETERMINATION OF MAXIMUMDRY UNIT WEIGHT:

Mold DimensionsHeight (m) 0.154Internal Diameter (m) 0.152

Table 3: Mold dimensions for maximum unit weight

Maximum Dry Unit Weight – Vibratory table Method:

Description Symbol Trial-1 UnitMass of mold without collar

Mm 10149 g


Mms 15037 g

Table 4: Maximum Dry unit weight- vibratory table method

SPECIFIC GRAVITY

From the previous lab, the obtained values of specific gravities are the following:

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Gs,t= 50

341.14−(372.2−50) = 2.64

Gs = 2.64 (0.9976830.998021 ) = 2.639

CALCULATIONS & RESULTS

DETERMINATION OF MINIMUM DRY UNIT WEIGHT:

1 2 3 AvgHeight (m) 0.116 0.116 0.116 0.116Internal Diameter (m)

0.1 0.1 0.1 0.1

Volume (m3) 9.11×10-4 9.11×10-4 9.11×10-4 9.11×10-4

Table 5: Volume calculation

Sample Calculation for volume (m 3 ):

Vm= π ×0.12

4×0.116=¿9.11×10-4 m3


Description Symbol Trial-1 Trial-2 Trial-3 UnitMass of mold without collar

Mm 4184.91 4184.91 4184.91 g

Mass of mold Mms 5620.75 5646.75 5630 g

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with dry soilMass of dry soil Ms 1435.84 1461.84 1445.09 gWeight of dry soil

Ws 14.086×10-3 14.341×10-3 14.176×10-3 kN

Volume of mold Vm 9.11×10-4 m3

Minimum dry unit weight

d,min

15.462 15.742 15.560kN/m3

Average Min. Dry Unit Weight

d,minav 15.588 kN/m3

Table 6: Minimum Dry Unit Weight – Tube Method

Sample Calculation for minimum dry density and average minimum dry density :

d,min = W sV m = 14.086×10

−3

9.11×10−4 = 15.462 kN/m3

d,minav = 14.922+15.192+15.017

3 = 15.558 kN/m3

Minimum Dry Unit Weight – Funnel Method:

Description Symbol Trial-1 Trial-2 Trial-3 UnitMass of mold without collar

Mm 4192.3 4192.3 4192.3 g


Mms 5629 5626.1 5627.14 g

Mass of dry soil Ms 1436.7 1453.8 1434.8 gWeight of dry soil

Ws 14.094× 10-3 14.066× 10-3 14.076× 10-3 kN

Volume of mold Vm 9.11×10-4 m3

Minimum dry unit weight

d,min 15.471 15.440 15.451 kN/m3

Average Min. Dry Unit Weight

d,minav 15.454 kN/m3

Table 7: Minimum Dry Unit Weight – Funnel Method

Sample Calculation for minimum dry density and average minimum dry density:

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d,min = W sV m = 14.094×10

−3

9.11×10−4 = 15.471 kN/m3

d,minav = 15.471+15.440+15.451

3 = 15.454 kN/m3

DETERMINATION OF MAXIMUM DRY UNIT WEIGHT:

1Height (m) 15.4 × 10-2

Internal Diameter (m)

15.2 × 10-2

Volume (m3) 2.79 × 10-3

Table 8: Mold Dimensions

Sample Calculation for volume :

Vm= π ×0.1522

4×0.154=2.79×10-3 m3

Maximum Dry Unit Weight – Vibratory Table Method:

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Description Symbol Values UnitMass of mold without collar

Mm 10149 g


Mms 15037 g

Mass of dry soil Ms 4888 gWeight of dry soil

Ws 47.902× 10-3 kN

Volume of mold Vm 2.79 × 10-3 m3

Maximum dry unit weight

d,max 17.169 kN/m3

Table 9: Maximum Dry Unit Weight – Vibratory Table Method

Sample Calculation for maximum dry density:

d,max = W sV m = 47.902×10−3

2.79×10−3 = 17.169 kN/m3

MAXIMUM VOID RATIO emax


d,minav = 14.922+15.192+15.017

3 = 15.558 kN/m3

emax=ρwG s

ρmin−1=

γwGsγmin

−1=10(2.64 )

15.558=1.696

Minimum Dry Unit Weight – Funnel Method:

d,minav = 15.471+15.440+15.451

3 = 15.454 kN/m3

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emax=ρwG s

ρmin−1=

γwGsγmin

−1=10(2.64 )

15.454=1.708

DISCUSSION

In order to get the loosest possible state of the soil or getting the maximum void ratio which the soil can have, we proceeded two methods: tube and funnel. Both tests gave us the minimum dry density where in funnel method d,minav = 15.454 KN/m3 and in tube method d,minav = 15.588 KN/m3. According to the results calculated, the minimum dry density is the lowest number. Thus, the funnel is a better method and d,min of the soil is 15.454 KN/m3.

% error = tube−funelfunel × 100

% error = 15.588−15.454

15.454 × 100

% error = 0.87%

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The percentage error is 0.87% which is relatively negligible and it is due to the compaction of the sand in the tube before filling it in the mold.

Research question

There are two principal types of compaction force: static and vibratory. To quote from Multiquip's Soil Compaction Handbook: "Static force is simply the deadweight of the machine, applying downward force on the soil surface, compressing the soil particles. The only way to change the effective compaction force is by adding or subtracting the weight of the machine. Static compaction is confined to the upper soil layers and is limited to any appreciable depth. Kneading and pressure are two examples of static compaction.

"Vibratory force uses a mechanism, usually engine-driven, to create a downward force in addition to the machine's static weight…. The compactors deliver a rapid sequence of blows (impacts) to the surface, thereby affecting the top layers as well as deeper layers. Vibration moves through the [soil], setting particles in motion and moving them closer together for the highest density possible."

Dr = emax – e fieldemax−emin

Where: Dr = 0.9

emax = 0.78

emin = 0.43

we get efield = 0.465

V v=0.465V s∧V t=V s+0.465V s=1m3

V s=0.682m3Gs , t=

γ sγw , 20

γs=2.67×9.789=26.137kN /m3

γs=W s

V ssoW s=26.137

kNm3×0.682m3=17.825 kN

γd=W s

V t=17.825

1=17.825 kN /m3

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ρ s=γ sg

=26.1379.81

=2664.32kg /m3

ρd=γ dg

=17.8259.81

=1817.02kg /m3

REFERENCES

- CIE 445 Hand-out Eng.Ursula Merchak

- ASTM D 4253

- ASTM D 4254

- http://www.tritonsws.com/downloads/99-Soil-Compaction-Article.pdf

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http://www.tritonsws.com/downloads/99-Soil-Compaction-Article.pdf

Lab 4 soil

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