DETERMINATION OF FIELD DENSITY OF SOILS BY SAND REPLACEMENT & CORE CUTTER METHOD

FACULTY OF CIVIL ANG ENVIRONMENTAL ENGINEERING DEPARTMENT OF INFRASTRUCTURE AND GEOMETIC LAB GEOTECHNIC

FULL REPORT Subject Code Code & Experiment Title Course Code Date Section / Group Name Members of Group

Lecturer/Instructor/Tutor Received Date

Comment by examiner

BFC 31703 U5 – DETERMINATION OF FIELD DENSITY OF SOILS BY SAND REPLACEMENT & CORE CUTTER METHOD 2 BFF 3RD MAY 2012 SECTION 9 / GROUP 7 MUHAMMAD IKHWAN BIN ZAINUDDIN (DF100018) 1. NUR EZRYNNA BINTI MOHD ZAINAL (DF100118) 2. MUHAMMAD HUZAIR BIN ZULKIFLI (DF100040) 3. NUR EEZRA ATHIRLIA BINTI GHAZALI (DF100147) 4. MUHAMMAD NUH BIN AHMAD ZAIRI (DF100093) 5. ZIRWATUL FAUZANA BINTI CHE JEMANI (DF100027) EN. MOHD FAIZAL BIN PAKIR 10TH MAY 2012

Received

STUDENT CODE OF ETHIC (SCE) DEPARTMENT OF INFRASTRUCTURE AND GEOMETIC FACULTY OF CIVIL & ENVIRONMENTAL ENGINEERING UTHM

We, hereby confess that we have prepared this report on our effort. We also admit not to receive or give any help during the preparation of this report and pledge that everything mentioned in the report is true.

Name

___________________________

___________________________

Student Signature

Student Signature

: MUHAMMAD IKHWAN BIN ZAINUDDIN

Name

: NUR EZRYNNA BINTI MOHD ZAINAL

Matric No. : DF100018

Matric No. : DF100118

Date

Date

Name

: 10/05/2012

: 10/05/2012

___________________________

___________________________

Student Signature

Student Signature

: NUR EEZRA ATHIRLIA BINTI GHAZALI

Name

: MUHAMMAD HUZAIR BIN ZULKIFLI

Matric No. : DF100147

Matric No. : DF100040

Date

Date

Name

: 10/05/2012

: 10/05/2011

_______________________

_______________________

Student Signature

Student Signature

: MUHAMMAD NUH BIN AHMAD ZAIRI

Name

: ZIRWATUL FAUZANA BINTI CHE JEMANI

Matric No. : DF100093

Matric No. : DF100027

Date

Date

: 10/05/2012

: 10/05/2012

B) FIELD DENSITY OF SOILS BY CORE CUTTER METHOD 1.0

INTRODUCTION In-situ density of soil is an important parameter for soil engineers. This is needed for

determination of bearing capacity of soils, stability analysis, and natural slopes and for determining degree of compaction of fills. Density is used in calculating the stress in the stress in the soil due to its overburden pressure. It is needed in estimating the bearing capacity of soil foundation system, settlement of footings, earth pressures behind the retaining walls, dams, embankments. Stability of natural slopes, dams, embankments and cutis checked with the help of deity of these soils. It is the density of controls the field of soils. Permeability of soils depends upon its density. Relative density of cohesion less soils is determined by knowing by knowing the dry density of that soil in natural, loosest and densest states. Void ratio, porosity and degree of saturation need the help of density of soils. This method consists of driving a core cutter of known volume into the soil after placing it on a cleaned surface. The cutter filled with soil is removed and excess soil trimmed off. The cutter with soil is weighed which is divided by volume of cutter and hence the in-situ unit weight is determined. The core cutter is dug out, trimmed and the soil inside, weighed and dried for moisture and density determination. 2.0

OBJECTIVE To determine in-situ density of fine-Grained natural or compacted soils free form

aggregate using a core cutter. 3.0

THEORY Core cutter method is used for finding field density of cohesive/clayey soils placed as fill.

It is rapid method conducted on field. It cannot be applied to coarse grained soil as the penetration of core cutter becomes difficult due to increased resistance at the tip of core cutter leading to damage to core cutter.

A cylindrical core cutter is a seamless steel tube. For determination of the dry density of the soil, the cutter is pressed into the soil mass so that it is filled with the soil. The cutter filled with the soil is lifted up. The mass of the soil in the cutter is determined. The dry density is obtained as

Where M

= mass of the wet soil in the cutter

V

= internal volume of the cutter

w

= water content.

Core cutter method in particular, is suitable for soft to medium cohesive soils, in which the cutter can be driven. It is not possible to drive the cutter into hard, boulder or marrowy soils. In such case other methods are adopted. 4.0

EQUIPMENTS i) Cylindrical core cutter seamless steep tube, 130mm long 10cm internal diameter with wall thickness of 3mm, bevelled at one end; giving a volume of 1000cm3. ii) Steel dolly, 2.5cm high and 10cm internal diameter with wall tickness of 7.5mm with a lip to enable it to be fitted on top the core-cutter.

iii) Steel rammer with solid mild steel foot 14cm diameter and 7.5cm height with a concentrically screwed 2.5cm diameter solid mild steel staff iv) Balance. v) Palette knife having balde approx. 20cm long and 3cm wide vi) Steel rule. vii) Container for determination of water content. viii) Soil sample = Fine grained soil where 90% of soil passes through 4.75mm I.S Sieve

Figure 1 – The dimention of cylindrical core cutter

Figure 2 - Steel dolly

Figure 5 - Weighing scale

Figure 3 – Oil

Figure 4 - Hammer

Figure 6 – Palette knife

Figure 7 – Steel Ruler

5.0

PROCEDURE 1)

The internal volume of core cutter is calculated.

2)

The weight of the empty core cutter is recorded

3)

The oil is applied on inner surface of core cutter

4)

The core is placed on a freshly prepared plain ground with dolly on it; and gently hammer it so that the cutter will get pushed in the soil completely

5)

The side material is removed and taken out from the field of core cutter gently and properly trim the top and bottom surface and weight it

6)

The soil core will be removed from the cutter and a representative sample will be placed in an air tight container to determine water content

Figure 8 - Soil core in cutter

Figure 9 - Sample for core cutter

6.0

RESULT

a) Determination of bulk and dry density of soil. Determination No. 1

Mass of empty core-cutter (M1)

g

930

2

Mass of core - cutter + wet soil (M2)

g

2911

3

Mass of wet soil (M2-M1)

g

1981

4

Volume of core-cutter (V)

cm3

988.09

5

Bulk density ρb =

g/cm3

2.00

6

Dry density of soil ρd =

g/cm3

1.65

b) Determination of water content of soil Container No. 1

Mass of empty container with lid (M1)

g

9.8

2

Mass of container with lid and wet (M2)

g

54.30

3

Mass of container with lid and dry soil (M3)

g

46.40

4

Water content, w =

%

21.58

=

x100

7.0

DATA ANALYSIS a) Determination of bulk and dry density of soil. i.

Mass of empty core-cutter (M1)

= 930g

ii.

Mass of core - cutter + wet soil (M2)

= 2911g

iii.

Mass of wet soil (M2-M1) = 2911 - 930

= 1981g

iv.

Bulk density ρb =

= 2911 – 930 988.09 = 2.00 g/cm3

v.

Dry density of soil ρd =

=

2.00

.

1 + (21.58/100) = 1.65

b) Determination of water content of soil i.

Mass of empty container with lid (M1)= 9.8g

ii.

Mass of container with lid and wet (M2)

iii.

Mass of container with lid and dry soil (M3) = 46.4g

iv.

Water content, w =

=

x100

= 54.3g

= 54.3g – 46.4g 46.4g – 9.8g = 21.58 %

8.0

DISCUSSION Core cutter method is used for finding field density of cohesive or clayey soils placed as

fill. The result of this experiment, that bulk density, dry density and water content it is shown that the soils is cohesive and clayey soils. From the experiment, the result that we got are : Bulk density of soil, (g/cm3) Dry density of soil, (g/cm3)

Core Cutter Method 2.00

Sand Replacement Method 1.90

1.65

1.61

The data is acceptable because the density value between the core cutter method and sand replacement method have small different. The different exist come from error balance reading and the hole for the test core cutter and sand replacement method were make far from each other. Type of error factors affect soil permeability it is from when doing the test is environmental error, systematic or equipment error and parallax error. 9.0

CONCLUSIONS In conclusion, the relationship between compaction effort and the density of soil are the

compaction is a process of increasing soil density and removing air. The size of the individual soil particles does not change, neither is water removed. There is usually no change in water content. The degree of compaction is measured by dry unit weight and depends on the water content and compactive effort. The factors will effect the compaction and density are nature and type of soil such as sand, clay, grading or plasticity; water content at the time of compaction, site conditions include with weather, type of site, layer thickness; and compactive effort. The other two methods that can be used are sand replacement method and water displacement method. Each method is selected based on the type of soil to be tested, as well as the limitation or restriction that may be present in the soil sample to be tested. 10.0 i.

REFERENCES Holtz, Robert D. (1981), “An Introduction to Geotechnical Engineering”,Prentice Hall, United States of America.

ii.

John N. Cernica (1995), “Geotechnical Engineering Soil Mechanics”, John Wiley & Sons, Inc.