Carol Project2

7/30/2019 Carol Project2

1/31

PROJECT TITLE: INVESTIGATION OF CAUSES OF

FAILURE OF GRAVEL ROAD

CASE STUDY : LUMO ALI MBOA

PROJECT TYPE: PROBLEM SOLVING

NAME OF STUDENT:CAROL ANDREW PANTALEO

ADMISSION :100101P7312


2/31

INTRODUCTIONLumo Ali mboa road, is located at Temeke

Municipality in Dar es salaam. It has the length of

1.2km. The road is made of natural gravel laid on asub grade. The road is unpaved and due to rapid

development of that area, the road has become

very useful for the transportation.


3/31

PROBLEM STATEMENTThe road is characterized by existence of ruts,

corrugations, pot holes, skidding and depressionswhich lead to unsafe to road users, delays to

passengers and their goods, lack of freedom to

drivers maneuverability and uncomfortability to

passengers.


4/31

OBJECTIVE

MAIN OBJECTIVE

To investigate the causes of failure of gravel road.

SPECIFIC OBJECTIVE

To determine the traffic volume.

To determine the drainage system.To conduct material testing for strength.


5/31

OUTCOME OF THE PROJECTAt the end of this project ,causes of failure along the

road will be identified


6/31

METHODOLOGYLiterature Review

Data CollectionData Analysis

Recommendation


7/31

LITERATURE REVIEW

Agravel road

Is a type of unpaved road surfaced with gravel that hasbeen brought to the site from a quarry or stream bed.

They are common in less-developed nations, and also

in the rural areas of developed nations such as

Canada and the United States. In New Zealand, theyare known as 'metal roads'. They may be referred to

as 'dirt roads' in common speech, but that term is used

more for unimproved roads with no surface material

added. If well constructed and maintained, a gravelroad is an all-weather road.


8/31

CHARATERISTICS OF GRAVEL ROADA good gravel road surface, a proper worn and

adequate drainage. Its good condition ismaintained by periodically, smoothing and

reshaping its surface and shoulders. This bulletin

describes the characteristics of the gravel road and

how to maintain one.

Also good gravel needs gravel sands and silt in

the proper proportions to support traffic load, resist

abrasion, shed water and enhance the soil abilityto absorb and disperse water.

A good gravel should have ditches should have a

v shape and should be moved and cleared of

sediments and debris to prevent washout.


9/31

TYPES OF GRAVEL ROAD SECTIONS

FEATHER EDGE TYPE

Is constructed over the sub grade with varying thickness,

so as to obtain the desired cross slope for the pavement

surface.

TRENCH TYPE

The sub grade is prepared by excavating a shallow

trench where this method of construction is the most

preferred for construction of gravel road.


10/31

TYPES OF DEFECTS ON GRAVEL ROAD

POTHOLES

is a type of disruption in the surface of a

roadway where a portion of the road material

has broken away, leaving a hole.Causes

Potholes almost always result from road

sections on poorly drained soils

Water penetrate on the road surfaceERROSION GULLIES

They are in the form of channels, It may

increase in size and destroy the road

section once it has formed.


11/31


12/31

DEPRESSIONThese are small hollows occurs in the pavement.

Usually they develop from local defects such as low

compaction or insufficient pavement strength . They

increase the roughness of the pavement

SOFT SPORTS

These are weak points which can be found on the surface ofunpaved road.

CAUSES

Insufficient camber (water does not drain off quickly)

Poor or lack camber which does not

shade off rain water quickly.


13/31

GENARAL CAUSES OF FAILURE OF

GRAVEL ROAD

The following are the causes of failure of a gravel road;Increase in traffic volume

Environmental factors

Unsuitable materials of construction

Poor drainage system

Poor construction practice


14/31

Increase in traffic volume

Traffic volume is the counting process whichinvolving number of traffic (car, bus truck,trailers) passing through out the road onwhich a movement is per unit time at aspecified time, a selected time period inhours, days, week month or year.

Purpose of traffic volume study

It is important in traffic design, research and

planning. Information obtained is used in the research

of gravel rod deteriorations.


15/31

Environmental factors

This involve rainfall and water disposal fromchambers and people residential houses where by

water cause wearing off (wash out of looses) materialon surface of gravel road.

Also too much moisture will cause the crust to breakup and reducing capacity and leading to rapid surfacedeterioration.

Unsuitable material for constructionSome material are not proper for construction

purporse of gravel road also lead to poor blending

process because for good all weather surface, gravelroad must be properly blended where for poorblending will make stones and fines not compactedtogether and forming weak, undurable surface crust tocarry the traffic load and shed water.


16/31

Poor drainage system

Proper side ditches and cross surface drainage are

also important, without proper drainage, road surfaces

become rutted, surface material wash away and road

can become flooded and impassable.

Ditches collect run off from shoulders and carry it to

streams and other natural drainage locations. The right ofthe way usually limits ditch sizes, the most common and

economical to build ditch shape is a V.

Also ditches are clogged with sediments which lead to

overflowing and possible washout.


17/31

Poor construction practice

This involve shoulders should also be constructed of

aggregate, the shoulder must slope as much or more

than the crown for good drainage and to prevent waterfrom flowing back toward the road surface.

A strong and durable side drains for gravel road

should be constructed with stones ( stone armoreddrains ) with cement.

Poor compaction of crown and surface material also

affects cross surface drainage, If the crown will

designed properly, then water will run off and into theshoulders and poor compaction surface material has

many voids to absorb water and let most of it run off.


18/31

DATA COLLECTION

I. FIELD MEASURING

Field measuring of defect occurring and types. Collection of sample at the site

Provide photographs

II. SOIL LABORATORY TEST Sieve analysis (Grading) Test,

Atterberg Limit test,

Compaction Test, California bearing ratio ( CBR) Test.


19/31

III. FIELD TESTING Field density for compaction with Maximum Dry

density (MDD)

Field water content for compaction with Optimum

Moisture Content(OMC).

DATA COLLECTION


20/31

DATA COLLECTION

SAMPLING OF THE GRAVEL MATERIAL

The test sample were obtained from Lumo- Ali mboa road which islocated at Temeke municipal. One sample was collected in order todetermine the engineering properties of the soil along this strength.Representative sample were taken at a 1.3m depth

PREPARATION OF THE SAMPLE FOR TEST

It is necessary that the soil sample material for laboratory test is free fromexcess moisture beyond its natural moisture content, due to this effect thesoil was air dried by spreading over dry polythene sheets. This is importantfor sensitive sieving methods such as those required in the determination ofparticle size distribution, as the moist soil will be difficult to pass over theseparating micro sieves

PROGRESSING OF THE TEST

In order to determine the engineering properties of the soil sample, thefollowing test have been carried out starting from ch:

0+250,0+500,0+750,1+000.

.


21/31

DATA ANALYSIS

The test performed for analyzing the data were

Compaction Test

California Bearing Ratio Test

Atterberg Limit Test

Sieve analysis

And the results through the tests conductedwere obtained

S f th i F l i l i i bt i i D t f l i


22/31

Some of the main Formula involving in obtaining Data for analysis are:

Bulk Density = mass/volume

Dry Density = bulk density1+moisture content

Compaction = Dry density

MDD

Plastic Index = Liquid Limit

Plastic Limit

Moisture content = 100x mass of water/mass of dry soil

Linear Shrinkage = Initial Length(LO) Final Length(Lf)

Initial Length (LO)

The results obtained shows the various relationship between

engineering properties of soil materials as follows:-

Th l b i d h h i


23/31

The results obtained shows the various

relationship between engineering properties of soil

materials as follows:-


24/31

SAND

Chainage OMC MDD

0+250 11.88% 1.948kg/m3

0+750 9.60% 1.950kg/m3

GRAVEL

0+750 8.97% 2.013kg/m3

SUMMARY OF RESULTS FOR SOIL TEST

Table 1:compaction test results

Table 2: California Bearing Ratio Test resultsT bl 3 Si l i l


25/31

SAND

chainage 56 blows

5 layers

4.5 kg rammer

30 blows

5 layers

4.5 kg rammer

56 blows

3 layers

2.5 kg rammer

0+250 17 16 17

0+750 20 19 18

GRAVEL

0+750 48 46 43

Table 2: California Bearing Ratio Test results

CBR Values

CLASSIFICATION

SAND (0+250) SAND(0+750) GRAVEL(0+750)

USCS

%Gravels 11 7 51

%Sand 80 69 44

%Fines 9 23 5

LL(%) 20 31 20

PL(%) NP NP 10

PI(%) NP NP 10

Table 3: Sieve analysis results


26/31

From the graph above,

it shows that there is a decrease of Optimum moisture content from chainage 0+250 to

chainage 0+750 but there is an increase of maximum dry density from chainage 0+250

to chainage 0+750.

VARIATION OF OMC AND MDD AT DIFFERENT

CHAINAGE FOR A SUB GRADE


27/31

VARIATION OF CBR VALUE AT DIFFERENT

CHAINAGE FOR A SUB GRADE

From the graph above,

it shows that there is a increase of CBR value from chainage 0+250 to chainage 0+750.


28/31

RELATIONSHIP BETWEEN %MDD(COMPACTION) AND CBR VALUE

AT CHAINAGE 0+250 FOR SUB GRADE.

1.0

10.0

100.0

90.0 92.0 94.0 96.0 98.0 100.0 102.0 104.0 106.0 108.0 110.0

CBR4daysSoaked(%)

% MDD

Plot of CBR, 4 days soaked (log scale) versus% of Maximum Dry Density


29/31

RELATIONSHIP BETWEEN %MDD(COMPACTION) AND CBR VALUE

AT CHAINAGE (0+750) FOR SUB GRADE.

1.0

10.0

100.0

90.0 92.0 94.0 96.0 98.0 100.0 102.0 104.0 106.0 108.0 110.0

CBR4daysSoaked(%)

% MDD



30/31

RELATIONSHIP BETWEEN %MDD(COMPACTION) AND CBR

VALUE AT CHAINAGE (0+750) FOR GRAVEL.

1.0

10.0

100.0

85.0 87.0 89.0 91.0 93.0 95.0 97.0 99.0 101.0

CBR4daysSoaked(%)

% MDD


REFERENCE


31/31

REFERENCEBrian Kent, K. a. (2010). Gravel Road Maintenance

Manual. Norway: Taylor and Francinc Group,LLC,Clyde

Walton, David Rocqure.CML,NOTEBY,SINTEF,VIANOVA. (2000). Laboratory

Testing Manual. Skjetten Norway: Novum Grafisk AS.

Justo, S. a. (1990). Highway Engineering. London New

York: Taylor and Francis Group,LLC.

Smith, G. S. (1995). Element of Soil Mechanics.

.

Carol Project2

Documents

Transcript of Carol Project2