The University of Jordan

Faculty Of Engineering and Technology

Student Name: Saif Eddin Zaki Sayed Ahmed

Student ID: 2130044

Department: Civil Engineering

Subject: Surveying

Section: “1”

Date: 04.04.2015

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Contents:

1. Introduction ………………………………………………........3

2. Project Objectives…………………………………………………..... 4

3. Leveling and its Applications………………………………… 5

3.1 Methods of leveling…………………………………………………….. 6

3.2 Main Equipment …………………………………………………….. 7

3.3 Types of Errors…………………………………………………….. 9

3.4 A list of Definitions…………………………………………………….. 9

4. Contouring…………………………………………………….. 11

4.1 Types of Contour Lines…………………………………………………….. 11

4.2 Methods of Contouring…………………………………………………….. 12

4.3 Characteristics of Contour lines………………………………… 14

4.4 Uses of Contour maps…………………………………………………….. 16

5. Longitudinal Section (profile) and cross-section……………. 16

5.1 Longitudinal Section (Profile)………………………………… 16

5.2 Cross-Section …………………………………………………….. 17

6. Earthwork Calculations…………………………………………………….. 18

6.1 Areas…………………………………………………….. 19

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6.2 Volumes…………………………………………………….. 21

6.3 Mass-Haul Diagram (MHD)………………………………… 23

7. A case study…………………………………………………….. 24

Abstract…………………………………………………….. 24

7.1 Introduction…………………………………………………….. 25

7.2 Route Location…………………………………………………….. 25

7.3 Profile and Cross-Sections ………………………………… 27

7.4 Calculation of Earthwork………………………………… 27

7.4.1 Areas of Cross-Sections………………………………… 27

7.4.2 Volumes of Earthwork………………………………… 28

7.5 Mass-Haul Diagram…………………………………………………….. 29

8. Conclusion…………………………………………………….. 29

Appendices…………………………………………………….. 30

References …………………………………………………….. 37

9.

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1. Introduction

“A man's feet should be planted in his country, but his eyes should survey the world.” -George Santayana

Surveying has been an essential element in the development of the human environment for so many centuries, as it is an imperative requirement in the planning and execution of nearly every form of construction. It can be regarded as that discipline which encompasses all methods for measuring and collecting information about the physical earth and our environment, processing that information, and disseminating a variety of resulting products to a wide range of clients.

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2. Project Objectives

This project aims to expand our knowledge behind leveling and its applications, understand contour maps and how to use them, introduce different ways of area and volume calculation, and open a new door for creativity to delve into the practical life of an engineer.

The following topics should be understood at the end of this project:

(i) Definitions of: leveling, contouring, longitudinal section, cross section, areas, volumes and mass –haul diagram.

(ii) Characteristics of contour maps and their uses(iii) Leveling procedures.(iv) Applications of leveling.(v) Types of Sections (Profile and Cross-section.)(vi) Earthwork calculations.

The following objectives should be accomplished at the end of this project:

(i) Design a route between two known points.(ii) Design Profile and cross-section of the ground level

and formation level for a proposed road.(iii) Calculate the areas of each x-section. (iv) Calculate the cumulative volume.(v) Make mass-haul diagram.

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3. Leveling and its Applications

Leveling is one of the types of geodetic measurements used to create a geodetic elevation reference grid and conduct topographic surveying, as well as to plan, construct, and maintain engineering structures such as railroads and highways. The science of leveling goes back to the ancient Greeks, Egyptians, and Romans and their massive construction projects; the first data on a leveling instrument are associated with the Roman architect Vitruvius (first century B.C.) and the ancient Green scientist Hero of Alexandria (first century A.D.).

It can be defined as the art of determining and establishing the relative height, as well as the difference in elevation, between different points on earth surface. The elevation or relative height (R.L) of a point is the vertical distance above and below a given reference level surface (zero elevation) usually a mean sea level, which can be calculated using ‘Height of Collimation’ method or by ‘Rise and Fall’ method.

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3.1 Methods of leveling

(i) Height of collimation method:

The instrument is set up where the benchmark can be viewed within correct parameters, and a reasonable number of sights can be viewed. The back sight is read to the benchmark and booked. This is recorded as a backsight and establishes the height of the instrument above the benchmark. The actual Reduced Level of the Bench Mark is also recorded. Staff readings are added (BS) to benchmark to get the elevation of the line of sight (HC).Subtract staff readings of the rest of the points from the line of sight to establish elevations of these unknown points.

H.C = R.L of a point + reading at AR.L of B = H.C – reading at B

(Refer to appendix A)

(ii) Rise and Fall method:

Backsight, intermediate sight and foresight readings are entered in the appropriate columns on different rows. However, backsights and foresights are placed on the same row if the level instrument is changed. The first reduced level is the height of the datum, benchmark or R.L. If an intermediate sight or foresight is smaller than the immediately preceding staff reading then the difference between the two readings is place in the rise column. If an intermediate sight or foresight is

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larger than the immediately preceding staff reading then the difference between the two readings is place in the fall column. A rise is added to the preceding reduced level (RL) and a fall is subtracted from the preceding RL.

R.L of a point=R.L of previous point (+ rise OR –fall)

(Refer to appendix B)

3.2 Main equipment

The main equipment needed to carry out leveling works is:

(i) Level with tripod (device which gives a truly horizontal line).

(ii) Leveling staff (a suitably graduated staff for reading vertical heights).

(iii) Chain/Tape (to enable the points leveled to be located relative to each other on a map).

(iv) Change plate (staff base plate).(v) Staff bubble (to ensure the staff is erected

vertically).

The level, its tripod, the staff and the staff bubble are all precision items of equipment upon which the accuracy of the work is highly dependent. They shall be kept correctly calibrated, and be used and stored with care.

There are three types of levels:

(i) Dumpy levels: these are more basic levels often used in construction work. The telescope is rigidly attached to a single bubble and the assembly is adjusted either by means of a

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screwed ball-joint or by foot screws which are adjusted first in one direction, then at 90°.

(ii) Tilting levels: This type of level is fitted with a circular bubble for preliminary approximate leveling and a main bubble which is attached to

(iii) Auto

matic levels: This more modern type of level is now in general use. It has a compensator which consists of an arrangement of three prisms. The two outer ones are attached to the barrel of the telescope. The middle prism is suspended by fine wiring and reacts to gravity. The instrument

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3.3 Types of errors

There are three types of errors in leveling:

(i) Blunder: Large mistakes which occur due to inexperience, fatigue or carelessness of surveyor. For example, miscounting tape length.

(ii) Systematic: Instrumental defects. For example, collimation error in the instrument.

(iii) Random: Such errors happen due to physical and climatic conditions. For example, effect of wind and temperature on the height of collimation causing a slight change.

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In order to reduce the errors and gain accurate and precise leveling results, measurements must be performed carefully using high quality instruments kept in good adjustment, since a surveyor depends mainly on their equipment. Additionally, measurements must be repeated. Last but not least, a closure check must be done.

3.4 A list of definitions:

Level surface: is a surface which is everywhere perpendicular to the direction of the force of gravity. An example is the surface of a completely still lake. For ordinary leveling, level surfaces at different elevations can be considered to be parallel.

Datum: is an arbitrary level surface to which elevations are referred. The most common surveying datum is mean sea-level (MSL)

Elevation: also called reduced level, is the vertical distance between a survey point and the adopted level datum.

Bench Mark: is the term given to a definite, permanent accessible point of known height above a datum to which the height of other points can be referred

Back Sight: The first reading taken on the staff after setting up the level. It is taken at a point of known height.

Fore Sight: The last reading taken before changing the position of the level.

Intermediate sight: All staff readings made between back sight and fore sight.

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Change point: are points of measurement which are used to carry the measurements forward in a run. Each one will be read first as a foresight, the instrument position is changed, and then it will be read as a backsight.

Height of collimation: is the elevation of the optical axis of the telescope at the time of the setup. The line of collimation is the imaginary line at the elevation.

4.

Contouring

A Contour line is an imaginary outline of the terrain obtained by joining its points of equal elevation above a given level, such as mean sea level. It is sometimes visible, such as the shorelines of a lake, since water

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Level and Tripod

Leveling Staff

assumes a level surface. A map illustrating contour lines is called a contour map. An example would be a topographic map, which thus depicts change in elevation and the shape of landforms showing valleys and hills, and the steepness of slopes. Often contour lines will form concentric shapes around each other.

4.1 Types of contour lines

Following are the essentials of the three types of contour lines:

(i) Index: Evenly spaced lines accented with a heavier mark in order to attract attention; these lines will be the first thing the eye catches. They are marked with the elevation above sea level and they are usually figured in intervals, which differ from one contour map to another depending on many factors (see table 4.1.)

(ii) Intermediate: A set of intermediate contour lines exist between each pair of index contour lines, where the elevation change between one index contour line and an adjacent intermediate contour has the same value as the change between two intermediate contour lines that are located next to each other.

(iii) Supplementary: This type of contour lines is expressed as a dashed line, representing half the elevation change that is found between intermediate and index contour lines. These lines are only used on contour maps where the overall change in elevation is very gradual or slight.

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(Table 4.1)

4.2 Methods of contouring

Broadly speaking there are two methods of contour surveying:

(i) Direct method: It is the most precise method out of all, in which the line of each contour is traced and marked on the ground. These lines are then plan surveyed so that they can be mapped.

(ii) Indirect methods: In this method, the spot levels of selected guide points are taken with a level and their levels are computed. The horizontal positions of these points are measured or computed and the points are plotted on the plan. The contours are then drawn by a process called interpolation of contours from the levels of the guide points. The following

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No. Factor Big intervals e.g. 1m, 2m, 5m or more

Small intervals e.g. 0.5m, 0.25m, 0.1m or less

1 Nature of ground

If the ground has large variation in levels, for instance, hills and ponds

If the terrain is fairly level

2 Scale of the map

For small scale maps covering a wide area of varying terrain

For large scale mapsshowing details of a small area

3 Extent of survey

For rough topographical mapmeant for initial assessment only

For preparation of detailed map for execution of work

4 Time and resourcesavailable

If less time and resources areavailable

If more time and resources are available

are the indirect methods are commonly used for locating contours.

(a) Grid method: It is the most commonly used method, where the area to be surveyed is divided into a grid or series of squares using a ranging rod. The elevation of points located at the intersections is then determined by leveling. Contour lines are then drawn by interpolation. The size of the squares you lay out depends on the accuracy needed. (Fig 4.1)

(b) Radiating method: In this method several radial lines at selected angle interval are taken from a point in the area. On these lines at selected distances points are marked and levels determined. This method is particularly used for large and hilly areas. Theodolite with tachometry facility is commonly used in this method. (Fig 4.2)

Table 4.2 below summarizes the pros and cons, as well as the features that differentiate each of the two methods in indirect contouring.

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Direct Method Indirect Method

1 Very accurate but slow and tedious Not very accurate but quicker and less tedious.

2 Expensive Reasonable cost

3

Appropriate for small projects requiring high accuracy, e.g., layout of building,

factory, structural foundations, etc.

Suitable for large projects requiring moderate to low

accuracy, e.g., layout of highway, railway, canal,

etc.

4 More suitable for low undulating terrain. Suitable for hilly terrain.

5Calculations need to be carried out in the

fieldCalculation in the field is

not mandatory.

6After contouring, calculation cannot be

checked.

Calculations can be checked as and when

needed

(Table 4.2)

4.3 Characteristics of contour lines

Contours show distinct characteristic features of the terrain as follows:

(i) All points on a contour line are of the same elevation.

(ii) Two contour lines can meet or cross each other except in the rare case of an overhanging vertical cliff or wall

(iii) Closely spaced contour lines indicate steep slope

(iv) Widely spaced contour lines indicate gentle slope

(v) Equally spaced contour indicates uniform slope(vi) Irregular contours indicate uneven surface.(vii) Closed contour lines with increasing values

towards center indicate hills(viii) Closed contour lines with decreasing values

towards center (Fig. 4.3) indicate a pond or other depression.

(ix) Contour lines of ridge show higher elevation within the loop of the contours. Contour lines cross ridge at right angles (Fig. 4.4).

(x) Contour lines of valley show reducing elevation within the loop of the contours. Contour lines cross valley at right angles (Fig. 4.5).

(xi) Contour lines must close, not necessarily in the limits of the plan.

(xii) If contour lines are meeting in some portion, it shows existence of a vertical cliff (Fig. 4.6).

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4.4

4.4 Uses of contour maps

Contour maps are extremely useful for various engineering works:

(i) Finding out the nature of the ground to identify. (ii) It is possible to identify suitable site for any

project from the contour map of the region.

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Fig 4.1Fig 4.3Fig 4.2

Fig 4.4

Fig 4.5 Fig 4.6

(iii) By drawing the section in the plan, it is possible to find out profile of the ground along that line. It helps in finding out depth of cutting and filling, if formation level of road/railway is decided.

(iv) Inter-visibility of any two points can be found by drawing profile of the ground along that line. This is most useful for locating communication towers.

(v) The routes of the railway, road, canal or sewer lines can be decided so as to minimize and balance earthworks.

The process of determining the elevations of a series of points at measured intervals lengthwise along the centerline of a proposed road. This process provides data from which the depth of fill or cut required to bring the existing surface up to, or down to, the grade elevation required for the highway can be determined.

5. Longitudinal Section (Profile) and Cross Section

5.1 Longitudinal Section (Profile)

The process of determining the elevations of a series of points at measured intervals lengthwise along the centerline of a proposed road. This process provides data from which the depth of fill or cut required to bring the existing surface up to, or down to, the grade elevation required for the highway can be determined.

5.2 Cross Sections

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Cross sections are short profiles made at right angle to the center line of the project. Cross sections are

usually taken at regular intervals along the length wise line of the highway and at sudden changes in the profile (intermediate breaks in the ground). The cross sections must extend a sufficient distance on

each side of the center line to provide a view of the surrounding terrain.

These two types of sections are used in linear facilities such as highways, railways, transmission lines, canals and water mains.

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6. Earthwork Calculations

On any highway or road construction project, the single largest cost item is almost always the earthwork; therefore it is something that transportation projects seldom avoid. When designers engineer a road, it is important to make the best possible determination of the quantity of soil and rock materials that must be moved on the project, which includes the excavation of existing earth material and any placement of fill material required for constructing the embankment. The methods used to determine earth excavation and embankment amounts are discussed below.

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6.1 Areas

To be able to calculate the volume of earthwork, the area of the cross-sections along the center line at each station must be calculated. These areas tell us the amount of cut and fill.

The ground levels may be horizontal, sloped and even variable across the section; accordingly several methods are used to determine the area of cross-section.

(i) Level Across:

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(ii) Section with Cross Fall

(iii) Part Cut Part Fill

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(iv) Section of Variable Level

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6.2 Volumes

Earthwork is expressed in units of volumes (cubic meters in metric.)

To determine the amount of earthwork to occur on a given site, the volumes are calculated, depending on the shape of the site, in three ways:

i) By cross-sections, generally used for long, narrow works such as roads, railways, pipelines, etc.

ii) By contours, generally used for larger areas such as reservoirs, landscapes,

redevelopment sites, etc.iii) By spot height, generally used for small areas

such as underground tanks, basements, building sites, etc.

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Since this report is concerned with roads, then volume calculations are done by relating cross-sections along the center line to the distances between them.

There are three methods of Calculating volumes using cross-sections:

(a) Mean Area Method:

The mean area of cross sections A1 to An is found, and multiplied by the distance between A1 and An. This method is the least accurate out of all, as it is an approximation.

(b) End Area Method: In this method, the area between two consecutive cross-sections is averaged, and then multiplied by the distance between them. When dealing with road construction, this method uses the Trapezoidal rule for volumes. It assumes that there is no variation between two successive sections,

and that the area of the midway section is the mean.

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(c) Volume by Prismoidal Method:

The geometrical shape and size of a substance must be known in order to calculate volume, and since in most approaches a mass of earth has no regular geometrical figure, this method is used. It is accurate, however necessitates a long time to obtain any desired result.

Where Am is the area of the plane in between the two cross-sections, and L is the distance between A1 and A2.

Most excavated materials are found to increase in volume after excavation (bulking), but after being re-compacted by roller or other means, soils in particular might be found to occupy less volume than originally, i.e. a 'shrinkage' has taken place when compacted in the in situ volume.

6.3 Mass-Haul Diagram (MHD)

Mass diagrams (or mass-haul diagrams) are a graphical representation of the cumulative volumes of cut and fill (earthwork moved) along an alignment. At any station, the value is the accumulated cut

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volume minus the accumulated fill volume up to that point. The difference in Mass Haul between two points indicates the volume of surplus (positive difference) or deficit (negative difference). By using this diagram, engineers can minimize material waste or borrow. It also provides quick, qualitative information about the cut and fill movements.

To construct the Mass Haul Diagram manually:

The cross-sectional area at each station must be calculated.

The net volume between two successive stations is then calculated; cuts have a positive value, net fills have a negative value. The shrink factor is applied.

The value at the first station (origin) is equal to 0.

The cumulated volume of each succeeding station; equal to the algebraic sum of the volumes to that point, is then plotted against the chaiange.

Characteristics of Mass-Haul Diagrams:

(i) They are a diagrammatic representation of earthwork volumes along a linear profile, presenting a picture of the earthwork requirements.

(ii) Horizontal stationing is plotted along the X-axis.

(iii) Cumulative earthwork values from the origin to that point are plotted along the Y-axis.

(iv) Net cut values are plotted above the X-axis (positive Y value.)

(v) Net fill values are plotted below the X-axis (negative Y value.)

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(vi) Upward sloping curves indicate (rising left to right) indicate a cut.

(vii) Downward sloping (falling left to right) curves occur in a fill section.

(viii) Peaks indicate a change from cut to fill and valleys occur when the earthwork changes from fill to cut Mass Haul Diagrams.

(ix) The accumulated volume of earthwork at the horizontal axis (Y=0) is 0.

(x) When a horizontal line intersects two or more points along the curve, the accumulated volumes at those points are equal.

(xi) A negative value at the end of the curve indicates that borrow is required to complete the fill.

(xii) A positive value at the end of the curve indicates that a waste operation will be the net result.

7. A Case Study

Abstract

This project revolves around locating and designing the most suitable and economical road alignment between two specific points, while referring to a contour map of specific area, and calculating the earthwork quantities involved in the alignment. As a result, three types of diagrams are constructed. The methodology behind these diagrams has been explained in section 5 and section 6.3, and is applied in section 7.3 and 7.5. These are:

Longitudinal Section (Profile.) Cross-Section. Mass-Haul Diagram.

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7.1 Introduction

The project is to locate and draw the best route between two selected points on a contour map, and to calculate the amount of earthwork needed to construct it.

7.2 Contouring and Route Location  

Planning with respect to road construction takes into account present and future uses of the transportation system; satisfying maximum service with a minimum of financial and environmental cost. Therefore, the road designed has to be efficient and economical.

The two selected points A and B on the contour map (size 62.5x46cm, scale 1:7000) are located in a mountainous region, at an elevation of 400m and 360m (relative to Mean Sea level.) When the route was designed, certain standards had to be met; the slope between any two stations had to be less than 4%, balance between cut and fill, and only one curve was allowed. Other aspects were taken into account as well, such as physical environmental factors (topography) and safety.

Once route design was complete, reduced levels of stations along the center line where interpolated

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using

trigonometry. The technique is described below.

Where LA = R.L of A – R.L of B = Contour interval.

Detailed interpolation of the Reduced Level for stations 2,3,5,6,8,11 and 12 is found in appendix C, D, E, F, G, H and I. Stations 1, 4, 7, 9, 10 and 13 did not need any interpolation as they were located on a contour line of known height.

The reduced levels along with the chianages of the stations are found in appendix J.

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A Brief Insight into the route designed:

Total distance of the route on map is 35cm, scale 1:7000.

It has 13 stations along the center line starting at A and ending at B.

The horizontal distance between each station is 3cm, except for the distance between station 9 and 10 which is 2cm.

7.3 Profile and Cross-Sections

The reduced levels of the stations along the formation level are calculated using algebraic equations; each slope has its own equation. Therefore, substituting the chainage x into the equation gives its reduced level y.

Formation Level Equations:

Chainage Equation0+000 to 0+420 y= 0.0049286x +400.000+420 to 0+630 y= 0.0377619x +386.210+630 to 1+300 y= -0.0074627x +414.701+300 to 2+450 y= -0.0391304x +455.87

The longitudinal section (profile) includes the reduced levels of both the formation levels as well as the ground level (y-axis), plotted against the chainage (x-axis). (Refer to appendix K)

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The cross-section of every station is a

trapezium. Further details are found in section 8.4.1. The cross-section of station (5) is found in appendix L as an example.

7.4 Calculations of Earthwork

7.4.1 Areas of cross-sections

For each station, the cross-sectional area has been found using the trapezium rule.

With a road width set to 10m, a depth of cut/Fill (x), and each side slope of width 2(x), the equation above was derived. Values of the cross-sectional areas for each station are found appendix M.

7.4.2 Volumes of Earthwork

Excavation and embankment are calculated with cross sections using the average end area method. Firstly, the area between the existing ground and

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10

x

2x2x 10 m

proposed ground is calculated at each cross-section. Secondly, the area between two consecutive cross-sections (A1 and A2) is averaged. Lastly, this area is multiplied by the distance (L) between two cross-sections (See Diagram 7.1.) Cut volumes are taken to be positive and fill volumes to be negative. The corrected volume is calculated by taking in consideration a shrinkage factor of 0.8 applicable to fill. The list of Data about volumes, corrected volumes and cumulative volumes are found appendix M.

A volume of cut and fill exits in between station 8 and 9 (wedge); therefore the resultant of those two had to be calculated (see Diagram7.2.) This was done by finding the intersection point of the formation level with the ground level, then calculating the volumes before and after that point. The method is explained in appendix N.

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7.5 Mass-Haul Diagram

The concept behind the Mass-Haul Diagram has been discussed in section 7.3. This is essentially a plot of cumulative volume of soil against distance along the road (chainage.) Cut volumes are taken to be positive and fill volumes to be negative. (Refer to appendix O)

8. Conclusion

The route designed runs a total horizontal distance of 2450m, with 13 stations starting at A and ending at B. The distance between each station is 210m, except for the distance between station 9 and 10 which is 140m. The Road width is 10m, while side slopes width are two times the depth of cut or fill. Throughout the project there are no horizontal formation lines connecting two stations to maintain water flow. There are 4 gradients:

(i) 0+000 to 0+420: 0.493%(ii) 0+420 to 0+630: 3.78%(iii) 0+630 to 1+300: -0.746%(iv) 1+300 to 2+450: -3.91%

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Diagram 7.1Diagram 7.2

And last but not least, the cumulative volume result is +11404.62 m3 excessive cut.

Appendices:

Appendix A:

Appendix B:

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Appendix C:

x=0.9y=(10*0.9)/(0.3) =3

R.L= 403.00

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Appendix D:

x=0.6y=(10*0.6)/(2.9) =2.07

R.L=402.07

Appendix E:

x=1y=(10*1)/(2.9)

=3.45

R.L= 403.45

Appendix F:

x=1.1

y=(10*1.1)/(3.1)

=3.55

R.L= 393.55

Appendix G:

x=2.4y=(10*2.4)/(5.4) =4.44

R.L=394.44

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Appendix H:

x=1.4

y=(10*1.4)/(2.4) =5.83

RL=385.13

Appendix I:

x=1.2

y=(1.2*10)/(2.9) =4.14

R.L=374.14

Appendix J:

Station Chainage Reduced Level

1 0+000 400.00

2 0+210 403.00

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3 0+420 402.07

4 0+630 410.00

5 0+840 403.45

6 1+050 393.55

7 1+260 390.00

8 1+470 394.44

9 1+680 400.00

10 1+820 400.00

11 2+030 385.83

12 2+240 374.14

13 2+450 360.00

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Appendix K:

Appendix L:

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0 210 420 630 840 1050 1260 1470 1680 1820 2030 2240 2450330.00

340.00

350.00

360.00

370.00

380.00

390.00

400.00

410.00

420.00

Reduced LevelFormation Level

Appendix M:

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Appendix O:

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0 210 420 630 840 1050 1260 1470 1680 1820 2030 2240 2450

-220000

-200000

-180000

-160000

-140000

-120000

-100000

-80000

-60000

-40000

-20000

0

20000

40000

Mass-Haul Diagram

Cumulative Volume

Chainage

References:

http://onlinelibrary.wiley.com/doi/10.1029/RG018i002p00505/abstract [online]

http://encyclopedia2.thefreedictionary.com/Leveling [online]

http://www.engineeringcivil.com/explain-terms-used-in-contouring.html [online]

http://theconstructor.org/surveying/contour-maps-uses/6441/ [online]

http://en.wikipedia.org/wiki/Contour_line [online]

http://hcgl.eng.ohio-state.edu/~cegs400/lecture5intro2levels.pdf [online]

http://www.engineeringcivil.com/what-are-the-uses-of-contours.html [online]

http://www.engineeringcivil.com/what-are-the-factors-governing-selection-of-contour-intervals.html [online]

http://www.ustudy.in/node/7799 [online]

http://theconstructor.org/surveying/methods-of-contouring/6451/ [online]

http://nptel.ac.in/courses/105107122/modules/module5/html/97.htm [online]

http://en.wikibooks.org/wiki/Fundamentals_of_Transportation/Earthwork [online]

http://www.fao.org/docrep/006/t0099e/T0099e02.htm [online]

http://www.brainyquote.com/quotes/keywords/survey.html#IJvLxQAx7FYWrLRo.99 [online]

http://www.whycos.org/fck_editor/upload/File/Pacific-HYCOS/Surface_Waters/Levelling_and_surveying.pdf [online]

http://www.trails.com/list_9909_contour-lines-found-topographical-map.html [online]

Other Resources:

‘The polar planimeter and its use in Engineering Calculations’ by J. Y. Wheatley, C. E.

‘Elementary Surveying An Introduction to Geomatics’ by Charles D. Ghilani .and Paul R. Wolf

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‘Introduction to Leveling’ by Robert J. Mergel, P.E., P.S. ‘Watershed management field manual’ by T.C. Sheng. Lecture Notes and Study Sheets by Prof. Khair Jadaan. ‘Earthwork and Mass Diagrams’ at NNOD Construction Conference 2011. ‘Structure of Surveying Instruments’ by Prof. Dr. M. Zeki Coskun. ‘Mass-Haul Diagrams’ by Sr Dr. Mohd Saidin Misnan.

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