Assignment 2 Profile Levelling PDF

Preview

Summary

Download Assignment 2 Profile Levelling PDF

Description

ASSIGNMENT 2 PROFILE LEVELLING OBJECTIVE -To run a profile levelling along the center line of the road INTRODUCTION Levelling Levelling is mainly about determining the relatively height between points, whether it is above or even below the surface.

In levelling, there are many types which are direct-levelling, trigonometric-levelling, barometriclevelling, and stadia-levelling. Most commonly types of levelling is direct levelling. Direct levelling itself, it is deeply divided again into: simple-levelling, differential-levelling, flylevelling, profile-levelling, precise-levelling, as well as reciprocal-levelling. However, in this time of experiment, it is particularly focus on profile-levelling. Carrying this experiment will later obtain the parameters. In order to practically work this experiment, it needs to use the data that obtained during experiment and use it to find the parameters. Later, it has to be deeply analyses to find out the parameters to presented it. This methodology is particularly known as longitudinal levelling/sectioning. This is a kind of methodology in surveying that has been implied along center of the line of a track of land in a

way that the work of engineering is contracture there. It is usually the center line of railway, road, canal, sewers, retaining walls, etc. The adoption of profile levelling is actually to find the point of elevation along the line. The case of profile-levelling. Readings of the stations are taken and find the RL.

The capability of this methodology can determine even the small ground surface’s elevation in which at small spatial interval along the line. And this also provides side view and crosssectional view of surface of earth. In the field, there are different kinds of types of ground and profile level that we face. Therefore, in order to tackle all this of its suitable forms of land and the function of it, it is require to do the cut and fill process in order to use effectively all the land and good ground profile can be achieved. Basically, cut and fill means when constructing that used land which can be used to construct MRT, railway, building, road, canal which needs to be cut the amount of material roughly matches of the amount of fill needed to make nearby embankments. In this case, it can minimized the used of labor which make the construction more effective and efficient.

A cut is actually when RL> the grade elevation while fill is when RL< the grade of elevation

PROCEDURE Apparatus: 30 m measuring tape, 2 ranging poles and chalk a) Taping 1. The starting and ending point of a line with unknown length was marked as A and B respectively using chalk. 2. Two ranging poles were each positioned about 0.3 m from each end on the extension of the line 3. Each group member was then assigned as surveyor, leader, follower and recorder respectively. 4. Signal was given by surveyor positioned at the ranging pole near point A to align the ranging pole near point B. Leader and follower must not block the line of sight of surveyor during alignment of ranging poles. 5. The length between AB was then measured and recorded by the recorder. 6. The experiment was then repeated in reverse from B to A and then direct again from A to B.

Figure 2.1- Taping Method

B) Pacing 1. Each member is required to walk along the distance AB marked in first experiment. 2. Number of paces along the distance was counted and recorded while walking along the survey line. 3. The experiment was repeated for minimum three times . 4. The average unit pace and relative accuracy of pacing of each member were then computed.

Figure 2.2- Pacing Method

RESULTS AND CALCULATION Points

BS

IS

FS

HPC

RL

Grade

Cut / Fill Remarks

Elevatio A B C D

1.37

101.37 1.57 1.858

1.05

2.155

100.26

100 99.8 99.512 99.215

n 100 99.630 99.144 98.918

0 0.170 0.368 0.297

5 E F G

1.339 1.847 2.00

98.926 98.682 98.418 98.433 98.265 98.265 Table 5.3.1

Calculation 𝐻 𝐻𝐻 𝐻 = 𝐻𝐻 𝐻 + 𝐻𝐻 𝐻 = 100 + 1.370 = 101.37𝐻 𝐻𝐻𝐻 = 𝐻𝐻𝐻𝐻 − 𝐻𝐻𝐻 = 101.37 − 1.570 = 99.8 𝐻𝐻𝐻 = 𝐻𝐻𝐻𝐻 − 𝐻𝐻𝐻 = 101.37 − 1.858 = 99.512𝐻 𝐻𝐻𝐻 = 𝐻𝐻𝐻𝐻 − 𝐻𝐻 𝐻 = 101.37 − 2.155 = 99.215 𝐻

𝐻𝐻𝐻𝐻 = 𝐻𝐻𝐻 + 𝐻𝐻𝐻 = 99.215 + 1.05 = 100.265 𝐻 𝐻𝐻𝐻 = 𝐻𝐻𝐻𝐻 − 𝐻𝐻𝐻 = 100.265 − 1.339 = 98.926

0.244 -0.015 0

𝐻𝐻𝐻 = 𝐻𝐻𝐻𝐻 − 𝐻𝐻𝐻 = 100.265 − 1.847 = 97.418 𝐻 𝐻𝐻𝐻 = 𝐻𝐻𝐻𝐻 − 𝐻𝐻𝐻 = 100.265 – 2.000 = 98.265 𝐻 𝐻𝐻𝐻𝐻 = 𝐻𝐻𝐻 − 𝐻𝐻𝐻 = 100 − 97.265 = 1.735𝐻 𝐻𝐻𝐻𝐻𝐻 𝐻 𝐻𝐻𝐻𝐻𝐻𝐻𝐻 = 13.98𝐻 RL ( AG ) x Slope Distance of points+ RL ( G ) Slope Distance

Grade Elevation =

Grade Elevation G =

1.735 13.98

x 0 + 98.265

=98.265 Grade Elevation F =

1.735 13.98

x 1.35+ 98.265

=98.433 Grade Elevation E =

1.735 13.98

x 3.36+ 98.265

=98.682 Grade Elevation D =

1.735 13.98

x5.26 + 98.265

=98.918 Grade Elevation C =

1.735 x 7.08+ 98.265 13.98

=99.144 Grade Elevation B =

1.735 x 11+ 98.265 13.98

=99.630 Grade Elevation A =

1.735 x 13.98+ 98.265 13.98

=100

Cut/Fill = RL of point – Grade elevation of point Cut/FillA= RLA – Grade elevationA =100-100 =0

Cut/FillB= RLB – Grade elevationB =99.8-99.630 =0.170 Cut/FillC= RLC – Grade elevationC =99.512-99.144 =0.368 Cut/FillD= RLA – Grade elevationA =99.215-98.918 =0.297 Cut/FillE= RLA – Grade elevationA =98.926-98.682 =0.244 Cut/FillF= RLA – Grade elevationA =98.418-98.433 =-0.015 Cut/FillG= RLG – Grade elevationG =198.265-98.265

=0 Arithmetic checking ∑BS - ∑FS = 2.42 – 4.155 = -1.735 Last RL – 1st RL = 98.265 – 100 = -1.735

DISCUSSION 1. GAN ZHI SHENG For this assignment, we are required to select a location in INTI INTERNATIONAL UNIVERSITY to measure the reduced level of that location. The location needs to have a slope for us to measure the reduced level. We learn how to set up the apparatus before initiating the experiment. Points were marked in a straight line with different value starting from point A. Then all the points have different distance between each other. Their distance is measured and tabulated for further calculations. A theodolite is used in measuring the reduced level. It is used to measure the reduced level for each point. Height of instruments remains in all points to decrease the errors. After taking the measurements from each point, the value is calculated and then tabulated. Precautions need to be taken into considerations for any errors involved before starting the experiment. Make sure the staff has its own bubble to ensure that it is in a straight line. For the theodolite, adjust the bubble for an accurate reading and maintain the height of instrument to prevent errors.

2. TEAH KAI TZEN In this assignment we are needed to choose a location with has a slope to measure the reduced level. 7 points are marked with different length but remains in a straight line. A measuring tape is used to measure each distance. Theodolite is used to measure the reduced level for each point. Then a table for BS, IS, FS is made. After determining the HPC and RL, we need to calculate whether the land need to be fill or cut. If the reduced level is greater than the grade elevation, it has to be cut whereas if it is lower is has to be filled. For this assignment, we learned how to conduct the theodolite and calculate the BS, IS, FS and cut/fill which is important for surveyors. Based on our results, points B, C, D, E and F need to be fill. Other than that, we can check our results by doing arithmetic checking. The difference between the sum of BS and FS should be same as the difference of the last RL and last RL. From this method we can be sure that our results

have no errors and further calculations can be made. It is crucial to have arithmetic checking before any further calculations to ensure zero errors.

3. MALVIN Profile levelling is important in surveying as it is used to build highways, canal, railways and others. Rise and fall method and height of collimations are two different method used commonly but, in our assignment, we select height of collimation method. Different value of BS, IS, and FS were recorded using a theodolite and staff. From the experiment, all the results are recorded for further calculations. For point A the reduced level is 100 and the HPC value is 101.37. Errors can be found as a spirit bubble need to be attached on the staff to ensure the people holding it is in a vertical line. Other than that, the measuring tape used has some error such as wear and tear as it has been used for many years. The theodolite has its own spirit bubble and before the experiment starts it has to be adjusted so that the readings taken is accurate. After all the readings has been recorded, calculation is needed to determine whether it has to be fill or cut. From this assignment, we have learned how to conduct the experiment and setting up all the instruments and avoiding the errors can be found and taken the highest accuracy from this experiment. 4. SANDRA LAM In this profile levelling experiment, we are required to take measurement of the RL in the surroundings of INTI INTERNATIONAL UNIVERSITY cope. This experiment taught fundamental things of surveying which is how to setup the levelling instrument correctly and what we should prepare and face like the safety and welfare to do the experiment as long as the precautions to what not to do to reduce the level of errors or mistakes in doing this experiment. As written in manual lab, the requirements stated that we have to mark 7 points with a given shape. All is A, B,C,D,E,F and G would be the last point. In order to prevent any confusion, we set all the height of the instrument remain the same from point to point of different location. In this experiment, we basically know the terms of cut and fill where cut is basically when RL Is greater than the grade elevation whole fill is when RL is lower than the grade elevation

5. DAYANGKU MUNIRAH In this experiment that we conducted, basically we learn about profile levelling. Here, we should mark at 7 given points with its shape which are point A, B, C,D,E as well as point G. This experiment was starting from BM at point A with elevation of 100 m. In point A, RL is 100 and the grade elevation is 99.63. From the calculation that we made, point A to D is meant to be cut as the ground elevation > grade the elevation along all the points. Other than that, E and G should be filled in this case. To ensure accuracy and preventing error to happen, we check the data twice. Double check is made but of course again in every experiment there will be a small percentage of error that is unavoidable. It maybe because of the member that hold the rod not vertical or even bubble is not centered correctly as its procedural. 6. DARREN POI This profile levelling experiment basically taught us how to determine the different points of the ground using its methodology. From the table, it clearly show that the RL from A to F point keep decreasing. In this experiment, we use checking method and it seems to be that the sum of BS and FS is same to the difference of First and last RL. This made an evidence that the data collection was done in a proper manner and this experiment is successfully been done. Therefore, it is very useful and important to do this kind of checking method in order to get correct and precise value. This profile levelling experiment is very useful to be used to design infrastructure facilities in such highways, transmission lines, canals, water mains, etc. From all those calculations is using the Height of collimation and rise and fall method.

CONCLUSION 1. MALVIN To conclude, we have discovered that how to experience the profile levelling on a street which has different slopes. Profile levelling is used commonly to determine the elevations for different points with different distances between them. Each point has its own distance and different slopes. Differential levelling is almost the same as profile levelling, but profile levelling has an additional back sight to the known elevations. Thus, in this method, instrument get to set up number of times to observe the reading along a route in between the points. For each set up, staff readings are taken back to a point of known elevation final sight to the terminal station. Errors may occur during this field work so precautions need to ne taken into considerations beforehand. The theodolite needs to be adjusted so that the spirit bubble is in the circular shape. In addition, measuring tape has to be in a good condition where there is no wear and tear as it have been used for many years. The sensitivity of the instruments may wear off. After recording all the results, calculations are needed. To double check the results, the difference of the sum of BS and sum of FS has to be the same with the difference of the last RL and first RL. 2. SANDRA LAM Overall, profile levelling is a process in determining the elevation points that is measured along the line. This method of surveying is important as it is useful in locating drains, road and dams. We have chosen a location and 7 different points were marked. The points are in a straight line with a desired slope. Using a theodolite, the value of BS, IS, and FS is recorded. After calculating the grade elevation, we need to decide whether it has to be cut or fill. If the reduced level is greater than the grade elevation, it has to be cut whereas if it is lower is has to be filled. Before starting the fieldwork, all the instruments need to be in a good condition. Theodolite need to be checked if it is fully charged. Before starting, the theodolite needs to be adjusted so that the spirit bubble is in the circular shape. The staff need to have an attached spirit bubble to ensure the person holding it is standing in a vertical position. All the results are tabulated and with sample calculations.

3. TEAH KAI TZEN Profile levelling is a method in surveying where is has been carried out along the central line of a track of land. Profile levelling is a method of surveying that has been carried out along the central line of a track. From this fieldwork we are able to learn hands on experience of surveying. A location is selected where points are marked in a straight line with slope. Normally the elevation is set to a value of 100. Measuring tape is used in measuring the distance between two points. Measuring tape need to be in a good condition without wear and tear to increase the accuracy of results. Theodolite need to be adjusted where the spirit bubble is in the circular shape. Errors can be checked by checking the sum of BS, IS, last RL and first RL . In a nutshell, we learn how to set up all the instrument and applying all the precautions to minimise the errors can increasing the accuracy of results. 4. DAYANGKU MUNIRAH To sum everything, from this profile levelling experiment, we learn the way to measure and take the reading with a profile levelling method on road which in a way it has different level of slopes. Basically, profile levelling is a process of determination of the series of elevation at measuring intervals along the line of it. For example, the centre line of proposed ditch or the long stretch road. Actually, profile levelling is approximately the same with differential levelling like we do the same manner of the determination of the elevation. Definition, terms, methodology as well as the concept is same. From that both, it also can gain the errors and mistakes which get it from bench mark to benchmark. 5.DARREN POI In conclusion, this experiment taught us how to undergo profile-levelling which in this case in road with different of slopes. Actually, the theory behind the profile-levelling is by add back the sight to the known elevation. Therefore, we would be able to obtain the instrument height. Then, to be able to obtain the elevation where we took the point, we must first subtract the height of instrument to the foresight. And then, we need to repeat this again and again until we finally obtain the benchmark. Finally, we would obviously know whether the actual length is shorter or longer than the actual measurement. In reality, this profile levelling is very useful to establish boundaries too and lines as well as elevation of structure needed to work out of .

6. GAN ZHI SHENG As a final observation, this slope that we did the experiment is various slopes and it requires fill to get a better surface that we want. Throughout the experiment,we face some challenges and discuss a lot with solving many problems. But, it is accomplished quite well with a bit of improvement needed in the future. Errors of course are made as some of the tape scale has some scale off or not really accurate at some point as it has been used for long time. Now, equipment has been improved quite well as they use digital measuring tape or it can even used some kind of device to measure. This profile levelling is important for the work of engineering as for planning and layout of project.

REFERENCES 1. The constructor (2019), types of levelling methods used in surveying, available at :

https://theconstructor.org/surveying/types-of-leveling-methods/14679/ 2. VWikipedia (2019), the definition and terms of cut and fill, available at:

https://en.wikipedia.org/wiki/Cut_and_fill 3. Brainkart (2019), profile levelling sectioning in the field, available at:

https://www.brainkart.com/article/Proceed-profile-leveling-or-longitudinal-sectioning-inthe-field_4626/

APPENDIX...