FACULTY OF CIVIL AND ENVIRONMENTAL
ENGINEERING
DEPARTMENT OF INFRASTRUCTURE AND
GEOMATIC ENGINEERING
LABORATORY SHEET
SUBJECT CODE
BFC 20703
PARTIAL CODE
MG 03
PRACTICAL NAME TRAVERSE (HORIZONTAL CONTROL)
COURSE CODE
BFC 20703
FACULTY OF CIVIL AND ENVIRONMENTAL ENGINEERING
DEPARTMENT OF INFRASTRUCTURE AND GEOMATIC
ENGINEERING
GEOMATIC LAB
FULL REPORT
Subject Code BFC 20703
Practical Name TRAVERSE ( HORIZONTAL CONTROL ) Course Code BFC 20703
Practical Date
Group 6
Group Leader Faizzatul Aqma binti Md. Noor ( AF130096 ) Name 1. Fasha Farhana binti Karim ( AF130140 )
2. Hanif bin Kormain ( CF130177 )
3. Sharifah Shahida binti Syed Idrus ( AF130140 ) 4. Wahyu Hidayat bin Usman ( AF130083 )
Lecturer’s name/ Instructor/ Tutor
Dr. Mustaffa bin Anjang Ahmad
Marks Introduction / 5% Objective / 5% Theory / 10% Instrument / 5% Procedure / 5% Data / Table / 10% Data Analysis / 20% Discussion / 15% Presentation / Ploting / 10% Calculation / Recommendation / 10% Reference / 5% Total Mark / 100% Comments by Examiner Received
1.0 INTRODUCTION
Horizontal control is a form of a control survey that requires the establishment of a series of stations that are linked together by angles and distances. The used of horizontal control is very fundamental and has become one of the most common methods in civil engineering work.
2.0 OBJECTIVE
To expose students in field work procedures of establishing horizontal control network.
3.0 THEORY
In survey, traverse is defined as the field operation of measuring the lengths and directions of a series of straight lines connecting a series of points on the earth. Each of these straight lines is called a traverse line, and each point is called a traverse station. Traverse stations are commonly marked with wooden peg, stake, nail or iron pipe.
Traverse lines are measured using the total station. Traversing need to start from reference datum (coordinate, bearing and distance are known). At each traverse station, a horizontal angle is measured and used to determine the bearing and bearing of the next traverse line. These measurements are used to compute the relative horizontal position of each unknown traverse station. The main purposes of traverse are:
Property surveys to locate and establish boundaries
Supplementary horizontal control for topographic mapping surveys
Location and construction layout surveys for highways, railways and other private or public works
4.0 PRACTICE EQUIPMENTS
All groups will be issued with the following equipment:
No. Items Quantity 1. Total Station 1 2. Prisms 2 3. Pegs -4. Nails -5. Tripod 3 6. Hammer 1 5.0 FIELDWORK PROCEDURES
I. Planning and Reconnaissance: Walked over the area in the field and the suitable traverse for survey work were looked out.
II. Pegging traverse station: Since they will remain for the duration of the survey camp, the line of sight of each control point and its susceptibility to disturbance were considered.
III. Establish datum: The survey need to be start with three known control points. The distance were measured to the nearest 10 mm and the angle were measured to the nearest 10”. If the measurements differ by more than 30 mm / 20”, the survey must be repeated or the other control point must be find.
IV. There are several steps which should be followed and will lead to a smooth traverse.
a) First, the instrument was set up over the station. b) The instrument was levelled and centred. c) The instrument was set to the required datum.
d) Face left horizontal reading to backsight station was recorded. (bearing & distance)
e) The instrument and sight foresight station was turned.
f) Face left horizontal reading to foresight station was recorded. (bearing & distance)
g) The instrument was transited from Face Left to Face Right. h) The required datum (bearing) to backsight station was set. i) Face left horizontal reading to backsight station was recorded.
(bearing & distance)
j) The instrument was turned to face foresight station.
k) Face left horizontal reading to foresight station was recorded. l) The mean bearing foresight station was calculated.
m) The instrument was moved to the next station (foresight station).
n) The next traverse line bearing were respect or correspond to the previous mean bearing.
DATA ANALYSIS AND CALCULATION
- Bearing shoud be read = 306º08’35’’ - Bearing read = 306º08’30’’
- Misclosure = 306º08’35’’ - 306º08’30’’ = 05’’
- Correction = 5/4 = 1.25’’
Our group has been given a site to observe the area to measure the length and direction of series of a straight line connecting of point on the earth. We start the fieldwork with observation and making decision of picking point. Four station point has been establishes with marked pickets. The location of each point pick must be free from the disturbance and safe. Traverse station should be numbered continuously clockwise. There are a few factor which might influenced the reading that obtained. There are :
1) Human factor - The readings not consistence due to many observer recorded the value.
2) Environment factor - The hot weather disturbed the concentration of observer till hard to focus on prism.
-The soil :sandy soil weak between the correctivity of each particle and not able to apply load on top of it. So when the instrument applied at the specific areas, the possibilities to obtain error reading more high.
3) Equipment factor - The total station might be not in good condition.
CONCLUSION
Based on the work that we done, we achieved to perform one horizontal traverse control fieldwork. From the booking analysis and calculation, we obtained our linear misclosure is 0.5’’ with four station point. Therefore, the correction for each point is 1’’ . Futhermore our precision is 1:4228.48 . After process the data that we obtained by
