Primary Division and Principle of Surveying — Transcript

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1. 0:00welcome to the lecture series of basic
2. 0:02civil engineering
3. 0:04in this lecture we are going to learn
4. 0:06about primary Division and principle of
5. 0:10serving
6. 0:11so let us start with outline of the
7. 0:13session
8. 0:15in this session we are going to learn
9. 0:18primary division of serving and
10. 0:22we will learn about fundamental
11. 0:24principle of serving so let us start
12. 0:27with primary division of surveying
13. 0:30basically there are two division of
14. 0:33serving first is clean serving and
15. 0:35geodetic serving
16. 0:37let us start with the plane surveying
17. 0:40the survey in which Earth is assumed to
18. 0:43a plane and the curvature of Earth is
19. 0:47ignored it is called plane serving
20. 0:50geodetic survey is the survey in which
21. 0:52the earth's surface is assumed as a cow
22. 0:56surface as it is we know that the shape
23. 1:00of Earth is parallel so when such shape
24. 1:04of Earth is considered and Survey is
25. 1:07conducted that is called geodetic survey
26. 1:10so in geodetic survey we considered the
27. 1:13cow surface of Earth
28. 1:15in plane serving we ignored such
29. 1:19curvature of Earth
30. 1:22the plane survey extended over the small
31. 1:25areas and the geodetic survey is
32. 1:29extended over the large area
33. 1:32as in the plane surveying it is
34. 1:35conducted over the small area the line
35. 1:37connecting any two point on the surface
36. 1:40of Earth are considered as straight line
37. 1:43whereas in geodetic survey the line
38. 1:46joining any two station on the surface
39. 1:50of Earth is considered as Cloud line
40. 1:54in plane serving any triangle means if
41. 1:57we connect any three point the triangle
42. 2:00form is considered as a plane triangle
43. 2:03whereas in geodetic survey
44. 2:07the triangle are considered as
45. 2:10spheroidal triangle as you can see here
46. 2:14when the surface area is less than 250
47. 2:17kilometer Square it is considered as
48. 2:19plane serving and we do not consider the
49. 2:23curvature shape of Earth but when the
50. 2:26area to be surveyed is more than 250
51. 2:30kilometer Square in that case will
52. 2:33conduct geodetic survey plane survey are
53. 2:36used for layout of Highway Railway
54. 2:40Canal fixing the boundary of pillars
55. 2:43construction of bridges Factory
56. 2:46etcetera whereas the geodetic survey is
57. 2:50used for preparing the map of a larger
58. 2:56area like preparing the map of state
59. 3:00preparing the map of country preparing
60. 3:02the map of continent so this is about
61. 3:05primary division of survey now let us
62. 3:08move to next topic that is fundamental
63. 3:11principle of serving two basic principle
64. 3:14of serving are there first always work
65. 3:18from Whole to part and the second
66. 3:22to locate the new position by at least
67. 3:24two measurement from fixed reference
68. 3:27point
69. 3:29so let us see one by one
70. 3:31first principle is always work from
71. 3:35Whole to path
72. 3:37this is the main principle of serving
73. 3:40achieve this in actual field
74. 3:43a sufficient number of primary control
75. 3:45Point are established with very high
76. 3:49Precision in around area to be surveyed
77. 3:53like here
78. 3:55p q and R are established with very high
79. 4:00accuracy and with very precise equipment
80. 4:03after that the minor control Point here
81. 4:07we can see a b and c
82. 4:11are located between the primary control
83. 4:14point and
84. 4:16this point are established with less
85. 4:19precise method
86. 4:20further
87. 4:22details our survey means M and O which
88. 4:26are interior detail
89. 4:28these are surveyed with reference to
90. 4:31minor control Point by adopting any one
91. 4:34of the method of serving
92. 4:37the main idea of working from Whole to
93. 4:40part is to minimize the error
94. 4:44it prevents the accumulation of error
95. 4:47and
96. 4:48it localized the Minor error within the
97. 4:52frame out of control point on other hand
98. 4:55if we work the reverse principle means
99. 4:58to work from part to Hall the error
100. 5:01would be expand greater magnitude and
101. 5:04the scale of survey will be distored
102. 5:07beyond the control
103. 5:10in general practice area is divided in
104. 5:14large triangle here I have shown only
105. 5:16one but the complete area are divided in
106. 5:20many triangles
107. 5:22and positions of their vertices are
108. 5:25surveyed with the grid accuracy using
109. 5:28very sophisticated instrument these
110. 5:30triangles are further divided into
111. 5:33smaller triangle and the vertices are
112. 5:37surveyed with less accuracy
113. 5:39so this is the first and important
114. 5:42principle of working from Hall to part
115. 5:44now let us learn the second one
116. 5:48that is to locate a new position of any
117. 5:52stations by at least two measurement
118. 5:55from fixed reference point
119. 5:59so here A and B are the reference fixed
120. 6:02reference point and we want to locate
121. 6:05the point C so first method is to take
122. 6:09the linear measurement of C point from a
123. 6:12and b means major distance AC and BC
124. 6:18the next method the C Point can be
125. 6:21located by taking linear measurement in
126. 6:24perpendicular Direction
127. 6:27the next one we can locate the C Point
128. 6:31by taking linear measurement from any
129. 6:34one station means station b means we can
130. 6:37measure the length BC and the angle
131. 6:40angular measurement is taken means the
132. 6:43angle ABC is measured
133. 6:47in the next method we cannot take any
134. 6:50linear measurement but C point is
135. 6:53located by taking two angles means angle
136. 6:57c a b and angle a b c
137. 7:03in the next method
138. 7:05the C point is located by one linear
139. 7:08measurement and opposite angle can be
140. 7:10measured so by any of the method we can
141. 7:14locate the new point which takes minimum
142. 7:18to measurement so that the fixed
143. 7:21reference point can fix accurately
144. 7:25so these are all about
145. 7:27primary division of serving and
146. 7:29principle of serving thank you very much
147. 7:31for watching this video if you have any
148. 7:34doubt or query please write in the
149. 7:36comment box I will be there to help you
150. 7:39thank you thank you very much