Stub Setting
CHAPTER – 4
STUB SETTING
1.0
1.1
EXCAVATION PIT MARKING:
After the location marking has been done, the marking of the pits for excavation for the foundation of the location is carried out. This is based on the specific foundation drawing of the type and make of the tower which is to be erected at that location.
1.2
The tower legs, footings and faces are designated as shown in the drawing below.
1.3
The pit marking shall be carried out according to the pit marking drawing which is prepared from the foundation drawing of the tower. The size of the pit, in case of open cut foundations, is worked out by adding 150 mm to the sides of the base pad on all the four sides for allowing working space. No margin is necessary in case of undercut foundations.
1.4
The excavation pit marking drawing indicates the distance of centres, sides and corners of the pits with reference to the centre point of the tower. These distances are measured and each pit boundary is marked in the field by means of spade or pick axe along the sides of the pit.
68
Construction Manual for Transmission Lines
1.5
A typical excavation pit marking drawing is given below.
1.6
From the dimensions shown in the drawing, the triangle ABC is first marked with the help of a measuring tape. The distance CD, equal to F (width of the pit) is marked on the ground.
The triangle AB'C is then marked by shifting the point B and without changing the points A and C. The distance CD', equal to F, is then marked. The sides DE and D'E, both equal to
F, are then marked. The procedure is repeated for marking the other three pits.
1.7
The dimension G shown in the drawing is the centre to centre distance between stubs of the tower at their lowest point. The dimension M is the diagonal distance between the ends of the stubs of the tower. The excavation pit marking drawing is prepared on the basis of these dimensions. 1.8
Sample calculation of the volume of
STUB SETTING
1.0
1.1
EXCAVATION PIT MARKING:
After the location marking has been done, the marking of the pits for excavation for the foundation of the location is carried out. This is based on the specific foundation drawing of the type and make of the tower which is to be erected at that location.
1.2
The tower legs, footings and faces are designated as shown in the drawing below.
1.3
The pit marking shall be carried out according to the pit marking drawing which is prepared from the foundation drawing of the tower. The size of the pit, in case of open cut foundations, is worked out by adding 150 mm to the sides of the base pad on all the four sides for allowing working space. No margin is necessary in case of undercut foundations.
1.4
The excavation pit marking drawing indicates the distance of centres, sides and corners of the pits with reference to the centre point of the tower. These distances are measured and each pit boundary is marked in the field by means of spade or pick axe along the sides of the pit.
68
Construction Manual for Transmission Lines
1.5
A typical excavation pit marking drawing is given below.
1.6
From the dimensions shown in the drawing, the triangle ABC is first marked with the help of a measuring tape. The distance CD, equal to F (width of the pit) is marked on the ground.
The triangle AB'C is then marked by shifting the point B and without changing the points A and C. The distance CD', equal to F, is then marked. The sides DE and D'E, both equal to
F, are then marked. The procedure is repeated for marking the other three pits.
1.7
The dimension G shown in the drawing is the centre to centre distance between stubs of the tower at their lowest point. The dimension M is the diagonal distance between the ends of the stubs of the tower. The excavation pit marking drawing is prepared on the basis of these dimensions. 1.8
Sample calculation of the volume of