SPECIFICATION OF WORKS AND GIVEN DATA

The following technical specifications were carried out during the work.

a.     Number of station should be selected in such a way that at least one station is visible from one forward and one backward station.

b.     Number of station should be selected less as far as possible.

c.      The ratio of traverse leg should not more than twice of minimum traverse leg. (1:2)

d.     Two-way measurements of traverse legs were taken with in the permissible limit of 1:2000.

e.      The permissible angular error of sum of interior /exterior traverse angles should be as

Major traverse                        

Minor traverse                        

Bridge site Triangulation                  

f.       Bowditch’s Rule should do balancing of traverse.

g.     Major traverse stations should be selected in such a way that at least one if its legs should be common leg for the minor traverse .i.e. minor traverse is in major traverse.

h.     Fixation of major/minor traverse is done by consecutive coordinate method on perfectly drawn grid line.

i.       R.L of common Temporary Bench Mark (TBM) is found out by fly leveling from the B.M. The fly leveling should be done in two ways. The permissible error in leveling should not be greater than ±2.5’Jk. Where, k=distance in km. In this case only central reading should be taken should transfer the R.L of all the major traverse station.

j.       In minor traverse, tachometer and plane tabling should take the detailing.

k.     The selection of IP should be at least visible one forward and one backward from one IP.

l.       Establishing of control points forming well condition triangle on bridge site survey. Detailing of the area is 150 m upstream and about 100 m downstream from the axis of bridge were taken by tachometer.

m.  Reciprocal leveling and fly leveling should be done in road site and bridge site survey for checking.

n.     After computation of all fields’ observations, following specified scale should used for plotting: