Skip to main content

civil engineering-->>Equipments for baseline Measurements in surveying

Equipments for baseline Measurements


In triangulation the base line is of prime importance (b/c). it is the only hor distance to measured. It should be measured very accurately since the accuracy of the computed sides of triangulation system depends on it. Length of base line varies form afraction of (0.5-10)km and a fradion of a mile to 10 miles.
According to the grades of Triangulation

Baseline Site:

In selecting site for a base line, the following requirement should be considered.
  1. The site should be fairly leveled or uniformly sloping or gauntly undulating.
  2. Should be free form obstructions throughout the entire length.
  3. Ground should be firmed and smooth.
  4. The site should can be such that the whole length can be laid out the extremities of the line being intrevesible at ground level.
  5. The site should be such that well shaped triangle can be obtained in connecting the end stations of the base line to the main triangulation stations.

Base Net:

A series of triangles connecting a base line to the main triangulation is called a base net. The base should be gradually expended by triangulation as shown figure (i) and (ii)

Equipments for baseline Measurements

  1. Tape
  2. Straining Device
  3. Spring balance or weight and pulley
  4. Thermometers and a finely divided scale
  5. Marking tripod or station rakes
  6. Supporting tripods or stakes.

Comments

Post a Comment

Popular posts from this blog

civil engineering-->> overview of arches

Arches An arch is an opening spanned by a collection of wedge shaped pieces ( voussoirs ) which stay in position by pressing in on one another. The joints between the pieces appear to radiate from some central point lying within the opening, and sometimes from points which lie outside, so every type of arch has a characteristic curvature. The simplest and visually most natural shape for an arch is the semicircle but many other designs have been used. How an Arch "Works" The central voussoir ( keystone ) is traditionally the last to be set into position to "lock" the whole thing into a strong and stable structure. A keystone is not always necessary, however; there may be a joint at the apex instead, as is common in Gothic arches.  Gravity tries to pull the keystone downwards, but the thrust is carried on either side by the voussoirs immediately flanking it. These in turn have their total thrust carried through the whole semicircle of pieces in a sideways direc...
Post a Comment
Read more

civil engineering-->>Determinacy, Indeterminacy and Stability of Frames

Determinacy, Indeterminacy and Stability of Frames : Structural engineers must be able to apply judgment rather than stated rules. The most important aspect of structural design is not the ability to apply formulas or manipulate mathematics. The most important skill for the structural engineer is to be able to stand back, look at a drawing or sketch and determine whether a structure is stable, and if it is stable, to be able to determine how it will carry the applied loads. For a very complicated structure this might be more difficult and a computer can provide some help, but ultimately it is the skill and concern of a good structural engineer which produces good structural designs which have integrity. Another important closely related skill is the ability to determine whether, and to what degree, a structure is statically indeterminate. There really aren’t  many rules and rules may be difficult to apply in any case. For this reason, we need experience. A skilled structural...
1 comment
Read more

civil engineering-->> truss types

                                                                                                                           Modified-Queen-Scissors                                                          Baby Barn and Shed Trusses                                                                        floor truss       ...
1 comment
Read more