Chaining on Sloping Ground (Simple Notes) When measuring distances on a hill or slope, we always need to find the flat horizontal distance , not the actual sloped ground distance. There are two main ways to do this: 1. Direct Method (Stepping Method) In this method, you measure the flat horizontal distance directly on the field by creating small, flat steps. Best For: Short, bumpy, irregular, or gentle slopes. How it works (Step-by-Step): Start: The Follower holds the 0-end of the tape flat on the starting ground point A. Stretch: The Leader pulls a short, comfortable length of the tape forward and lifts it up until it looks perfectly flat and straight by eye judgment. Drop: Because the front end of the tape is hanging in the air, the Leader drops a plumb-bob (a weight on a string) down to find the exact vertical point on the ground. Mark & Repeat: They stick an arrow into that ground point. The Follower moves to this new arrow, and they repeat the steps all the way u...
Pitch
It is the distance between the centre of two consecutive rivets measure along a row of rivets i.e measure parallel to the stress in a member .It is denoted by p .
Minimum pitch
If Φ= 20mm then pmin= 2.5x21.5= 54mm
Where Φ= nominal Diameter of rivet
Maximum pitch
Maximum pitch is kept under following standard.
(a) pitch maximum when tacking rivets are provided then take lesser value of 32t or 300mm, where t= thickness of plate of least thickness
(b)- For tension member it should be lesser value of 16t or 200mm.
(c) For compression memeber 12t or 200mm which is less.
Gauge(g)-
it is the distance between adjacent rivets lines which is perpendicular to the stress in a member .it is denoted by g
Edge distance
it is distance between centre of rivet and edge of the plate measured perpendicular to the direction of load.
End distance
it is distance between centre of rivet and edge of plate element parallel to the direction of force.
Eccentricity
Eccentricity is the perpendicular distance between the forces.
Types of riveted joint
1- Lap Joint
2- Butt Joint.
Lap joint
In this joint two plates place one on other and are joined with chain or diamond riveting.plates may be same thickness or different thicknesses.
Butt joint
When same thickness plates in two numbers are placed face to face and associated closely with cover plates,is known as butt joint.
These joints are of two types
1 Single cover butt joint - when in butt joint single cover plate is used as shown in the fig it is known as single cover butt joint.
2- Double cover butt joint - when two cover plates are used in butt joint is called double cover butt joint .
Also see...
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