What does rl mean in construction

Relative level in surveying refers to equating elevations of survey points with reference to a common assumed datum. It is a vertical distance between survey point and adopted datum plane. Hello and welcome to Just Answer. It is a measurement of height taken from some known datum.

The levels on the site plan are the numbers next to the crosses on the site plan. They look like this: The cross marks where the level was taken on the site with the equipment, and the number is the height. The heights where these 'levels' are located are referred to as the Reduced Level or R.

L for short The R. L can be referenced in 2 ways. If you look at the site plan, on the bottom left of the corner of the site is the level Height of Instrument Method. In any particular set up of an instrument height of instrument, which is the elevation of the line of sight, is constant. The elevation of unknown points can be obtained by subtracting the staff readings at the desired points from the height of instrument.

What is the first principle of surveying? Explanation: The first principle of surveying is to work from whole to part. A surveying term used in spirit leveling for the height of the line of sight of a leveling instrument above the adopted datum, in trigonometric leveling for the height of the center of the theodolite above the ground or station mark, in stadia surveying for the height of the center of the telescope of the transit or …. In spirit leveling, the vertical distance from datum to line of sight of the instrument.

Height of Collimation is the height of the horizontal plane through the telescope. The survey station is below the horizontal plane through the instrument, so to find reduced level, or ground height, take the staff reading away from Height of Collimation. A foresight is a reading taken on a position of unknown coordinate s. The verb survey means to look something over.

Survey is also a verb. If you survey an area hit by an earthquake, you look closely at it to measure the damage. A backsight BS is a sight taken with the level to a point X of known elevation E X , so that the height of the instrument HI can be found.

A backsight in direct levelling is usually taken in a backward direction, but not always. Entry 1 of 2 transitive verb. Surveys are used to gather or gain knowledge in fields such as social research and demography. To do all this, you will need to be able to interpret a contour map provided by the building surveyor or other authority such as the local council. In the above example the datum for the site has been shown at a reduced level RL of 10 The fall from the datum to Point A is mm.

The fall from the datum to Point B is mm. The fall from Point A to Point B is mm mm - mm.