Search results
Results from the WOW.Com Content Network
The water level at each end of the tube will be at the same elevation, whether the two ends are adjacent or far apart, so a line between them will be horizontal at its midpoint and a shed base, building foundation or similar structure laid out using several such lines will be "horizontal" within building tolerances on any scale over which use ...
In 1914 and 1915, the Forestry Quarterly published a series of articles on the use of the Abney level. [6] [7] [8] These tutorial articles remain useful today, but the primary reference for usage is the 1927 Abney Level Handbook. [3] The Abney level is typically used at the eye height of the surveyor, either hand-held or mounted on a staff at ...
The level staff is placed with its foot on the point for which the level measurement is required. The telescope is rotated and focused until the level staff is plainly visible in the crosshairs. In the case of a tilting level, the fine level adjustment is made by an altitude screw, using a high accuracy bubble level fixed to the telescope.
Instruments used in surveying include: Alidade; Alidade table; Cosmolabe; Dioptra; Dumpy level; Engineer's chain; Geodimeter; Graphometer; Groma (surveying) Laser scanning; Level; Level staff; Measuring tape; Plane table; Pole (surveying) Prism (surveying) (corner cube retroreflector) Prismatic compass (angle measurement) Ramsden surveying ...
In time, this resulted in major land subsidence by the 1970s with local areas having 0.30 to 8.5 m (1 to 28 ft) of subsidence. With the creation and use of the California Aqueduct along these regions, surface water being transported put a halt on significant compaction and a recovery in ground water levels now with less ground water pumping. [22]
The baseline stations are first deployed in the corners of a work site. Their relative position is then precisely measured using the AquaMap system's automatic acoustic self-survey capability. For geo-referenced operations, the baseline positions are surveyed by differential GPS or a laser positioning equipment (total station).
A radio telemetry wireline extensometer monitoring slope deformation. Deformation monitoring (also referred to as deformation survey) is the systematic measurement and tracking of the alteration in the shape or dimensions of an object as a result of stresses induced by applied loads.
The terminus of the Angeles Tunnel at the Castaic Power Plant The Angeles Tunnel is a 7.2-mile-long (11.6 km), 30-foot-diameter (9.1 m) [ 1 ] water tunnel located in the Sierra Pelona Mountains in Los Angeles County , California , about 50 miles (80 km) north of Los Angeles .