Zero reading level measurement method and accurate adjustment structure for height of leveling instrument

Abstract

The invention discloses a zero reading level measurement method and an accurate adjustment structure for the height of a leveling instrument; the zero reading level measurement method is characterized by comprising the following steps of: in a measurement process, respectively erecting the leveling instrument and a rearview leveling staff at places which are equal to the elevation of the top surface of a measured constructional element; adjusting the height of the leveling instrument so that the top surface of the measured constructional element is flush with the height of a level mark silk thread in the leveling instrument; maintaining the height of the adjusted leveling instrument, defining the position of the corresponding height of the level mark silk thread in the leveling instrument on a rearview leveling staff as a viewpoint A; and measuring the elevation of the rearview point A on the rearview leveling staff by using a known leveling point B, wherein the elevation of the rearview point A is the elevation of the top surface of the measured constructional element. A fore-view leveling staff is not needed to be erected on the top surface of the measured constructional element, thereby being very effective for avoiding the difficulty and insecurity caused by ascending of levellers.

Description

technical field [0001] The invention relates to an elevation measurement method, more specifically, it is mainly used for elevation level measurement across rivers or deep ditches in highway engineering. Background technique [0002] There are many bridge projects across rivers or deep ditches in highway engineering, among which the leveling survey in the construction process of high piers is particularly important. At present, the methods of leveling surveys for high piers in our country include: level instrument inverted ruler method, ordinary total station triangulation Elevation method, direct measurement by GPS or direct measurement by using a long tape, these measurement methods all require surveyors to climb to the top of the high pier and set up a forward-looking leveling rod on the top of the high pier, which not only increases the cost of climbing the vertical ruler The resulting measurement difficulty also brings greater safety risks to the measurement personnel. ...

AI Technical Summary

Problems solved by technology

[0002] There are many bridge projects across rivers or deep ditches in highway engineering, among which the leveling survey in the construction process of high piers is particularly important. At present, the methods of leveling surveys for high piers in our country include: level instrument inverted ruler method, ordinary total station triangulation Elevation method, direct measurement by GPS or direct measurement by using a long tape, these measurement methods all require surveyors to climb to the top of the high pier and set up a forward-looking leveling rod on the top of the high pier, which not only increases the cost of climbing the vertical ruler The resulting measurement difficulty also brings a greater safety risk to the measurement personnel

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