A Guide on Geodetic Survey and Monitoring
A Guide on Geodetic Survey and Monitoring
August 28, 2019
If used judiciously with geotechnical instrumentation, geodetic monitoring provides co-related data which is relevant and extensively used in civil construction and structural monitoring. Encardio Group uses an in-house developed control box with advanced software to control robotic total stations.
The system ensures valuable and timely monitoring of the displacements, providing high measurement density, simultaneous wireless transmission and automatic entry of the results in the monitoring database.
Geodic survey is used at pre-construction, during construction, and post-construction stages.
Several geotechnical instruments are used to monitor the fundamental parameters affecting the construction.
Due to its relatively low-cost, it is widely spread and used in all civil engineering projects.
Let’s discuss more on geodetic surveying, its importance, and application areas.
What is the geodetic survey?
When there’s a large area, usually beyond 100 square kilometres, the surveying requires the consideration of curvature of the earth. Such type of surveying is known as the geodetic survey.
In geodetic surveying, two stations (points) at a considerable distance from each other are chosen.
The latitude and longitude of these two points are determined astronomically. The line joining these two points is known as the baseline, which is measured precisely.
The position of a third station is defined by the angle made with each end of the baseline.
The complete process is known as triangulation. It is continued until the entire survey land is mapped.
What is the geodetic level?
Geodetic levelling is the process of determining the relative height of the stations or points on the earth’s surface.
Level surface: It is defined as the surface, which is parallel to the earth’s mean spheroidal surface.
Level Line: It is the line lying in the level surface and, hence, it is normal to the plumb line at all points.
Horizontal Line: It is a straight line tangential to the level line.
Vertical Line: It is the line normal to the level surface.
What is the objective of geodetic surveying?
Following are the objectives of geodetic surveying:
The main objective of geodetic surveying is to determine the precise position of distant points on the surface of the earth.
To get reconnaissance information and preliminary data required by engineers for selecting suitable routes and sites.
To prepare efficient structural designs.
To define selected locations by establishing a system of reference points
To guide construction forces by setting stakes or otherwise marking lines, grades, and principle points and by giving technical assistance.
To measure construction items in place to prepare progress reports
To carry out dimensioning of structures for preparation of as-built plans
To detect settlement using pre installed targets on buildings, structures, pavements, embankments etc.
To monitor the on-going construction project 24/7 so that the mishaps can be avoided.
To monitor deformations taking place in the structures, bridges, tunnels, buildings.
To ensure the safety of the nearby assets to the construction land.
|Also Read: A Guide on Geotechnical Instruments: Types, & Application |
Geodetic Surveying Application
Geodetic monitoring, along with geotechnical instrumentation< provides data widely used for structural monitoring.
Settlement detection
Levelling measurement of preinstalled targets on buildings, structures, pavements, deep points, embankments using high accuracy digital levels and invar staffs.
3D optical targets
Three-dimensional displacement measurements with bi-reflex targets or monitoring prisms that are installed in tunnels, structures and buildings etc., using high-end total stations provide for manual as well as automatic data.
An in-house software by Encardio-rite named Terramon is available that can be installed on a tablet, laptop or a PC to achieve semi-automatic measurement, to maximize their accuracy, and to minimize the field time.
For automatic monitoring, Drishti or Terramove is available depending on the requirement from project to project.
Terramove can also be used for co-relating data from TBM sensors with data available from geotechnical and geodetic instrumentation, whether manual or automatic.
Automatic monitoring system
Projects safety requires 24/7, high frequency, & accurate measuring monitoring systems.
The Encardio group uses an in-house developed system that consists..[Continue Reading]
