PURPOSE OF INCLINATION MONITORING
- Determining tilt values, absolute and relative displacement of the building compared to the initial state.
- Evaluating working capacity, stability of the foundation of the construction during constructing and using later.
- Finding and detecting dangerous displacement, based on that offering appropriate solutions to prevent possible incidents.
METHOD OF INCLINATION MONITORING
The inclination of the construction during the using period appears due to many reasons: Due to the impact of the load, the wind, the effect of uneven settlement. So that the determination of the inclination of the construction in this stage need to be done cyclely to monitor and evaluate its development over time. The monitoring cycle is long or short depending on the development speed of the tilt and is decided by the Designer or the Building Management Board.
Before monitoring horizontal displacement and inclination of a house or building, it is necessary to build a grid of standard landmarks. These benchmarks are stable compared to the horizontal plane of the columns and can be used to place the machine for measuring inclination marks. Comparing the difference between the horizontal distances of the measuring points will determine the horizontal displacement or tilt of the building in each direction at different heights.
Monitoring the settlement and displacement of foundation of a house and construction is carried out during construction and use until achieving stability. Monitoring the displacement of construction during using time is also carried out when it detects that there are large cracks or obvious changes in working conditions of houses and buildings.
Using electronic total station machine to monitoring inclination points by flat coordinates and elevation (xyh).
Determining the inclination of a construction by comparing the measured value of the first cycle with the current cycle, the difference in the coordinates is the inclination of the construction.
The monitoring process is conducted as follows:
- Each monitoring cycle must check the accuracy of the benchmark which is used to placing monitoring machine and shown in the monitoring report;
- Placing the machine at the benchmark, sighting at the monitoring points attached on the construction one by one and measuring the corresponding flat coordinates. In case of standing at benchmarks do not see all the monitoring points, then installing additional points. The measured data is flat coordinates and altitude (xyh) stored by memory of the total station.
- TCVN 9400:2012 “Buildings and tower structures – Tilt monitoring by surveying method”