Installation method of Meishan observation mark settlement observation point

Description :

　　Those familiar with settlement observation can skip it directly. This article is aimed at friends who are just starting to conduct settlement observation and are not very familiar with the process.

　　According to regulations, the number of elevation reference points for special grade settlement observations should not be less than 4, and the number of elevation reference points for other grade settlement observations should not be less than 3. The elevation work base point can be set as needed, and the base point and work base point should form a closed loop or a node network composed of attached routes.

　　Since the requirements are all stipulated in this way, there must be some reason for it. First, let's familiarize ourselves with the layout and burial diagram of the reference points.

　　According to the site conditions, three settlement observation reference points are set up to form a ring shape, as shown in Figure 1. The reference points are located at the outer wall corner of the site, with stable foundation, good visibility, no external interference, and easy use. They are located 60 meters away from the building. G1 was built at the beginning of the project construction and has an elevation of 5 meters. The reference point for deformation measurement is set outside the deformation area, in a stable location that is easy to store for a long time, and is regularly retested. The retest period should be determined based on the stability of the reference point location. During the construction process, retesting should be conducted once every 1-2 months, and after the point location is stable, retesting should be conducted every six months.

　　Schematic diagram of benchmark point layout

　　The elevation benchmark stone is buried in the undisturbed soil layer and is a concrete ordinary leveling stone. The specifications and burial requirements for benchmark stones are shown in the figure

　　Ordinary concrete level marker stone

　　So, why do we choose three or more? Remember, the article mentions a very important reason for the rise of settlement observation points, which is the sinking of the reference point or working base point. In order to verify the sinking of a certain reference point, we need to conduct closed leveling measurements on three reference points. If we set two reference points in the early stage, we cannot verify the sinking of one reference point. However, if we set three reference points and one of them sinks, after the second measurement is completed, we can distinguish which point has a different height difference from the other two points. This way, we can easily determine that the third point has a problem and then rearrange the reference points.

　　So no matter what, it is necessary for us to set up three or more benchmark points in the early stage. In the actual measurement process, it is common for settlement observation points to rise in large quantities. In this case, we can rule out whether it is a problem with setting up benchmark points based on this.

AfterSalesService :

• Meishan observation marker