In building construction, settlement observation is an important work, especially for high-rise buildings. With the increase of floors, the load will increase and the settlement will inevitably increase. Through the construction monitoring of high-rise building settlement, it is beneficial to realize the informatization of settlement observation. By analyzing and comparing the displacement of different parts of the foundation pit, pipeline settlement, axial force of surrounding buildings and supports, the excavation law of the foundation pit is revealed. A large number of test data can provide reliable information and related data for future construction, survey and design, thus ensuring the safety of the structure itself and the surrounding environment. This is the key content of this article. Importance of building settlement observation (1) Determination of ultimate bearing capacity of foundation. The numerical value can be determined by selecting a typical stratum at the construction site and carrying out relevant load test of bearing plate. On the platform of the hillside, the counterforce device of the related anchor pile beam can be set. With the help of the self-weight of the mountain, the supporting counterforce device is set at the bottom of the hole and in the flat tunnel, and the force is measured by the pressure sensor and the settlement is measured by the displacement. It is helpful to improve the estimated value by manual means. (2) Analysis before design and construction drawing. According to the original geological survey data, combined with the relevant specifications and field load tests, it is necessary to investigate and compare with the adjacent projects, and make a comprehensive determination through the calculation of the original building experience and its theoretical formula. (3) Relevant geological exploration should be continued at the initial stage of construction. The geological conditions and structure of the bridge are complex, and many problems inconsistent with the original geological survey are usually encountered in the initial stage of construction. Therefore, it is very necessary to increase geological exploration work in the early stage of construction. In addition, some special tests can be carried out to judge the foundation bearing capacity of each bearing layer more accurately. 2 The connotation of informatization construction of settlement observation The so-called informatization construction refers to collecting and analyzing the actual settlement observation data in high-rise building construction through various instruments and measuring elements, and making necessary adjustments to the construction scheme and original design according to the analysis results, and giving feedback in the next construction process to predict and analyze the next construction stage, thus ensuring the economic and safe operation of high-rise building construction. See information construction schematic diagram 1. Figure 1 Schematic Diagram of Informational Construction Informational construction is gradually developed on the basis of management technology, computer technology and field measurement technology. The first detailed construction of settlement observation should meet the following conditions: (1) there are instruments and measuring elements needed for monitoring; Real-time monitoring can be performed; Having corresponding analysis and prediction methods and models; And relates to the application of computers. In the application of settlement observation information, grasping reliable information in time is the basis of prediction and analysis. Under the background of Scientific Outlook on Development, the rapid development of settlement observation technology and the wide application of computer technology have greatly promoted the real-time monitoring in the construction of high-rise buildings. Through the rapid processing of relevant data, it provides technical guidance for monitoring management in construction projects. 3. Specific application of settlement observation informatization in high-rise buildings 3. 1 Establishment of leveling control network Based on the site environment and plane of high-rise buildings, a feasible and reasonable settlement observation scheme is formulated, and an urban leveling control network is established according to the precise traverse points or leveling control points provided by local urban construction planning departments or construction units. The specific requirements include the following three aspects: ① At least three leveling points should be set around general high-rise buildings, and the spacing between leveling points should be controlled within 50m; (2) When setting measuring instruments anywhere in the plant area, at least two rear-view leveling points shall be ensured to facilitate closed calibration; (3) Benchmarks should be set outside the earthquake-stricken areas of buildings, ground subsidence and foundation pit excavation to ensure the accuracy of settlement observation during building construction. 3.2 The establishment of fixed observation line should determine the position of settlement observation point according to the requirements of embedding settlement observation point and leveling control network in the factory area, and input relevant parameters into computer to draw the layout, establish fixed observation line between observation point and leveling control point, mark the location and corner of instrument erection, and stake in order to ensure the unity of survey line. 3.3 Implementation of settlement observation design and analysis before construction drawing. According to the original geological survey data, combined with the relevant specifications and field load tests, it is necessary to investigate and compare with the adjacent projects, and make a comprehensive determination through the calculation of the original building experience and its theoretical formula. Observe the settlement according to the established observation period and observation scheme. Generally speaking, high-rise buildings will have basements with 1 ~ 2 floors. When observing for the first time, we should start from the foundation and mark temporary observation points outside the foundation, and then we can start the first observation. The initial measurement of elevation value of settlement observation point is the basis of lagging observation, and its accuracy must be very high, and the measurement must be very careful. The elevation data of each observation point should be observed twice, and the average value should be obtained. With the increase of the number of floors in high-rise buildings, temporary observation points will move up each floor once, and make corresponding observations and records. Then bury a permanent observation point (generally located at 0.500 m) in accordance with the regulations, and then make observation records again according to the predetermined observation period. If the design needs to calculate the foundation deflection and relative inclination of high-rise buildings due to uneven foundation settlement, the final settlement observation results can be calculated according to the calculation formula of foundation deflection and relative inclination in Appendix VI of the specification. 3.4 Settlement observation records are arranged. During each settlement observation, the inventory records shall be kept at any time, and shall be recorded and arranged in time after the observation, so as to find out the causes of abnormal phenomena in time and make reasonable retest and correction. After verification, the settlement and elevation values of each observation point are obtained by adjustment calculation immediately, and then the time-load-settlement curve is drawn. According to the settlement curve and settlement statistics table, the settlement trend of high-rise buildings can be predicted, so as to feed back to the competent department in time and make correct guidance for construction. Through the analysis of the settlement observation results, the settlement influencing factors of similar buildings in the same area can be clarified, which is convenient for the construction unit to guide the construction organization design of similar engineering achievements, and also provides first-hand valuable information for the design and investigation unit to improve the design of buildings. Due to the influence of construction and production, the environment between observation points and leveling points often changes, which will lead to the fact that most of the original observation points and leveling points are no longer intervisibility during later observation. For example, for the first observation, the completion of foundation construction is the image progress of construction; for the second observation, the completion of a layer of main body construction is the image progress of construction; for the second observation, the tool scaffold has been set up; if observation is carried out according to the original observation route, the excess part will not be visible. In order to avoid the influence of this problem on normal settlement observation, when dealing with buildings with many observation points, they should carefully plan the site before settlement observation, foresee possible obstacles, determine the best location for instrument installation, and then select several stable settlement observation points as temporary leveling points, and form a closed loop with the leveling points. In addition, the number of leveling points should be increased accordingly, generally more than three. 3.5 Settlement observation management (1) uses computers to carry out daily management of observation values, collect data such as internal force and deformation of engineering structures in real time, and compare the daily management values with the observation values to judge whether the gap between monitoring engineering safety and management system is too large; (2) According to the observation results, the design parameters are calculated through the current situation analysis and the next stage prediction, and the new design parameters are analyzed to judge the safety of the engineering structure in the construction stage, so as to predict the internal force and deformation of the structure in the construction stage; (3) Adjust the settlement observation design scheme according to the predicted structure. If necessary, change the construction scheme and redesign it. The adjustment chart based on the prediction results is shown in Figure 2. Fig. 2 Schematic diagram of adjustment based on predicted structure 4 Key points of informatization application of settlement observation in high-rise building construction (1) Settlement observation points must be set in strict accordance with the specification requirements, so as to make careful observation, careful recording, careful checking and accurate drawing; (2) Observers, leveling staff and instruments remain fixed, which ensures the accuracy of the forecast results; (3) Each observation must be carried out in accordance with the prescribed route, and direct sunlight should be avoided during observation to ensure that the imaging is clear and stable before reading and recording; (4) When observing before and after the rainy season, check whether there is any change in the elevation of the leveling point in advance, and adjust it in time when there is any change to ensure that the observation is not affected; (5) After each observation, the settlement and elevation of each observation point should be calculated in time, and whether it is normal or not should be analyzed. If there is any abnormality, it shall timely feedback to relevant departments and implement corresponding countermeasures; (6) After the project is put into use, it is still necessary to regularly observe the settlement of high-rise buildings, and the construction personnel and instruments should remain the same as those in the construction stage.
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