What techniques and methods are currently used for subsidence observation?

1. Observation of the construction stage of the building:

After pouring on the first floor of the building, the settlement observation mark is buried and the initial observation is carried out. After that, the load of each upper layer is observed once until the main body is capped, and the infill wall is observed once after completion, and the floor is counted as 16 floors, a total of 17 times.

2. Observation of the use stage of the building:

After the completion of the building, it will be observed every 2 3 months after the completion of the building, and then every 4 6 months until the settlement of the building is stable, and it is expected that a total of 3 observations will be observed.

When the building sinks, floats, the uneven settlement is more serious, or the crack develops rapidly, it should be continuously observed every day or several days.

3. Building settlement stability standard.

The stability standard of foundation deformation settlement should be determined by the settlement time relationship curve. It is pointed out in the "Building Deformation Measurement Regulations" (JGJ T8-97) that if the settlement rate of general engineering is less than that, it can be considered that the building has entered the stabilization stage, and the specific value should be determined according to the compressibility of the foundation soil in each region. The value of this project is as follows:

6. Instruments and personnel composition.

Instruments used: This settlement observation uses Suguang DSZ2 FS1 level (with micrometer), and the measurement accuracy is up to, accurate reading to, estimated reading to. The leveling rod uses an indium steel ruler.

Composition: Establish a subsidence observation team, including a technical leader, a project leader, and two observers.

Monitoring information and reports.

1. The observation results should be sorted out on the same day, and the results should be reported to Party A, the supervision and the construction unit in a timely manner, and if the observation results are found to be abnormal, Party A, the supervision and the construction unit shall be notified in time. If the difference settlement of the building exceeds 1 1000L (L is the distance between two adjacent settlement points), the police must be called immediately

2. After the completion of the observation work, the following results should be submitted: (1) The completion settlement monitoring report of Hengda Jiayuan shall be submitted to the owner within one week after the completion of the building, including: the settlement observation results table; Subsidence observation point distribution map and subsidence map of each period; v-t-s (sedimentation rate, time, sedimentation) curve; Settlement observation and analysis report.

2) Submit the Hengda Jiayuan subsidence monitoring report to the owner within one week after the completion of all the subsidence observation work, including: subsidence observation results table; Subsidence observation point distribution map and subsidence map of each period; v-t-s (sedimentation rate, time, sedimentation) curve; Settlement observation and analysis report.

1. The nature and tasks of the course.

Building Surveying is a compulsory professional basic course for building construction and management majors. The main task of the course is to learn the basic theories, basic knowledge, basic methods and basic operation skills necessary for this major, so as to lay the foundation for cultivating front-line construction and management professionals in construction engineering.

2. Cohesion and cooperation with related courses.

The prerequisite courses required for "Building Surveying" include "Fundamentals of Advanced Mathematics", "Architectural Drawing and Mapping", etc., and "Building Surveying" is the basis for learning "Building Construction Technology", "Construction Engineering Quality Inspection and Accident Handling" and other subsequent courses.

3. The basic teaching requirements of the course.

1. Master the composition, use, inspection and general calibration of conventional measuring instruments.

2. Master the basic measurement methods and lofting methods of elevation, angle and distance, and understand the basic knowledge of error.

3. Be able to correctly select measuring instruments and measurement methods according to the characteristics of building construction.

4. Be able to read topographic maps correctly, and have the preliminary ability to use topographic maps to obtain topographic information and related data.

5. Preliminary understanding of the application of new instruments and technologies in modern surveying and mapping.

4. Suggestions on teaching methods and teaching forms.

1. This course is a course that attaches equal importance to theory and practice, and the method of combining teaching and practice should be adopted in teaching, so as to enhance the intuitiveness and practicality of course teaching, and improve students' ability to analyze problems, solve problems and operate hands-on.

2. In the experimental teaching, the instrument operation, specific observation, recording and calculation should be the focus, and the implementation of the experimental teaching link should be ensured.

3. In teaching, try to use physical objects and multi-courseware for teaching and experimental demonstration, and strengthen and supplement teaching through multi-courseware.

4. Online teaching tutoring, Q&A, periodic summary and review, etc.

The purpose of building settlement observation is to find abnormal settlement and uneven settlement; In order to take timely measures to prevent damage to the building.

Instruments and methods for sedimentation observation:

Settlement observation should be carried out by precision level and copper level, and when the above instruments are lacking, precision engineering level (with conforming level) and a level with accurate scale can also be used.

Fixed measuring tools should be used for observation, and personnel should also be immobilized.

Each observation is to be inspected on the spot using the annular closure method or the round-trip closure method.

The difference between two observations at the same observation point shall not be greater than 1 mm, and the leveling shall be carried out by the closed method.

The use of second-class level measurement should meet the requirements;

The use of third-class level measurement should meet the requirements.

n is the number of times the level is installed during the leveling process).

1.Instrument. The level should be a high-precision indium steel barcode ruler that is less affected by changes in the environment and temperature differences.

In the absence of indium steel baryards, the first row of the barscale should be used as much as possible when using a general ruler. The high-precision level shall not be lower than the DS2 level, and the accuracy of the ordinary level shall not be lower than the DS3 level.

The accuracy of the settlement observation should depend on the nature of the building.

1) The settlement observation of multi-storey buildings can be carried out by using the DS3 level and the method of ordinary leveling, and the closing difference of the leveling route should not exceed the opening square mm of n (the number of measuring stations of n).

2) The settlement observation of high-rise buildings should be carried out by using the DS1 precision level and the method of second-class level measurement, and the closing difference of the level route should not exceed the square mm (n is the number of stations).

16.Job Requirements:

Settlement observation is a long-term and continuous work, in order to ensure the correctness of the observation results, we should try to achieve four determinations, that is, fixed observers, the use of fixed levels and leveling rulers, the use of fixed level base points, according to the fixed measured routes and stations.

17.Collation of the results of settlement observations.

1) After the end of each observation, the recorded data and calculations should be checked to see if the recorded data and calculations are correct, and whether the fine section distribution degree is qualified, and then adjust the height difference closure difference, calculate the elevation of each settlement observation point, and fill in the "settlement observation table".

2) Calculate the amount of settlement The content and method of calculation are as follows:

1) Calculate the amount of this settlement at each settlement observation point:

The current settlement of the settlement observation point = the elevation of the current observation - the elevation of the last observation.

2) Calculate the cumulative settlement:

Cumulative settlement = this settlement + last cumulative settlement.

The calculated settlement observation point, the current settlement, the cumulative settlement, the observation date, and the load are recorded in the "Settlement Observation Table".

18.Drawing a settlement curve is a settlement curve diagram.

The settlement curve is divided into two parts, namely the time and settlement curve and the time and load curve.

1) Draw the relationship curve between time and settlement First, take the settlement S as the vertical axis and the time T as the horizontal axis to form a Cartesian coordinate system. Then, the position of the settlement observation point was marked with each cumulative settlement amount as the ordinate and each observation date as the abscissa. Finally, the curves are used to connect the marked points, and the number of settlement observation points is indicated at one end of the curve, so that the relationship between time and settlement is plotted.

2) Draw the relationship curve between time and load First, take the load as the vertical axis and the time as the horizontal axis to form a Cartesian coordinate system. Then, according to the time of each observation and the corresponding load, each point is marked, and the points are connected to draw the time and load relationship curve.

Building settlement observation is an important part of construction engineering, which can detect building settlement in time and provide important data support for the safety and reliability of the project. The following are the commonly used methods for building settlement observation:

Building leveling method: The method is to measure the elevation of the building through leveling instruments, so as to obtain the settlement of the building. The advantage of this method is that it has high measurement accuracy and is suitable for settlement observation of high-rise buildings.

Reinforcement sign method: This method is to set up some reinforcement signs in the building structure, and obtain the settlement of the building by observing the settlement of these signs. The advantage of this method is that it is simple to operate and is suitable for settlement observation of small buildings.

Horizontal displacement method: This method obtains the settlement of the building by measuring the horizontal displacement of the building. The advantage of this method is that it can easily measure the horizontal displacement and settlement of the building at the same time, and is suitable for comprehensive settlement observation of the building.

GPS Measurement Method: This method measures the position of the building through the GPS global positioning system, so as to obtain the settlement of the building. The advantage of this method is that it can achieve accurate measurement of the position of the building, and it is suitable for long-term settlement observation of the building.

The above are the commonly used methods for building settlement observation, and different methods are suitable for different types of buildings and settlement situations. In actual engineering, it is necessary to choose the appropriate method for settlement observation according to the specific situation.