Automated monitoring of foundation pits is an important means to ensure the safety of foundation pit construction and the stability of the surrounding environment. The following are some precautions:
Monitoring scheme design
Comprehensiveness: Fully consider the geological conditions of the foundation pit, the surrounding environment (such as buildings, underground pipelines, etc.), the form of foundation pit support, and construction technology to determine reasonable monitoring items, monitoring point layout, monitoring frequency, and warning values. For example, for foundation pits adjacent to important buildings, it is necessary to focus on monitoring the displacement of the pit slope and the settlement of the building, increase monitoring points, and reduce warning values.
Targeted: Set monitoring content according to the characteristics and potential risks of the foundation pit. For deep and large foundation pits, special attention should be paid to deep horizontal displacement, and for soft soil areas, emphasis should be placed on monitoring the uplift of the pit bottom.
Sensor selection and installation
Selection and adaptation: Select appropriate sensors based on the monitoring project and on-site environment to ensure that their accuracy, range, stability, and other performance meet the monitoring requirements. If measuring the horizontal displacement of deep foundation pits, inclinometers can be used. For areas with large displacement changes, inclinometers with a large range should be selected.
Installation specifications: Strictly follow the installation instructions of the sensor to ensure accurate and secure installation position. For example, when burying a soil pressure box, it is necessary to ensure good contact with the soil medium and avoid any overhead or deflection.
Protective measures: After installation, take effective protective measures for the sensors to prevent them from being damaged during the construction process. Clear signs can be set up to add protective devices to sensors exposed in the foundation pit.
Data collection and transmission
Collection frequency: Determine the data collection frequency reasonably based on the construction progress and deformation of the foundation pit. In the initial stage of excavation, the collection frequency can be appropriately reduced; Encrypt the collection frequency during critical excavation stages or when abnormal situations occur.
Stable transmission: Ensure the stability and reliability of the data transmission system. When using wired or wireless transmission methods, signal interference and interruption should be prevented. Regularly inspect transmission equipment and replace batteries or charge wireless transmission equipment in a timely manner.
Data backup: Establish a data backup mechanism to provide real-time backup of collected data to prevent data loss. A combination of local storage and cloud storage can be used.
data analysis and processing
Accuracy verification: Conduct accuracy verification on the collected data, eliminate abnormal data, and analyze the reasons for the abnormalities. If sudden changes in data are detected, it is necessary to promptly check whether the sensor is faulty or subject to external interference.
Multidimensional analysis: Combining multiple monitoring data for comprehensive analysis, such as combining displacement data with stress data, water level data, etc., to comprehensively evaluate the stability of the foundation pit.
Trend prediction: Using data analysis methods to predict the deformation trend of foundation pits, providing a basis for construction decisions. If regression analysis, time series analysis and other methods are used to predict the future displacement changes of the foundation pit.
Personnel and Safety Management
Professional personnel operation: Monitoring work should be carried out by personnel with professional knowledge and experience, and operators should be familiar with the use of monitoring equipment and data processing methods.
Safety training: Provide safety training to personnel involved in monitoring to enable them to understand the safety risks and preventive measures at the excavation construction site. It is necessary to wear safety helmets and other protective equipment when entering the excavation site.
On site safety: During the monitoring process, attention should be paid to the safety of monitoring personnel, and necessary safety passages and protective facilities should be set up. When there are signs of danger in the foundation pit, monitoring personnel should evacuate the site in a timely manner.
Quality control and management
Regular calibration: Regularly calibrate and maintain monitoring equipment to ensure measurement accuracy. Generally, sensors and other equipment are calibrated every six months or one year.
Quality inspection: Establish a quality inspection system, conduct regular inspections on monitoring data, monitoring reports, etc., to ensure the quality of monitoring work.
Emergency plan: Develop a comprehensive emergency plan that can be quickly activated and corresponding measures taken when monitoring data shows abnormalities or reaches warning values.
