Foundation pit monitoring

1. Background of Foundation pit monitoring

Foundation pit monitoring is to monitor the displacement of supporting pile, anchor cable stress, anchor rod stress, soil pressure and steel support axial force of foundation pit.Urban foundation pit excavation has the characteristics of high construction risks and high construction difficulty.At present, the excavation of foundation pits in Shenzhen, Guangzhou, Dongguan and other places is getting deeper and deeper, from the initial four to eight meters to the current depth of more than 20 meters.Due to the complexity of underground soil properties, load conditions, and construction environments, determining design and construction plans based solely on geological survey data and indoor geotechnical test parameters often contains many uncertain factors.Monitoring changes in the environment, adjacent buildings, and underground facilities has become an indispensable part of engineering construction.It is also the eye that guides correct construction, a necessary measure to avoid accidents, and is a kind of information technology.Currently, foundation pit monitoring, project design, and construction are both listed as the three basic elements for quality assurance of deep foundation pit projects.

2.Overview of Foundation pit monitoring system

As a pioneer in China's structural safety monitoring industry, our company is the first to combine structural health monitoring with technologies such as the Internet of Things structural system, cloud computing, LAN/communication network and other seamless connection technologies to establish an intelligent foundation pit online monitoring system for foundation pits.Real-time monitoring of construction sites.The monitoring system based on the cloud computing service center can accommodate monitoring data of tens of thousands of bridges, tunnels, slopes and other structures, forming a regional structural health monitoring platform to achieve unified monitoring and management of all structures in the region.

3.Main monitoring contents of Foundation pit monitoring

1.Building foundation pit: settlement and horizontal displacement of the top of the retaining pile (wall), deep horizontal displacement of the retaining pile (wall), internal force of the retaining pile (wall), deep horizontal displacement of the soil outside the pit, axial force of the anchor rod, groundwater position, support axial force, pit bottom bulge

2.Surrounding risk sources: surface settlement, pipeline settlement, building tilt, uneven settlement of buildings, building cracks, bridge pier tilt, uneven settlement of bridge piers

4.List of Foundation pit monitoring monitoring projects

5.Basis for Foundation pit monitoring

"Technical Specifications for Construction Monitoring of Urban Rail Transit Engineering DG/TJ 08-2224-2017"

"Technical Specification for Monitoring of Urban Rail Transit Engineering GB50911-2013"

"Technical Specification for Monitoring of Construction Foundation Pit Engineering GB50497-2009"

"Technical Standard for Monitoring of Construction Foundation Pit Engineering GB 50497-2019"

6.Foundation pit monitoring implementation function

1.24-hour real-time monitoring: Through real-time online monitoring of supporting structures, surface settlement, inclination of retaining piles, etc., the structural changes of the building foundation pit can be grasped in real time.

2.Report push: Monitoring results are displayed and released in real time, and monitoring reports are pushed to users regularly.

3.Multiple graded early warning: Establish a three-level alarm mechanism.When abnormal data is detected, users will be notified immediately through SMS, fax, broadcast, etc., to achieve a comprehensive early warning function.

4.Emergency plan processing: directly extract corresponding processing methods from the expert system, and take timely measures such as personnel intervention and road blockade to eliminate potential safety hazards in the bud.

5.Structural trend analysis: Through monitoring data analysis and safety evaluation during the foundation pit construction period, structural stability trend analysis can be achieved.

6.Historical data storage: The storage of monitoring data provides an analogous basis for the design and construction of similar projects in the future.