Foundation pit monitoring

1.Foundation pit monitoring background

Foundation pit monitoring is used to monitor the deformation and internal forces of supporting structures during foundation pit excavation and underground engineering structure operation and maintenance.Urban foundation pit excavation has the characteristics of high construction risks and high construction difficulty.At present, the excavation of foundation pit construction in Shenzhen, Guangzhou, Dongguan and other places is getting deeper and deeper, from the initial four to eight meters to the current deepest, it has reached more than twenty meters.Due to the complexity of underground soil properties, load conditions, and construction environment, determining the design and construction plan based on geological survey data and indoor geotechnical test parameters often contains many uncertain factors.Monitoring changes in soil properties, environment, adjacent buildings, and underground facilities caused during the construction process has become an indispensable and important link in engineering construction.It is also an eye for guiding correct construction.It is a necessary measure to avoid accidents and an information technology.At present, foundation pit monitoring and engineering 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 took the lead in combining structural health monitoring with technologies such as IoT structural system, cloud computing, local area network/communication network and other multi-network seamless connections, and established an intelligent foundation pit online monitoring system to conduct real-time monitoring of the foundation pit construction site.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, and realizing unified monitoring and management of all structures in the region.

3.Foundation pit monitoring content

1.Building foundation pit: settlement and horizontal displacement at the top of the enclosed pile (wall), deep horizontal displacement of the enclosed pile (wall), internal force of the enclosed pile (wall), deep horizontal displacement of the soil outside the pit, anchor shaft force, groundwater level, support shaft force, pit bottom up

2.Peripheral risk sources: surface settlement, pipeline settlement, building inclination, uneven settlement of buildings, building cracks, piers inclination, uneven settlement of bridge piers

4.List of Foundation pit monitoring monitoring projects

5.Foundation pit monitoring basis

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

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

"Technical Specifications for Monitoring of Building Foundation Pit Projects GB50497-2009"

"Technical Standard for Monitoring of Building Foundation Pit Projects GB 50497-2019"

6.Foundation pit monitoring implements functions

1.24-hour real-time monitoring: Through real-time online monitoring of support structures, surface settlement, enclosure pile tilt, etc., we can grasp the structural changes of building foundation pits in real time.

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

3.Multi-level warning: Establish a three-level alarm mechanism.When detecting abnormal data, notify users in the form of text messages, faxes, broadcasts, etc.as soon as possible to realize the comprehensive warning function.

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

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

6.Storage of historical data: The storage of monitoring data provides an analogy basis for future similar engineering design and construction.