Construction Overpass above the Subway Tunnels
Finite Element Analysis
The first urban belt road
on the section from Dzerzhinskiy Ave.
to Tolstoy St. in Minsk
The complexity of the construction of the overpass was located under it and fell into the zone of influence of the construction of the tunnels running the third line of the Minsk metro.
In order to ensure a trouble-free operation of the structures, it was decided to conduct monitoring - continuous monitoring in full-scale conditions for deformations and forces in the main load-bearing building structures of the transport structure (the overpass), tunnels running, ventilation subway connection, and checking their compliance with the calculated values.
We developed a program for monitoring the stress-strain state of the load-bearing structures of an overpass construction, tunnels running, and the metro ventilation subway connection in the area of influence of the transport structure construction
for continuous monitoring in full-scale conditions of deformations and forces
in the main building structures and checking their compliance with the calculated values ensuring trouble-free operation
of the structures.
Calculation on minimizing the impact of the construction of a transport structure on the metro tunnels
Development of the design model was carried out on the basis of design drawings, the results of engineering and geological surveys, and taking into account the technology of work on the construction of a transport structure.
Based on the analysis and generalization
of the research materials and the calculation to minimize the impact of the transport structure on the metro tunnels,
a comprehensive assessment was carried out and recommendations were made
on the need for monitoring with scientific support for design and construction,
as well as conducting full-scale tests
after the completion of the construction
and installation work.
The point cloud received resulting from 3D scanning, has been loaded into the developed spatial data model of the monitored objects.
The three-dimensional model and the point cloud were united due to coordinate snapping and altitude for sight control of the actual position of constructions on the construction site to the design position.
Monitoring of VAT structures
in the process of construction of the overpass and underground tunnels
Continuous monitoring of the stress-strain state of the structures of the overpass and the tunnels running was carried out with the help of the automated monitoring system SciBIM.
SciBIM SVW string overhead strain gauges and SciBim BIV two-axis inclinometers were installed to measure deformations in the load-bearing structures of the tunnels running.
Readings from strain gauges and two-axis inclinometers are interrogated by recorders installed in metro tunnels. The SciBIM DL recorder is part of the SciBIM Automated construction activity monitoring system, which allows you to query the readings of measuring equipment in offline and real-time modes and transmit them to a remote server.
In order to monitor the stress-strain state of the structures of the tunnels running and the overpass (in the piles, posts, and grillages of the supports, as well as in the factory conditions when manufacturing the beams of the superstructures), were installed:
- 102 overhead SciBim SVW;
- 69 embedded SciBim EVW;
- 18 two-axis SciBim BIV inclinometers;
- 4 SciBim DL recorders.
To solve the issue of electronic marking of structural elements, the authors, together with SciBim LLC, developed an object management and maintenance system based on RFID technology.
Full-scale tests of
The work program provided for loading the roadway of the flyover in several stages with concentrated temporary test loads.
During the tests, the following parameters are measured:
- stresses (relative strains) in the lower and upper fibers of the reinforced concrete beams of the superstructure in the most loaded sections;
- stresses (relative strains) in the lower fibers of the reinforced concrete slab of the roadway above the beams of the superstructures;
- vertical movements (deflections) of the most loaded beams of superstructures in the middle of the span;
- stresses (relative strains) in the fibers
of reinforced concrete structures of the metro tunnel section on the inner side;
- vertical and horizontal displacements
of the controlled sections
of the metro tunnel section.