| The TBM excavation process is mainly a rock-machine interaction process in mechanics,involving the TBM machine equipment itself and the geotechnical conditions of the rock mass.The TBM excavation process will generate massive rock-machine interaction information.The real-time sensing of rock-machine interaction information is the key to guide the optimization and selection of TBM excavation scheme and realize the safe and efficient tunneling of TBM.In this paper,the real-time monitoring method of TBM scraper wear is proposed.Combined with the research of the cutter disc vibration,tool force,surrounding rock and shield interaction monitoring method,the rock-machine interaction intelligent monitoring hardware and software platform of TBM excavation process is carried out.Development,relying on the water supply tunnel project of Lanzhou City,carried out the construction of the rock-machine interaction intelligent monitoring and early warning system,and analyzed the rock-machine interaction information during the TBM excavation process.The main research work and results are as follows:(1)In order to realize real-time monitoring of composite TBM and shield scraper wear,a new real-time monitoring method for scraper wear is proposed.The resistance grid installed on the surface of the scraper is composed of a plurality of fine-resistance and high-temperature resistant carbon film resistors in parallel,and the resistance value of the resistance grid changes with the synchronous wear of the scraper,thereby causing the resistance grid in the closed circuit of the monitoring system.The voltage at the terminal changes,and the blade wear value can be calculated by measuring the voltage across the resistance grid.Based on this principle,a real-time monitoring system for scraper wear was developed.The system consists of four parts: wear sensing module,data reading and sending module,wireless receiving gateway and host computer software.The wear sensing module is the core of the system,and senses the wear amount of the scraper in real time,and the signal is wirelessly transmitted by the data reading and transmitting module,and is transmitted to the upper computer software after receiving the data through the wireless gateway.The theoretical derivation formula of the scraper wear monitoring is proposed and the indoor wear test is carried out.The test results show that the scraper wear sensing module is stable and undistorted during wear,and the wear error is controlled within 1mm.The wireless transmission distance in indoor environment Up to 30 meters.The monitoring system enables real-time monitoring of scraper wear with high accuracy.(2)Developed a hardware platform for the TBM excavation rock-machine interaction intelligent monitoring system,integrated the interaction tool between the cutter cutter and the face surface,and the monitoring sensor for the surrounding rock and shield,and developed the automatic sensor power supply system.Make sure the sensor is working properly.The automatic acquisition program written by RoboTask periodically collects and stores the sensor-aware data,connects the data transmission module of the TBM communication optical network,and transmits the monitoring data in the tunnel to the outside of the tunnel in real time.The intelligent monitoring system hardware platform integrates functions such as automatic power supply,timing acquisition,timing storage,operation correction,real-time transmission,and unattended operation.(3)Analyzed the functional requirements of the TBM tunneling intelligent monitoring software system,and independently completed the software system development based on the LabVIEW environment.By using the ActiveX function in the wireless sensor network OCX control,the corresponding event node is called to acquire the sensor data in the software.Real-time monitoring,control and acquisition of cutter disk vibration,tool wear and tool force are realized.Considering that the software functions based on LabVIEW development need to be improved,cooperated with professional software companies to develop a TBM intelligent tunneling and disaster warning big data platform based on B/S architecture.The big data platform is deployed in the cloud or server without installing an application.The browser is ready to use.The big data monitoring platform replaces the monitoring software of each sensor/reader,realizes the automatic connection,error correction and error feedback of the sensor and monitoring platform;has monitoring project management,monitoring data acquisition and analysis,TBM excavation parameter acquisition,monitoring data warning Features such as viewing and user management can analyze the relationship between monitoring data and driving parameters in real time,provide disaster warning information,and provide guidance for TBM tunneling decision-making.(4)Based on the Lanzhou City water source tunnel,the TBM excavation rock-machine interaction intelligent monitoring system and long-term monitoring test were carried out to verify the feasibility,effectiveness and long-term stability of the monitoring system.The time-domain analysis results of the vibration of the cutterhead on-site monitoring show that the acceleration amplitude of the TBM is about 1.2g when it is normally drilled in the interbed of claystone.In the two days before the TBM occurs,the amplitude of the vibration acceleration of the TBM cutter increases,and the amplitude mostly exceeds 2.0g.The frequency domain analysis of the vibration acceleration of the cutterhead shows that the cutter amplitude is 43 Hz during normal TBM tunneling.In the first two days before the TBM card machine,there are multiple peaks in the vibration frequency domain curve of the TBM cutter,which are about 43 Hz,50 Hz,and 90 Hz,which indicates that the front of the card cutter is forced by abnormal force.Vibration state.The on-site monitoring results of the shield strain indicate that when the TBM occurs,the surrounding rock and the shield are mutually squeezed,and the shield is deformed.Analysis of the change in strain amplitude at each monitoring point of the shield can infer the approximate orientation of the contact point between the surrounding rock and the shield. |
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