Vibration and strain monitoring method for key positions of tunnel boring machine

Abstract

The present invention provides a vibration and strain monitoring method for key positions of a tunnel boring machine (TBM), and belongs to the technical field of real-time monitoring for underground construction of the TBM. The present invention aims to provide a monitoring device and an all-weather monitoring and forecasting system thereof. The present invention acquires monitoring data through vibration and strain sensors and a wireless data transmission system, thereby realizing long-term real-time monitoring for vibration and strain states of key positions of a main machine system of the TBM during operation, reminding operators in time for maintenance and repair, preventing fatigue breakage on key weak positions of the main machine system of the TBM and ensuring safe and reliable operation of the TBM. The present invention further provides an evaluation method for strain states of positions which cannot be measured, i.e., an equivalent mapping method, thereby building a set of vibration monitoring and strain monitoring systems for the tunneling process of the key positions of the main machine system of the TBM.

Claims

1. A vibration and strain monitoring method for key positions of a tunnel boring machine (TBM), comprising the following steps: the arrangement of sensor nodes: step 1, overall safety layout the monitoring method is used to measure a cutterhead, a front shield, drive electric motors, a main beam and gripper shoes of tunnel boring machine; a monitored component requires that a measurement point reflects a motion state and is relatively safe; and a specific layout is as follows: cutterhead sensor nodes are arranged in two manholes and two water pipe passages of the cutterhead; only vibration sensors are arranged in the manholes, and a vibration and a strain sensor are arranged in the water pipe passages; vibration sensor nodes are arranged on the top and the inner surface of the front shield; a vibration sensor node is arranged on the side surface of a motor box of the drive electric motor; a vibration sensor node is arranged on the upper surface of the front end of the main beam; a vibration sensor node is arranged on the inner side surface of the gripper shoe; step 2, local strengthening protection and connection metal protection covers are added for sensor nodes and industrial batteries to provide impact resistance and water and moisture resistance; all the metal protection covers are fixed by welding; the sensor nodes and the metal protection covers are connected through a powerful magnetic connector, and a groove corresponding to the magnetic connector is formed in the bottom of the metal protection cover; wireless signal transmitting and receiving antennas are provided; and the strain sensor for collecting strain information is connected and fixed with the detected positions through threads; step 3, power supply the sensors in the cutterhead are powered by industrial batteries; and the sensors in other monitoring positions are powered directly by a power line; step 4, signal transmission and monitoring a wireless gateway is arranged in an operator's console of the TBM, and accepts vibration and strain signals of the cutterhead and vibration signals of the front shield, the main beam, the drive electric motor and the gripper shoe; the wireless gateway gives an early warning for detected strain and vibration signals which are higher than normal values, and displays the detected strain and vibration signals on a computer of the operator's console to generate a work log of the tunnel boring machine; establishment of an equivalent mapping measuring model: an evaluated value of an equivalent mapping to-be-measured point S0 is as follows: ${\mathrm{.Math.}}_0=\frac{}{.Math.{}_i}{\left(\underset{i=1}{\overset{4}{.Math.}}{\left({}_i{\mathrm{.Math.}}_i\right)}^P\right)}^{\frac{1}{P}}$ in the formula: .sub.0 is the strain of a to-be-measured point S0; .sub.i is the strain of measurement points S1, S2, S3 and S4; .sub.i is a position parameter of each measurement point; .sub.1=110; the shorter the distance from each measurement point to the point S0, the larger the corresponding .sub.1 is; P is a local structural parameter of a measured position formed by the measurement points S1, S2, S3 and S4; if no reinforcing rib is arranged, P=1; and if reinforcing ribs are arranged, P=110; the more the reinforcing ribs are, the larger the P is; is a sudden change coefficient; when reinforcing ribs are arranged at the to-be-measured point S0, =0.30.7; when sudden change of the strain occurs at the to-be-measured point S0, =1.11.6; and when no special structure is arranged at the to-be-measured point S0, =1.

2. The vibration and strain monitoring method for key positions of the tunnel boring machine according to claim 1, wherein the diameter of a measuring circle formed by the measurement points S1, S2, S3 and S4 is not greater than 0.5 m.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is an overall diagram of TBM;

(2) FIG. 2 is a structural diagram of a back surface of a cutterhead;

(3) FIG. 3 is a partial enlarged drawing of a position of a manhole of a cutterhead;

(4) FIG. 4 is a partial enlarged drawing of a position of a water pipe passage;

(5) FIG. 5 is a partial enlarged drawing of a front shield;

(6) FIG. 6 is a partial enlarged drawing of a front end of a main beam;

(7) FIG. 7 is a structural diagram of a gripper shoe;

(8) FIG. 8 is a schematic diagram of an industrial battery and a protection cover thereof;

(9) FIG. 9 is a schematic diagram of sensor nodes (including vibration and strain) and protection covers thereof;

(10) FIG. 10 is a schematic diagram of an equivalent mapping measuring model.

(11) In the figures: 1: the cutterhead; 2: the front shield; 3: the main beam; 4: the gripper shoe;

(12) a1: the manhole; a2: the water pipe passage; b1: the top inner surface of front shield;

(13) c1: side surface of motor box of the drive electric motor; c2: front end of the main beam; d1: inner side surface of the gripper shoe;

(14) e1: the protection cover of the industrial battery; e2: the industrial battery;

(15) e3: the powerful magnetic connector; e4: the groove of protection cover of the industrial battery; f1: the protection cover of the node; f2: the node(sensor);

(16) I: the node(sensor) and protection cover thereof; II: the voltage node (matched with a strain gauge) and protection cover thereof;

(17) III the strain gauge; IV: the industrial battery and protection cover thereof; V: the antenna; S0: equivalent mapping to-be-measured point;

(18) S1, S2, S3, S4: four direct measurement points;

(19) h1, h2, h3, h4: distances from direct measurement points to equivalent mapping to-be-measured point;

(20) A: measuring circle for limiting a measuring range.

DETAILED DESCRIPTION

(21) Specific embodiments of the present invention are described in detail below in combination with drawings and technical solutions. FIG. 1 is a schematic diagram of a main machine system of TBM of a project, including the major components of a cutterhead, a front shield, drive electric motors, a main beam, gripper shoes and the like. During operation, the cutterhead of the TBM continuously cuts rock; and under the impact action of the rock, the cutterhead generates a large load and the load is transferred to components behind the cutterhead, causing vibration of the front shield, the drive electric motor, the main beam and the gripper shoe.

(22) In the position of the cutterhead, the vibration sensor arranged in the water pipe passage of the cutterhead is powered by a battery. At proper sampling frequency, the lifetime of the battery is about 1 week, and a collected vibration signal is transmitted through an antenna. The strain gauge arranged in the water pipe passage of the cutterhead measures a strain score of the to-be-measured point; the strain gauge is matched with the voltage node to measure a strain signal; and the signal is amplified through the antenna and then transmitted to a gateway. In addition, the vibration sensors of the front shield, the drive electric motor, the front section of the main beam and the gripper shoe respectively transmit vibration signals to the gateway through the antenna.

(23) After all the sensors transmit the signals to the wireless gateway, all the data are processed by supported software of the computer, and are displayed and stored in real time. For the equivalent mapping measuring model, the strain sensors are arranged at S1, S2, S3 and S4 and the equivalent mapping to-be-measured point S0, so as to determine various parameters of the assessment model and further calculate the strain of S0. Through this data flow mode, real-time vibration and strain signals generated during operation of the TBM are displayed on the computer of the operator's console of the TBM, and a work log of the TBM is generated to achieve expected functional requirements.

INDUSTRIAL APPLICABILITY

(24) The present invention provides a monitoring device and an all-weather remote monitoring and forecasting system thereof. The present invention acquires monitoring data through the vibration and strain sensors and the wireless data transmission system, thereby realizing long-term real-time monitoring for vibration and strain states of key positions of the main machine system of the TBM during operation, conducting equivalent mapping evaluation on other positions which cannot be directly measured so as to feed back the operating state of the TBM to operators in time, preventing sudden fault in key positions of the main machine system of the TBM and ensuring safe and reliable operation of the TBM.