CN100442013C - Method and device for monitoring deformation of tunnel engineering - Google Patents

Abstract

The invention discloses a method and device for monitoring deformation of tunnels (including tunnels, karst caves, wells, etc.) Real-time monitoring highlights the advantage that the survey line can be disconnected and closed at any time during construction, and the digital monitoring of the deformation of underground concealed engineering caves is carried out by using the computer collection and transmission method of monitoring data. The device comprises a deformation gauge (1), a test base (2), a displacement sensor (3), a data transmission line (4), a data acquisition instrument (5) and a PC computer (6) which are sequentially connected. The present invention can monitor and collect rock mass deformation in complex working conditions in real time; it not only has significant advantages in monitoring the deformation of caves during construction and operation under complex conditions, but also can be applied to foundation pit excavation, underground mining, etc. geotechnical engineering deformation monitoring field.

Description

Method and device for monitoring deformation of tunnel engineering

technical field

The invention relates to geotechnical engineering deformation monitoring, in particular to a deformation monitoring method and device for engineering deformation of tunnels (including tunnels, karst caves, shafts, etc.). Specifically, it is mainly aimed at the real-time monitoring of tunnel engineering deformation under complex construction conditions, highlighting the advantage that the measuring line can be disconnected and closed at any time during construction, and using the computer collection and transmission method of monitoring data to carry out underground concealed engineering caves Digital monitoring of deformation.

Background technique

Geotechnical deformation monitoring is an important part of geotechnical engineering. A variety of monitoring methods have been widely used in the deformation of tunnel projects such as mines, railways, highways, and water conservancy projects. With the increase of expressway, high-speed railway, energy engineering construction and western development, my country's infrastructure construction is in the ascendant. There are more and more tunnel projects involved, but it is quite difficult to accurately predict the basic condition of rock and soil mass and its changes during construction and operation in the engineering design stage. Engineering practice shows that effective monitoring means throughout the whole process of engineering construction and operation. On-site monitoring of the actual conditions and stability of geotechnical engineering has become an indispensable and important means in the process of engineering survey, design, construction and operation.

CDJ-II rod-type drilling multi-point displacement meter (rod-type drilling multi-point displacement meter, used to accurately measure the longitudinal displacement of rock mass and concrete drilling.) On-site monitoring of tunnel engineering and high slope engineering of Ertan Hydropower Station It has been successfully applied in the cavern surrounding rock and rock slope, and the displacement rate, displacement amount and radial displacement in the cavern at different depths on the surface and interior are obtained. The relationship between the displacement of the surrounding rock and the construction footage.

Comprehensive utilization of the convergent gauge (the convergent gauge is mainly composed of a test steel ruler coiled on a reel with punched holes, and the reel is fixed on the instrument frame.) and multi-point displacement gauge (multi-point drilling displacement gauge, used for accurate Measure the axial deformation of drilling holes in the rock mass and concrete body.) It can test the changes of the surface and internal displacement of the rock mass, directly reflect the law of ground pressure activity, and play an important role in understanding the deformation law and time-space of the surrounding rock of the underground mining roadway during the excavation process. It plays a key role in the effective prediction and prediction of the stability of the surrounding rock during the production period of the roadway.

However, traditional convergence gauges and multi-point displacement gauges are used to monitor the deformation of the cave itself and the surrounding rock mass, which will inevitably affect the construction work, and the survey line is easily damaged during the construction process.

In addition, mechanically anchored or grouted multi-point displacement meters are difficult to install on site; differential resistance multi-point displacement meters will cause hysteresis and temperature drift in displacement changes due to temperature changes.

Based on the current characteristics of geotechnical engineering monitoring and the particularity of tunnel engineering deformation monitoring, it is of great engineering application value to study the deformation monitoring methods and devices suitable for tunnel engineering under construction or operation conditions.

Contents of the invention

The object of the present invention is to provide a method and device for monitoring deformation of tunnel engineering in order to overcome the above-mentioned shortcomings and deficiencies in the prior art.

The purpose of the present invention is achieved like this:

1. Method of monitoring deformation of tunnel engineering

This method comprises the following steps:

① Carry out linear drilling at the monitoring points on both side walls of the monitored section;

② The measuring line is a stainless steel wire connected by a male and female buckle. One end of the measuring line is fixed at the measuring point on one side wall with an expanded wood, and the other end of the measuring line is bypassed at the measuring point on the other side wall by an expanding wood. fixed fixed pulley;

③Fix the test base with expansion screws on the side wall of the fixed pulley, adjust the rotating handle, place the adjustable pulley at an appropriate position, wind out the measuring line, and use a heavy hammer to keep it plumb and tight;

④Install the wire fixing disk on the measuring line between the adjustable pulley and the weight, so that the wire fixing disk corresponds to the position of the fixture on the test base;

⑤ Install the rod-type displacement sensor on the fixture of the test base, place the sensor telescopic probe on the fixed plate of the wire, and set the initial value of the sensor by adjusting the position of the sensor on the fixture;

⑥ Use the data transmission line to transmit the data of the displacement sensor to the data acquisition instrument, and the data acquisition instrument is connected to the computer through the computer bus;

⑦ Use computer to control the collection, transmission, display and recording of cave deformation information.

2. Tunnel deformation monitoring device

As shown in Fig. 1 and Fig. 2, the device includes a deformation gauge 1, a test base 2, a displacement sensor 3, a data transmission line 4, a data acquisition instrument 5, and a PC computer 6 connected in sequence.

1. Deformation gauge

Deformation meter 1 includes: first expansion wood 1.1, measuring line 1.2, male buckle 1.3, female buckle 1.4, fixed pulley 1.5, second expansion wood 1.6, wire clamping plate 1.7 and weight 1.8;

Set the first expansion wood 1.1 and the second expansion wood 1.6 in the borehole 0 on both sides of the tunnel; one end of the measuring line 1.2 is connected to the first expansion wood 1.1, and the middle of the measuring line 1.2 is connected to the male buckle 1.3 and the female buckle 1.4 , the other end of the measuring line 1.2 bypasses the fixed pulley 1.5 and the adjustable pulley 2.1 connected with the second expansion wood 1.6 in turn, and then connects with the weight 1.8;

Cassette fixed disk 1.7 is placed on the measuring line 1.2 between adjustable pulley 2.1 and weight 1.8.

The male snap ring 1.3 and the female snap ring 1.4 are disconnected during construction and fastened during testing.

2. Test base

The test base 2 includes: an adjustable pulley 2.1, a rotating handle 2.2, a fixture 2.3 and a base 2.4;

The adjustable pulley 2.1, the rotating handle 2.2 and the clamp 2.3 are all arranged on the base 2.4; the rotating handle 2.2 can control any swing angle of the adjustable pulley 2.1, and the clamp 2.3 is used to clamp the displacement sensor 3.

3. Displacement sensor

The displacement sensor 3 is fixed on the fixture 2.3.

4. Data transmission line

The measuring head at the movable end of the data transmission line 4 is placed on the wire fixed disk 1.7; the test data is transmitted to the PC computer 6 through the data transmission line 4 and the data acquisition instrument 5 for recording and storage.

5. Data acquisition instrument

The data acquisition instrument 5 includes a multi-way switch 5.1, an A/D conversion chip 5.2 and a data buffer 5.3 connected in sequence.

6. PC computer 6

The PC computer 6 includes a computer bus 6.1 and a computer 6.2 connected to each other.

The working principle of this device:

Using the expansion characteristics of the expansion wood, the stainless steel wire measuring line is firmly fixed relative to the wall of the drilled hole. The measuring line passes through the weight hammer to maintain a certain degree of tension and force. The expansion and contraction of the measuring line represents the deformation of the measured hole. . Specifically, during the construction or operation of tunnels, karst caves, shafts, etc., if the readings of the displacement sensor placed on the fixed plate of the wire increase, it indicates that the shape of the cave has shrunk and deformed; similarly, if the reading of the displacement sensor decreases , it indicates that the hole shape is expanded and deformed. The amount of deformation is obtained through the readings of the displacement sensor collected and recorded by the data acquisition instrument.

The whole process realizes real-time deformation monitoring without affecting construction and operation conditions.

After on-site testing, the technical indicators of this device are as follows:

Sensitivity: 0.06mm; Range: 60mm;

Power supply: 12V; Working temperature: 0℃～50℃;

Number of test channels: 8; Sampling frequency: 100kHz.

The present invention has the following advantages and positive effects:

①During the monitoring process, real-time monitoring and acquisition of deformation of rock and soil caves under complex working conditions can be carried out.

②The measuring line can be disconnected during the construction process, and can be connected again after the construction is completed to continue monitoring without hindering the construction; this is especially important for underground and surface cave projects with complex construction conditions.

③The test principle of the device is intuitive, simple in structure, high in precision, good in stability, easy to operate, easy to disassemble, and has no strong technical requirements for installation and testing personnel.

④The device can transmit the collected monitoring data to achieve the purpose of long-distance monitoring of deformation, thereby effectively saving manpower, material resources and financial resources.

⑤ The present invention not only has significant advantages in monitoring the deformation of the cave body during construction and operation under complex conditions, but also can be applied to the field of geotechnical engineering deformation monitoring such as excavation of foundation pits and underground mining.

Description of drawings

Figure 1 - block diagram of the device;

Figure 2 - a schematic diagram of the assembly structure of the device;

Figure 3 - Diagram of a data acquisition process for an analog signal.

in:

0 - drilling;

1-deformation gauge,

1.1-First expansion wood, 1.2-Measuring line, 1.3-Male buckle,

1.4-Female buckle, 1.5-Fixed pulley, 1.6-Second expansion wood,

1.7-cass fixed plate, 1.8-weight hammer;

2- Test base,

2.1-Adjustable pulley, 2.2-Turning handle, 2.3-Clamp, 2.4-Base;

3- Displacement sensor;

4- data transmission line;

5- Data acquisition instrument;

5.1-Multi-channel switch, 5.2-A/D conversion chip, 5.3-Data buffer;

6-PC computer,

6.1 - Computer bus, 6.2 - Computer.

Detailed ways

Below in conjunction with accompanying drawing and implementation example the present invention is further described:

1. The device is produced and installed according to Figure 1, Figure 2, and Figure 3.

2. The structure of each part

1. Displacement sensor

Displacement sensor 3 adopts WAP-30 rod-type sensor, which can directly output analog voltage signal. Connecting with data acquisition instrument 5, the analog signal can be converted into digital signal. The built-in circuit can directly output analog voltage; after conversion, it can be converted into actual displacement.

Measuring range: 0~60mm (unidirectional); Linearity: ±0.3%;

Sensitivity: 16.6mV/mm; Power supply: ±12VDC;

Working temperature: 0℃～70℃; Overall dimension: 255mm×φ21.4mm

2. Data acquisition instrument

Data acquisition instrument 5 selects AP-5921D/U60108-F.

The output signal of the rod-type displacement sensor 3 is a voltage analog signal, which needs to be converted into a digital signal by the data acquisition instrument 5 and stored in the PC computer 6 for subsequent analysis. The data acquisition instrument 5 used with this type of sensor is WS-5921D/U series data acquisition instrument, which is a new type of computer external A/D product. It is connected to the USB interface of the computer and can provide ±12V power for the sensor. Small in size and easy to use, it is the best choice for notebook computer data collection, and is also suitable for desktop microcomputers.

Optional program-controlled 8th-order elliptic low-pass filter can be programmed to select the cut-off frequency of low-pass filter, which can effectively suppress external noise interference. The data acquisition instrument 5 is equipped with a 7-core socket and a 2-core standard BNC socket, which can be switched with a switch. In addition to collecting sensor signals that require power supply, other signals that meet the range can also be collected.

Analog input channels: 16, 32, 64, 128; Sampling frequency: 100kHz;

Number of channels: 8; Supply bridge voltage: ±12V; Digital I/O: 1 channel, TTL electric screen;

Range: ±10V; Linearity: <0.01%FS; A/D resolution: 16 bits;

Low-pass filter: 8th-order elliptic low-pass filter, programmable filter range 10Hz ~ 50kHz; analog input socket: 7-pin socket; computer interface: USB1.1;

Working temperature: 0～50℃ Power supply: AC220V/50Hz;

Data acquisition software: WS-DAQ data acquisition software;

Analog signal data acquisition is carried out through LabVIEW.

3. A data acquisition process of analog signal

A data acquisition process of an analog signal is shown in Figure 3. The data acquisition instrument 5 converts the multi-channel analog signal into a digital signal and stores it in the data buffer 5.3 through multiplexer 5.1, A/D conversion chip 5.2 and data buffer (Buffer) 5.3, and the computer 6.2 passes The data acquisition in LabVIEW controls the actions of several components in the data acquisition instrument 5, and the data acquisition instrument 5 and the computer 6.2 realize communication, exchange data and control information through the computer bus 6.1.

Claims (2)

1. A tunnel engineering deformation monitoring method, characterized in that it comprises the following steps: ① Carry out linear drilling at the monitoring points on both side walls of the monitored section; ② The measuring line is a stainless steel wire connected by a male and female buckle. One end of the measuring line is fixed at the measuring point on one side wall with an expanded wood, and the other end of the measuring line is bypassed at the measuring point on the other side wall by an expanding wood. fixed fixed pulley; ③Fix the test base with expansion screws on the side wall of the fixed pulley, adjust the rotating handle, place the adjustable pulley at an appropriate position, wind out the measuring line, and use a heavy hammer to keep it plumb and tight; ④Install the wire fixing disk on the measuring line between the adjustable pulley and the weight, so that the wire fixing disk corresponds to the position of the fixture on the test base; ⑤ Install the rod-type displacement sensor on the fixture of the test base, place the sensor telescopic probe on the fixed plate of the wire, and set the initial value of the sensor by adjusting the position of the sensor on the fixture; ⑥ Use the data transmission line to transmit the data of the displacement sensor to the data acquisition instrument, and the data acquisition instrument is connected to the computer through the computer bus; ⑦ Use computer to control the collection, transmission, display and recording of cave deformation information. 2. A deformation monitoring device for tunnel engineering, characterized in that it comprises a deformation gauge (1), a test base (2), a displacement sensor (3), a data transmission line (4), a data acquisition instrument (5), PC computer (6); The deformation gauge (1) includes a first expansion wood (1.1), a measuring line (1.2), a male buckle (1.3), a female buckle (1.4), a fixed pulley (1.5), a second expansion wood (1.6) , wire fixing plate (1.7) and weight (1.8); respectively set the first expansion wood (1.1) and the second expansion wood (1.6) in the boreholes (0) on the two side walls of the tunnel; measuring line (1.2) One end is connected to the first expansion wood (1.1), the middle of the measuring line (1.2) is connected to the male buckle (1.3) and the female buckle (1.4), and the other end of the measuring line (1.2) is bypassed in turn with the second expansion wood (1.6) The connected fixed pulley (1.5) and adjustable pulley (2.1) are then connected with the weight (1.8); the wire fixed disc (1.7) is placed on the measuring line between the adjustable pulley (2.1) and the weight (1.8) (1.2) above; The test base (2) includes an adjustable pulley (2.1), a rotary handle (2.2), a fixture (2.3) and a base (2.4), an adjustable pulley (2.1), a rotary handle (2.2), a fixture (2.3) are all arranged on the base (2.4); The displacement sensor (3) is fixed on the clamp (2.3); The measuring head at the movable end of the data transmission line (4) is placed on the wire fixing plate (1.7); The data acquisition instrument (5) comprises a sequentially connected multi-way switch (5.1), an A/D conversion chip (5.2) and a data buffer (5.3); The PC computer (6) includes a computer bus (6.1) and a computer (6.2) connected to each other.

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