Tunnel construction method based on cantilever type heading machine

Abstract

The invention provides a tunnel construction method based on a cantilever type heading machine, and relates to the technical field of tunnel construction. The sensing system comprises a stress sensor arranged around the cutting head, a vibration sensor arranged on the arm, a displacement sensor arranged at the joint of the cutting head and the arm, and an acoustic emission sensor arranged at the front end of the cutting head; collecting surrounding rock stress, vibration, displacement and sound signal data detected by the sensing system; a parameter optimization model is established according to the data, and the rotating speed, the propelling speed and the cutting depth of the cutting head are obtained through calculation; and performing construction control on the heading machine according to the parameters. A three-dimensional laser scanner is adopted to monitor the tunneling section in real time, construction parameters are adjusted in time, and real-time monitoring of the surrounding rock state and intelligent regulation and control of the construction parameters are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a tunnel construction method based on a cantilever type tunnel boring machine. Background Art

[0002] Tunnel engineering is an important part of infrastructure construction. At present, tunnel construction mainly adopts the drilling and blasting method. This method has the disadvantages of low construction efficiency, high safety risks, and large disturbance to the surrounding rock. It is very easy to cause safety accidents and is not conducive to the smooth development of the project.

[0003] In order to overcome the shortcomings of the drilling and blasting method, people have developed a cantilevered tunnel boring machine for tunnel construction. Compared with the drilling and blasting method, the cantilevered tunnel boring machine has the advantages of high mechanization and good construction continuity. However, the existing cantilevered tunnel boring machines still have many problems in practical applications: first, the setting of construction parameters mainly depends on the experience of construction personnel, lacks scientific theoretical basis, and it is difficult to achieve the optimal construction effect; second, it is impossible to perceive the changes in the state of the surrounding rock in real time during the construction process. Once the surrounding rock instability and other dangerous situations occur, it will cause major safety hazards; third, the surrounding rock is greatly disturbed during the construction process, which is easy to cause over-excavation or under-excavation, affecting the construction quality and service life of the tunnel.

[0004] Therefore, it is urgent to provide a tunnel construction method based on a cantilever tunnel boring machine to achieve intelligent control of construction parameters, real-time monitoring of surrounding rock conditions, and effective control of construction accuracy. Summary of the invention

[0005] The object of the present invention is to provide a tunnel construction method based on a cantilever type tunnel boring machine, so as to realize intelligent regulation of construction parameters, real-time monitoring of surrounding rock conditions and effective control of construction accuracy.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A tunnel construction method based on a cantilever type tunnel boring machine comprises the following steps:

[0008] S1: installing a sensing system on the cantilever type roadheader, wherein the sensing system includes a stress sensor arranged around the cutting head, a vibration sensor arranged on the machine arm, a displacement sensor arranged at the connection between the cutting head and the machine arm, and an acoustic emission sensor arranged at the front end of the cutting head;

[0009] S2: collecting surrounding rock stress data, tunnel boring machine vibration data, cutting head position data and rock fracture sound signal data detected by the sensing system;

[0010] S3: Establishing a parameter optimization model according to the data, and calculating the cutting head rotation speed, propulsion speed and cutting depth;

[0011] S4: Controlling the construction of the tunnel boring machine according to the cutting head rotation speed, advancing speed and cutting depth.

[0012] Furthermore: 8 stress sensors are evenly arranged around the cutting head, and the interval between adjacent stress sensors is 45°.

[0013] Furthermore: the vibration sensor includes a three-way vibration sensor arranged at the root, middle and end of the machine arm.

[0014] Furthermore: four acoustic emission sensors are arranged in a cross shape at the front end of the cutting head.

[0015] Further: the cutting head speed n is calculated by the following formula:

[0016]

[0017] Among them, n0 is the reference speed, σ is the surrounding rock stress, σ max is the maximum allowable surrounding rock stress, v is the vibration velocity, and v max is the maximum allowable vibration speed, d is the displacement deviation, d max is the maximum allowable displacement deviation.

[0018] Further: the propulsion speed V is calculated by the following formula:

[0019]

[0020] Among them, V0 is the reference advancement speed, k1 and k2 are adjustment coefficients, σ ​​is the surrounding rock stress, and σ max is the maximum allowable surrounding rock stress, AE is the acoustic emission signal intensity, and AE max To allow for maximum acoustic emission signal intensity, θ is the inclination of the rock formation.

[0021] Further: the cutting depth D is calculated by the following formula:

[0022]

[0023] Among them, D0 is the reference cutting depth, α and β are adjustment coefficients, σ ​​is the surrounding rock stress, and σ max is the maximum allowable surrounding rock stress, ρ0 is the standard rock density, ρ is the actual rock density, and h is the surrounding rock grade.

[0024] Further: Step S4 includes: when the monitored surrounding rock stress exceeds 85% of the set threshold, reducing the advancement speed by 20%; when the vibration amplitude exceeds the warning value, adjusting the cutting head rotation speed; when the displacement deviation exceeds ±10mm, performing trajectory correction; and dynamically adjusting the cutting depth according to the intensity of the acoustic emission signal.

[0025] Furthermore: the step S4 also includes: using a three-dimensional laser scanner to scan the excavation section in real time, and comparing the actual contour data obtained with the designed contour data; comparing the deviation between the actual contour data and the designed contour data every 1m of excavation, and when the deviation exceeds ±5cm, adjusting the cutting head rotation speed, propulsion speed and cutting depth.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. This device realizes multi-dimensional real-time monitoring of the surrounding rock status by arranging stress sensors, vibration sensors, displacement sensors and acoustic emission sensors on the cantilever tunnel boring machine, overcoming the technical defect that the traditional construction method cannot perceive the surrounding rock status in real time, and can effectively prevent the occurrence of construction safety accidents.

[0028] Second, based on the data collected by multiple sensors, a parameter optimization model for the cutting head rotation speed, propulsion speed and cutting depth was established, breaking away from the limitation of over-reliance on manual experience in the traditional construction process. Through the synergistic relationship between the various parameters, the scientific setting and intelligent regulation of the construction parameters can be achieved.

[0029] 3. Use 3D laser scanning technology to monitor the excavation section in real time, and adjust the construction parameters in time according to the deviation between the actual contour and the designed contour, ensuring that the over-excavation and under-excavation accuracy is controlled within ±5cm, significantly improving the accuracy of tunnel construction and effectively solving the technical problem of over-excavation and under-excavation caused by traditional construction methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a flow chart of a tunnel construction method based on a cantilever type tunnel boring machine in an embodiment; DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] The tunnel construction method provided by the present invention is implemented based on a cantilever tunnel boring machine. First, a sensing system needs to be installed on the cantilever tunnel boring machine. The sensing system includes a stress sensor, a vibration sensor, a displacement sensor and an acoustic emission sensor. Specifically, 8 stress sensors are evenly arranged in a circumferential direction around the cutting head of the tunnel boring machine, and the interval between adjacent stress sensors is 45°, which is used to monitor the stress state of the surrounding rock in real time. Three-way vibration sensors are respectively installed at the root, middle and end of the machine arm to monitor the vibration of various parts of the machine arm during the tunneling process. A displacement sensor is installed at the connection between the cutting head and the machine arm to accurately control the position of the cutting head. Four acoustic emission sensors are arranged in a cross shape at the front end of the cutting head to monitor the acoustic signals of rock fracture.

[0034] After the installation is completed, a data acquisition system is established to collect data from each sensor. An industrial-grade PLC is used as the main control unit, and the acquisition frequency of stress data is set to 100Hz, the acquisition frequency of vibration data is set to 1kHz, the acquisition frequency of displacement data is set to 50Hz, and the acquisition frequency of acoustic emission data is set to 10kHz. At the same time, a data cache and preprocessing module are set to perform real-time filtering and noise reduction on the collected data.

[0035] Based on the collected data, a parameter optimization model is established to calculate the cutting head rotation speed, propulsion speed and cutting depth.

[0036] The cutting head speed n is calculated by the following formula:

[0037]

[0038] Among them, n0 is the reference speed, σ is the surrounding rock stress, σ max is the maximum allowable surrounding rock stress, v is the vibration velocity, and v max is the maximum allowable vibration speed, d is the displacement deviation, d max is the maximum allowable displacement deviation.

[0039] The propulsion speed V is calculated by the following formula:

[0040]

[0041] Among them, V0 is the reference advancement speed, k1 and k2 are adjustment coefficients, σ ​​is the surrounding rock stress, and σ max is the maximum allowable surrounding rock stress, AE is the acoustic emission signal intensity, and AE max To allow for maximum acoustic emission signal intensity, θ is the inclination of the rock formation.

[0042] The cutting depth D is calculated by the following formula:

[0043]

[0044] Among them, D0 is the reference cutting depth, α and β are adjustment coefficients, σ ​​is the surrounding rock stress, and σ max is the maximum allowable surrounding rock stress, ρ0 is the standard rock density, ρ is the actual rock density, and h is the surrounding rock grade.

[0045] During the construction control process, when the surrounding rock stress is monitored to exceed 85% of the set threshold, the advancement speed will be automatically reduced by 20%; when the vibration amplitude exceeds the warning value, the cutting head speed will be adjusted in time; when the displacement deviation exceeds ±10mm, the trajectory will be corrected immediately; according to the change of the acoustic emission signal intensity, the cutting depth will be dynamically adjusted. At the same time, a three-dimensional laser scanner is used to scan the excavation section in real time to obtain the actual contour data and compare it with the designed contour data. Contour detection is performed every 1m of excavation. When the deviation between the actual contour and the designed contour exceeds ±5cm, the cutting head speed, advancement speed and cutting depth are adjusted in time to ensure construction accuracy.

[0046] In actual construction, a certain tunnel project was constructed using the construction method of the present invention. The surrounding rock of the tunnel is Grade III, and the rock compressive strength is 50MPa. The initial setting of the cutting head speed is 70r / min, the advancement speed is 0.8m / h, and the cutting depth is 80mm. During the construction process, when the surrounding rock stress reaches 90% of the warning value, the system automatically reduces the advancement speed to 0.64m / h; when it is detected that the vibration amplitude exceeds the warning value, the cutting head speed is adjusted to 60r / min; when it is found that the displacement deviation reaches 12mm, the system immediately corrects the trajectory; when it is found through three-dimensional laser scanning that the local position over-excavation reaches 6cm, the cutting depth is adjusted to 65mm in time. By adopting the construction method of the present invention, the construction efficiency of the tunnel project is improved by 35%, the over-excavation and under-excavation are controlled within ±5cm, and the surrounding rock disturbance range is reduced by 45% compared with the traditional method.

[0047] The above is a brief introduction to the present invention. The present invention will be described in detail below through specific embodiments.

[0048] A tunnel construction method based on a cantilever type tunnel boring machine comprises the following steps:

[0049] S1: installing a sensing system on the cantilever type roadheader, wherein the sensing system includes a stress sensor arranged around the cutting head, a vibration sensor arranged on the machine arm, a displacement sensor arranged at the connection between the cutting head and the machine arm, and an acoustic emission sensor arranged at the front end of the cutting head;

[0050] In some embodiments, eight stress sensors are evenly arranged around the cutting head, and the interval between adjacent stress sensors is 45°;

[0051] In other embodiments, the vibration sensor includes a three-way vibration sensor disposed at the root, middle, and end of the machine arm;

[0052] Four acoustic emission sensors are arranged in a cross shape at the front end of the cutting head;

[0053] S2: collecting surrounding rock stress data, tunnel boring machine vibration data, cutting head position data and rock fracture sound signal data detected by the sensing system;

[0054] S3: Establishing a parameter optimization model according to the data, and calculating the cutting head rotation speed, propulsion speed and cutting depth;

[0055] The cutting head speed n is calculated by the following formula:

[0056]

[0057] Among them, n0 is the reference speed, σ is the surrounding rock stress, σ max is the maximum allowable surrounding rock stress, v is the vibration velocity, and v max is the maximum allowable vibration speed, d is the displacement deviation, d max is the maximum allowable displacement deviation.

[0058] The propulsion speed V is calculated by the following formula:

[0059]

[0060] Among them, V0 is the reference advancement speed, k1 and k2 are adjustment coefficients, σ ​​is the surrounding rock stress, and σ max is the maximum allowable surrounding rock stress, AE is the acoustic emission signal intensity, and AE max To allow for maximum acoustic emission signal intensity, θ is the inclination of the rock formation.

[0061] The cutting depth D is calculated by the following formula:

[0062]

[0063] Among them, D0 is the reference cutting depth, α and β are adjustment coefficients, σ ​​is the surrounding rock stress, and σ maxis the maximum allowable surrounding rock stress, ρ0 is the standard rock density, ρ is the actual rock density, and h is the surrounding rock grade.

[0064] S4: Controlling the construction of the tunnel boring machine according to the cutting head rotation speed, advancing speed and cutting depth.

[0065] In some embodiments, step S4 includes: when the monitored surrounding rock stress exceeds 85% of the set threshold, reducing the propulsion speed by 20%; when the vibration amplitude exceeds the warning value, adjusting the cutting head rotation speed; when the displacement deviation exceeds ±10mm, performing trajectory correction; and dynamically adjusting the cutting depth according to the intensity of the acoustic emission signal.

[0066] In other embodiments, step S4 also includes: using a three-dimensional laser scanner to perform real-time scanning of the excavation section, and comparing the actual contour data obtained with the designed contour data; comparing the deviation between the actual contour data and the designed contour data every 1m of excavation, and when the deviation exceeds ±5cm, adjusting the cutting head rotation speed, propulsion speed and cutting depth.

[0067] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A tunnel construction method based on a cantilever type tunnel boring machine, characterized in that: The following steps are involved: S1: installing a sensing system on the cantilever type roadheader, wherein the sensing system includes a stress sensor arranged around the cutting head, a vibration sensor arranged on the machine arm, a displacement sensor arranged at the connection between the cutting head and the machine arm, and an acoustic emission sensor arranged at the front end of the cutting head; S2: collecting surrounding rock stress data, tunnel boring machine vibration data, cutting head position data and rock fracture sound signal data detected by the sensing system; S3: Establishing a parameter optimization model according to the data, and calculating the cutting head rotation speed, propulsion speed and cutting depth; S4: Controlling the construction of the tunnel boring machine according to the cutting head rotation speed, advancing speed and cutting depth.

2. A tunnel construction method based on a cantilever type tunnel boring machine according to claim 1, characterized in that: Eight stress sensors are evenly arranged around the cutting head, and the interval between adjacent stress sensors is 45°.

3. A tunnel construction method based on a cantilever type tunnel boring machine according to claim 1, characterized in that: The vibration sensor comprises a three-way vibration sensor arranged at the root, middle and end of the machine arm.

4. A tunnel construction method based on a cantilever type tunnel boring machine according to claim 1, characterized in that: The acoustic emission sensors are arranged in four in a cross shape at the front end of the cutting head.

5. The tunnel construction method based on a cantilever type tunnel boring machine according to claim 1, characterized in that: The cutting head speed n is calculated by the following formula: Among them, n0 is the reference speed, σ is the surrounding rock stress, σ max is the maximum allowable surrounding rock stress, v is the vibration velocity, and v max is the maximum allowable vibration speed, d is the displacement deviation, d max is the maximum allowable displacement deviation.

6. A tunnel construction method based on a cantilever type tunnel boring machine according to claim 1, characterized in that: The propulsion speed V is calculated by the following formula: Among them, V0 is the reference advancement speed, k1 and k2 are adjustment coefficients, σ ​​is the surrounding rock stress, and σ max is the maximum allowable surrounding rock stress, AE is the acoustic emission signal intensity, and AE max To allow for maximum acoustic emission signal intensity, θ is the inclination of the rock formation.

7. The tunnel construction method based on a cantilever type tunnel boring machine according to claim 1, characterized in that: The cutting depth D is calculated by the following formula: Among them, D0 is the reference cutting depth, α and β are adjustment coefficients, σ ​​is the surrounding rock stress, and σ max is the maximum allowable surrounding rock stress, ρ0 is the standard rock density, ρ is the actual rock density, and h is the surrounding rock grade.

8. The tunnel construction method based on a cantilever type tunnel boring machine according to claim 1, characterized in that: Step S4 includes: when the surrounding rock stress is monitored to exceed 85% of the set threshold, the advancement speed is reduced by 20%; when the vibration amplitude exceeds the warning value, the cutting head rotation speed is adjusted; when the displacement deviation exceeds ±10mm, the trajectory is corrected; according to the intensity of the acoustic emission signal, the cutting depth is dynamically adjusted.

9. The tunnel construction method based on a cantilever type tunnel boring machine according to claim 1, characterized in that: The step S4 also includes: using a three-dimensional laser scanner to scan the excavation section in real time, and comparing the actual contour data obtained with the designed contour data; comparing the deviation between the actual contour data and the designed contour data every 1m of excavation, and when the deviation exceeds ±5cm, adjusting the cutting head rotation speed, propulsion speed and cutting depth.

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