Intelligent control method and system suitable for shield microwave-assisted rock breaking in composite stratum

Abstract

The present application belongs to the technical field of shield tunnel construction, and discloses an intelligent control method and system for shield microwave-assisted rock breaking in composite strata. The present application defines the relevant parameters of each cutter; real-time acquisition of the front face excavation composite strata interface position information, hard rock hardness information and cutterhead speed information, and transmission of the real-time acquired information to the microwave control system; according to the initial position parameters of each cutter, the configuration radius parameters, the received composite strata interface position information and the cutterhead speed information, the time for each cutter to reach the soft and hard composite strata interface is deduced, and the strata type in which each cutter is located at the current time is judged; according to the real-time strata type of each cutter and the hardness grade of the hard rock, the microwave irradiation device corresponding to each cutter is independently controlled. The present application reduces the strength of hard rock, narrows the strength difference between soft and hard strata, improves the stress state of the cutter and improves the shield tunneling efficiency and construction safety under the condition of composite strata.

Description

Technical Field

[0001] This invention belongs to the field of shield tunnel construction technology, and particularly relates to an intelligent control method and system for microwave-assisted rock breaking in shield tunnels in composite strata. Background Technology

[0002] In shield tunnel construction and underground space development projects, composite strata with soft upper layers and hard lower layers are a common and challenging geological condition. These strata typically consist of a relatively loose soil layer, strongly weathered rock layer, or weak rock layer at the excavation face, and a medium-hard or hard rock layer with good integrity, high strength, and high wear resistance at the lower layer. Due to the significant differences in the physical and mechanical properties of the soft and hard strata, the stress state of the cutterhead changes significantly when cutting different areas during tunneling. Particularly at the boundary between soft and hard strata, the cutterhead is susceptible to sudden load changes, leading to increased impact vibration, localized cutting instability, abnormal cutter wear, and decreased rock-breaking efficiency.

[0003] Currently, mechanical rock breaking remains the primary method for addressing the challenges of hard rock tunneling, supplemented by blasting and hydraulic crushing. However, traditional mechanical rock breaking methods rely mainly on cutting tools to apply pressure, shearing, and impact to the rock mass, resulting in drawbacks such as high rock-breaking resistance, rapid tool wear, uncontrollable crack propagation, and significant construction disturbance. To improve hard rock breaking efficiency, microwave-assisted mechanical rock breaking technology has gained increasing attention in recent years. This technology typically utilizes the selective heating effect of microwaves on the internal mineral components of the rock, creating a temperature gradient and thermal stress field within the rock, thereby inducing the generation and propagation of microcracks, reducing the overall strength of the rock, and then using mechanical cutting tools to complete subsequent cutting and stripping, thus reducing rock-breaking energy consumption, increasing cutting efficiency, and extending tool life.

[0004] Existing technical solutions typically employ fixed microwave power and irradiation time to uniformly irradiate the entire hard rock sample or the entire excavation face, followed by mechanical cutting tools for rock breaking. While this approach has some application value in all-hard rock or homogeneous rock strata, its control method is essentially a holistic, uniform heating control, treating the excavation face as a single object for microwave treatment. It fails to consider the geological differences corresponding to different positions of the cutterhead on the shield tunneling machine, nor does it address the differentiated treatment needs when soft and hard rock coexist in composite strata.

[0005] Existing technologies have poor adaptability to complex formations and struggle to address the uneven tool stress caused by differences in hardness between soft and hard strata. Most current microwave-assisted rock breaking technologies focus on entirely hard or homogeneous rock formations, typically failing to incorporate the physical and mechanical differences between different regions within composite soft-hard strata into their control strategies. Due to significant differences in strength, deformation characteristics, and wear resistance between soft and hard rock in composite strata, the actual resistance experienced by the tool at different locations on the cutterhead varies considerably during cutting. This is especially true at the soft-hard interface, where the tool is susceptible to sudden impact loads, leading to uneven tool stress, increased impact vibration, decreased rock breaking efficiency, and accelerated abnormal tool wear. Existing integrated microwave heating solutions cannot effectively address this problem.

[0006] Existing methods of uniform irradiation are prone to causing accidental irradiation of soft rock, affecting the stability of the excavation face. Current technologies often employ uniform irradiation of the entire excavation face or the entire hard rock area. When implemented in complex strata, soft rock areas are often simultaneously subjected to microwave radiation. Because soft rock has relatively low strength and poor stability, unnecessary microwave heating can easily cause overheating, softening, or even localized collapse of the soft rock, thereby reducing excavation face stability and increasing construction risks. Existing technologies lack effective avoidance mechanisms for soft rock areas, making it difficult to balance the weakening of hard rock with the stability of soft rock.

[0007] Current technologies suffer from low energy utilization and high system energy consumption. In complex strata, only hard rock areas have a strong need for microwave weakening, while soft rock areas typically do not require microwave heating. Existing monolithic irradiation methods result in a large amount of microwave energy being ineffectively applied to soft rock areas, which not only fails to improve rock breaking performance but also leads to energy waste and increased overall system energy consumption, reducing the economic viability and engineering applicability of microwave-assisted rock breaking technology.

[0008] Existing technologies struggle to adapt to the dynamic changes in geological formation ratios and cutterhead rotation speed during tunnel boring machine (TBM) excavation. In actual TBM construction, the ratio of soft to hard strata at the excavation face continuously changes as the TBM advances, and the cutterhead rotation speed is dynamically adjusted based on construction conditions, torque requirements, and muck removal conditions. Current microwave-assisted rock breaking technologies primarily employ fixed power, fixed irradiation time, and fixed effective range control methods, failing to adjust the microwave irradiation strategy in real-time according to changes in the geological interface and cutterhead motion, thus making them ill-suited for complex dynamic conditions. Summary of the Invention

[0009] To overcome the problems existing in related technologies, the present invention discloses an intelligent control method and system for microwave-assisted rock breaking of shield tunnels in composite strata, specifically involving an intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata with soft upper and hard lower formations. The purpose of this invention is to solve the problems of existing microwave-assisted rock breaking technologies, which are mainly designed for all-hard rock strata, have poor adaptability to composite strata, are prone to accidental irradiation of soft rock due to the overall irradiation method, have high energy consumption, uneven cutter stress, and are difficult to adapt to dynamic changes in strata proportions and cutterhead rotation speed.

[0010] The technical solution is as follows: An intelligent control method for microwave-assisted rock breaking in composite strata using shield tunneling machines includes the following steps: S1. In the distributed precision action structure of one tool and one microwave, a microwave irradiation device is arranged at each tool, and the relevant parameters of each tool are defined. S2. During the shield tunneling process, the location information of the composite stratum interface at the front excavation face, the hard rock hardness information, and the cutterhead rotation speed information are acquired in real time, and the acquired information is transmitted to the microwave control system. S3. The microwave control system deduces the time for each tool to reach the interface between soft and hard composite formations based on the initial position parameters, configuration radius parameters, received composite formation interface position information, and tool head rotation speed information of each tool, and determines the formation type of each tool at the current moment. S4. The microwave control system independently controls the microwave irradiation device corresponding to each tool based on the real-time formation type and hardness level of the hard rock.

[0011] In step S1, a microwave irradiation device is set at each cutter on the cutter head to cooperate with the cutter. The irradiation position of each microwave irradiation device matches the rock-breaking position of the corresponding cutter, forming a distributed precision action structure of one cutter, one tool, one microwave, and one irradiation.

[0012] In step S1, defining the relevant parameters for each tool includes defining the initial position and configuration radius parameters for each tool. Establish a coordinate system with the center of the cutter head as the origin, and rotate the cutter head counterclockwise to number each cutter. And define the relevant tool parameters; The total number of cutting tools is The time is The radius of the cutter head is The angular velocity of the cutter head is The speed of the cutter head is , No. The initial angle of each tool is Configuration radius is The configuration radius parameter is the radial distance of each tool relative to the center of the cutter head; No. A knife in The vertical axis of time is ; The location of the composite stratum interface is: ; Define the dimensionless interface ratio as: ; In the formula, It is the interface of a composite strata.

[0013] In step S2, during the tunnel boring machine excavation process, a three-dimensional advance prediction system is used to monitor in real time the location of the composite stratum interface, the ratio of soft to hard rock, and the hardness of hard rock at the excavation face ahead; a speed sensor installed at the cutterhead is used to monitor the cutterhead speed in real time; and the composite stratum interface location information, stratum ratio, hard rock hardness information, and cutterhead speed information are transmitted to the microwave control system in real time.

[0014] In step S3, the composite strata are divided into three types according to the relationship between the proportion of soft rock and the proportion of hard rock: soft rock proportion is less than hard rock, soft rock proportion is greater than hard rock, and soft rock proportion is equal to hard rock. The microwave control system determines the microwave irradiation device opening and closing intervals of the corresponding tools according to different strata types and the initial position status of each tool. When determining the geological formation type of each tool at the current moment, if it is determined to be a hard rock area, the hardness characterization parameters corresponding to the hard rock area are further read, and the hardness level of the hard rock is determined.

[0015] Furthermore, based on the initial position parameters, configuration radius parameters, received composite formation interface position information, and cutterhead rotation speed information of each tool, the microwave control system deduces the time it takes for each tool to reach the interface between the soft and hard composite formations, and determines the formation type of each tool at the current moment, including: Condition 1: The cutting tool passes through both hard rock and soft rock areas; when ,Right now At that time, the formation type indicator function is defined as follows: ; In the formula, The dimensionless interface ratio indicates the location of the composite stratum interface relative to the first... The ratio of the radius of each tool configuration, This is a stratigraphic type indicator function, representing the first... The geological strata type where the cutting tool is located. Here, the Heaviside step function represents a numerical abrupt change, specifically: ; In the formula, For Heaviside step function, representing a numerical abrupt change; Indicates the first The geological strata in which the cutting tool is located are specifically as follows: ; The corresponding time interval for the hard rock region is: ; The corresponding time interval for the soft rock area is: ; Microwave on / off times at the interface between soft and hard strata: ; Microwave activation time: ; ; ; In the formula, For the first The activation time of the microwave device near the cutting tool For any integer, It is all integers; Pi is the mathematical constant for a circle, representing a half-circle angle when the angle unit is radians. at this time, The cutter will enter the hard rock area; Microwave shutdown time: ; ; In the formula, For the first The shut-off time of the microwave device near the cutting tool; at this time, The cutting tool is about to enter the soft rock area.

[0016] In step S3, the microwave control system, based on the initial position parameters, configuration radius parameters, received composite formation interface position information, and cutterhead rotation speed information of each tool, deduces the time it takes for each tool to reach the interface between the soft and hard composite formations, and further determines the formation type of each tool at the current moment, including: Condition 2: The cutting tool is always in the hard rock area or always in the soft rock area; when At that time, the cutting tool remained in the hard rock area; when At that time, the cutting tool was always in the soft rock area; When the region is identified as hard rock, further, the first definition is made. The hardness characterization parameters of the hard rock region corresponding to each cutting tool Hardness thresholds are preset based on rock mineral composition, rock integrity, porosity, and water content parameters. and , The hardness of hard rock is divided into three levels.

[0017] Furthermore, hard rock hardness is divided into three levels, including: Low hardness setting: ; Medium hardness setting: ; High hardness setting: ; The hardness characterization parameters obtained from the cutting tool are determined by the microwave control system. The hardness level of hard rock is determined by which gear it belongs to.

[0018] In step S4, the microwave control system independently controls the microwave irradiation device corresponding to each tool based on the real-time formation type and hardness level of the hard rock. When a tool is in a soft rock area, the corresponding microwave irradiation device is turned off; when a tool is in a hard rock area, the corresponding microwave irradiation device is turned on. Through this method, microwave energy is consistently applied to the hard rock area to be weakened. Specifically, this includes: Definition of the first The microwave switch status corresponding to each tool is: When the first When the cutting tool is in the soft rock area Turn off the microwave switch of the microwave irradiation device corresponding to the tool; when the first When the cutting tool is in the hard rock zone Turn on the microwave switch of the microwave irradiation device corresponding to the tool; ; Based on the hardness level of the hard rock, the corresponding microwave irradiation power level is preset in the microwave control system: The low hardness setting corresponds to low power irradiation. Medium hardness corresponds to medium power irradiation. High hardness setting corresponds to high power irradiation. ; Three power levels are sufficient All of these are within the safe operating range of the microwave irradiation device; If hardness characterization parameters If it falls into the low hardness range, then the microwave irradiation device uses... Low-power irradiation; if hardness characterization parameters If the hardness is in the medium range, then the microwave irradiation device uses... Medium power irradiation; if hardness characterization parameters If it falls into the high hardness category, then the microwave irradiation device uses... High-power irradiation.

[0019] Another objective of this invention is to provide an intelligent control system for microwave-assisted rock breaking of shield tunnels in complex strata. This system implements the aforementioned intelligent control method for microwave-assisted rock breaking of shield tunnels in complex strata. The system includes: The tool-related parameter configuration module is used to arrange microwave irradiation devices at each tool and define the relevant parameters of each tool. The information transmission module is used to acquire real-time information on the location of the composite stratum interface at the excavation face, the hardness of the hard rock, and the rotation speed of the cutterhead during the shield tunneling process, and to transmit the acquired information to the microwave control system. The formation type determination module is used by the microwave control system to deduce the time when each tool reaches the interface between soft and hard formations based on the initial position parameters, configuration radius parameters, received composite formation interface position information, and tool head rotation speed information of each tool, and to determine the formation type of each tool at the current moment. When it is determined to be a hard rock area, the module further reads the hardness characterization parameters corresponding to the hard rock area and determines the hardness level of the hard rock. The microwave irradiation device control module is used by the microwave control system to independently control the microwave irradiation device corresponding to each tool according to the real-time formation type and hardness level of each hard rock. When the tool is in a soft rock area, the corresponding microwave irradiation device is turned off, and when the tool is in a hard rock area, the corresponding microwave irradiation device is turned on, and the power of the microwave irradiation device is adjusted according to the hardness level of the hard rock.

[0020] Combining all the above technical solutions, the beneficial effects of this invention are as follows: First, this invention installs microwave irradiation devices at each cutterhead of the tunnel boring machine (TBM). Combining the location information of the composite stratum interface obtained from a three-dimensional advanced prediction system, the cutterhead rotation speed information obtained from a rotation sensor, and the initial position and configuration radius parameters of each cutter, a spatiotemporal correspondence between the cutter's motion trajectory and the interface between soft and hard strata is established. The time it takes for each cutter to reach the interface between soft and hard strata is derived, and based on this, the microwave irradiation device corresponding to each cutter is independently and intelligently controlled. By activating microwave irradiation only when the cutter is cutting hard rock and deactivating it when cutting soft rock, the microwave energy is directed onto the hard rock area, reducing the hard rock strength, narrowing the strength difference between soft and hard strata, improving the stress state of the cutter, and increasing the TBM's rock-breaking efficiency, construction stability, and energy utilization rate under composite strata conditions.

[0021] Secondly, this invention enables accurate identification of the geological regions corresponding to different cutting tools during shield tunneling, and independently adjusts the microwave irradiation device according to the real-time geological type of the cutting tool, so that microwave energy acts only on hard rock areas, thereby reducing the strength of hard rock, narrowing the strength difference between soft and hard strata, improving the stress state of the cutting tool, and improving the shield tunneling efficiency and construction safety under composite geological conditions.

[0022] Third, this invention addresses the engineering challenges in shield tunneling in complex strata, including low hard rock breaking efficiency, rapid cutter wear, high impact loads at the hard-soft interface, high overall microwave irradiation energy consumption, and high risk of accidental irradiation of soft rock. It proposes a "one cutter, one microwave" distributed precision control scheme at the cutter level. After technological transformation, microwave energy can be precisely applied to the hard rock areas requiring weakening, with differentiated power output based on the hardness level of the rock. This reduces rock-breaking resistance, improves cutter stress, reduces abnormal cutter wear, downtime for maintenance and cutter replacement, and increases the efficiency of continuous shield tunneling and equipment utilization. Simultaneously, it avoids overheating, softening, or decreased excavation face stability in soft rock areas due to unnecessary microwave irradiation, reducing the risks of construction in complex strata. This scheme can be widely applied to shield tunneling projects in complex strata such as urban rail transit, railway tunnels, highway tunnels, integrated utility tunnels, and underground space development. It can also be transformed into a cutterhead-equipped microwave irradiation module, a shield intelligent microwave control system, multi-source information fusion control software, and an upgrade and renovation scheme for existing shield equipment, resulting in reduced construction costs and improved tunneling efficiency.

[0023] Fourth, existing microwave-assisted rock breaking technology is mainly geared towards hard rock or homogeneous strata, typically employing fixed power, fixed irradiation time, and a uniform overall irradiation method. It lacks a precise microwave control method at the cutter level suitable for complex strata. Especially in complex strata, the position of the soft-hard interface and the cutterhead rotation speed dynamically change during the tunneling process. Cutters with different radii on the same cutterhead may be operating in soft rock and hard rock zones simultaneously. Existing technology fails to establish a real-time correspondence between "strata interface information—cutterhead motion state—cutter spatial position—independent microwave control." This invention establishes a spatiotemporal mapping relationship between the cutter's motion trajectory and the composite stratum interface by combining a distributed action structure of "one cutter and one microwave" with three-dimensional advance prediction information, cutterhead rotation speed information, cutter initial position and configuration radius parameters. It also independently starts and stops the microwave device and adjusts its power according to the real-time stratum type and hard rock hardness level of the cutter. This forms a cutter-level, selective, and dynamic microwave-assisted rock breaking control system for shield tunneling in composite strata, which makes up for the deficiencies of existing technologies in terms of adaptability to composite strata, precise cutter-level control, dynamic microwave action strategy and differentiated thermal weakening. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the disclosure of this invention and, together with the description, serve to explain the principles of this disclosure; Figure 1 This is a flowchart of the intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata provided by the present invention; Figure 2 This is a schematic diagram of the arrangement of one tool and one microwave in the distributed precision action structure of one tool and one microwave provided by the present invention. Figure 3 This is a schematic diagram showing the real-time formation type of the cutting tool under working conditions provided by the present invention. Figure 4 This is a schematic diagram of the real-time formation type 2 where the cutting tool is located under working condition 1 provided by the present invention; Figure 5 This is a schematic diagram of the three formation types where the cutting tool is located in real time under working conditions provided by the present invention; Figure 6 This is a schematic diagram showing the real-time formation type of the cutting tool under working condition two provided by the present invention; Figure 7 This is a schematic diagram of the formation type 2 where the cutting tool is located in real time under working condition 2 provided by the present invention; In the diagram: 1. Cutter head; 2. Cutter; 3. Microwave irradiation device; 4. Soft rock; 5. Hard rock; 6. Cutter rotation trajectory. Detailed Implementation

[0025] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] The innovation of this invention lies in its approach to shield tunneling in complex geological conditions. Breaking away from existing integrated, fixed-parameter microwave irradiation modes, this invention proposes a distributed, precise action structure of "one cutter, one microwave," corresponding the microwave irradiation position to the rock-breaking position of a single cutter. By integrating information on the geological interface and hard rock 5 obtained from three-dimensional advanced prediction, the rotational speed of the cutterhead 1, and the spatial distribution parameters of the cutter 2, a spatiotemporal mapping relationship between the movement trajectory of the cutter 2 and the complex geological interface is established. This allows for real-time determination of the soft and hard geological types of each cutter 2 and prediction of the times it enters and leaves the hard rock area. Furthermore, the microwave irradiation device 3 corresponding to each cutter 2 is independently activated, deactivated, and its power is graded and controlled, ensuring that microwave energy acts only on the hard rock area requiring weakening. Differential irradiation is achieved based on the hard rock hardness, with higher power for higher hardness and lower power for lower hardness. This avoids accidental irradiation of soft rock 4, reduces the strength difference between hard rock 5 and soft and hard geological layers, improves the stress state of the cutter 2, and enhances the efficiency, energy utilization, and construction safety of shield tunneling in complex geological conditions.

[0027] Example 1.

[0028] This invention proposes a cutter-level distributed microwave-assisted rock breaking control approach suitable for composite strata with soft upper layers and hard lower layers. Unlike existing technologies that uniformly irradiate the entire excavation face or the entire hard rock area, this invention sets up microwave irradiation devices 3 at each cutter 2 of the shield cutterhead 1, forming a distributed precision action structure of "one cutter, one microwave". This ensures that the microwave irradiation position corresponds to the rock breaking position of the cutter, realizing the transformation of microwave energy from a generalized, extensive action to a cutter-level precision action.

[0029] A spatiotemporal determination mechanism for cutter 2 based on the geological interface and the motion state of cutterhead 1 was established. This invention comprehensively utilizes parameters such as the location of the composite geological interface, the rotational speed of cutterhead 1, the initial position of cutter 2, and the configuration radius of cutter 2 to deduce the time node when each cutter 2 reaches the interface between soft and hard geological formations, thereby determining the geological type of each cutter 2 at different times. Compared with the fixed parameter control method in existing technologies, this invention achieves predictive control for dynamic shield tunneling conditions.

[0030] A selective microwave irradiation strategy suitable for the differential characteristics of composite strata is proposed. Addressing the issue of significant differences in the physical and mechanical properties of soft rock 4 and hard rock 5 in composite strata with a soft upper layer and a hard lower layer, and the potential for accidental irradiation of soft rock 4 by overall microwave irradiation, this invention employs a tool-level independent control method to ensure that microwave energy acts only on the hard rock region. This avoids overheating and softening of the soft rock region and a decrease in excavation face stability, significantly improving microwave energy utilization efficiency and construction safety.

[0031] An intelligent control system coupling formation information, cutterhead 1 motion information, and cutter 2 spatial distribution information was constructed. This invention comprehensively couples formation information obtained from a three-dimensional advance prediction system, equipment operation information obtained from a rotation speed sensor, and cutter 2 spatial distribution information to establish a correspondence between the real-time formation position of cutter 2 and the microwave switch status, realizing intelligent control of multi-source information fusion during shield tunneling rock breaking in complex formations.

[0032] A dynamic microwave control method is provided that can adapt to changes in the proportion of complex strata and the rotational speed of the cutterhead 1. Existing microwave-assisted rock breaking technologies mostly use fixed power, fixed irradiation time, and uniform heating methods, which are difficult to adapt to the dynamic changes in the proportion of complex strata and the rotational speed of the cutterhead 1 during shield tunneling. This invention can adjust the on / off state of the microwave irradiation device 3 corresponding to different cutters 2 in real time according to changes in working conditions, and has better adaptability to working conditions.

[0033] This invention proposes a correlation between hard rock hardness and target irradiation temperature. This invention establishes a correlation between the hardness grade of hard rock (grade 5) and microwave irradiation power, achieving differentiated thermal attenuation where "higher hardness corresponds to higher irradiation power, and lower hardness corresponds to lower irradiation power."

[0034] like Figure 1 As shown in the embodiments of the present invention, the intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata includes: S1. In the distributed precision action structure of one tool and one microwave, a microwave irradiation device 3 is arranged at each tool 2, and the relevant parameters of each tool 2 are defined. S2. During the shield tunneling process, the location information of the composite stratum interface at the front excavation face, the hardness information of hard rock 5, and the rotation speed information of cutterhead 1 are acquired in real time, and the acquired information is transmitted to the microwave control system. S3. The microwave control system deduces the time when each tool 2 reaches the interface between soft and hard composite formations based on the initial position parameters, configuration radius parameters, received composite formation interface position information and tool head 1 rotation speed information of each tool 2, and determines the formation type of each tool 2 at the current moment. When the area is identified as a hard rock region, the hardness characterization parameters corresponding to the hard rock region are further read, and the hardness level of the hard rock 5 is determined. S4. The microwave control system independently controls the microwave irradiation device 3 corresponding to each tool 2 based on the real-time stratum type and hardness level of the hard rock 5.

[0035] When the tool 2 is in a hard rock area, the corresponding microwave irradiation device 3 is turned on, and the power of the microwave irradiation device 3 is adjusted according to the hardness level of the hard rock; when the tool 2 is in a soft rock area, the corresponding microwave irradiation device 3 is turned off, so that the microwave energy selectively acts on the hard rock area.

[0036] For example, in step S1, a microwave irradiation device 3 is respectively set at each cutter 2 on the cutterhead 1 (shield cutterhead) to cooperate with the corresponding cutter 2. Each microwave irradiation device 3 is respectively set near the corresponding cutter 2, so that the irradiation position of each microwave irradiation device 3 matches the rock breaking position of the corresponding cutter 2, forming a distributed precision action structure of one cutter, one tool, one microwave, one irradiation.

[0037] Specifically, such as Figure 2 The distributed precision action structure of one cutter and one microwave includes a cutter head 1 arranged in a circle; multiple cutters 2 are arranged on the cutter head 1; and a microwave irradiation device 3 is installed on one side of the cutter 2. For example, the initial position and configuration radius of each tool 2 are defined as follows: Establish a coordinate system with the center of the tool head 1 as the origin, number each tool 2, and determine the initial position parameters and configuration radius parameters of each tool 2; The initial position parameters include at least the initial angle of the tool 2, and the configuration radius parameter is the radial distance of each tool 2 relative to the center of the cutter head 1; each tool 2 is numbered sequentially according to its distribution position on the cutter head 1. The relevant parameters of tool 2 are defined; specifically, a coordinate system is established with the center of tool head 1 as the origin, tool head 1 is rotated counterclockwise, and each tool 2 is numbered. And define the relevant parameters for tool 2: The total number of cutting tools 2 is (Unit: pieces), time period (Unit: s), the radius of cutter head 1 is (Unit: m), the angular velocity of cutter head 1 is (Unit: rad / s), the rotational speed of cutter head 1 is... (Unit: r / min), the The initial angle of the two cutters is... Configuration radius is The configuration radius parameter is the radial distance of each tool 2 relative to the center of the cutter head 1; No. Two cutting tools The vertical axis at time is: ; The location of the composite stratum interface is: ; Define the dimensionless interface ratio as: ; In the formula, It is the interface of a composite strata.

[0038] For example, in step S2, during the tunnel boring machine (TBM) excavation, a three-dimensional advance prediction system is used to monitor in real time the location of the composite stratum interface (the interface location of the upper soft and lower hard composite stratum), the proportion of soft rock 4 and hard rock 5, and the hardness information of hard rock 5 at the excavation face; simultaneously, a rotational speed sensor installed on the cutterhead 1 is used to monitor the rotational speed of the cutterhead 1 in real time. The composite stratum interface location information, stratum proportion, hard rock 5 hardness information, and cutterhead 1 rotational speed information are transmitted to the microwave control system in real time.

[0039] The principle of the three-dimensional advance prediction system is seismic wave reflection imaging. It distinguishes between soft and hard strata and monitors the hardness of rocks by the difference in wave velocity and reflection coefficient. The device can output a three-dimensional profile of the strata ahead, the location of the soft and hard interface, and the hardness of the rocks. The rotation speed sensor adopts the inductive proximity detection principle. By detecting the alternating changes of the tooth tip and tooth valley of the rotating gear ring, it outputs a periodic pulse electrical signal. The system calculates the real-time rotation speed of the cutterhead 1 based on the pulse frequency and the number of teeth on the gear ring.

[0040] For example, in step S3, the microwave control system establishes the spatiotemporal correspondence between the tool rotation trajectory 6 and the composite stratum interface based on the initial position parameters, configuration radius parameters, received composite stratum interface position information, and tool head 1 rotation speed information of each tool 2. It derives the time node when each tool 2 reaches the interface between soft and hard strata (the time node when each tool 2 enters the hard rock region and the soft rock region), determines the stratum type where each tool 2 is located at the current moment, and when it is determined to be a hard rock region, it further reads the hardness characterization parameters corresponding to the hard rock region and determines the hardness level of the hard rock 5.

[0041] Among them, the composite strata (soft upper and hard lower composite strata) are divided into three types according to the relationship between the proportion of soft rock 4 and the proportion of hard rock: the proportion of soft rock 4 is less than that of hard rock 5, the proportion of soft rock 4 is greater than that of hard rock 5, and the proportion of soft rock 4 is equal to that of hard rock 5. The microwave control system determines the opening and closing intervals of the microwave irradiation device 3 for the corresponding tool 2 according to different strata types and the initial position state of each tool 2.

[0042] For example, define the first The geological stratum where the second cutting tool is located is: When the first When tool 2 is in a hard rock area , start the The microwave irradiation device 3 corresponds to the first cutting tool 2; when the first... When the two cutting tools are in the soft rock area Close the first The microwave irradiation device 3 corresponds to each cutting tool 2.

[0043] For example, when the configuration radius of a certain cutting tool 2 is less than or equal to the vertical distance between the composite stratum interface and the centerline of the excavation face, the microwave control system determines that the cutting tool 2 is always in the same stratum area under the current working conditions, and keeps the microwave irradiation device 3 corresponding to the cutting tool 2 in a constant on or constant off state.

[0044] For example, the following is the derivation of the time node formula for each tool 2 to reach the interface between soft and hard strata, and the determination of the stratum type where the tool 2 is located at the current time. Select any tool 2 as the analysis object.

[0045] Working condition 1: Cutting tool 2 passes through both hard rock and soft rock areas; like Figure 3 The present invention provides a schematic diagram of the formation type where the cutting tool 2 is located in real time under working conditions. Figure 4 The present invention provides a schematic diagram of the real-time formation type of the cutting tool 2 under working condition 1. Figure 5 The schematic diagram of the geological formation type 3 where the tool is located in real time under working condition 1 provided by the present invention is shown in the figure. Figure 3 In the middle, the upper layer is soft rock 4, and the lower layer is hard rock 5; the circumference of the tool 2 is the tool rotation trajectory 6; as Figure 4 In the middle, the upper layer is soft rock 4, the lower part is hard rock 5, and the circumference where the cutting tool 2 is located is the cutting tool rotation trajectory 6; Figure 5 In the middle, the upper layer is soft rock 4, the lower layer is hard rock 5, and the circumference where the cutting tool 2 is located is the cutting tool rotation trajectory 6.

[0046] when ,Right now At that time, the formation type indicator function is defined as follows: ; In the formula, The dimensionless interface ratio indicates the location of the composite stratum interface relative to the first... The ratio of the radii of the two tools configured. This is a stratigraphic type indicator function, representing the first... The geological stratum type where the second cutting tool is located. Here, the Heaviside step function represents a numerical abrupt change, specifically: ; In the formula, For Heaviside step function, representing a numerical abrupt change; Indicates the first The geological formation type where tool 2 is located is as follows: ; The corresponding hard rock time interval is: ; The corresponding time interval for the soft rock area is: ; Microwave on / off times at the interface between soft and hard strata: ; Microwave activation time: ; ; ; In the formula, For the first The activation time of the microwave device near the tool 2 For any integer, It is all integers; Pi is the mathematical constant for a circle, representing a half-circle angle when the angle unit is radians. at this time, Cutter 2 will enter the hard rock area; Microwave shutdown time: ; ; In the formula, For the first The shutdown time of the microwave device near the tool 2; at this time, Cutter 2 is about to enter the soft rock area.

[0047] It can be seen that the formula of the present invention no longer needs to be derived separately for the three stratigraphic types. The present invention can derive formulas for all three stratigraphic types using this formula. middle It can be positive or negative, but the final time point remains unchanged.

[0048] Condition 2: Tool 2 is always in the hard rock area or always in the soft rock area.

[0049] like Figure 6 The present invention provides a schematic diagram of the formation type in real time for tool 2 under working condition 2. At that time, tool 2 remained in the hard rock area; such as Figure 7 The schematic diagram of the formation type 2 where the tool 2 is located in real time under working condition 2 provided by the present invention, when At that time, the cutting tool 2 was always in the soft rock area.

[0050] When the region is identified as hard rock, further, the first definition is made. The hardness characterization parameters of the hard rock region corresponding to each tool 2 are as follows: Hardness thresholds are preset based on parameters such as rock mineral composition, rock integrity, porosity, and water content. and , Hard rock hardness is divided into three levels: Low hardness setting: ; Medium hardness setting: ; High hardness setting: ; The hardness characterization parameters obtained by tool 2 are determined by the microwave control system. This determines which gear it belongs to, thus establishing the Hard Rock 5 hardness rating.

[0051] For example, in step S4, the microwave control system independently controls the microwave irradiation device 3 corresponding to each tool 2 according to the real-time formation type obtained for each tool 2. When a tool 2 is in a soft rock area, its corresponding microwave irradiation device 3 is turned off; when a tool 2 is in a hard rock area, its corresponding microwave irradiation device 3 is turned on. In this way, microwave energy is always applied to the hard rock area that needs to be weakened.

[0052] Definition of the first The microwave switch state corresponding to tool 2 is: When the first When tool 2 is in the soft rock area Turn off the microwave switch of the microwave irradiation device 3 corresponding to the tool 2; when the first When tool 2 is in the hard rock 5 zone Turn on the microwave switch of the microwave irradiation device 3 corresponding to the cutting tool 2; ; Based on the hardness level of Hard Rock 5, the corresponding microwave irradiation power level is preset in the microwave control system: The low hardness setting corresponds to low power irradiation. Medium hardness corresponds to medium power irradiation. High hardness setting corresponds to high power irradiation. ; Three power levels are sufficient All of these are within the safe operating range of the microwave irradiation device 3; If hardness characterization parameters If it falls into the low hardness range, then microwave irradiation device 3 adopts... Low-power irradiation; if hardness characterization parameters If the hardness is medium, then microwave irradiation device 3 uses... Medium power irradiation; if hardness characterization parameters If it falls into the high hardness category, then microwave irradiation device 3 adopts... High-power irradiation.

[0053] This allows us to obtain the opening and closing ranges of the microwave irradiation device 3 for each cutter 2 under different composite stratum ratios and different cutterhead 1 rotation speeds, as well as the opening power of the microwave irradiation device 3, thus achieving intelligent control of the shield microwave irradiation device 3 under composite stratum conditions of soft upper and hard lower.

[0054] In summary, the technical solution of this invention essentially constructs a microwave action spatiotemporal mapping mechanism based on the relationship between the cutter movement trajectory and the composite stratum interface, realizing the on-demand allocation and precise action of microwave energy on hard rock areas during shield tunneling. This solution differs from the existing unified irradiation method; instead, it refines the microwave action granularity to the individual cutter level, matching the microwave irradiation position with the rock-breaking position of the cutter and the microwave irradiation power with the hardness of the hard rock.

[0055] Ultimately, it is possible to obtain the switching status and power level of the microwave irradiation device 3 of each cutter 2 under different composite stratum ratios and different cutterhead 1 rotation speeds, thus realizing intelligent control of the shield microwave irradiation device 3 in composite strata with soft upper and hard lower layers.

[0056] This invention establishes a spatiotemporal mapping relationship between the movement trajectory of the cutter 2 and the composite stratum interface by setting an independent microwave irradiation device 3 at each cutter 2 of the shield cutterhead and combining the stratum interface information, hard rock 5 hardness information and cutterhead 1 rotation speed information obtained by the three-dimensional advanced prediction system. It can deduce the time node when each cutter 2 enters the soft rock area or hard rock area in real time, and independently control the microwave irradiation device 3 corresponding to each cutter 2. When the cutter 2 enters the hard rock area, it can match the appropriate microwave irradiation power according to the hardness level of the hard rock 5.

[0057] This invention is used to generate thermal stress and induce microcrack development in the hard rock 5 by microwave heating only the hard rock area, thereby reducing the strength of the hard rock 5 and narrowing the strength difference between the soft rock 4 and the hard rock 5. This improves the uneven stress on the tool 2 under composite strata conditions, reduces the impact at the strata interface, and reduces the wear of the tool 2.

[0058] As can be seen from the above embodiments, the present invention has the following advantages: Improving rock-breaking efficiency under complex geological conditions. This invention improves the rock-breaking efficiency of shield tunneling machines under complex geological conditions by implementing microwave heating when the cutter 2 cuts the hard rock area, thereby generating thermal stress inside the hard rock 5 and inducing the development of microcracks, reducing the strength of the hard rock 5, decreasing the cutting resistance of the hard rock 5, and thus improving the rock-breaking efficiency of shield tunneling machines under complex geological conditions.

[0059] This invention improves the stress state of the cutting tool 2 and reduces its wear. By applying microwave weakening treatment only to the hard rock area, the present invention can effectively reduce the strength difference between soft rock 4 and hard rock 5, reduce the impact load on the cutting tool 2 at the interface between soft and hard strata, improve the problem of uneven stress on the cutting tool 2, and thus reduce abnormal wear and replacement frequency of the cutting tool 2.

[0060] To avoid accidental irradiation of soft rock 4 and improve the stability of the excavation face, this invention employs a two-stage independent control strategy for the cutting tool. When the cutting tool 2 enters the soft rock area, the corresponding microwave irradiation device 3 is shut off, preventing microwave energy from acting on the soft rock area that does not require heating. This prevents the soft rock 4 from overheating and softening, as well as the resulting local instability of the excavation face, thus improving construction safety.

[0061] This invention improves microwave energy utilization and reduces energy consumption. Because it uses a two-stage selective control method for the cutting tool to concentrate microwave energy onto the hard rock region, it avoids the problem of a large amount of energy being ineffectively applied to the soft rock region in the overall irradiation method. Therefore, it can improve microwave energy utilization and reduce the overall system energy consumption.

[0062] This invention adapts to dynamic changes in working conditions during tunnel boring machine (TBM) excavation. By combining parameters such as the location of the composite stratum interface, the stratum ratio, and the rotational speed of the cutterhead 1, it can make real-time judgments on the stratum type of each cutter 2 under different working conditions and dynamically adjust the working state of the microwave irradiation device 3 corresponding to each cutter 2. Therefore, it can adapt to the effects of changes in the composite stratum ratio and the rotational speed of the cutterhead 1 during TBM excavation.

[0063] This invention achieves precise matching between the microwave irradiation position and the rock-breaking position of the cutting tool 2. By using a "one cutting tool, one microwave" setup, the microwave irradiation position corresponds spatially to the rock-breaking position of the cutting tool 2, enabling higher precision microwave-assisted rock-breaking control and enhancing the synergistic effect between microwave and mechanical rock-breaking.

[0064] This invention establishes a graded control of irradiation power based on the hardness differences of hard rock (5). It establishes a correlation between the hardness of hard rock (5) and the microwave target irradiation temperature, achieving adaptive control of "higher hardness – higher irradiation power, lower hardness – lower irradiation power," thus better matching the microwave weakening intensity with actual rock-breaking requirements.

[0065] Example 2. The intelligent control system for microwave-assisted rock breaking of shield tunnels in complex strata provided in this embodiment of the invention includes: The tool-related parameter configuration module is used to arrange the microwave irradiation device 3 at each tool 2 and define the initial position and configuration radius of each tool 2, as well as other tool-related parameters. The information transmission module is used to acquire in real time the location information of the composite stratum interface at the front excavation face, the hardness information of hard rock 5, and the rotation speed information of cutterhead 1 during the shield tunneling process, and transmit the acquired information to the microwave control system. The formation type determination module is used by the microwave control system to deduce the time when each cutter 2 reaches the interface between soft and hard composite formations based on the initial position parameters, configuration radius parameters, received composite formation interface position information and cutter head 1 rotation speed information of each cutter 2, and determine the formation type of each cutter 2 at the current moment. When it is determined to be a hard rock area, the module further reads the hardness characterization parameters corresponding to the hard rock area and determines the hardness level of the hard rock 5. The microwave irradiation device control module is used by the microwave control system to independently control the microwave irradiation device 3 corresponding to each tool 2 according to the real-time formation type and hardness level of the hard rock 5. When the tool 2 is in the soft rock area, the corresponding microwave irradiation device 3 is turned off, and when the tool 2 is in the hard rock area, the corresponding microwave irradiation device 3 is turned on, and the power of the microwave irradiation device 3 is adjusted according to the hardness level of the hard rock 5.

[0066] As demonstrated by the above embodiments, this invention can apply microwave weakening only to hard rock areas, avoiding accidental irradiation of soft rock 4; it can reduce the strength difference between soft rock 4 and hard rock 5, improving the problem of uneven stress on the cutter head 2; it can reduce the impact load on the cutter head 2 at the interface between soft and hard strata, reducing cutter head 2 wear; it can improve microwave energy utilization and reduce system energy consumption; and it can adapt to changes in the proportion of composite strata and the rotational speed of the cutterhead 1 during shield tunneling, showing good engineering application prospects. It can also match appropriate microwave irradiation power according to the hardness level of hard rock 5, achieving precise targeting of hard rock areas.

[0067] Example 3.

[0068] In the specific embodiments of this invention, the composite stratum interface is specifically defined as a horizontal straight line, excluding oblique lines and curves. However, in other possible embodiments, the soft and hard stratum interface can also be an inclined interface, a piecewise curved interface, or a fitted boundary interface. The microwave control system can deduce the time for the tool 2 to enter different stratum regions based on the interface function model.

[0069] To further illustrate the effects of the embodiments of the present invention, the following experiments were conducted.

[0070] To further illustrate the positive effects that the embodiments of the present invention can achieve during use, the technical effects of the present invention will now be analyzed from a theoretical perspective, taking into account the control logic, the motion law of the shield cutter 2, the stress characteristics of composite strata, and the microwave-assisted rock breaking mechanism.

[0071] This invention does not employ the traditional monolithic, fixed-power, fixed-duration microwave irradiation method. Instead, it sets corresponding microwave irradiation devices 3 at each cutterhead 1 and each cutter 2, forming a distributed, precise action structure of "one cutter, one microwave." Simultaneously, based on the location of the composite stratum interface at the excavation face, the hardness information of the hard rock 5, the rotational speed of the cutterhead 1, the initial angle of the cutter 2, and the configuration radius of the cutter 2, the current stratum type of each cutter 2 is determined in real time, and the microwave irradiation device 3 corresponding to each cutter 2 is independently started, stopped, and its power is controlled in stages. This scheme achieves cutter-level microwave-assisted rock breaking control through the coupling of stratum information, cutterhead 1 motion information, and cutter 2 spatial distribution information.

[0072] (1) Theoretical analysis of the weakening effect of hard rock 5; In composite strata of soft upper and hard lower layers, the lower hard rock 5 typically exhibits high strength, good integrity, and strong wear resistance. When the cutting tool 2 cuts this area, it generates significant normal force, rolling force, and impact load. According to the microwave-assisted rock breaking mechanism, after being irradiated with microwaves, the different mineral components within the hard rock 5 exhibit varying absorption capacities for microwave energy, easily leading to uneven temperature rise and localized thermal stress concentration. When the thermal stress exceeds the threshold for the propagation of micro-cracks within the rock, primary and newly formed cracks within the rock mass will further expand, causing a decrease in the overall compressive strength, tensile strength, and fracture toughness of the hard rock 5.

[0073] Therefore, when the control system of the present invention determines that a certain cutting tool 2 is about to enter or has already entered the hard rock area, the microwave irradiation device 3 near the cutting tool 2 is turned on. The hard rock can be thermally weakened before or during the cutting process. After being thermally weakened, the hard rock 5 is more likely to produce crack propagation, spalling and breakage under the action of the mechanical cutting tool 2. In theory, this can reduce the rock breaking resistance of a single cutting tool 2 and improve the cutting efficiency of the hard rock area.

[0074] Compared with traditional mechanical rock breaking methods that do not use microwave-assisted rock breaking, the present invention can form a pre-damage zone before cutting hard rock 5, so that the cutter 2 no longer relies entirely on mechanical extrusion and shearing to break the rock. Therefore, under the same cutting disc 1 thrust and rotation speed, the present invention can theoretically reduce the instantaneous resistance when the cutter 2 cuts into hard rock 5 and improve the crushing efficiency of hard rock 5.

[0075] (2) Theoretical analysis of impact reduction at the soft-hard interface; One of the main construction risks in composite formations lies in the significant strength difference between soft and hard rock. When the cutting tool moves from the soft rock region to the hard rock region, the cutting resistance suddenly increases; conversely, when it moves from the hard rock region to the soft rock region, the resistance suddenly decreases. This periodic load abrupt change can cause vibration of the cutterhead 1, off-center loading of the cutter 2, impact on the tool holder, and abnormal wear of the cutter 2. This invention reduces the strength of the hard rock 5 by applying microwave thermal weakening only to the hard rock region, thereby reducing the strength difference between the soft and hard rock 5. With the strength difference reduced, the magnitude of the load abrupt change experienced by the cutter 2 when crossing the interface between soft and hard formations is correspondingly reduced, and the torque fluctuation of the cutterhead 1 and the impact vibration of the cutter 2 are also weakened.

[0076] Therefore, from a mechanical perspective, this invention can improve the problem of uneven stress on the tool 2 in composite formations, reduce the impact load at the soft-hard interface, and help reduce tool 2 chipping, uneven wear, abnormal wear of the tool ring, and fatigue damage to the tool holder.

[0077] (3) Theoretical analysis to avoid accidental irradiation of soft rocks; Existing integrated microwave irradiation methods typically treat the entire excavation face as a uniform irradiation target. In composite strata with soft upper layers and hard lower layers, soft rock areas may also be heated simultaneously. Due to the low strength, sensitivity to changes in water content, and poor structural stability of soft rock, unnecessary microwave heating may lead to softening of soft rock, localized water loss, structural disturbance, or a decrease in the stability of the excavation face. This invention determines the current stratum type based on the real-time position of the cutter 2. When the cutter 2 is in a soft rock area, the corresponding microwave irradiation device 3 is turned off; when the cutter 2 is in a hard rock area, the corresponding microwave irradiation device 3 is turned on. This control method ensures that microwave energy mainly acts on the hard rock areas that need to be weakened, rather than indiscriminately acting on the entire excavation face.

[0078] Therefore, compared with the overall irradiation method, the present invention can theoretically reduce the ineffective heat input in soft rock areas, reduce the risk of soft rock overheating and softening, help maintain the stability of the excavation face in composite strata, and improve the safety of shield tunneling.

[0079] (4) Theoretical analysis of improved energy utilization; The energy consumption of a microwave-assisted rock-breaking system mainly depends on the microwave irradiation range, irradiation time, and irradiation power. Existing integrated irradiation methods in complex formations tend to ineffectively irradiate soft rock areas and non-cutting areas, leading to reduced microwave energy utilization. This invention employs a tool-level independent control method, which determines whether the corresponding microwave device is activated based on whether each tool 2 is in a hard rock area. In other words, microwave irradiation is only performed when the tool 2 is in a hard rock area requiring thermal weakening; when the tool 2 is in a soft rock area, the corresponding device is turned off. This method reduces unnecessary irradiation time and range. Simultaneously, this invention also sets different power levels according to the hardness grade of the hard rock 5: low power for low-hardness hard rock 5, medium power for medium-hardness hard rock 5, and high power for high-hardness hard rock 5. This avoids overheating of low-hardness hard rock 5 and underheating of high-hardness hard rock 5.

[0080] Therefore, from the perspective of energy input matching, the present invention can achieve "irradiation on demand and energy supply according to hardness", which can theoretically improve the microwave energy utilization rate and reduce the energy consumption of rock breaking per unit volume.

[0081] (5) Theoretical analysis of dynamic adaptability; During shield tunneling, the location of the geological interface ahead, the ratio of soft rock 4 to hard rock 5, and the rotational speed of the cutterhead 1 are not constant. Traditional control methods with fixed power, fixed irradiation time, and fixed irradiation area are difficult to adapt to such dynamic changes. This invention obtains real-time information on the location of the composite geological interface, the hardness of hard rock 5, and the rotational speed of the cutterhead 1. Combined with parameters such as the initial angle and configuration radius of the cutterhead 2, the invention calculates the positional state of the cutterhead 2 at different times, thereby determining the geological type. This control method establishes a dynamic mapping relationship between geological identification, cutterhead 2 movement, and microwave control.

[0082] Therefore, when the interface between soft and hard formations changes, the rotation speed of the cutter head 1 is adjusted, or cutters 2 of different radii enter different formation areas, the present invention can still adjust the microwave on / off and power output strategies according to the real-time status. Compared with the fixed control method, the present invention has stronger adaptability to complex formations and field conditions.

[0083] In summary, based on the microwave thermal weakening mechanism, the motion law of the tunnel boring machine cutter 2, the stress characteristics of composite strata, and the energy distribution logic of the control system, this invention can achieve the following positive effects during use: 1. It can reduce the strength of hard rock and improve the crushing efficiency in hard rock areas.

[0084] 2. It can reduce the equivalent strength difference between soft rock 4 and hard rock 5, and reduce the impact load of the tool 2 at the soft-hard interface.

[0085] 3. It can reduce the off-center load and abnormal wear of tool 2, and improve the service life of tool 2.

[0086] 4. It can avoid unnecessary microwave irradiation in soft rock areas, reducing the risk of soft rock overheating, softening, and local instability of the excavation face.

[0087] 5. It can match different microwave powers according to the hardness level of hard rock 5 to achieve differentiated heat input.

[0088] 6. It can adjust the control strategy in real time according to the location of the formation interface and the rotation speed of cutterhead 1, thereby improving the adaptability of construction in composite formations.

[0089] 7. It can reduce ineffective microwave irradiation, improve microwave energy utilization, and reduce the overall energy consumption of the system.

[0090] Analogous to the verifiability description of existing experimental designs Although no field test was conducted in this embodiment, the technical effects of the present invention can be verified by referring to the experimental designs commonly used in the field of microwave-assisted mechanical rock breaking. Common verification approaches include: 1. A composite stratum model with soft upper layer and hard lower layer was prepared using five materials: soft rock and hard rock. 2. Three comparative working conditions were set up: no microwave assistance, overall microwave irradiation, and independent microwave control at the tool level according to the present invention; 3. Under the same conditions of cutterhead 1 rotation speed, penetration depth and advance, the cutting force of cutter 2, the torque of cutterhead 1, vibration response, rock mass temperature rise, crack propagation and unit rock breaking energy consumption were collected respectively. 4. Compare the crushing efficiency of hard rock 5, the temperature rise of soft rock, the force fluctuation of cutter 2, and the energy utilization under different control methods; 5. Further change the interface position of soft and hard rock 5, the hardness grade of hard rock 5, and the rotation speed of cutterhead 1 to verify the adaptability of the present invention to dynamic composite formations.

[0091] Based on the above analogous test design, it can be theoretically expected that: compared with the method without microwave assistance, the present invention can reduce the cutting resistance of hard rock and improve the rock breaking efficiency; compared with the integral microwave irradiation method, it can reduce the ineffective heating of soft rock areas, improve energy utilization, and reduce the risk of excavation face instability.

[0092] Therefore, compared with existing integral, fixed-parameter microwave-assisted rock breaking technology, this invention has stronger adaptability to complex formations, higher precision of microwave action, better soft rock protection effect, and better stress improvement effect on the cutting tool 2, and has significant technological progress and engineering application value.

[0093] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention and within the spirit and principles of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A smart control method for microwave-assisted rock breaking in shield tunneling in complex strata, characterized in that, The method includes the following steps: S1. In the distributed precision action structure of one tool and one microwave, a microwave irradiation device (3) is arranged at each tool (2), and the relevant parameters of each tool (2) are defined. S2. During the shield tunneling process, the location information of the composite stratum interface at the front excavation face, the hardness information of hard rock (5) and the rotation speed information of the cutterhead (1) are obtained in real time, and the information obtained in real time is transmitted to the microwave control system. S3. The microwave control system deduces the time when each tool (2) reaches the interface between soft and hard composite formations based on the initial position parameters, configuration radius parameters, received composite formation interface position information and rotation speed information of the cutter head (1), and determines the formation type of each tool (2) at the current moment. S4. The microwave control system independently controls the microwave irradiation device (3) corresponding to each tool (2) based on the real-time stratum type of each tool (2) and the hardness level of the hard rock (5).

2. The intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata according to claim 1, characterized in that, In step S1, a microwave irradiation device (3) is set at each cutter (2) to cooperate with the cutter (2). The irradiation position of each microwave irradiation device (3) matches the rock-breaking position of the corresponding cutter (2), forming a distributed precision action structure of one cutter, one tool, one microwave, and one irradiation.

3. The intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata according to claim 1, characterized in that, In step S1, the relevant parameters of each tool (2) are defined, including: defining the initial position and configuration radius parameters of each tool (2); establishing a coordinate system with the center of the tool head (1) as the origin; rotating the tool head (1) counterclockwise; and numbering each tool (2). , and define the relevant parameters of the tool (2); The total number of cutting tools (2) is The time is The radius of the cutter head (1) is The angular velocity of the cutter head (1) is The rotational speed of the cutter head (1) is , No. The initial angle of the two cutting tools is (2) Configuration radius is The configuration radius parameter is the radial distance of each tool (2) relative to the center of the cutter head (1); No. Two cutting tools (2) The vertical axis of time is ; The location of the composite stratum interface is: ； Define dimensionless interface ratio for: ； In the formula, It is the interface of a composite strata.

4. The intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata according to claim 3, characterized in that, In step S2, during the shield tunneling process, a three-dimensional advance prediction system is used to monitor in real time the location of the composite stratum interface, the proportion of soft rock (4) and hard rock (5) and the hardness of hard rock (5) at the excavation face ahead; a rotation speed sensor set at the cutterhead (1) is used to monitor the rotation speed of the cutterhead (1) in real time; the location information of the composite stratum interface, the stratum ratio, the hardness information of hard rock (5) and the rotation speed information of the cutterhead (1) are transmitted to the microwave control system in real time.

5. The intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata according to claim 4, characterized in that, In step S3, the composite strata are divided into three types according to the relationship between the proportion of soft rock and the proportion of hard rock (5): the proportion of soft rock is less than that of hard rock (5), the proportion of soft rock is greater than that of hard rock (5), and the proportion of soft rock is equal to that of hard rock (5). The microwave control system determines the opening and closing intervals of the microwave irradiation device (3) of the corresponding tool (2) according to the different strata types and the initial position status of each tool (2). When determining the formation type of each tool (2) at the current moment, if it is determined to be a hard rock area, the hardness characterization parameters corresponding to the hard rock area are further read, and the hardness level of the hard rock (5) is determined.

6. The intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata according to claim 5, characterized in that, The microwave control system deduces the time it takes for each cutter (2) to reach the interface between the soft and hard composite strata based on the initial position parameters, configuration radius parameters, received composite stratum interface position information, and cutterhead (1) rotation speed information of each cutter (2), and determines the stratum type of each cutter (2) at the current moment, including: Condition 1: The cutting tool (2) passes through both hard rock and soft rock areas; when ,Right now At that time, the formation type indicator function is defined as follows: ； In the formula, The dimensionless interface ratio indicates the location of the composite stratum interface relative to the first... The ratio of the radii of each tool (2) configuration. Here is the stratigraphic type indicator function, representing the first... The geological stratum type where the cutting tool (2) is located. Here, the Heaviside step function represents a numerical abrupt change, specifically: ； Indicates the first The geological strata in which the cutting tool (2) is located are specifically as follows: ； The corresponding time interval for the hard rock region is: ； The corresponding time interval for the soft rock area is: ； Microwave on / off times at the interface between soft and hard strata: ； Microwave activation time: ； ； ； In the formula, For the first The activation time of the microwave device near the tool (2), For any integer, It is all integers; Pi is the mathematical constant for a circle, representing a half-circle angle when the angle unit is radians. at this time, The cutting tool (2) will enter the hard rock area; Microwave shutdown time: ； ； In the formula, For the first The shutdown time of the microwave device near the tool (2); at this time, The cutting tool (2) is about to enter the soft rock area.

7. The intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata according to claim 6, characterized in that, In step S3, the microwave control system, based on the initial position parameters of each cutter (2), the configuration radius parameters, the received composite formation interface position information, and the rotation speed information of the cutterhead (1), deduces the time when each cutter (2) reaches the interface between the soft and hard composite formations, and determines the formation type of each cutter (2) at the current moment, further including: Condition 2: The cutting tool (2) is always in the hard rock area or always in the soft rock area; when At that time, the cutting tool (2) was always in the hard rock area; when At that time, the cutting tool (2) was always in the soft rock area; When the region is identified as hard rock, further, the first definition is made. The hardness characterization parameters of the hard rock region corresponding to each cutting tool (2) are: Hardness thresholds are preset based on rock mineral composition, rock integrity, porosity, and water content parameters. and , The hardness of hard rock (5) is divided into three levels.

8. The intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata according to claim 7, characterized in that, Hard rock (5) is classified into three levels of hardness, including: Low hardness setting: ; Medium hardness setting: ; High hardness setting: ; The hardness characterization parameters obtained by the cutting tool (2) are determined by the microwave control system. To determine which gear it belongs to, thus determining the hardness level of hard rock (5).

9. The intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata according to claim 1, characterized in that, In step S4, the microwave control system independently controls the microwave irradiation device (3) corresponding to each tool (2) based on the real-time formation type of each tool (2) and the hardness level of the hard rock (5). When a tool (2) is in a soft rock area, the corresponding microwave irradiation device (3) is turned off; when a tool (2) is in a hard rock area, the corresponding microwave irradiation device (3) is turned on. In this way, microwave energy is always applied to the hard rock area that needs to be weakened. Specifically, this includes: Definition of the first The microwave switch state corresponding to each tool (2) is as follows: When the first When the cutting tool (2) is in the soft rock zone, Turn off the microwave switch of the microwave irradiation device (3) corresponding to the cutting tool (2); when the first When the cutting tool (2) is in the hard rock zone Turn on the microwave switch of the microwave irradiation device (3) corresponding to the cutting tool (2); ； Based on the hardness level of the hard rock (5), the corresponding microwave irradiation power level is preset in the microwave control system: The low hardness setting corresponds to low power irradiation. Medium hardness corresponds to medium power irradiation. The high hardness setting corresponds to high-power irradiation. Three power levels are sufficient All of them are within the safe operating range of the microwave irradiation device (3); If hardness characterization parameters If it belongs to the low hardness range, then the microwave irradiation device (3) adopts Low-power irradiation; if hardness characterization parameters If the hardness is medium, then the microwave irradiation device (3) adopts... Medium power irradiation; if hardness characterization parameters If it belongs to the high hardness range, then the microwave irradiation device (3) adopts High-power irradiation.

10. An intelligent control system for microwave-assisted rock breaking in shield tunneling in complex strata, characterized in that, The system implements the intelligent control method for microwave-assisted rock breaking of shield tunnels in composite strata as described in any one of claims 1-9, and the system includes: The tool-related parameter configuration module is used to arrange the microwave irradiation device (3) at each tool (2) and define the relevant parameters of each tool (2); The information transmission module is used to acquire in real time the location information of the composite stratum interface at the front excavation face, the hardness information of hard rock (5) and the rotation speed information of the cutterhead (1) during the shield tunneling process, and transmit the acquired information to the microwave control system. The stratum type determination module is used by the microwave control system to deduce the time when each tool (2) reaches the interface between soft and hard strata based on the initial position parameters, configuration radius parameters, received composite stratum interface position information and cutter head (1) rotation speed information of each tool (2), and determine the stratum type of each tool (2) at the current moment. When it is determined to be a hard rock area, the module further reads the hardness characterization parameters corresponding to the hard rock area and determines the hardness level of the hard rock (5). The microwave irradiation device control module is used by the microwave control system to independently control the microwave irradiation device (3) corresponding to each tool (2) according to the real-time stratum type of each tool (2) and the hardness level of the hard rock (5). When the tool (2) is in the soft rock area, the corresponding microwave irradiation device (3) is turned off, and when the tool (2) is in the hard rock area, the corresponding microwave irradiation device (3) is turned on. The power of the microwave irradiation device (3) is adjusted according to the hardness level of the hard rock (5).

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