A deepwater large pile cap foundation hard rock milling excavation bottom cleaning dynamic control method and system

Abstract

The application discloses a deep water large-scale pile cap foundation pit hard rock milling and digging bottom cleaning dynamic control method and system, the method comprises the following steps: according to the hard rock lithology parameters of the deep water foundation pit, the deformation limit value of the cofferdam and the operation space constraint, the whole construction process is divided into a hard rock crushing section, a transition section and a foundation bottom cleaning section, safety constraint conditions and target optimization functions are constructed for each section, and initial matching parameters are determined through numerical simulation and field trial digging data fitting. In the hard rock crushing section, the milling and digging efficiency is maximized, parameters are collected in real time, and the milling and digging feed speed and rotating speed are dynamically adjusted. In the transition section, the crushing and deslagging are balanced and coordinated, the milling and digging parameters and the gas lift lifting pressure are linked and adjusted to prevent the accumulation of debris from disturbing the foundation pit. In the foundation bottom cleaning section, the elevation and flatness are targeted, data are collected in real time, and optimal control is sought to complete the overall bottom cleaning operation.

Description

Technical Field

[0001] This invention belongs to the field of deep-water large-scale foundation pit construction technology, and more specifically, relates to a dynamic control method and system for hard rock milling and bottom cleaning of deep-water large-scale foundation pits. Background Technology

[0002] In the construction of large deep-water foundation pits, hard rock milling and bottom clearing is one of the key processes. Its construction quality and efficiency directly determine the safety, stability and overall quality of subsequent foundation construction, and have a significant impact on the structural durability and service life of the entire water-related project.

[0003] Currently, the milling and cleaning of hard rock in deep-water large-scale foundation pits faces numerous technical challenges. Existing construction methods mostly adopt a uniform milling model without taking into account the different working conditions at different stages of foundation pit construction, resulting in many hidden dangers during construction. On the one hand, in deep-water environments, the rock properties of foundation pits are complex and variable. Hard rock has high strength and strong wear resistance, and the milling process is prone to problems where the milling parameters are mismatched with the rock properties. This can lead to either low milling efficiency, prolonging the construction period and increasing construction costs, or excessive milling intensity, causing excessive deformation of the cofferdam, or even causing the foundation pit to collapse, threatening construction safety.

[0004] On the other hand, existing construction methods lack effective control over the coordination of crushing and slag removal. Debris generated during milling tends to accumulate in the foundation pit, not only affecting the normal progress of milling operations but also disturbing the surrounding rock mass, reducing pit stability, and increasing construction risks. Simultaneously, during the foundation cleaning stage, existing methods struggle to achieve precise control over elevation deviation and flatness, easily leading to problems such as foundation undulations and excessive elevation, affecting the quality of subsequent foundation pouring and increasing later rectification costs.

[0005] Furthermore, existing control methods largely rely on manual experience to adjust milling parameters, lacking scientific quantitative control basis. This makes them ill-suited to the dynamic changes in complex deep-water conditions, resulting in poor construction stability and reliability. Therefore, to address the practical problems of low milling efficiency, high safety risks, poor cleaning quality, and unscientific parameter adjustment in the milling and bottom clearing of hard rock in deep-water large foundation pits, it is crucial to develop a method that enables refined and dynamic control throughout the entire process. This method has significant practical engineering implications and application value for ensuring the safety of deep-water foundation pit construction, improving construction quality and efficiency, and reducing construction costs. Summary of the Invention

[0006] This invention aims to address the problems of low efficiency, high risk of cofferdam deformation, and difficulty in ensuring the quality of foundation pit and base formation during the milling and cleaning of hard rock in deep-water large foundation pits. It provides a segmented dynamic control scheme to achieve safe, efficient, precise and controllable construction throughout the entire process, thereby improving project quality and construction stability.

[0007] To address the aforementioned deficiencies or improvement needs of existing technologies, as a first aspect of this invention, the present invention provides a dynamic control method for milling and cleaning the bottom of hard rock in deep-water large-scale foundation pits, comprising: S1. Based on the lithological parameters of hard rock in deep water foundation pits, the allowable deformation limit of cofferdams and the constraints of working space, the entire construction process is divided into hard rock breaking section, transition section and base cleaning section. Safety constraints and objective optimization functions are constructed for each section. Through numerical simulation and fitting of field test excavation data, the initial matching parameter set of milling head torque, feed speed and air lift reverse circulation displacement for each section is determined. S2. Entering the hard rock crushing section, with the core optimization goal of maximizing milling efficiency, the milling head torque, actual feed speed, cofferdam radial deformation and slag concentration data are collected in real time. Based on the segmented constraint optimization algorithm, the deviation between the real-time data and the safety threshold of this section is compared, and the milling feed speed and milling head speed are dynamically adjusted. S3. After entering the transition section, switch the optimization target to the coordinated balance of crushing and slag removal, gradually reduce the milling intensity, monitor the siltation thickness and slag removal efficiency in the pit in real time, adjust the milling parameters and air lift reverse circulation lifting pressure in linkage, correct the slag removal flow rate, and prevent the pit disturbance caused by the accumulation of crushed debris. S4. After entering the base clearing section, with the base elevation deviation and flatness meeting the standards as the core objectives, the actual base elevation, milling depth and rock surface flatness data are collected in real time, and real-time optimization is performed until the entire foundation pit milling and clearing process is completed.

[0008] Furthermore, the process of constructing safety constraints for each segment in S1 is as follows: For the hard rock fractured section, the safety constraints include: the radial deformation of the cofferdam does not exceed the allowable deformation limit of the cofferdam, the milling head torque does not exceed the rated torque of the milling equipment, and the milling feed speed does not exceed the maximum allowable feed speed determined based on the hard rock lithology parameters; For the transition section, the safety constraints include: the thickness of siltation in the pit does not exceed the preset siltation limit, the slag concentration is maintained within the preset reasonable concentration range, and the milling intensity does not exceed the maximum allowable milling intensity of the transition section. For the base clearing section, the safety constraints include: the base elevation deviation does not exceed the design allowable elevation deviation, the rock surface flatness does not exceed the design allowable flatness deviation, and the milling disturbance intensity does not exceed the base allowable disturbance intensity.

[0009] Furthermore, the process of constructing the initial matching parameter set in S1 is as follows: Using the safety constraints of each segment as rigid boundaries, and combining lithological parameters including the compressive strength of hard rock in deep water foundation pits and rock mass integrity, as well as the stiffness of the cofferdam structure, allowable deformation limits and working space dimensions, we first simulated the operational safety and feasibility under different combinations of milling head torque, feed speed and air lift reverse circulation displacement through numerical simulation, and then screened out the parameter range that meets the safety constraints. Then, through on-site trial excavation tests, the measured data of milling efficiency, slag removal effect and cofferdam deformation corresponding to different parameter combinations within the parameter range were collected. Parameter combinations that did not meet safety requirements or had too low efficiency were eliminated. Finally, the initial values ​​of the milling head torque, feed speed and air lift reverse circulation displacement of each segment were determined to form the initial matching parameter set for subsequent dynamic optimization adjustment. The initial matching parameter set provides a benchmark for dynamic optimization of each segment, and the initial values ​​are all within the safety constraint range of the corresponding segment, avoiding problems such as excessive deviation of the optimization starting point, safety hazards or low efficiency caused by traditional experience-based values.

[0010] Furthermore, the objective optimization function for the hard rock fractured section in S2 is: in This is a comprehensive deviation objective function used to quantify the deviation between milling parameters and safety boundaries and efficiency targets. For the first The actual torque of the milling head collected in this second sampling. The torque safety threshold for the corresponding segment; For the first The actual radial deformation of the cofferdam was collected in this second measurement. The deformation safety threshold for the corresponding segment. , These represent the number of real-time data acquisitions for torque and deformation, respectively.

[0011] Furthermore, the adjustment process of the milling feed rate and the milling head rotation speed in S2 is as follows: The adjustment of the feed rate is based on the initial feed rate. Combined with the inherent coefficients related to the cofferdam structure and safety control requirements, the sum of squares of the deviation between the real-time collected radial deformation of the cofferdam and the corresponding allowable deformation limit is divided by the sum of squares of the allowable deformation limit for normalization. Then, it is substituted into the exponential function to obtain the real-time feed rate. This quantifies the degree of deformation deviation from the safety requirements and achieves adaptive adjustment. For adjusting the milling head speed, the initial speed is used as a reference. Combined with the inherent coefficients related to hard rock characteristics and equipment performance, the sum of squares of the deviations between the real-time collected torque and the corresponding torque limit is divided by the sum of squares of the torque limit for normalization. Then, it is substituted into an exponential function to obtain the real-time speed. This quantifies the degree of torque deviation from the safety limit and achieves adaptive adjustment.

[0012] Furthermore, the objective optimization function for the transition section in S3 is: in The objective function for the coordinated equilibrium of crushing and slag discharge in the transition section is... For real-time foundation pit siltation thickness, The baseline siltation thickness for the foundation pit. For real-time milling feed speed, To determine the real-time slag concentration, To increase the pressure through air lift reverse circulation, The effective flow area of ​​the lifting channel, This refers to the time allotted for the assignment.

[0013] Furthermore, the adjustment process of the milling parameters and the air-lift reverse circulation lifting pressure in S3 is as follows: Based on the conservation of debris in the foundation pit, the real-time generation and discharge of debris inside the foundation pit are used as bidirectional control objects. The balance between debris income and expenditure in the foundation pit is determined according to the debris accumulation state. Then, combined with the inherent matching relationship between the milling head rotation speed and the feed speed, linkage adjustment is performed. When the amount of debris generated in the pit is detected to be greater than the amount discharged, the milling feed speed and the milling head speed are reduced simultaneously, while the air-lift reverse circulation lifting pressure is increased to enhance the slag discharge capacity; when the amount discharged is detected to be greater than the amount generated, the milling feed speed and the milling head speed are gradually increased, while the air-lift reverse circulation lifting pressure is reduced to reduce power consumption.

[0014] Furthermore, the objective optimization function for the substrate clearing section in S4 is: in The overall control objective function for the base clearing section is... The base design elevation, The actual elevation of the base is monitored in real time. The rate of change of the base elevation over time is used to characterize the flatness of the rock surface.

[0015] As a second aspect of the present invention, a dynamic control system for deep-water large-scale foundation pit hard rock milling and bottom clearing is also provided, comprising: The segmentation and parameter initialization unit is used to divide the entire construction process into hard rock breaking section, transition section and base cleaning section based on the hard rock lithology parameters of deep water foundation pit, the allowable deformation limit of cofferdam and the constraints of working space. Safety constraints and objective optimization functions are constructed for each segment. Through numerical simulation and fitting of field test excavation data, the initial matching parameter set of milling head torque, feed speed and air lift reverse circulation displacement of each segment is determined. The crushing section efficiency optimization control unit is used to enter the hard rock crushing section. With the core optimization goal of maximizing milling efficiency, it collects data on milling head torque, actual feed speed, cofferdam radial deformation, and slag concentration in real time. Based on the segmented constraint optimization algorithm, it compares the deviation between the real-time data and the safety threshold of the section and dynamically adjusts the milling feed speed and milling head speed. The transition section crushing and slag removal coordination unit is used to switch the optimization target to crushing-slag removal coordination balance after entering the transition section, gradually reduce the milling intensity, monitor the siltation thickness and slag removal efficiency in the pit in real time, and adjust the milling parameters and air lift reverse circulation lifting pressure in linkage to correct the slag removal flow rate and prevent pit disturbance caused by the accumulation of crushed debris. The bottom clearing section elevation and flatness optimization unit is used after entering the bottom clearing section. With the bottom elevation deviation and flatness meeting the standard as the core objectives, it collects the actual elevation of the bottom, milling depth and rock surface flatness data in real time, and performs real-time optimization until the entire foundation pit milling and bottom clearing process is completed.

[0016] As a third aspect of the present invention, a computer-readable storage medium is also provided, on which a computer program is stored, which is executed by a processor as described in any one of the claims: a dynamic control method for milling and cleaning the bottom of a deep-water large-scale foundation pit in hard rock.

[0017] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. The present invention provides a dynamic control method for milling and cleaning the bottom of hard rock in deep-water large-scale foundation pits. Based on the lithological parameters of the hard rock in the deep-water foundation pit, the allowable deformation limit of the cofferdam, and the constraints of the working space, the entire construction process is divided into a hard rock fracturing section, a transition section, and a bottom cleaning section. Safety constraints and objective optimization functions are established for each section. Initial matching parameter sets for the milling head torque, feed rate, and air-lift reverse circulation displacement of each section are obtained by fitting numerical simulation and field test excavation data. This achieves refined segmented control of the construction process, providing a reliable initial parameter basis for subsequent dynamic adjustments in each stage. It avoids construction risks caused by unreasonable parameter settings and ensures that the overall control strategy is highly adapted to the actual engineering conditions, improving the rationality of the early planning and the stability of the milling and cleaning operation.

[0018] 2. The present invention provides a dynamic control method for hard rock milling and bottom clearing in deep-water large-scale foundation pits. This method focuses on maximizing milling efficiency in the hard rock fracture section, collecting real-time data on milling head torque, feed rate, cofferdam radial deformation, and slag concentration. It uses a segmented constraint optimization algorithm to compare the deviation between real-time data and safety thresholds and dynamically adjusts milling parameters. In the transition section, it switches to a balanced approach of fracture and slag removal. Based on the pit's siltation thickness and slag removal efficiency, it adjusts milling parameters and air-lift reverse circulation pressure, effectively balancing hard rock fracture efficiency and slag removal capacity. This suppresses pit disturbance caused by debris accumulation while ensuring cofferdam deformation remains within safe limits. This method improves construction efficiency while enhancing the safety and continuity of the operation, meeting the construction control needs under complex deep-water foundation pit conditions.

[0019] 3. The dynamic control method for hard rock milling and bottom cleaning of deep-water large-scale foundation pits of the present invention takes the achievement of the standard for foundation elevation deviation and flatness as the core objective in the bottom cleaning stage. It collects the actual elevation of the foundation, milling depth and rock surface flatness data in real time and performs real-time optimization. Based on the constructed optimization function, the operation parameters are dynamically adjusted so that the foundation construction indicators continuously approach the design requirements. It accurately realizes the fine control of layered micro-milling, ensuring that the foundation elevation and flatness of the pit meet the design standards. At the same time, it forms a coherent system with the control logic of the previous segment, and completes the dynamic control of the entire process of milling and bottom cleaning. While ensuring the quality of bottom cleaning, it improves the overall construction accuracy and lays a stable and reliable foundation condition for the subsequent construction of deep-water large-scale foundation pits. Attached Figure Description

[0020] Figure 1 This is a flowchart of the dynamic control method for deep-water large-scale foundation pit hard rock milling and bottom cleaning according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the system units in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] Example 1 Please refer to Figure 1 This embodiment 1 provides a dynamic control method for milling and cleaning the bottom of hard rock in deep-water large foundation pits, including: S1. Based on the lithological parameters of hard rock in deep water foundation pits, the allowable deformation limit of cofferdams and the constraints of working space, the entire construction process is divided into hard rock breaking section, transition section and base cleaning section. Safety constraints and objective optimization functions are constructed for each section. Through numerical simulation and fitting of field test excavation data, the initial matching parameter set of milling head torque, feed speed and air lift reverse circulation displacement for each section is determined. S2. Entering the hard rock crushing section, with the core optimization goal of maximizing milling efficiency, the milling head torque, actual feed speed, cofferdam radial deformation and slag concentration data are collected in real time. Based on the segmented constraint optimization algorithm, the deviation between the real-time data and the safety threshold of this section is compared, and the milling feed speed and milling head speed are dynamically adjusted. S3. After entering the transition section, switch the optimization target to the coordinated balance of crushing and slag removal, gradually reduce the milling intensity, monitor the siltation thickness and slag removal efficiency in the pit in real time, adjust the milling parameters and air lift reverse circulation lifting pressure in linkage, correct the slag removal flow rate, and prevent the pit disturbance caused by the accumulation of crushed debris. S4. After entering the base clearing section, with the base elevation deviation and flatness meeting the standards as the core objectives, the actual base elevation, milling depth and rock surface flatness data are collected in real time, and real-time optimization is performed until the entire foundation pit milling and clearing process is completed.

[0023] This embodiment 1 further elaborates on the above steps.

[0024] (1) Segmentation and initial parameter determination When carrying out hard rock milling and bottom clearing operations in deep-water large foundation pits, the on-site working conditions are complex and the safety management requirements are stringent. Simply relying on experience to set construction parameters can easily lead to insufficient safety redundancy or low construction efficiency. Therefore, it is necessary to establish a systematic parameter planning process based on the actual conditions of the project.

[0025] In the early stages of construction, a comprehensive analysis was conducted on the hard rock lithology parameters inside the deep water foundation pit, the deformation limits that the cofferdam structure could withstand, and the constraints of the actual working space on site. Based on the differences between the construction progress stages and control objectives, the overall milling and bottom clearing process was divided into a hard rock breaking section, a transition section, and a base clearing section. Then, in combination with the operational characteristics and risk control priorities of each section, corresponding safety constraints were established.

[0026] For hard rock fracture sections where the main task is to efficiently break up rock masses, safety constraints are focused on the safety of the cofferdam structure and the operating limits of the equipment, ensuring that the radial deformation of the cofferdam does not exceed the allowable deformation limit of the cofferdam, the torque of the milling head does not exceed the rated torque of the milling equipment, and the milling feed speed does not exceed the maximum allowable feed speed determined based on the hard rock lithology parameters. For the transition section that balances crushing and slag discharge stability, the safety constraints include: the siltation thickness in the pit does not exceed the preset siltation limit, the slag discharge concentration is maintained within the preset reasonable concentration range, and the milling intensity does not exceed the maximum allowable milling intensity of the transition section. For the base clearing section, which focuses on forming quality, the safety constraints include: the base elevation deviation does not exceed the design allowable elevation deviation, the rock surface flatness does not exceed the design allowable flatness deviation, and the milling disturbance intensity does not exceed the base allowable disturbance intensity.

[0027] After completing the construction of safety constraints for each segment, the constraint system is used as an insurmountable rigid control boundary. The initial construction parameters are screened and determined by comprehensively integrating lithological indicators such as hard rock compressive strength and rock mass integrity, as well as engineering parameters such as cofferdam structure stiffness, allowable deformation limits and working space dimensions.

[0028] First, numerical simulation is used to simulate the working conditions of various combinations of milling head torque, feed speed and air-lift reverse circulation displacement to determine the safety and feasibility of the construction process under different parameter schemes. The parameter ranges that meet all safety constraints are initially screened out, and parameter combinations that pose structural risks or equipment overload hazards are eliminated.

[0029] Subsequently, based on on-site trial excavation tests, typical combinations were selected within the aforementioned parameter range for actual construction. Simultaneously, measured data on milling efficiency, slag removal smoothness, and cofferdam deformation were collected. Parameter combinations that met safety requirements but had low construction efficiency or poor slag removal were further eliminated. After dual optimization through simulation screening and on-site verification, the initial values ​​for milling head torque, feed rate, and air-lift reverse circulation displacement for each segment were finally determined, forming a complete initial matching parameter set.

[0030] This parameter set serves as the benchmark parameter for subsequent dynamic adjustment. All values ​​are strictly within the safety constraint range of the corresponding segment. It can effectively avoid problems such as excessive starting deviation, construction safety hazards, and insufficient operation efficiency caused by relying on manual experience to determine initial parameters in the traditional way, and lay a stable and reliable foundation for dynamic control of the entire process.

[0031] (2) Optimization and control of crushing section efficiency After completing the segmentation and initial parameter determination in the pre-construction phase, the work proceeds to the hard rock fracture section. The core task of this stage is to maximize the efficiency of hard rock milling while ensuring construction safety, thereby saving time and reducing costs for subsequent construction phases. Due to the high strength of hard rock in deep-water foundation pits and the limited bearing capacity of cofferdam structures, improper parameter adjustment during milling can easily lead to safety hazards such as equipment overload damage or excessive deformation of the cofferdam. At the same time, conservative parameters may also result in low milling efficiency. Therefore, it is necessary to establish a scientific dynamic parameter adjustment mechanism to achieve dual control over efficiency and safety.

[0032] The core optimization objective for the hard rock crushing section is to maximize milling efficiency. During operation, four key data points are continuously collected in real time: actual milling head torque, actual feed rate, cofferdam radial deformation, and slag concentration. Milling head torque directly reflects the equipment's operating load and the difficulty of hard rock crushing, while cofferdam radial deformation relates to the safety of the cofferdam structure; these two are the core basis for parameter adjustment. Slag concentration is used to help determine the smoothness of the milling operation. The objective optimization function is: in This is a comprehensive deviation objective function used to quantify the deviation between milling parameters and safety boundaries and efficiency targets. For the first The actual torque of the milling head collected in this second sampling. The torque safety threshold for the corresponding segment; For the first The actual radial deformation of the cofferdam was collected in this second measurement. The deformation safety threshold for the corresponding segment. , These represent the number of real-time data acquisitions for torque and deformation, respectively.

[0033] The adjustment process relies on a piecewise constraint optimization algorithm, using a pre-constructed comprehensive deviation objective function as the quantitative basis. The adjustment of the feed rate is based on the initial feed rate, combined with the inherent coefficients related to the cofferdam structure and safety control requirements. The sum of squares of the deviations between the real-time collected radial deformation of the cofferdam and the corresponding allowable deformation limit is divided by the sum of squares of the allowable deformation limit for normalization, and then substituted into the exponential function to obtain the real-time feed rate. This quantifies the degree of deformation deviation from the safety requirements and achieves adaptive adjustment. For adjusting the milling head speed, the initial speed is used as a reference. Combined with the inherent coefficients related to hard rock characteristics and equipment performance, the sum of squares of the deviations between the real-time collected torque and the corresponding torque limit is divided by the sum of squares of the torque limit for normalization. Then, it is substituted into an exponential function to obtain the real-time speed. This quantifies the degree of torque deviation from the safety limit and achieves adaptive adjustment.

[0034] Based on this, the specific adjustment function expressions for the feed rate and milling head rotation speed are as follows: in The milling head speed is adjusted in real time; The initial parameter reference value for the milling head rotation speed in the hard rock fracture section; These are inherent coefficients related to hard rock lithology parameters and the dynamic characteristics of milling equipment, obtained by fitting field geological survey data with equipment performance. For the first The actual torque of the milling head collected in real time; For the first The milling head torque limit corresponding to the next data acquisition time; This is the sum of squares of the deviations between the measured torque value and the corresponding limit, used to quantify the overall degree to which the torque deviates from the safety limit. This is the sum of squares of the torque limits, used to normalize torque deviations to eliminate dimensional effects; The milling feed rate is adjusted in real time. The initial parameter reference value for the milling feed rate in the hard rock fractured section is given. These are inherent coefficients related to the stiffness of the cofferdam structure and the safety control requirements of the foundation pit, obtained by fitting the on-site cofferdam structural parameters with safety monitoring data; For the first The radial deformation of the cofferdam was collected in real time. For the first The allowable limit for radial deformation of the cofferdam at the time of the next data acquisition. This is the sum of squares of the deviations between the measured values ​​of cofferdam deformation and the allowable limits, used to quantify the degree to which the overall deformation deviates from safety requirements. This is the sum of squares of the allowable deformation limits of the cofferdam, used to normalize the deformation deviation to eliminate the influence of dimensions.

[0035] (3) Coordinated crushing and slag discharge in the transition section After the hard rock fracturing section is completed, construction enters the transition section. This stage is a crucial link between hard rock fracturing and base cleaning. Its core function is to achieve a smooth transition in milling intensity, avoiding disturbance to the foundation pit caused by sudden changes in milling parameters, and simultaneously addressing the issue of debris accumulation. The hard rock fracturing section aims for maximum efficiency with high milling intensity, while the base cleaning section requires precise control with lower milling intensity. Therefore, the transition section needs to switch its optimization objectives, no longer simply pursuing milling efficiency, but focusing on a balanced approach to fracturing and slag removal. By gradually reducing the milling intensity, a smooth transition with subsequent base cleaning operations is achieved, while preventing the accumulation of debris in the foundation pit, avoiding debris disturbance to the surrounding rock mass, and ensuring the stability of the foundation pit structure.

[0036] The optimization control of the transition section is based on the principle of conservation of debris in the foundation pit. The core is to maintain a dynamic equilibrium between the debris generation rate from milling and crushing and the debris discharge rate from the air-lift reverse circulation system. To this end, a corresponding objective optimization function is constructed to quantify the difference between the debris generation and discharge rates. By minimizing this difference, the milling intensity and slag removal capacity are synchronously adapted. The expression of the objective optimization function is as follows: in The objective function for the coordinated equilibrium of crushing and slag discharge in the transition section is... For real-time foundation pit siltation thickness, The baseline siltation thickness for the foundation pit. For real-time milling feed speed, To determine the real-time slag concentration, To increase the pressure through air lift reverse circulation, The effective flow area of ​​the lifting channel, This refers to the time allotted for the assignment.

[0037] This function is constructed based on the principle of conservation of debris in the foundation pit. The first term is the accumulation rate of debris generated by the milling operation, which is obtained by differentiating the integral of the accumulation thickness deviation and the feed rate with respect to time. The second term is the debris discharge rate of the air-lift reverse circulation system, which is obtained by differentiating the integral of the slag concentration, the lifting pressure and the flow area with respect to time. By minimizing the difference between the two rates, the generation and discharge of debris are kept in dynamic balance. In the transition section, the milling intensity is smoothly reduced and the slag discharge capacity is synchronously adapted, thereby linking and adjusting the feed rate and the lifting pressure to suppress the foundation pit disturbance caused by debris accumulation.

[0038] During the operation, the thickness of silt accumulation and the slag removal efficiency in the foundation pit are monitored in real time. The silt accumulation thickness directly reflects the accumulation of debris in the foundation pit, while the slag removal efficiency reflects the slag removal capacity of the air-lift reverse circulation system. Both serve as the core basis for parameter adjustment. At the same time, key parameters such as milling feed rate, milling head working cross-sectional area, hard rock bulk density, slag concentration, air-lift reverse circulation lifting pressure, and effective flow area of ​​the lifting channel are collected simultaneously to provide data support for linkage adjustment.

[0039] The parameter adjustment of the transition section adopts a two-way linkage control mode. Based on the principle of conservation of debris in the foundation pit, a dynamic balance relationship is established between the generation rate of milling and crushing debris and the air-lift reverse circulation slag removal rate. The adjustment logic is quantified through mathematical formulas, specifically: in This represents the rate of debris accumulation within the foundation pit. For real-time milling feed speed, The cross-sectional area for the excavator head operation. This refers to the density of hard rock accumulation. To determine the real-time slag concentration, To increase the pressure through air lift reverse circulation, This represents the effective flow area of ​​the air-lift reverse circulation lifting channel; During the adjustment process, the above parameters are collected in real time, and combined with the established correlation between the milling head rotation speed and the feed rate, when... When this occurs, it indicates that the rate of debris generation in the foundation pit is greater than the rate of debris removal; at this point, the milling feed rate should be reduced simultaneously. And the corresponding milling head speed, while increasing the lifting pressure. To increase the slag discharge rate, until ; when When the slag discharge rate is greater than the debris generation rate, the milling feed rate should be gradually increased. And the milling head speed, while reducing the lifting pressure. To avoid wasting lifting power, maintain constant... The dynamic equilibrium state; The entire adjustment process relies on real-time monitoring of the siltation thickness in the foundation pit (from... (derived through integral derivation) and slag discharge efficiency (from...) (Quantitative characterization) forms a closed-loop control of "monitoring-quantitative comparison linkage adjustment-balance maintenance", realizing the synchronous adaptation of the gradual reduction of milling intensity in the transition section and the slag discharge capacity, and preventing the foundation pit disturbance caused by the accumulation of broken debris.

[0040] (4) Optimize the elevation and flatness of the bottom section After the transition phase is completed, construction enters the final foundation cleaning phase. This stage directly determines the quality of the foundation pit formation and the foundation conditions for subsequent pier construction, and is crucial to the overall structural stability and durability of the project. Following the initial crushing and transition phases, most of the hard rock within the foundation pit has been milled. At this stage, milling efficiency is no longer the primary focus; instead, the core objectives are controlling the foundation elevation deviation and ensuring the rock surface flatness meets standards. Through refined parameter adjustments and real-time optimization, the foundation morphology is ensured to fully meet design requirements, preventing subsequent construction from being affected by excessive elevation or insufficient flatness, while also preventing over-milling from disturbing the bearing stratum of the foundation.

[0041] A corresponding comprehensive control objective function is constructed for the base cleaning section. This function uses the difference between the base design elevation and the actual elevation monitored in real time as the core indicator. At the same time, it introduces the rate of change of base elevation over time to indirectly reflect the rock surface smoothness. By quantifying the comprehensive deviation of the two indicators, a unified evaluation standard is provided for the cleaning operation. The expression of its objective optimization function is as follows: in The overall control objective function for the base clearing section is... The base design elevation, The actual elevation of the base is monitored in real time. The rate of change of the base elevation over time is used to characterize the flatness of the rock surface.

[0042] Real-time data collection during optimization process and And substitute it into the function to calculate, when At the same time, based on the physical relationship between elevation deviation and flatness change rate, the milling feed speed and milling head rotation speed are adjusted synchronously to ensure... Towards Approaching and tending to stabilize, when When the current milling status is determined to meet the requirements of the base elevation and flatness, the next work area is advanced according to the layered micro-milling method. The closed-loop process of data collection, function calculation and parameter adjustment is repeated until the entire pit is cleared.

[0043] Example 2 Please refer to Figure 2 This embodiment 2 provides a dynamic control system for deep-water large foundation pit hard rock milling and bottom cleaning, including: The segmentation and parameter initialization unit is used to divide the entire construction process into hard rock breaking section, transition section and base cleaning section based on the hard rock lithology parameters of deep water foundation pit, the allowable deformation limit of cofferdam and the constraints of working space. Safety constraints and objective optimization functions are constructed for each segment. Through numerical simulation and fitting of field test excavation data, the initial matching parameter set of milling head torque, feed speed and air lift reverse circulation displacement of each segment is determined. The crushing section efficiency optimization control unit is used to enter the hard rock crushing section. With the core optimization goal of maximizing milling efficiency, it collects data on milling head torque, actual feed speed, cofferdam radial deformation, and slag concentration in real time. Based on the segmented constraint optimization algorithm, it compares the deviation between the real-time data and the safety threshold of the section and dynamically adjusts the milling feed speed and milling head speed. The transition section crushing and slag removal coordination unit is used to switch the optimization target to crushing-slag removal coordination balance after entering the transition section, gradually reduce the milling intensity, monitor the siltation thickness and slag removal efficiency in the pit in real time, and adjust the milling parameters and air lift reverse circulation lifting pressure in linkage to correct the slag removal flow rate and prevent pit disturbance caused by the accumulation of crushed debris. The bottom clearing section elevation and flatness optimization unit is used after entering the bottom clearing section. With the bottom elevation deviation and flatness meeting the standard as the core objectives, it collects the actual elevation of the bottom, milling depth and rock surface flatness data in real time, and performs real-time optimization until the entire foundation pit milling and bottom clearing process is completed.

[0044] Example 3 This embodiment 3 also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement any step of a dynamic control method for milling and cleaning the bottom of a deep-water large foundation pit in hard rock.

[0045] The computer-readable storage medium may include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0046] For a description of the computer-readable storage medium provided in this application, please refer to the above method embodiments; further details will not be repeated here.

[0047] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dynamic control method for milling and cleaning the bottom of hard rock in deep-water large-scale foundation pit, characterized in that, include: S1. Based on the lithological parameters of hard rock in deep water foundation pits, the allowable deformation limit of cofferdams and the constraints of working space, the entire construction process is divided into hard rock breaking section, transition section and base cleaning section. Safety constraints and objective optimization functions are constructed for each section. Through numerical simulation and fitting of field test excavation data, the initial matching parameter set of milling head torque, feed speed and air lift reverse circulation displacement for each section is determined. S2. Entering the hard rock crushing section, with the core optimization goal of maximizing milling efficiency, the milling head torque, actual feed speed, cofferdam radial deformation and slag concentration data are collected in real time. Based on the segmented constraint optimization algorithm, the deviation between the real-time data and the safety threshold of this section is compared, and the milling feed speed and milling head speed are dynamically adjusted. S3. After entering the transition section, switch the optimization target to the coordinated balance of crushing and slag removal, gradually reduce the milling intensity, monitor the siltation thickness and slag removal efficiency in the pit in real time, and adjust the milling parameters and air lift reverse circulation lifting pressure in a coordinated manner to correct the slag removal flow rate. S4. After entering the base clearing section, with the base elevation deviation and flatness meeting the standards as the core objectives, the actual base elevation, milling depth and rock surface flatness data are collected in real time, and real-time optimization is performed until the entire foundation pit milling and clearing process is completed.

2. The method for dynamic control of hard rock milling and bottom cleaning in deep-water large-scale foundation pits according to claim 1, characterized in that, The process of constructing safety constraints for each segment in S1 is as follows: For the hard rock fractured section, the safety constraints include: the radial deformation of the cofferdam does not exceed the allowable deformation limit of the cofferdam, the milling head torque does not exceed the rated torque of the milling equipment, and the milling feed speed does not exceed the maximum allowable feed speed determined based on the hard rock lithology parameters; For the transition section, the safety constraints include: the thickness of siltation in the pit does not exceed the preset siltation limit, the slag concentration is maintained within the preset reasonable concentration range, and the milling intensity does not exceed the maximum allowable milling intensity of the transition section. For the base clearing section, the safety constraints include: the base elevation deviation does not exceed the design allowable elevation deviation, the rock surface flatness does not exceed the design allowable flatness deviation, and the milling disturbance intensity does not exceed the base allowable disturbance intensity.

3. The method for dynamic control of hard rock milling and bottom cleaning in deep-water large-scale foundation pits according to claim 1, characterized in that, The process of constructing the initial matching parameter set in S1 is as follows: Using the safety constraints of each segment as rigid boundaries, and combining lithological parameters including the compressive strength of hard rock in deep water foundation pits and rock mass integrity, as well as the stiffness of the cofferdam structure, allowable deformation limits and working space dimensions, we first simulated the operational safety and feasibility under different combinations of milling head torque, feed speed and air lift reverse circulation displacement through numerical simulation, and then screened out the parameter range that meets the safety constraints. Then, through on-site trial excavation tests, the measured data of milling efficiency, slag removal effect and cofferdam deformation corresponding to different parameter combinations within the parameter range were collected. Parameter combinations that did not meet safety requirements or had too low efficiency were eliminated. Finally, the initial values ​​of the milling head torque, feed speed and air lift reverse circulation displacement of each segment were determined to form the initial matching parameter set for subsequent dynamic optimization adjustment. The initial matching parameter set provides a benchmark for dynamic optimization of each segment, and the initial values ​​are all within the safety constraint range of the corresponding segment.

4. The method for dynamic control of hard rock milling and bottom cleaning in deep-water large-scale foundation pits according to claim 1, characterized in that, The objective optimization function for the hard rock fractured section in S2 is: in This is a comprehensive deviation objective function used to quantify the deviation between milling parameters and safety boundaries and efficiency targets. For the first The actual torque of the milling head collected in this second sampling. The torque safety threshold for the corresponding segment; For the first The actual radial deformation of the cofferdam was collected in this second measurement. The deformation safety threshold for the corresponding segment. , These represent the number of real-time data acquisitions for torque and deformation, respectively.

5. The dynamic control method for deep-water large-scale foundation pit hard rock milling and bottom cleaning according to claim 4, characterized in that, The adjustment process of the milling feed rate and the milling head rotation speed in S2 is as follows: The adjustment of the feed rate is based on the initial feed rate. Combined with the inherent coefficients related to the cofferdam structure and safety control requirements, the sum of squares of the deviation between the real-time collected radial deformation of the cofferdam and the corresponding allowable deformation limit is divided by the sum of squares of the allowable deformation limit for normalization. Then, it is substituted into the exponential function to obtain the real-time feed rate. This quantifies the degree of deformation deviation from the safety requirements and achieves adaptive adjustment. For adjusting the milling head speed, the initial speed is used as a reference. Combined with the inherent coefficients related to hard rock characteristics and equipment performance, the sum of squares of the deviations between the real-time collected torque and the corresponding torque limit is divided by the sum of squares of the torque limit for normalization. Then, it is substituted into an exponential function to obtain the real-time speed. This quantifies the degree of torque deviation from the safety limit and achieves adaptive adjustment.

6. The method for dynamic control of hard rock milling and bottom cleaning in deep-water large-scale foundation pits according to claim 1, characterized in that, The objective optimization function for the transition section in S3 is: in The objective function for the coordinated equilibrium of crushing and slag discharge in the transition section is... For real-time foundation pit siltation thickness, The baseline siltation thickness for the foundation pit. For real-time milling feed speed, To determine the real-time slag concentration, To increase the pressure through air lift reverse circulation, The effective flow area of ​​the lifting channel, This refers to the time allotted for the assignment.

7. The method for dynamic control of hard rock milling and bottom cleaning in deep-water large-scale foundation pits according to claim 1, characterized in that, The adjustment process of the milling parameters and the air lift reverse circulation lifting pressure in S3 is as follows: Based on the conservation of debris in the foundation pit, the real-time generation and discharge of debris inside the foundation pit are used as bidirectional control objects. The balance between debris income and expenditure in the foundation pit is determined according to the debris accumulation state. Then, combined with the inherent matching relationship between the milling head rotation speed and the feed speed, linkage adjustment is performed. When the amount of debris generated in the pit is greater than the amount discharged, the milling feed speed and the milling head speed are reduced simultaneously, while the air lift reverse circulation lifting pressure is increased to enhance the slag discharge capacity. When the discharge volume is detected to be greater than the generation volume, the milling feed speed and milling head speed are gradually increased, while the air lift reverse circulation lifting pressure is reduced to reduce power consumption.

8. The method for dynamic control of hard rock milling and bottom cleaning in deep-water large-scale foundation pits according to claim 1, characterized in that, The objective optimization function for the substrate clearing section in S4 is: in The overall control objective function for the base clearing section is... The base design elevation, The actual elevation of the base is monitored in real time. The rate of change of the base elevation over time is used to characterize the flatness of the rock surface.

9. A dynamic control system for milling and cleaning the bottom of hard rock in deep-water large-scale foundation pit, characterized in that, include: The segmentation and parameter initialization unit is used to divide the entire construction process into hard rock breaking section, transition section and base cleaning section based on the hard rock lithology parameters of deep water foundation pit, the allowable deformation limit of cofferdam and the constraints of working space. Safety constraints and objective optimization functions are constructed for each segment. Through numerical simulation and fitting of field test excavation data, the initial matching parameter set of milling head torque, feed speed and air lift reverse circulation displacement of each segment is determined. The crushing section efficiency optimization control unit is used to enter the hard rock crushing section. With the core optimization goal of maximizing milling efficiency, it collects data on milling head torque, actual feed speed, cofferdam radial deformation, and slag concentration in real time. Based on the segmented constraint optimization algorithm, it compares the deviation between the real-time data and the safety threshold of the section and dynamically adjusts the milling feed speed and milling head speed. The transition section crushing and slag discharge coordination unit is used to switch the optimization target to crushing-slag discharge coordination balance after entering the transition section, gradually reduce the milling intensity, monitor the silt thickness and slag discharge efficiency in the pit in real time, and adjust the milling parameters and air lift reverse circulation lifting pressure in linkage to correct the slag discharge flow rate. The bottom clearing section elevation and flatness optimization unit is used after entering the bottom clearing section. With the bottom elevation deviation and flatness meeting the standard as the core objectives, it collects the actual elevation of the bottom, milling depth and rock surface flatness data in real time, and performs real-time optimization until the entire foundation pit milling and bottom clearing process is completed.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is executed by a processor as described in any one of claims 1-8: a dynamic control method for milling and cleaning the bottom of a deep-water large-scale foundation pit in hard rock.

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