Cutter type selection method and device for shield cutting pile group and computer equipment

Abstract

The invention provides a cutter type selection method and device for a shield cutting pile group and computer equipment. The method comprises the steps that the main abrasion form of the shield cutting pile group of a sandy gravel stratum is determined; determining influence factors of the cutterhead torque according to the main wear form; analyzing the influence significance of each influence factor on the cutterhead torque to obtain an influence significance result; and according to the influence significance result, determining a cutterhead structure form with a smaller wear degree in combination with stratum characteristics. By means of the method, a set of scheme standard of cutter head and cutter type selection is provided for sandy gravel stratum shield cutting pile group, the single-time tunneling distance without cutter changing of a shield is prolonged, the construction efficiency is improved, and the engineering cost is reduced; meanwhile, significant influence analysis is conducted on the cutterhead torque based on cutterhead configuration, a theoretical basis can be provided for key parameters such as the structural design of the cutterhead and the configuration mode of the cutter, the design method of the cutterhead and the cutter is expanded, and a theoretical basis is provided for shield type selection design.

Description

Technical Field

[0001] The invention relates to the technical field of subway shield construction, and in particular to a cutter selection method and device for shield cutting pile groups, and computer equipment. Background Art

[0002] In the process of urban subway rail transit construction, the shield method is widely used in urban tunnel construction in complex environments because of its safety, lack of climate and environmental influences, low environmental hazards such as vibration and noise, and underground construction that does not affect ground traffic. Sand and gravel strata are widely distributed in Beijing, Shenyang and other regions. In view of the engineering structural characteristics of loose sand and gravel strata, unbonded or weakly bonded particles, large particle size, and strong water permeability, the construction of large-diameter shield cutting pile groups often presents a series of engineering problems such as poor shield face stability, severe wear of the cutterhead, high formation loss rate, large settlement deformation, and floating shield segments. Among them, the damage and replacement of the cutterhead means an increase in construction period and an increase in project cost. Summary of the invention

[0003] To this end, the present invention provides a shield cutting pile group tool selection method and device, and computer equipment, aiming to solve the technical problem of tool wear during shield cutting pile group excavation in sand and gravel strata in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions:

[0005] According to a first aspect of the present invention, the present invention provides a method for selecting a cutter for cutting a pile group by a shield machine, the method comprising:

[0006] Determine the main wear modes of shield cutting piles in sandy and gravel strata;

[0007] Determine the influencing factors of the cutter head torque according to the main wear forms;

[0008] Analyze the significance of the influence of each of the influencing factors on the cutter head torque to obtain the significance result of the influence;

[0009] According to the significant impact results, combined with the formation characteristics, determine the cutterhead structure with less wear;

[0010] The influencing factors include at least one of the tool configuration mode, the cutter head opening rate, the cutter head width ratio and the formation friction coefficient.

[0011] Furthermore, the determination of the main wear forms of shield cutting pile groups in sandy and gravel formations includes:

[0012] Collect historical shield engineering data, and determine the main wear forms of shield cutting piles in sandy and gravel formations based on the historical shield engineering data;

[0013] The main wear forms include friction wear and cutting wear of tool materials.

[0014] Furthermore, the influencing factors of the cutter head torque are determined according to the main wear forms, including:

[0015] The calculation formula of the cutter head torque is defined according to the main wear form, as shown below:

[0016] T=T f +T cut +T mix +T seal

[0017]

[0018] T cut ≈1%T~5%T

[0019] T mix +T seal ≈10%T~15%T

[0020] Where, T is the cutter head torque, unit is (kN·m); T f is the friction torque between the front and side of the cutterhead and the soil; T cut is the tool cutting torque; T mix is the stirring torque of the spoke and the stirring wing; T seal is the friction torque between the mechanical seal and the bearing; De is the outer diameter of the shield, in m; b 刀盘 is the side width of the cutterhead; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; q e is the average lateral soil pressure acting on the cutterhead panel, in MPa; P m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; η is the cutterhead opening ratio;

[0021] Based on the influence of the tool cutting torque, the stirring torque of the spokes and stirring wings, and the friction torque of the mechanical seal and the bearing on the cutter disc torque, the calculation formula of the cutter disc torque is simplified;

[0022] According to the simplified target calculation formula, optimizable parameters are selected as influencing factors of the cutter head torque.

[0023] Furthermore, based on the influence of the tool cutting torque, the stirring torque of the spokes and the stirring wings, and the friction torque of the mechanical seal and the bearing on the cutter disc torque, the calculation formula of the cutter disc torque is simplified, including:

[0024] The target calculation formula is expressed as follows:

[0025]

[0026] Where, K = 120% to 130%; T f is the friction torque between the front and side of the cutterhead and the soil; De is the outer diameter of the shield, in m; μ = μ1 = μ2; μ is the friction coefficient of the stratum; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; P m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; the relationship between the lateral soil pressure of the panel and the vertical soil pressure on the side is q e =k*P m ; k is the lateral pressure coefficient; b 刀盘 / =ζ; ζ is the cutter disc width ratio; η is the cutter disc opening ratio.

[0027] Furthermore, the analysis of the significance of the influence of each of the influencing factors on the cutter head torque to obtain the significance of the influence result includes:

[0028] The target calculation formula is subjected to stress normalization, and the formula is expressed as follows:

[0029]

[0030] The partial derivative of the aperture ratio η is obtained, and the formula is expressed as follows:

[0031]

[0032] The partial derivative of the cutterhead width ratio ζ and the formation friction coefficient μ is obtained, and the formula is expressed as follows:

[0033]

[0034] The preset parameter values ​​are uniformly substituted to obtain the results of the significance of the influence, including: the influence of the cutter disc width ratio ζ on the cutter disc torque is the least significant, followed by the formation friction coefficient μ, and the influence of the cutter disc opening ratio η on the cutter disc torque is the most significant.

[0035] Furthermore, the method of determining a cutterhead structure with a smaller degree of wear based on the significant impact result and combining formation characteristics includes:

[0036] Based on the significance of the influence of each of the influencing factors on the cutter head torque, the cutter head structures with less wear are analyzed as follows:

[0037] Increase the cutterhead opening ratio, adopt a spoke structure, reduce the formation friction coefficient and / or reduce the cutterhead width.

[0038] Furthermore, the method further comprises:

[0039] Based on engineering applications, determine the impact of different tool configurations on the torque of the cutter disc, and select the target tool configuration with the lowest wear;

[0040] Among them, the target tool configuration includes a front scraper + a coil shell-shaped knife + a leading knife combination or a front scraper + a coil shell-shaped knife + a leading knife + a center fishtail knife combination.

[0041] According to a third aspect of the present invention, the present invention provides a method for selecting a tool for shield cutting pile groups, characterized in that the method comprises:

[0042] The tool configuration includes a front scraper + a coil shell-shaped knife + a leading knife combination or a front scraper + a coil shell-shaped knife + a leading knife + a center fishtail knife combination;

[0043] and / or,

[0044] Increase the cutterhead opening ratio, adopt a spoke structure, reduce the formation friction coefficient and / or reduce the cutterhead width;

[0045] and / or,

[0046] A spoke-type cutterhead structure that conforms to the envelope calculation formula for cutterhead torque estimation is used; the envelope calculation formula for cutterhead torque estimation is expressed as follows:

[0047]

[0048] Where, K = 120% to 130%; T f is the friction torque between the front and side of the cutterhead and the soil; De is the outer diameter of the shield, in m; μ = μ1 = μ2; μ is the friction coefficient of the stratum; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; P m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; the relationship between the lateral soil pressure of the panel and the vertical soil pressure on the side is q e =k*P m ; k is the lateral pressure coefficient; b 刀盘 / =ζ; ζ is the cutter disc width ratio; η is the cutter disc opening ratio.

[0049] According to a third aspect of the present invention, the present invention provides a tool selection device for shield cutting pile groups, the device comprising:

[0050] Wear form determination module, used to determine the main wear form of shield cutting piles in sandy and gravel formations;

[0051] An influencing factor analysis module, used to determine the influencing factors of the cutter head torque according to the main wear forms;

[0052] A significance calculation module, used for analyzing the significance of the influence of each of the influencing factors on the cutter head torque, and obtaining the significance result of the influence;

[0053] A cutterhead structure selection module is used to determine a cutterhead structure with a smaller wear degree according to the significance of the impact results and in combination with formation characteristics;

[0054] The influencing factors include at least one of the tool configuration mode, the cutter head opening rate, the cutter head width ratio and the formation friction coefficient.

[0055] According to a fourth aspect of the present invention, the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the tool selection method for shield cutting pile groups as described in any one of the first aspect of the present invention is implemented.

[0056] The present invention adopts the above technical solution and has at least the following beneficial effects:

[0057] Through the scheme of the present invention, the main wear forms of shield cutting pile groups in gravel and gravel formations are determined; the influencing factors of the cutter head torque are determined according to the main wear forms; the significance of the influence of each of the influencing factors on the cutter head torque is analyzed to obtain the significant influence results; according to the significant influence results, the cutter head structure with less wear is determined in combination with the formation characteristics. The present invention is suitable for piles that need to be worn, and for excavating under shallow overburden structures in gravel and sand layers, medium-coarse sand and gravel and gravel formations. It has the ability to break rocks and excavate in gravel and gravel layers. It can also cut reinforced concrete pile groups to improve the excavation efficiency of the shield machine, reduce the number and quantity of cutter changes due to abnormal wear, reduce the frequency and time of opening the shield machine to change cutters, save construction time, and reduce the safety risks of the construction environment and equipment.

[0058] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0060] Figure 1 A schematic flow chart of a method for selecting a cutter for cutting pile groups provided by a shield machine according to an embodiment of the present invention is shown;

[0061] Figure 2A diagram showing the proportions of the tool torque sub-items provided by an embodiment of the present invention is shown;

[0062] Figure 3 A diagram showing the arrangement of cutter heads provided by an embodiment of the present invention is shown;

[0063] Figure 4 A torque diagram of a cutter head cutting a pile group according to an embodiment of the present invention is shown;

[0064] Figure 5 A tool wear statistics diagram provided by an embodiment of the present invention is shown;

[0065] Figure 6 A schematic structural diagram of a tool selection device for shield cutting pile groups provided by an embodiment of the present invention is shown;

[0066] Figure 7 A schematic diagram of the physical structure of a computer device provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0067] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0068] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0069] The embodiment of the present invention provides a method for selecting a tool for cutting a pile group by a shield machine. Figure 1 As shown, at least the following steps S101 to S104 may be included:

[0070] Step S101, determining the main wear form of the shield cutting pile group in the sand and gravel stratum.

[0071] In actual engineering, shield cutting pile group operations in sandy and gravel strata will cause great damage and wear to the shield machine cutterhead tools. Therefore, it is extremely important to select cutterhead tools that are suitable for reducing the wear of cutting pile groups in sandy and gravel strata. However, the wear of shield cutterhead tools is usually difficult to measure during the shield excavation process, so it is difficult to determine the wear of the cutterhead tools during the shield excavation process.

[0072] The embodiment of the present invention provides a calculation formula for the real-time wear of the shield cutter head tool as follows:

[0073]

[0074] Among them, δ is the tool wear (mm); k is the soil wear coefficient (mm / km); D is the outer diameter of the tool (mm); N is the tool speed (rpm); L is the excavation distance (km); V is the excavation rate (mm / min).

[0075] Based on the above, it can be seen that the amount of tool wear depends on many factors, among which the tool rotation speed and excavation rate are both related to the cutter disc torque. Therefore, the cutter disc torque in the shield excavation data can be used to indirectly reflect the wear of the cutter disc tool in the process of cutting the pile group. The cutter disc tool wear is different, and the cutter disc torque also reflects different situations. The cutter disc wears slightly and the torque is small, while the cutter disc wears seriously and the torque is large. Therefore, the embodiments of the present invention can effectively reduce the cutter disc wear, improve the excavation efficiency, and enhance the pile breaking ability by reducing the cutter disc torque as much as possible.

[0076] Specifically, historical shield engineering data can be collected, and the main wear forms of shield cutting piles in gravel and sandy strata can be determined based on the historical shield engineering data. By analyzing the historical shield engineering data, it can be seen that the essence of shield tool wear is the result of the continuous friction and contact between the tool and the strata during the excavation process, and the continuous removal of metal materials from the tool alloy matrix. By observing the surface morphology of shield tools completed in gravel and sandy strata excavation, the tool wear forms can be divided into two types: impact damage (cutting wear) of the tool material and friction wear. In the process of cutting piles, the cutting mechanism of steel bars is shear cutting, and the cutting mechanism of concrete is extrusion damage.

[0077] Step S102, determining the influencing factors of the cutter head torque according to the main wear forms.

[0078] The embodiment of the present invention defines a calculation formula for the cutter head torque according to the main wear form, which is expressed as follows:

[0079] T=T f +T cut +T mix +T seal

[0080] Where, T is the cutter head torque, unit is (kN·m); T f is the friction torque between the front and side of the cutterhead and the soil; T cut is the tool cutting torque; T mix is the stirring torque of the spoke and the stirring wing; T seal It is the friction torque between mechanical seal and bearing.

[0081]

[0082] T cut ≈1%T~5%T

[0083] T mix +T seal ≈10%T~15%T

[0084] Where De is the outer diameter of the shield, in meters; b 刀盘 is the side width of the cutterhead; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; q e is the average lateral soil pressure acting on the cutterhead panel, in MPa; P m is the average soil pressure acting on the side of the cutterhead and the shield, unit: (MPa); η is the cutterhead opening ratio.

[0085] like Figure 2 As shown in the figure, it is a proportion diagram of each item of tool torque. It can be seen from the figure that the tool cutting torque accounts for less than 5% of the total torque of the cutter head, that is, the influence of the tool configuration on the cutter head torque is very small. Therefore, in the embodiment of the present invention, the cutter head torque is reduced mainly from factors such as the cutter head opening rate, the cutter head side width, and the soil friction coefficient. The design, configuration and optimization of the tool mainly consider its wear resistance and impact resistance, and there is no need to consider its influence on the cutter head torque too much.

[0086] Furthermore, based on the influence of tool cutting torque, stirring torque of spokes and stirring wings, and friction torque of mechanical seal and bearing on the cutter disc torque, the calculation formula of the cutter disc torque is simplified; for the simplified target calculation formula, optimizable parameters are selected as the influencing factors of the cutter disc torque.

[0087] Specifically, the ratio of scraper cutting torque to cutter disc torque is very small, and the additional torque values ​​such as stirring torque and sealing friction torque are relatively fixed and account for 10% to 15%. Therefore, the cutter disc torque calculation formula can be simplified to:

[0088] T * =K·T f

[0089] Where, K = 120% to 130%; T f It is the friction torque between the front and side of the cutterhead and the soil.

[0090] The friction coefficient between the front and side of the cutterhead and the stratum is set to be equal, that is, μ = μ1 = μ2; μ is the stratum friction coefficient; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; the relationship between the lateral soil pressure of the panel and the vertical soil pressure on the side is q e =k*P m ; k is the lateral pressure coefficient; b 刀盘 / = ζ; ζ is the cutter head width ratio. Therefore, the cutter head torque calculation formula can be simplified to:

[0091]

[0092] Where De is the outer diameter of the shield, in meters; η is the cutterhead opening ratio.

[0093] Based on the simplified formula for calculating the cutterhead torque, the optimizable parameters are selected to obtain the influencing factors of the cutterhead torque, including the tool configuration, cutterhead opening ratio, cutterhead width ratio and formation friction coefficient.

[0094] With respect to the tool configuration, the embodiments of the present invention can determine the influence of different tool configurations of the cutter head on the cutter head torque based on engineering applications, and select the target tool configuration with the lowest wear. Generally, there are three main types of tool configurations for shield cutters in sandy and gravel formations:

[0095] (1) Front scraper + peripheral scraper combination;

[0096] (2) Front scraper + peripheral scraper + roller combination;

[0097] (3) Front scraper + coil shell-shaped knife + leading knife or front scraper + coil shell-shaped knife + leading knife + center fishtail knife combination.

[0098] Through the study of domestic engineering applications, it is shown that the first and second types of tool configurations have poor engineering effects, severe tool wear, and a single tool change excavation distance of about 100m. By modifying the tool configuration and switching to the third type of tool configuration, tool wear can be significantly reduced, and the excavation distance can be greatly increased, usually completing about 1km of excavation in the entire subway section.

[0099] Engineering application example: When the shield machine of Shenyang Metro Line 6 is cutting pile groups under the Library Station, the cutter plane layout is as follows: Figure 3 As shown. Figure 4 and Figure 5As shown in the figure, the torque diagram and tool wear statistics of the cutter head in the process of cutting pile groups are respectively kept in the normal range in the process of shield pile breaking and excavation, the torque and wear of the cutter head configuration of the front scraper + disc shell cutter + leading cutter or the front scraper + disc shell cutter + leading cutter + center fishtail cutter are kept in the normal range.

[0100] It is understandable that different tool configurations have a great impact on tool wear and one-time excavation distance. The lead cutter plays a greater role in shield excavation in gravel formations, and its significance is far greater than that of ordinary scrapers. The life of the lead cutter in gravel formations determines the one-time excavation distance without changing the cutter. The scraper only assists in peeling and stirring. The roller cutter in the gravel formation does not directly break the pebbles, but loosens the original formation, which is equivalent to the lead cutter. However, since the material wear resistance and allowable wear amount are far less than the lead cutter, its excavation life is much lower than that of the lead cutter. Therefore, the third type of combination scheme is preferred for the shield cutter in the gravel formation in the embodiment of the present invention, and the lead cutter is used instead of the roller cutter. At the same time, reasonable construction auxiliary measures are taken to maximize the shield construction efficiency.

[0101] Step S103, analyzing the significance of the influence of each influencing factor on the cutter head torque to obtain the significance result of the influence.

[0102] In order to compare and study the relationship between the cutter head torque and the opening ratio in actual engineering under different formation stress levels, the embodiment of the present invention performs stress normalization processing on the target calculation formula, and the formula is expressed as follows:

[0103]

[0104] Among them, K can be taken as 1.25, and the formula is simplified to:

[0105]

[0106] The above formula can be used as an envelope calculation formula for the cutterhead torque estimation, and a reasonable safety margin factor is considered as the equipment torque of the equipment. Among the factors affecting the cutterhead torque, the cutterhead outer diameter is determined by the tunnel function, and the formation stress is determined by the geological conditions. Therefore, neither of them can be optimized. The factors that can be optimized include the cutterhead opening rate, the formation friction coefficient, and the cutterhead width ratio (the ratio of the cutterhead width to the cutterhead outer diameter). The significance analysis of each optimizable influencing factor is carried out.

[0107] Furthermore, the embodiment of the present invention analyzes the significance of the optimizable influencing factors on the cutter head torque by taking partial derivatives of the optimizable influencing factors, and the steps are as follows:

[0108] The partial derivative of the aperture ratio η is obtained, and the formula is expressed as follows:

[0109]

[0110] The partial derivative of the cutterhead width ratio ζ and the formation friction coefficient μ is obtained, and the formula is expressed as follows:

[0111]

[0112] Furthermore, the preset parameter values ​​are uniformly substituted to obtain the significant impact results. Among them, the preset parameter values ​​include: k = 0.4, η = 0.35, ζ = 0.065, and the significant analysis results are as follows:

[0113]

[0114] Among them, it can be seen from the above results that the influence of the cutterhead width ratio ζ on the cutterhead torque is the least significant, followed by the formation friction coefficient μ, and the cutterhead opening ratio η has the highest significant influence on the cutterhead torque.

[0115] Step S104: Determine a cutterhead structure with a smaller degree of wear based on the impact significance result and in combination with the formation characteristics.

[0116] It can be understood that different influencing factors have their own engineering value ranges, from which the corresponding torque increment range can be calculated to reflect the adjustment ability of different influencing factors on the cutter head torque. The calculation results are shown in Table 1 below:

[0117] Table 1 (Adjustment ability of various influencing factors on cutter head torque)

[0118]

[0119]

[0120] As can be seen from Table 1, the cutter disc width design affects the cutter disc structural strength and rigidity, and there is little room for optimization. The adjustment range of the cutter disc torque is -10.17% to 4.41%, that is, the maximum torque can be reduced by 10.17% and increased by 4.41%; the formation friction coefficient is reduced from 0.4 to 0.3, the cutter disc torque can be reduced by 33.33%, the opening rate is increased from 35% to 75%, and the torque can be reduced by 32.65%. According to the above analysis, the embodiments of the present invention can reduce the cutter disc torque mainly from two aspects: increasing the cutter disc opening rate and reducing the formation friction coefficient. At the same time, under the premise of ensuring the strength and rigidity of the cutter disc structure, the cutter disc width is optimized and reduced as much as possible to achieve the best engineering effect. Therefore, the cutter disc structure with less wear is obtained by increasing the cutter disc opening rate, adopting a spoke structure, reducing the formation friction coefficient, and reducing the cutter disc width.

[0121] In summary, reasonable selection of cutterheads is the primary prerequisite for realizing long-distance shield tunneling in sandy and gravel formations. Reasonable tool configuration on this basis is an important guarantee for realizing long-distance shield tunneling. Since the cutterhead structure can hardly be changed during tunneling, cutterhead selection is more important than tool configuration. The spoke-type cutterhead has the strongest comprehensive adaptability in sandy and gravel formations, and the "front scraper + disk shell-shaped cutter + leading cutter + center fishtail cutter" configuration scheme has the best effect.

[0122] In addition, the cutterhead opening rate and the formation friction coefficient have the most significant impact on the cutterhead torque. Increasing the cutterhead opening rate and taking effective slag improvement measures can effectively reduce the cutterhead torque. The tool cutting torque accounts for a very small proportion of the total cutterhead torque. Its impact on the cutterhead torque can be ignored when designing and configuring the tool. Improving the wear resistance and impact resistance of the tool is the correct principle for tool configuration design. Increasing the cutterhead opening rate cannot directly reduce the normal wear coefficient of the tool, but it can effectively reduce the abnormal wear of the scraper. The use of a spoke-type cutterhead and a large opening rate design can effectively increase the excavation speed, shorten the tool cutting trajectory line length under the premise of the same excavation mileage, reduce tool wear, and increase the shield's one-time excavation distance; and the use of a spoke-type cutterhead can ensure that only the advance cutter is used for excavation under the premise of a large number of scrapers failing, thereby enhancing the cutterhead's ability to resist risks.

[0123] Based on this, an embodiment of the present invention further provides a method for selecting a tool for shield cutting pile groups, comprising:

[0124] The tool configuration includes a front scraper + a coil shell-shaped knife + a leading knife combination or a front scraper + a coil shell-shaped knife + a leading knife + a center fishtail knife combination;

[0125] and / or,

[0126] Increase the cutterhead opening ratio, adopt a spoke structure, reduce the formation friction coefficient and / or reduce the cutterhead width;

[0127] and / or,

[0128] A spoke-type cutterhead structure that conforms to the envelope calculation formula for cutterhead torque estimation is adopted; the envelope calculation formula for cutterhead torque estimation is expressed as follows:

[0129]

[0130] Where, K = 120% to 130%; T f is the friction torque between the front and side of the cutterhead and the soil; De is the outer diameter of the shield, in m; μ = μ1 = μ2; μ is the friction coefficient of the stratum; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; p m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; the relationship between the lateral soil pressure of the panel and the vertical soil pressure on the side is qe =k*P m ; k is the lateral pressure coefficient; b 刀盘 / =ζ; ζ is the cutter disc width ratio; η is the cutter disc opening ratio.

[0131] The embodiment of the present invention provides a method for selecting cutterheads for shield cutting pile groups, provides a set of cutterhead tool selection standards for shield cutting pile groups in sandy and gravel formations, extends the shield tunneling distance without changing cutters, improves construction efficiency, and reduces engineering costs. At the same time, based on the significant impact analysis of the cutterhead configuration on the cutterhead torque, it can provide a theoretical basis for key parameters such as the cutterhead structural design and the configuration mode of the cutterhead, expands the cutterhead tool design method, and provides a theoretical basis for shield selection design.

[0132] Further, as Figure 1 In a specific implementation, an embodiment of the present invention provides a tool selection device for shield cutting pile groups, such as Figure 6 As shown, the device may include: a wear form determination module 610 , an influencing factor analysis module 620 , a significance calculation module 630 , and a cutter head structure selection module 640 .

[0133] The wear form determination module 610 can be used to determine the main wear form of the shield cutting pile group in the sand and gravel formation;

[0134] The influencing factor analysis module 620 can be used to determine the influencing factors of the cutter head torque according to the main wear forms;

[0135] The significance calculation module 630 can be used to analyze the significance of each influencing factor on the cutter head torque and obtain the significance result of the influence;

[0136] The cutterhead structure selection module 640 can be used to determine the cutterhead structure with less wear according to the impact significance results and combined with the formation characteristics;

[0137] The influencing factors include at least one of the tool configuration mode, the cutter head opening rate, the cutter head width ratio and the formation friction coefficient.

[0138] Optionally, the wear form determination module 610 may also be used to collect historical shield engineering data, and determine the main wear forms of shield cutting pile groups in sandy and gravel formations based on the historical shield engineering data;

[0139] Among them, the main wear forms include friction wear and cutting wear of tool materials.

[0140] Optionally, the influencing factor analysis module 620 can also be used to define a calculation formula for the cutter head torque according to the main wear form, which is expressed as follows:

[0141] T=Tf +T cut +T mix +T seal

[0142]

[0143] T cut ≈1%T~5%T

[0144] T mix +T seal ≈10%T~15%T

[0145] Where, T is the cutter head torque, unit is (kN·m); T f is the friction torque between the front and side of the cutterhead and the soil; T cut is the tool cutting torque; T mix is the stirring torque of the spoke and the stirring wing; T seal is the friction torque between the mechanical seal and the bearing; De is the outer diameter of the shield, in m; b 刀盘 is the side width of the cutterhead; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; q e is the average lateral soil pressure acting on the cutterhead panel, in MPa; P m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; η is the cutterhead opening ratio;

[0146] Based on the influence of the tool cutting torque, the stirring torque of the spokes and stirring wings, and the friction torque of the mechanical seal and bearing on the cutter head torque, the calculation formula of the cutter head torque is simplified.

[0147] According to the simplified target calculation formula, the optimizable parameters are selected as the influencing factors of the cutter head torque.

[0148] Optionally, the target calculation formula is expressed as follows:

[0149]

[0150] Where, K = 120% to 130%; T f is the friction torque between the front and side of the cutterhead and the soil; De is the outer diameter of the shield, in m; μ = μ1 = μ2; μ is the friction coefficient of the stratum; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; P m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; the relationship between the lateral soil pressure of the panel and the vertical soil pressure on the side is q e =k*P m ; k is the lateral pressure coefficient; b 刀盘 / =ζ; ζ is the cutter disc width ratio; η is the cutter disc opening ratio.

[0151] Optionally, the significance calculation module 630 may be used to perform stress normalization processing on the target calculation formula, and the formula is expressed as follows:

[0152]

[0153] The partial derivative of the aperture ratio η is obtained, and the formula is expressed as follows:

[0154]

[0155] The partial derivative of the cutterhead width ratio ζ and the formation friction coefficient μ is obtained, and the formula is expressed as follows:

[0156]

[0157] Substituting the preset parameter values ​​uniformly, the results of the significant influence are obtained, including: the influence of the cutterhead width ratio ζ on the cutterhead torque is the least significant, followed by the formation friction coefficient μ, and the influence of the cutterhead opening ratio η on the cutterhead torque is the most significant.

[0158] Optionally, the cutter head structure selection module 640 can be used to analyze the cutter head structure with less wear based on the significance of the influence of various influencing factors on the cutter head torque, including:

[0159] Increase the cutterhead opening ratio, adopt a spoke structure, reduce the formation friction coefficient and / or reduce the cutterhead width.

[0160] Optionally, the cutter head structure selection module 640 can also be used to determine the influence of different tool configurations of the cutter head on the cutter head torque based on engineering applications, and select the target tool configuration with the lowest wear amount;

[0161] Among them, the target tool configuration includes a front scraper + a coil shell-shaped knife + a leading knife combination or a front scraper + a coil shell-shaped knife + a leading knife + a center fishtail knife combination.

[0162] It should be noted that for other corresponding descriptions of the functional modules involved in the tool selection device for shield cutting pile groups provided in the embodiment of the present invention, reference can be made to Figure 1 The corresponding description of the method shown will not be repeated here.

[0163] Based on the above Figure 1 The method shown, accordingly, an embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the tool selection method for shield cutting pile groups described in any of the above embodiments are implemented.

[0164] Based on the above Figure 1The method shown and Figure 6 The embodiment of the device shown in the figure, the embodiment of the present invention also provides a physical structure diagram of a computer device, such as Figure 7 As shown, the computer device may include a communication bus, a processor, a memory and a communication interface, and may also include an input and output interface and a display device, wherein each functional unit can communicate with each other through the bus. The memory stores a computer program, and the processor is used to execute the program stored in the memory and execute the steps of the tool selection method for shield cutting pile groups described in the above embodiment.

[0165] Those skilled in the art can clearly understand that the specific working processes of the systems, devices, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and for the sake of brevity, they are not further described here.

[0166] In addition, the functional units in various embodiments of the present invention may be physically independent of each other, or two or more functional units may be integrated together, or all functional units may be integrated into one processing unit. The above integrated functional units may be implemented in the form of hardware, or in the form of software or firmware.

[0167] Those skilled in the art can understand that if the integrated functional unit is implemented in the form of software and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention can essentially or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, which includes a number of instructions to enable a computing device (such as a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention when running the instructions. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes.

[0168] Alternatively, all or part of the steps of implementing the aforementioned method embodiments may be accomplished by hardware associated with program instructions (such as a computing device such as a personal computer, a server, or a network device), and the program instructions may be stored in a computer-readable storage medium. When the program instructions are executed by a processor of a computing device, the computing device executes all or part of the steps of the methods described in the embodiments of the present invention.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that within the spirit and principles of the present invention, the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not deviate from the protection scope of the present invention.

Claims

1. A method for selecting a tool for shield cutting pile groups, characterized in that: The method comprises: Determine the main wear modes of shield cutting piles in sandy and gravel strata; Determine the influencing factors of the cutter head torque according to the main wear forms; Analyze the significance of the influence of each of the influencing factors on the cutter head torque to obtain the significance result of the influence; According to the significant impact results, combined with the formation characteristics, determine the cutterhead structure with less wear; The influencing factors include at least one of the tool configuration mode, the cutter head opening rate, the cutter head width ratio and the formation friction coefficient.

2. The method according to claim 1, characterized in that The main wear forms of shield cutting piles in sandy and gravel strata are determined as follows: Collect historical shield engineering data, and determine the main wear forms of shield cutting piles in sandy and gravel formations based on the historical shield engineering data; The main wear forms include friction wear and cutting wear of tool materials.

3. The method according to claim 1, characterized in that The factors affecting the cutter head torque determined according to the main wear forms include: The calculation formula of the cutter head torque is defined according to the main wear form, as shown below: T=T f +T cut +T mix +T seal T cut ≈1%T~5%T T mix +T seal ≈10%T~15%T Where, T is the cutter head torque, unit is (kN·m); T f is the friction torque between the front and side of the cutterhead and the soil; T cut is the tool cutting torque; T mix is the stirring torque of the spoke and the stirring wing; T seal is the friction torque between the mechanical seal and the bearing; De is the outer diameter of the shield, in m; b 刀盘 is the side width of the cutterhead; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; q e is the average lateral soil pressure acting on the cutterhead panel, in MPa; P m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; η is the cutterhead opening ratio; Based on the influence of the tool cutting torque, the stirring torque of the spokes and stirring wings, and the friction torque of the mechanical seal and the bearing on the cutter disc torque, the calculation formula of the cutter disc torque is simplified; According to the simplified target calculation formula, optimizable parameters are selected as influencing factors of the cutter head torque.

4. The method according to claim 3, characterized in that The calculation formula of the cutter head torque is simplified based on the influence of the tool cutting torque, the stirring torque of the spokes and the stirring wings, and the friction torque of the mechanical seal and the bearing on the cutter head torque, including: The target calculation formula is expressed as follows: Where, K = 120% to 130%; T f is the friction torque between the front and side of the cutterhead and the soil; De is the outer diameter of the shield, in m; μ = μ1 = μ2; μ is the friction coefficient of the stratum; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; P m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; the relationship between the lateral soil pressure of the panel and the vertical soil pressure on the side is q e =k*P m ; k is the lateral pressure coefficient; b 刀盘 / =ζ; ζ is the cutter disc width ratio; η is the cutter disc opening ratio.

5. The method according to claim 4, characterized in that The analysis of the significance of the influence of each of the influencing factors on the cutter head torque to obtain the significance of the influence result includes: The target calculation formula is subjected to stress normalization, and the formula is expressed as follows: The partial derivative of the aperture ratio η is obtained, and the formula is expressed as follows: The partial derivative of the cutterhead width ratio ζ and the formation friction coefficient μ is obtained, and the formula is expressed as follows: The preset parameter values ​​are uniformly substituted to obtain the results of the significance of the influence, including: the influence of the cutter disc width ratio ζ on the cutter disc torque is the least significant, followed by the formation friction coefficient μ, and the influence of the cutter disc opening ratio η on the cutter disc torque is the most significant.

6. The method according to claim 5, characterized in that The method of determining a cutterhead structure with less wear based on the significant impact result and combining formation characteristics includes: Based on the significance of the influence of each of the influencing factors on the cutter head torque, the cutter head structures with less wear are analyzed as follows: Increase the cutterhead opening ratio, adopt a spoke structure, reduce the formation friction coefficient and / or reduce the cutterhead width.

7. The method according to any one of claims 1 to 6, characterized in that: The method further comprises: Based on engineering applications, determine the impact of different tool configurations on the torque of the cutter disc, and select the target tool configuration with the lowest wear; Among them, the target tool configuration includes a front scraper + a coil shell-shaped knife + a leading knife combination or a front scraper + a coil shell-shaped knife + a leading knife + a center fishtail knife combination.

8. A method for selecting a tool for shield cutting pile groups, characterized in that: The method comprises: The tool configuration includes a front scraper + a coil shell-shaped knife + a leading knife combination or a front scraper + a coil shell-shaped knife + a leading knife + a center fishtail knife combination; and / or, Increase the cutterhead opening ratio, adopt a spoke structure, reduce the formation friction coefficient and / or reduce the cutterhead width; and / or, A spoke-type cutterhead structure that conforms to the envelope calculation formula for cutterhead torque estimation is used; the envelope calculation formula for cutterhead torque estimation is expressed as follows: Where, K = 120% to 130%; T f is the friction torque between the front and side of the cutterhead and the soil; De is the outer diameter of the shield, in m; μ = μ1 = μ2; μ is the friction coefficient of the stratum; μ1 is the friction coefficient between the front panel of the shield and the stratum; μ2 is the friction coefficient between the side of the cutterhead and the stratum; P m is the average soil pressure acting on the side of the cutterhead and the shield, in MPa; the relationship between the lateral soil pressure of the panel and the vertical soil pressure on the side is q e =k*P m ; k is the lateral pressure coefficient; b 刀盘 / =ζ; ζ is the cutter disc width ratio; η is the cutter disc opening ratio.

9. A tool selection device for shield cutting pile groups, characterized in that: The device comprises: Wear form determination module, used to determine the main wear form of shield cutting piles in sandy and gravel formations; An influencing factor analysis module, used to determine the influencing factors of the cutter head torque according to the main wear forms; A significance calculation module, used for analyzing the significance of the influence of each of the influencing factors on the cutter head torque, and obtaining the significance result of the influence; A cutterhead structure selection module is used to determine a cutterhead structure with a smaller wear degree according to the significance of the impact results and in combination with formation characteristics; The influencing factors include at least one of the tool configuration mode, the cutter head opening rate, the cutter head width ratio and the formation friction coefficient.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for selecting a cutter for shield cutting pile groups according to any one of claims 1 to 8 is implemented.

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