A method for synchronous grouting of slurry based on automatic control of PLC

Abstract

The application provides a synchronous grouting slurry injection method based on PLC automatic control, comprising the following steps: S100, a grouting system acquires a grouting mode selection signal and a tunneling state signal of a shield machine, if the shield machine is in a tunneling state, step S300 is executed; S300, the grouting system acquires a shield tunneling management stroke, and determines a current tunneling section, the section is divided by a tunneling step length L; S500, a grouting speed S of the current section is calculated according to a tunneling condition of a previous section i . The method realizes the functions of controllable synchronous grouting occasion, adjustable flow, on-demand control of single-hole grouting proportion and single-pipe over-limit pump stop, improves the synchronous grouting process control precision, and ensures that the synchronous grouting slurry is injected in sufficient, uniform and targeted manner.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) engineering technology, and specifically to a method for synchronous grouting injection in TBMs based on PLC automatic control. Background Technology

[0002] The purpose of synchronous grouting in tunnel boring machines (TBMs) is to promptly fill the gaps behind the tunnel lining segments, preventing excessive ground settlement and stabilizing the lining segments to prevent excessive floating. Most current TBM operating systems are equipped with a synchronous grouting module, operated by the TBM operator on the control panel. Generally, grouting begins approximately 10cm after the TBM starts excavating and completely stops approximately 10cm before the completion of a single ring. Grouting during intermediate excavation is controlled using a dual approach based on theoretical calculations of grouting pressure and volume. However, the grouting pressure and volume indicators cannot be perfectly matched simultaneously. Typically, if the grouting volume does not reach the theoretical volume after the pressure reaches the control value, the grouting pressure will be appropriately increased on-site to ensure full grouting. However, in actual construction, due to limitations in data acquisition methods and monitoring equipment, the obtained grouting volume and pressure data often cannot provide a reliable basis for grouting decisions. The specific timing of grouting depends entirely on the experience of the TBM operator. In addition, because tunnel boring machine operators need to take into account multiple construction parameters such as shield thrust, torque, and slag removal, they sometimes neglect to control synchronous grouting. Many factors lead to poor grouting quality, which often causes problems such as excessive ground settlement and segment floating. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a PLC-based automatic control method for synchronous grouting of tunnel boring machines. This method enables controllable timing of synchronous grouting, adjustable flow rate, on-demand control of grouting ratio in single holes, and pump shutdown when a single pipe exceeds its limit. It improves the control accuracy of the synchronous grouting process and ensures that the synchronous grouting is injected in sufficient quantity, uniformly, and in a targeted manner.

[0004] This invention provides a PLC-based automatic control method for synchronous grouting injection in tunnel boring machines, comprising the following steps:

[0005] S100: The grouting system acquires the grouting mode selection signal and the tunneling status signal of the tunnel boring machine. If the tunnel boring machine is in the tunneling state, then step S300 is executed.

[0006] S300, the grouting system obtains the shield tunneling management stroke and determines the current tunneling section, which is divided by the tunneling length L;

[0007] S500, Calculate the grouting rate S for this section based on the tunneling progress of the previous section. i .

[0008] Further, step S400 is included: determining whether the current tunneling section is the first section; if so, selecting the preset grouting speed of the first section as the grouting speed of this section according to the grouting mode; otherwise, step S500 is executed.

[0009] Furthermore, in step S500, if the current grouting mode is the general mode or the soft soil mode, the average tunneling speed V of the previous section is used as the basis for the grouting process. i-1 and the current remaining mortar volume M i Calculate the grouting rate S in this section. i .

[0010] Furthermore, the grouting speed S in this section i =M i / (LK i )×V i-1 , where V i-1 =D i-1 / T i-1 M i =M0-J i ×Q; where L is the excavation step length, K i For the current excavation process, D i-1 For the length of the previous segment, T i-1 M0 is the tunneling time for the previous section, M0 is the initial mortar volume, and J is the tunneling time for the previous section. i Q represents the cumulative number of strokes of the current grouting pump, and Q represents the grouting volume per stroke.

[0011] Furthermore, in step S500, if the current grouting mode is hard rock mode, then the maximum grouting speed of the grouting pump is taken as the grouting speed S of this section. i The grouting volume for this section is Q. i Q i Based on the theoretical grouting stroke number N of this section i Perform the calculation, where Q i-1 This represents the theoretical grouting volume corresponding to the previous section.

[0012] Further, step S600 includes: if the current grouting mode is normal mode or hard rock mode, then determine whether the current tunneling section is in the initial underpressure injection section or the final underpressure injection section. If so, send a reduction signal to the grouting pump to reduce the grouting speed S of this section. i The reduction is carried out, wherein the first underpressure injection section includes the first n sections in the tunneling length L, the last underpressure injection section includes the last m sections in the tunneling length L, and the tunneling length L includes the first underpressure injection section, the last underpressure injection section and the intermediate section between the two.

[0013] Further, step S700 is included: the grouting system obtains a pre-set grouting pipeline ratio, calculates the grouting speed of each grouting pipeline in the section based on the grouting speed of the section, sends an adjustment signal to each grouting pipeline respectively, adjusts the grouting speed of each grouting pipeline and starts grouting, wherein the grouting pipeline ratio is the ratio of the grouting speeds of each grouting pipeline.

[0014] Furthermore, the method includes controlling the grouting pressure of the grouting pipeline. The method for controlling the grouting pressure includes: the grouting system acquires the actual grouting pressure P1 on each grouting pipeline in real time, determines whether P1 is greater than P0, and if so, determines whether the stroke count of the grouting pump is greater than b during the duration that P1 is greater than P0. If so, an over-limit reduction signal is sent to the grouting pipeline to reduce the current grouting speed of the grouting pipeline from the over-limit. P0 is the pressure upper limit preset for each grouting pipeline.

[0015] Furthermore, the method for controlling grouting pressure also includes: after reducing the current grouting speed of a certain grouting pipeline beyond the limit, after the grouting pump on the grouting pipeline completes one stroke, determining whether P1 is greater than P0. If so, an over-limit reduction signal is sent to the grouting pipeline again to reduce the current grouting speed of the grouting pipeline beyond the limit again; otherwise, determining whether the stroke count during the duration when P1 is less than P0 is greater than b. If so, a recovery signal is sent to the grouting pipeline to restore the grouting speed of the grouting pipeline to the initial grouting speed.

[0016] Furthermore, the method for controlling grouting pressure also includes: when the grouting speed of a certain grouting pipeline recovers to the initial grouting speed, during subsequent grouting processes, it is determined whether P1 of the grouting pipeline is greater than P0. If P1 > P0 is detected again, it is determined whether the stroke count during the duration when P1 is less than P0 after the grouting speed of the grouting pipeline recovers to the initial grouting speed is less than d, and whether the stroke count during the duration when P1 is greater than P0 is greater than b. If so, an over-limit recovery signal is sent to the grouting pipeline, and the initial grouting speed of the grouting pipeline is multiplied by the over-limit recovery coefficient r as the new initial grouting speed of the grouting pipeline.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. This invention "differentiates" the tunnel boring process into different sections, that is, divides it into multiple sections. For the general mode and the soft soil mode, the grouting speed of the current section is calculated by using the average tunneling speed of the previous section. On the one hand, this can reduce the frequency of grouting speed adjustment and prevent insufficient grouting volume caused by program chaos. On the other hand, it can realize segmented adjustment of grouting flow rate, improve the control accuracy of synchronous grouting process, and make the synchronous grouting slurry of each section sufficient and uniform.

[0019] 2. This invention targets general strata and hard rock strata, dividing a tunneling length into an initial under-pressure injection section, an intermediate section, and a tail under-pressure injection section. Through programming, it achieves synchronous grouting under-pressure injection at a certain distance before and after the shield machine stops (the initial and tail under-pressure injection sections), thereby ensuring that the pressure at the tail of the shield machine is not too high, which is beneficial to the protection of the shield tail seal. The grouting system can also more accurately control the amount and time of grouting in the initial and tail under-pressure injection sections, which are divided into multiple sections.

[0020] 3. Based on changes in strata, shield posture, and segment posture, this invention pre-sets the ratio between different grouting pipelines, thereby enabling on-demand control of grouting volume for different grouting pipelines. This facilitates targeted control of strata settlement, segment and shield machine uplift, and can effectively improve the forming quality of lining segments.

[0021] 4. When calculating the grouting speed of the current section, this invention needs to obtain the current remaining mortar volume in real time. The current remaining mortar volume is an accurate value in real time, which reduces the impact of factors such as pump and pipe equipment wear and blockage on the grouting volume.

[0022] 5. This invention uses the relative value of grouting pressure to provide feedback on grouting resistance. When the grouting resistance exceeds the set value, the grouting speed is reduced or the pump is stopped in time to avoid excessive pressure from puncturing the shield tail and causing grout leakage at the shield tail.

[0023] 6. This invention uses stroke count as the standard for time determination. When the stroke count is large during the time period when the grouting pressure P1 recovers to less than the upper pressure limit P0 after the over-limit reduction of a certain grouting pipeline, the grouting speed is reduced again to accelerate the speed at which the grouting pressure P1 recovers to the normal pressure and prevents the pressure over-limit from lasting too long and causing the shield tail to be punctured.

[0024] 7. In this invention, if the grouting pressure P1 rises again to exceed the pressure limit P0 shortly after returning to normal, and the stroke count is too high, it is determined that the initial grouting speed is too high. In this case, the grouting speed is first reduced beyond the limit. After the grouting pressure P1 of the grouting pipeline returns to normal, the initial grouting speed of the grouting pipeline is multiplied by the over-limit recovery coefficient r to obtain the new initial grouting speed of the grouting pipeline. This prevents the grouting pressure from being too high due to the excessive grouting speed and avoids the situation where the pressure cannot be restored to normal after repeatedly reducing the over-limit of a certain grouting pipeline. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating the grouting speed control principle in the general mode and soft soil mode of this invention.

[0026] Figure 2 This is a flowchart of the grouting method of the present invention;

[0027] Figure 3 This is a flowchart of the grouting opening control under the general mode of the present invention;

[0028] Figure 4 This is a flowchart illustrating the grouting opening distribution of the grouting pipeline in this invention.

[0029] Figure 5 This is a flowchart illustrating the grouting pressure control process of the grouting pipeline in this invention. Detailed Implementation

[0030] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0031] like Figure 1 As shown, this invention calculates the grouting speed of the grouting pump by managing the tunnel boring machine's stroke and average tunneling speed. By proportionally allocating different grouting pipelines and controlling the grouting pressure, the specific grouting speed on each grouting pipeline is finally obtained, achieving sufficient, uniform, and targeted grouting.

[0032] This invention provides a PLC-based automatic control method for synchronous grouting injection in tunnel boring machines, comprising the following steps:

[0033] S1. The grouting system obtains the control signal from the control panel and determines whether it is automatic control. If not, the grouting is manually controlled by the driver. Otherwise, the grouting system obtains the tunneling status signal of the tunnel boring machine. If the tunnel boring machine is in the tunneling state, step S2 is executed. Otherwise, the grouting is shut down. The system then determines whether the single-ring tunneling has ended. If so, the tunneling of this ring ends. Otherwise, the system continues to obtain the control signal from the control panel.

[0034] Single-ring tunneling refers to one tunneling advance L of a tunnel boring machine (TBM). During the tunnel excavation process, the tunnel lining is assembled and connected ring by ring. The length of one ring is the width of the tunnel lining. Generally, the width of a single-ring lining for small-diameter TBM tunnels is 1.2m or 1.5m, while the width of a single-ring lining for large-diameter TBM tunnels is 1.8m or 2.0m. In this embodiment, L = 2m.

[0035] S2. The grouting system obtains the grouting mode selection signal. If the current grouting mode is the general mode, then execute step S2.1; if the current grouting mode is the soft soil mode, then execute step S2.2; if the current grouting mode is the hard rock mode, then execute step S2.3.

[0036] It should be noted that the soft soil model is suitable for strata with high compressibility and poor self-stability, the hard rock model is suitable for strata with high strength and good self-stability, and the general model is suitable for strata with relatively good self-stability.

[0037] S2.1 The grouting system obtains the shield tunneling management stroke and determines the current tunneling section. The section is divided by the tunneling length L. The shield tunneling management stroke is the hydraulic cylinder management stroke of the shield machine. It determines whether the current tunneling section is the first section. If so, the grouting speed of the section is set to zero. Otherwise, step S3 is executed.

[0038] S2.2 The grouting system obtains the shield tunneling management stroke, determines the current tunneling section, and judges whether the current tunneling section is the first section. If so, the grouting speed of the section is set to 40% of the maximum grouting speed; otherwise, step S3 is executed.

[0039] S2.3 The grouting system obtains the shield tunneling management stroke, determines the current tunneling section, and judges whether the current tunneling section is the first section. If so, the grouting speed of the section is set to zero; otherwise, step S4 is executed.

[0040] This method calculates the grouting parameters of the current section based on the grouting conditions of the previous section. Since the first section lacks the parameters of the previous section, it is necessary to preset the grouting speed of the first section. For strata with good self-stability and high strength with good self-stability, the first section may not need to be grouted. For strata with high compressibility and poor self-stability, the grouting speed can be determined according to the actual geological conditions.

[0041] The grouting speed is controlled by adjusting the injection frequency of the grouting pump. The grouting opening is defined as the ratio of the actual injection frequency of the grouting pump to the maximum injection frequency of the grouting pump. The maximum grouting speed is the grouting speed at the maximum grouting opening of the grouting pump.

[0042] S3, based on the average tunneling speed V of the previous section i-1 and the current remaining mortar volume M i Calculate the grouting rate S in this section. i Execute step S5; the grouting speed S in this section i =M i / (LK i )×V i-1 , where V i-1 =D i-1 / T i-1 M i =M0-J i ×Q; where L is the tunneling progress length, K is the tunneling depth, and Q is the tunneling depth. i For the current excavation process, D i-1 For the length of the previous segment, T i-1 M0 is the tunneling time for the previous section, M0 is the initial mortar volume, and J is the tunneling time for the previous section. iQ represents the cumulative number of strokes of the grouting pump, Q represents the grouting volume per stroke, and i represents the i-th section, i.e., this section.

[0043] The working principle of the shield tunnel grouting pump is similar to that of a piston, which reciprocates to suck in and discharge grout. The number of strokes is the number of reciprocating motions. One reciprocating suction and discharge of grout is one stroke, and the amount of grout injected in each stroke is a fixed value.

[0044] It should be noted that, in order to ensure that the planned grout is evenly filled in the excavation gap, the higher the tunneling speed, the higher the grouting speed, and the lower the tunneling speed, the lower the grouting speed. Without considering corrections, the two are linearly related.

[0045] In actual construction, the tunneling speed of the shield tunneling machine is dynamically adjusted in real time by the shield operator. If the shield operator constantly adjusts the grouting speed based on the tunneling speed, the adjustment frequency will be too high, and the grouting pump will receive a new instruction before completing the previous program instruction, causing program chaos. Since tunneling may be paused during tunneling, time cannot be used as the basis for dividing the grouting volume. Instead, the shield management stroke, i.e., the stroke of the hydraulic cylinder, should be used as the basis. Therefore, the shield management stroke is divided into multiple segments, with one shield management stroke corresponding to one tunneling length L, i.e., one ring. In addition, during the tunneling process... Since the tunneling speed that has not yet been executed in the current section cannot be obtained during the process, the average tunneling speed in a section is used to control the grouting speed of the next section. On the one hand, this can reduce the frequency of grouting speed adjustment and prevent insufficient grouting volume caused by program chaos. On the other hand, it can realize segmented adjustment of grouting flow rate, improve the control accuracy of synchronous grouting process, and ensure that the synchronous grouting slurry in each section is sufficient and uniform. Moreover, when calculating the grouting speed of the current section, it is necessary to obtain the current remaining mortar volume in real time. The current remaining mortar volume is an accurate value in real time, which reduces the impact of factors such as pump and pipe equipment wear and blockage on the grouting volume.

[0046] S4. The maximum grouting speed is taken as the grouting speed S for this section. i The grouting volume Q in this section i According to the theoretical grouting stroke number N of this section i Perform control and execute step S5; N i =Q i-1 / Q, Q i-1 =M i / (LK i )×D i-1 ;

[0047] In the formula, Q i-1 For the theoretical grouting volume corresponding to the previous section, M i This represents the current remaining mortar volume.

[0048] In the hard rock scenario, grouting in this section will be carried out at the maximum grouting rate, controlled according to the principle of "grouting one section at a time after tunneling". i In reality, the theoretical grouting volume required for the previous section is injected into this section. For example, if no grouting is done in the first section, when the second section begins, the grouting volume Q2 is injected at the maximum grouting speed, and then the grouting in the second section is stopped, waiting to enter the next section. When the third section begins, the grouting volume Q3 is injected at the maximum grouting speed, and so on...

[0049] S5. If the grouting mode is normal mode or hard rock mode, determine whether the current tunneling section is in the initial under-pressure injection section or the final under-pressure injection section. If so, send a reduction signal to the grouting pump to reduce the grouting speed S of this section. i The grouting rate of this section is reduced by multiplying the underpressure injection coefficient g, where g = 50%. This means that the grouting rate of the first or last underpressure injection section is 50% of the grouting rate calculated in step S3 or S4. The first underpressure injection section includes the first four sections in the tunneling length L, the last underpressure injection section includes the last section in the tunneling length L, and the remaining sections are intermediate sections.

[0050] For highly compressible soft soil strata, sufficient grouting is required throughout a single excavation length, so there is no need to distinguish between the initial under-pressure injection section and the final under-pressure injection section.

[0051] In this embodiment, the division of each section and the grouting speed are as follows:

[0052] 0-25mm is the first under-pressure injection section, with an initial grouting opening of 0%.

[0053] 25-50mm is the first under-pressure injection section. Calculate the grouting opening of this section and multiply it by the under-pressure injection coefficient of 50%.

[0054] 50-75mm is the first under-pressure injection section. Calculate the grouting opening of this section and multiply it by the under-pressure injection coefficient of 50%.

[0055] 75-100mm is the first under-pressure injection section. Calculate the grouting opening of this section and multiply it by the under-pressure injection coefficient of 50%.

[0056] The section from 100 to 1900 mm is the middle section. Divide the section into 100 mm segments and calculate the grouting opening for each segment.

[0057] The section from 1900 to 2000 mm is the tail section of the under-pressure injection, which is also the last section. Calculate the grouting opening of this section and multiply it by the under-pressure injection coefficient of 50%.

[0058] For the control method of grouting speed in each section under general mode, such as Figure 3 As shown.

[0059] S6. The grouting system obtains the pre-set grouting pipeline ratio, calculates the grouting speed of each grouting pipeline in this section based on the grouting speed of this section, sends an adjustment signal to each grouting pipeline to adjust the grouting speed of each pipeline, and starts grouting. The grouting pipeline ratio is the ratio of the grouting speeds of each grouting pipeline. If the grouting speed of one or several pipelines exceeds the rated grouting speed, the grouting speed of these pipelines is set to the maximum, and the remaining grouting volume is proportionally distributed to the remaining pipelines.

[0060] Specifically, each grouting pipeline has a grouting speed control signal, which can adjust the grouting speed (pump frequency, i.e., stroke speed). This control is expressed as a percentage; the grouting pump speed is fastest when the grouting opening is 100%. After setting the proportion of grouting pipelines and the corresponding grouting opening for each grouting speed, the opening of each grouting pipeline can be automatically calculated. To address issues such as floating and serpentine movement of tunnel lining segments during shield tunnel forming, adjusting the opening of each grouting pipeline and locally increasing the grouting volume can limit the displacement space of the lining segments, effectively improving the forming quality of the lining segments.

[0061] In this embodiment, four grouting pipelines are provided, with the ratio of No.1:No.2:No.3:No.4 = 2:2:1:1. Based on the average tunneling speed of the previous section, the grouting opening of this section is calculated to be 60%. Assuming the grouting opening of No.3 is x, then the grouting opening of No.1 is 2x, the grouting opening of No.2 is 2x, and the grouting opening of No.4 is x. Then (2x+2x+x+x) / 4 = 60, so x = 40. Therefore, the grouting opening of No.1 is 80%, the grouting opening of No.2 is 80%, the grouting opening of No.3 is 40%, and the grouting opening of No.4 is 40%. The grouting system can control the grouting according to the grouting opening of each grouting pipeline.

[0062] S7. Control the grouting pressure of the grouting pipeline. The method of controlling the grouting pressure includes: the grouting system obtains the actual grouting pressure P1 on each grouting pipeline in real time, determines whether P1 is greater than P0, and if so, determines whether the stroke count of the grouting pump is greater than b during the duration that P1 is greater than P0. If so, an over-limit reduction signal is sent to the grouting pipeline to reduce the current grouting speed of the grouting pipeline from the over-limit. P0 is the pressure upper limit preset for each grouting pipeline.

[0063] It should be noted that excessive grouting speed or blockage of the grouting pipe can lead to excessive grouting pressure. The stroke count is similar to time; the time of one stroke is basically fixed, and the larger the stroke count, the longer the time. Each grouting pipe is equipped with a pressure sensor to monitor the grouting pressure.

[0064] Specifically, overlimit reduction is performed by multiplying the current grouting speed by the overlimit reduction coefficient h, where 0 < h < 1. In this embodiment, b = 5 and the overlimit reduction coefficient h = 50%.

[0065] P1 is the difference between the pressure P2 monitored by the pressure sensor during shield tunneling and the pressure P3 at the beginning of the first ring of tunneling. P3 refers to the pressure reading of the pressure gauge when no grouting is carried out. Since the pressure sensor is easily affected by the mortar, resulting in the inability of the pressure sensor reading to return to zero, the relative value of the pressure during grouting and the pressure when no grouting is carried out is used to represent the grouting pressure P1 during the actual grouting process, making the grouting pressure P1 more accurate.

[0066] When P1 > P0 and the stroke count of the grouting pump during the duration when P1 remains greater than P0 is greater than five, that is, when it is monitored that P1 rises to be greater than P0 and the duration when P1 remains greater than P0 is greater than or equal to the time required for five strokes, it indicates that the grouting pressure P1 in this grouting pipeline lasts too long after exceeding P0 and the grouting pressure is too high. It is necessary to perform overlimit reduction on the grouting speed of this grouting pipeline, that is, reduce the grouting speed by half, so as to quickly reduce the grouting pressure, thereby ensuring that the grouting pressure is maintained within the normal range and avoiding the situation of shield tail leakage caused by excessive pressure piercing the shield tail; if P1 > P0 and the duration when P1 remains greater than P0 is less than the time required for five strokes and P1 returns to the normal pressure less than P0, it indicates that the grouting pressure is not abnormal.

[0067] S7.1. After performing overlimit reduction on the current grouting speed of a certain grouting pipeline, after the grouting pump on this grouting pipeline completes one stroke of grouting, determine whether P1 is greater than P0. If so, send an overlimit reduction signal to this grouting pipeline again and perform overlimit reduction on the current grouting speed of this grouting pipeline again; otherwise, determine whether the stroke count during the duration when P1 remains less than P0 is greater than b. If so, send a recovery signal to this grouting pipeline and restore the grouting speed of this grouting pipeline to the initial grouting speed.

[0068] It should be noted that after performing overlimit reduction on the grouting pressure of a certain grouting pipeline, it is necessary to quickly reduce the grouting pressure and restore the grouting speed to the initial grouting speed as soon as possible, in case the time from the overlimit reduction of the grouting speed to the restoration of the grouting speed to the initial grouting speed is too long, resulting in piercing the shield tail. The initial grouting speed refers to the grouting speed of the grouting pipeline calculated in step S6.

[0069] In this embodiment, it can be understood that if the grouting pressure P1 of the grouting pipeline recovers to less than P0 within one stroke after the current grouting speed is multiplied by the over-limit reduction factor h for over-limit reduction, it indicates that the grouting pressure P1 recovers to normal relatively quickly and the reduction degree is acceptable; otherwise, by applying over-limit reduction to the grouting speed that has been over-limited, the recovery of the grouting pressure P1 can be accelerated, which can prevent the recovery time from being too long and causing the shield tail to be penetrated.

[0070] S7.2 When the grouting speed of a certain grouting pipeline recovers to the initial grouting speed, during the subsequent grouting process, it is determined whether P1 of the grouting pipeline is greater than P0. If P1 > P0 is detected again, it is determined whether the stroke count of P1 is less than P0 for a duration after the grouting speed of the grouting pipeline recovers to the initial grouting speed is less than d, and whether the stroke count of P1 is greater than P0 for a duration of time. If so, an over-limit recovery signal is sent to the grouting pipeline, and the initial grouting speed of the grouting pipeline is multiplied by the over-limit recovery coefficient r as the new initial grouting speed of the grouting pipeline.

[0071] Specifically, d = 10, and the over-limit recovery coefficient r is the average of the total reduction coefficient during the pressure over-limit to normal pressure process and 1. For example, if two over-limit reductions are performed, each time by 50%, then the total reduction coefficient during the pressure over-limit to normal pressure process is 25%, then r = (25% + 1) / 2 = 62.5%, that is, the initial grouting speed of the grouting pipeline is multiplied by 62.5% as the new initial grouting speed of the grouting pipeline.

[0072] If, after the grouting speed of a grouting pipeline returns to its initial grouting speed, the duration for which the grouting pressure P1 remains below P0 is less than the time required for ten strokes, and if the duration for which the grouting pressure P1 rises above P0 and remains above P0 is greater than or equal to the time required for five strokes, then the grouting speed is too high. The initial grouting speed needs to be reduced, and an over-limit reduction should be applied first. After the grouting pressure P1 returns to normal, the grouting speed of the grouting pipeline should be restored to the initial grouting speed multiplied by the over-limit recovery coefficient d. This prevents excessive grouting pressure caused by excessive grouting speed and avoids the situation where repeated over-limit reductions are applied to a grouting pipeline without restoring it to normal pressure.

[0073] The specific grouting pressure control method for each grouting pipeline is as follows: Figure 5 As shown.

[0074] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for synchronous grouting injection in tunnel boring machines based on PLC automatic control, characterized in that: Includes the following steps: S100: The grouting system acquires the grouting mode selection signal and the tunneling status signal of the tunnel boring machine. If the tunnel boring machine is in the tunneling state, then step S300 is executed. S300, the grouting system obtains the shield tunneling management stroke and determines the current tunneling section, which is divided by the tunneling length L; S400. Determine whether the current tunneling section is the first section. If so, select the preset grouting speed of the first section as the grouting speed of this section according to the grouting mode. Otherwise, execute step S500. S500, Calculate the grouting rate S for this section based on the tunneling progress of the previous section. i ; In step S500, if the current grouting mode is the general mode or the soft soil mode, the average tunneling speed V of the previous section is used as the basis for the grouting process. i-1 and the current remaining mortar volume M i Calculate the grouting rate S in this section. i ; Grouting speed S in this section i =M i / (LK i )×V i-1 , where V i-1 =D i-1 / T i-1 M i =M0-J i ×Q; where L is the tunneling progress length, K i For the current excavation process, D i-1 For the length of the previous segment, T i-1 M0 is the tunneling time for the previous section, M0 is the initial mortar volume, and J is the tunneling time for the previous section. i Q represents the cumulative number of strokes of the grouting pump and Q represents the grouting volume per stroke. In step S500, if the current grouting mode is hard rock mode, then the maximum grouting speed of the grouting pump is taken as the grouting speed S of this section. i The grouting volume for this section is Q. i Q i Based on the theoretical grouting stroke number N of this section i Perform the calculation, N i =Q i-1 / Q, Q i-1 =M i / (LK i )×D i-1 In the formula, Q i-1 This represents the theoretical grouting volume corresponding to the previous section.

2. The shield tunnel synchronous grouting method based on PLC automatic control according to claim 1, characterized in that: Including step S600: If the current grouting mode is normal mode or hard rock mode, determine whether the current tunneling section is in the initial under-pressure injection section or the final under-pressure injection section. If so, send a reduction signal to the grouting pump to reduce the grouting speed S of this section. i The reduction is carried out, wherein the first underpressure injection section includes the first n sections in the tunneling length L, the last underpressure injection section includes the last m sections in the tunneling length L, and the tunneling length L includes the first underpressure injection section, the last underpressure injection section and the intermediate section between the two.

3. The shield tunnel synchronous grouting method based on PLC automatic control according to any one of claims 1 or 2, characterized in that: The process includes step S700: the grouting system obtains a pre-set grouting pipeline ratio, calculates the grouting speed of each grouting pipeline in the section based on the grouting speed of the section, sends an adjustment signal to each grouting pipeline, adjusts the grouting speed of each grouting pipeline, and starts grouting, wherein the grouting pipeline ratio is the ratio of the grouting speeds of each grouting pipeline.

4. The shield tunnel synchronous grouting method based on PLC automatic control according to any one of claims 1 or 2, characterized in that: This includes controlling the grouting pressure of the grouting pipeline. The method for controlling the grouting pressure includes: the grouting system acquires the actual grouting pressure P1 on each grouting pipeline in real time, determines whether P1 is greater than P0, and if so, determines whether the stroke count of the grouting pump is greater than b during the duration that P1 is greater than P0. If so, an over-limit reduction signal is sent to the grouting pipeline to reduce the current grouting speed of the grouting pipeline from the over-limit. P0 is the pressure upper limit preset for each grouting pipeline.

5. The shield tunnel synchronous grouting method based on PLC automatic control according to claim 4, characterized in that: The method for controlling grouting pressure also includes: after reducing the current grouting speed of a certain grouting pipeline beyond the limit, after the grouting pump on the grouting pipeline completes one stroke, it is determined whether P1 is greater than P0. If so, an over-limit reduction signal is sent to the grouting pipeline again to reduce the current grouting speed of the grouting pipeline beyond the limit again; otherwise, it is determined whether the stroke count during the duration when P1 is less than P0 is greater than b. If so, a recovery signal is sent to the grouting pipeline to restore the grouting speed of the grouting pipeline to the initial grouting speed.

6. The shield tunnel synchronous grouting slurry injection method based on PLC automatic control according to claim 5, characterized in that: The method for controlling grouting pressure also includes: when the grouting speed of a certain grouting pipeline recovers to the initial grouting speed, during subsequent grouting processes, it is determined whether P1 of the grouting pipeline is greater than P0. If P1 > P0 is detected again, it is determined whether the stroke count during the duration when P1 is less than P0 after the grouting speed of the grouting pipeline recovers to the initial grouting speed is less than d, and whether the stroke count during the duration when P1 is greater than P0 is greater than b. If so, an over-limit recovery signal is sent to the grouting pipeline, and the initial grouting speed of the grouting pipeline is multiplied by the over-limit recovery coefficient r as the new initial grouting speed of the grouting pipeline.

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