Method and system for attitude control of small-radius turning shield tunneling in soft-upper and hard-lower strata

Abstract

The present invention discloses a method and system for controlling the tunneling attitude of a small-radius turning shield in a soft upper and hard lower stratum. The method first calculates the tunneling deflection angle at the start of tunneling and sets the initial pitch angle at the shield tail to zero. Then, multiple oil pumps are controlled in zones, which can not only provide a large deflection torque but also calculate the vertical torque and the horizontal torque separately, greatly reducing the mutual influence between the two. Next, the vertical compensation torque and the horizontal deflection torque are preliminarily estimated, and then the oil pressure difference for providing the horizontal deflection force and the oil pressure difference for providing the vertical acting force are calculated, and finally the overall oil pressure difference is calculated comprehensively. The tunneling attitude is measured at each measurement interval of tunneling. When the tunneling attitude does not meet the design requirements, the yaw angle and the pitch angle at the shield tail are measured at this time, and the oil pressure differences in each area are recalculated to realize the automatic deviation correction of the shield attitude, so as to effectively control the tunnel axis and improve the slope at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, and in particular, to a method and system for controlling the tunneling attitude of a shield with a small turning radius in a soft upper and hard lower stratum. Background Art

[0002] When excavating urban underground tracks, shield construction can not only not affect ground traffic on the one hand, but also ensure the construction quality on the other hand. However, shield construction also has deficiencies. For example, the construction of a small turning radius is relatively difficult, which is likely to cause the rupture of shield segments, complex construction processes, and many times of deviation rectification. In the commonly used shield construction technology, a small turning radius refers to a turning radius within 350 meters. At this time, an articulated shield machine is generally used for construction. Since the tunnel turning radius is small, the power of the shield is that its main jacks are pressed against the already formed tunnel. For a small-radius tunnel curve, the thrust of the shield jacks is tangent to the tunnel curve, and the tunneling thrust is not completely provided by the tunnel. Therefore, there are problems such as large axis deviation, many cases of shield deviation rectification and poor attitude, segment fragmentation, and water leakage in small-turning-radius shield construction. Moreover, when the shield crosses a soft upper and hard lower stratum, due to the relatively soft soil quality in the upper part of the stratum, the resistance during cutting is small, while the lower part of the soil layer is harder, and a larger resistance will be encountered during cutting, resulting in a bending moment that makes the body move downward during tunneling. There are often phenomena such as difficulty in increasing the slope and difficulty in controlling the tunnel axis. It is necessary to frequently detect the shield attitude and rectify the shield attitude according to the detection results to ensure that the tunnel axis meets the design requirements. At the same time, in order to take into account the pressure gradient of the tunnel axis burial depth, the jacks on the shield machine are usually set so that the number of jacks in the lower part is greater than the number of jacks in the upper part. When adjusting the jacks at the top and bottom, the elevation moment of the jacks can be adjusted without affecting the plane moment. However, when adjusting the jacks on both sides, it is very difficult to avoid affecting the elevation moment when adjusting the plane moment. Therefore, when constructing a small-turning-radius shield in a soft upper and hard lower stratum, it is very difficult to control the tunneling attitude of the shield machine, resulting in difficulty in controlling the tunnel axis and difficulty in increasing the slope. Summary of the Invention

[0003] The present invention provides a method and system for controlling the tunneling attitude of a small-turning-radius shield in a soft upper and hard lower stratum to solve the technical problems of difficult control of the tunnel axis and difficult increase of the slope existing in the existing construction of a small-turning-radius shield in a soft upper and hard lower stratum.

[0004] According to one aspect of the present invention, a method for controlling the tunneling attitude of a small-turning-radius shield in a soft upper and hard lower stratum is provided, including the following contents:

[0005] Design the turning tunneling curve, measure the spacing, and calculate the initial yaw angle of the shield tail at the beginning of tunneling, with the initial pitch angle of the shield tail being zero;

[0006] Conduct zonal control over multiple hydraulic pumps in the shield machine;

[0007] Based on the initial yaw angle and initial pitch angle, preliminarily estimate the horizontal deflection moment and vertical compensation moment;

[0008] Based on the horizontal deflection moment and vertical compensation moment, calculate the oil pressure difference between the hydraulic pumps in each area, and start tunneling construction using the calculated oil pressure difference;

[0009] Every time the tunneling distance of the measured spacing is completed, use the shield attitude measuring device to detect whether the tunneling attitude of the shield machine meets the design requirements. If not, measure the yaw angle and pitch angle of the shield tail at this time, and recalculate the oil pressure difference based on the yaw angle and pitch angle at this time for automatic deviation correction.

[0010] Further, calculate the initial yaw angle of the shield tail at the beginning of tunneling based on the following formula:

[0011]

[0012] Among them, α0 represents the initial yaw angle, R represents the turning radius, and d represents the measured spacing.

[0013] Further, the specific process of conducting zonal control over multiple hydraulic pumps in the shield machine is as follows:

[0014] Divide multiple hydraulic pumps in the shield machine into upper and lower areas with the boundary line between hard and soft strata, and divide the upper half area into the top area Y1, the upper left area Y2, and the upper right area Y3, and divide the lower half area into the bottom area Y6, the lower left area Y4, and the lower right area Y5. Among them, the number of hydraulic pumps in the upper left area Y2, the upper right area Y3, the lower left area Y4, and the lower right area Y5 is the same, and the number of hydraulic pumps in the top area Y1 and the bottom area Y6 is the same.

[0015] Further, the calculation formula for the vertical compensation moment is:

[0016]

[0017] The calculation formula for the horizontal deflection moment is:

[0018]

[0019] Among them, M h represents the vertical compensation moment, γ1 and γ2 respectively represent the unit weights of the upper layer soil and the lower layer soil, r represents the radius of the shield machine body, K p1 and K p2They respectively represent the Coulomb passive earth pressure coefficients of the upper soil layer and the lower soil layer, which are obtained by referring to a table after conducting an earth pressure test. When referring to the table, the pitching angle of the shield tail is used as the inclination angle, M k represents the horizontal deflection moment, L represents the total length of the shield machine, and z0 represents the depth of the top of the shield machine from the ground surface.

[0020] Further, the process of calculating the oil pressure difference between the oil pressure pumps in each area based on the horizontal deflection moment and the vertical compensation moment is specifically as follows:

[0021] The top area Y1 and the bottom area Y6 do not provide horizontal deflection moments. Let F′2 = F′3 and F′4 = F′5, where F′2, F′3, F′4, and F′5 respectively represent the component forces exerted by the oil pressure pumps in each area in the horizontal direction. Based on the horizontal deflection moment, the required oil pressure differences for horizontal deflection between the upper left area Y2 and the upper right area Y3, and between the lower left area Y4 and the lower right area Y5 are calculated;

[0022] Let F″6 - F″1 = 2(F″5 - F″3), F″2 = F″3, and F″4 = F″5, where F″1, F″2, F″3, F″4, F″5, and F″6 respectively represent the component forces exerted by the oil pressure pumps in each area in the vertical direction. Based on the vertical compensation moment, the required oil pressure differences for vertical compensation between the upper left area Y2 and the lower left area Y4, between the upper right area Y3 and the lower right area Y5, and between the top area Y1 and the bottom area Y6 are calculated;

[0023] Based on multiple required oil pressure differences for horizontal deflection and required oil pressure differences for vertical compensation, the oil pressure differences between each area are calculated.

[0024] Further, taking the upper right area Y3 as a reference, the oil pressure difference between the top area Y1 and the upper right area Y3 is:

[0025] The oil pressure difference between the upper left area Y2 and the upper right area Y3 is:

[0026] The oil pressure difference between the lower left area Y4 and the upper right area Y3 is:

[0027] The oil pressure difference between the lower right area Y5 and the upper right area Y3 is:

[0028] The oil pressure difference between the bottom area Y6 and the upper right area Y3 is:

[0029] Among them, S represents the contact area of the oil pressure pump, n1 and n2 respectively represent the number of oil pressure pumps in the top area Y1 and the upper left area Y2, represents the central angle corresponding to the upper right area Y3 during the sectional control of the shield machine oil pressure pump.

[0030] Furthermore, the shield attitude measuring device includes:

[0031] A laser emitter, arranged at the segment above the completed construction, for continuously emitting laser;

[0032] A laser receiver, arranged at the shield tail, for receiving the laser emitted by the laser emitter;

[0033] An electromagnetic propulsion device, arranged at the shield tail, and electrically connected to the laser receiver and an external power supply to form a first series circuit;

[0034] An alarm device, arranged at the shield tail, for giving an alarm reminder;

[0035] A normally open self-resetting switch, arranged directly below the push head of the electromagnetic propulsion device, and electrically connected to the alarm device and an external power supply to form a second series circuit;

[0036] During the shield construction process, when the shield attitude meets the design requirements, the laser receiver receives the laser emitted by the laser emitter, the first series circuit is turned on, the electromagnetic propulsion device generates a strong magnetic field after being powered on to adsorb the magnetic push head, the second series circuit is disconnected, and the alarm device does not work; when the shield attitude does not meet the design requirements, the laser receiver cannot receive the laser emitted by the laser emitter, the first series circuit is disconnected, the electromagnetic propulsion device is not powered on, the push head of the electromagnetic propulsion device moves downward under the action of gravity and pushes the normally open self-resetting switch to close, the second series circuit is turned on, and the alarm device works and gives an alarm reminder.

[0037] Furthermore, a temporary guide rail is laid along the shield construction direction on the segment above the completed construction, the laser emitter is installed in the temporary guide rail and can move along the temporary guide rail, the laser emitter includes a sliding wedge block, a first-level base, a second-level base, a spherical head and a laser emitting gun, the sliding wedge block is fixedly arranged on the upper surface of the first-level base and is slidably connected to the temporary guide rail, the second-level base is installed below the first-level base and can rotate in the horizontal direction, the spherical head is installed below the second-level base and can rotate in the vertical direction, and the laser emitting gun is fixedly installed on the spherical head.

[0038] Furthermore, an annular scale is arranged on the front end face of the laser receiver for detecting the shield attitude deviation azimuth and deviation amplitude.

[0039] In addition, the present invention also provides a small-radius turning shield tunneling attitude control system for soft upper and hard lower strata, including:

[0040] A tunneling curve design module, which is used to design a turning tunneling curve, measure the spacing, and calculate the initial yaw angle of the shield tail at the beginning of tunneling, and set the initial pitch angle of the shield tail to zero;

[0041] An oil pump control module, which is used to control multiple oil pumps in the shield machine in zones;

[0042] A first calculation module, which is used to preliminarily estimate the horizontal deflection torque and the vertical compensation torque based on the initial yaw angle and the initial pitch angle;

[0043] A second calculation module, which is used to calculate the oil pressure difference between the oil pumps in each zone based on the horizontal deflection torque and the vertical compensation torque, and start tunneling construction with the calculated oil pressure difference;

[0044] An automatic deviation correction module, which is used to detect whether the tunneling attitude of the shield machine meets the design requirements by using a shield attitude measuring device after tunneling and measuring the spacing for each section. If not, measure the yaw angle and the pitch angle of the shield tail at this time, and recalculate the oil pressure difference based on the yaw angle and the pitch angle at this time for automatic deviation correction.

[0045] The present invention has the following effects:

[0046] For the small-radius turning shield tunneling attitude control method of the present invention for soft upper and hard lower strata, first design a small-radius turning tunneling curve and determine the measurement spacing, then calculate the tunneling deflection angle at the beginning of tunneling, that is, the initial yaw angle at the shield tail, and set the initial pitch angle at the shield tail to zero. Then, control multiple oil pumps in the shield machine in zones, which can not only provide a large deflection torque, but also calculate the vertical torque and the horizontal torque separately, greatly reducing the mutual influence between the two. Then, preliminarily estimate the vertical compensation torque and the horizontal deflection torque based on the initial yaw angle and the initial pitch angle. Among them, the horizontal deflection torque is used to realize the turning of the shield, and the vertical compensation torque is used to realize the elevation torque compensation to improve the tunneling slope of the shield. Then, calculate the oil pressure difference between the regions that can provide horizontal deflection force based on the horizontal deflection torque, and at the same time calculate the oil pressure difference between the regions that can provide vertical acting force based on the vertical compensation torque. Then, comprehensively obtain the overall oil pressure difference between the regions based on these two types of oil pressure differences, and start tunneling construction. During the construction process, measure the tunneling attitude of the shield machine every time a section of the measurement spacing is tunneled. When the tunneling attitude does not meet the design requirements, measure the yaw angle and the pitch angle of the shield tail at this time, and recalculate the oil pressure difference of each region to realize the automatic deviation correction of the shield attitude, so as to effectively control the tunnel axis and improve the slope at the same time.

[0047] In addition, the small radius turning shield tunneling attitude control system for the soft upper and hard lower strata of the present invention also has the above-mentioned advantages.

[0048] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the drawings. Brief Description of the Drawings

[0049] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0050] Figure 1 is a schematic flow chart of the small radius turning shield tunneling attitude control method for the soft upper and hard lower strata in the preferred embodiment of the present invention.

[0051] Figure 2 is a schematic diagram of construction with a tunneling deflection angle during initial excavation in the preferred embodiment of the present invention.

[0052] Figure 3 is a schematic diagram of the zoning control of multiple hydraulic pumps in the shield machine in the preferred embodiment of the present invention.

[0053] Figure 4 is a schematic diagram of the structural layout of the shield attitude measuring device in the shield tunnel in the preferred embodiment of the present invention.

[0054] Figure 5 is a schematic diagram of the circuit state when the shield attitude measuring device in the preferred embodiment of the present invention does not issue an alarm reminder.

[0055] Figure 6 is a schematic diagram of the circuit state when the shield attitude measuring device in the preferred embodiment of the present invention issues an alarm reminder.

[0056] Figure 7 is a schematic diagram of the structural design of the laser emitter with a 360-degree spherical camera structure in the preferred embodiment of the present invention.

[0057] Figure 8 is a schematic diagram of the annular scale on the front end face of the laser receiver in the preferred embodiment of the present invention.

[0058] Figure 9 is a schematic diagram of the module structure of the small radius turning shield tunneling attitude control system for the soft upper and hard lower strata in another embodiment of the present invention.

[0059] Description of the Reference Numerals

[0060] 10. Laser emitter; 20. Laser receiver; 30. Electromagnetic propulsion device; 40. Alarm device; 50. Normally open self-resetting switch; 60. Bracket; 101. Sliding wedge; 102. First-stage base; 103. Second-stage base; 104. Spherical head; 105. Laser emission gun. Detailed implementation manner

[0061] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the following.

[0062] As Figure 1 shown, a small-radius turning shield tunneling attitude control method for a soft upper and hard lower stratum provided by a preferred embodiment of the present invention includes the following contents:

[0063] Step S1: Design a turning tunneling curve, measure the spacing, and calculate the initial yaw angle of the shield tail at the beginning of tunneling, and set the initial pitch angle of the shield tail to zero;

[0064] Step S2: Control multiple oil pumps in the shield machine in zones;

[0065] Step S3: Based on the initial yaw angle and the initial pitch angle, preliminarily estimate the horizontal deflection moment and the vertical compensation moment;

[0066] Step S4: Calculate the oil pressure difference between the oil pumps in each zone based on the horizontal deflection moment and the vertical compensation moment, and start tunneling construction using the calculated oil pressure difference;

[0067] Step S5: Every time the tunneling distance of the measurement spacing is completed, use the shield attitude measurement device to detect whether the tunneling attitude of the shield machine meets the design requirements. If not, measure the yaw angle and the pitch angle of the shield tail at this time, and recalculate the oil pressure difference based on the yaw angle and the pitch angle at this time for automatic deviation correction.

[0068] It can be understood that for the small-radius turning shield tunneling attitude control method for the upper-soft and lower-hard stratum in this embodiment, first design the small-radius turning tunneling curve and determine the measurement interval, then calculate the tunneling deflection angle at the start of tunneling, that is, the initial yaw angle at the shield tail, and set the initial pitch angle at the shield tail to zero. Then, control multiple oil pumps in the shield machine in zones, which can not only provide a large deflection moment, but also calculate the vertical moment and the horizontal moment separately, greatly reducing the mutual influence between the two. Then, based on the initial yaw angle and the initial pitch angle, preliminarily estimate the vertical compensation moment and the horizontal deflection moment. Among them, the horizontal deflection moment is used to realize the shield turning, and the vertical compensation moment is used to realize the elevation moment compensation to improve the shield construction slope. Then, based on the horizontal deflection moment, calculate the oil pressure difference between the regions that can provide the horizontal deflection force, and at the same time, based on the vertical compensation moment, calculate the oil pressure difference between the regions that can provide the vertical acting force. Then, based on these two types of oil pressure differences, comprehensively obtain the overall oil pressure difference between the regions and start the tunneling construction. During the construction process, measure the tunneling attitude of the shield machine every time a measurement interval is advanced. When the tunneling attitude does not meet the design requirements, measure the yaw angle and the pitch angle at the shield tail at this time, and recalculate the oil pressure difference of each region to realize the automatic deviation correction of the shield attitude, so as to effectively control the tunnel axis and improve the slope at the same time.

[0069] It can be understood that in step S1, before the shield machine performs small-radius turning construction, the turning tunneling curve should be designed first, and the tunneling deflection angle at the start of tunneling, that is, the initial yaw angle at the shield tail, should be determined. As Figure 2 shown, when the shield machine turns and tunnels with a radius of 305 m, the designed turning tunneling curve is A. Since the shield machine advances by pushing the completed tunnel behind with jacks and the advancing route is along the tangent direction B without oil pressure adjustment, therefore, according to the design requirements, the tunneling should be carried out with the tunneling deflection angle α at the start of tunneling. After tunneling a measurement interval d, the tangent direction becomes C. Therefore, the tunneling deflection angle α is related to the turning radius R and the measurement interval d, where the measurement interval d is the Figure 2 arc length of the op segment in. And the included angle between the two tangents on the circle is equal to the central angle corresponding to the arc length of the two tangent points, then where α0 represents the initial yaw angle (i.e., the tunneling deflection angle at the start), R represents the turning radius, and d represents the measurement interval. In addition, the pitch angle at the shield tail where D represents the position difference between the upper edge and the lower edge of the shield machine body, and r represents the radius of the shield machine body. Before the start of tunneling, the position of the shield tail should be determined so that the initial pitch angle β0 at the shield tail = 0, and deflect in the horizontal direction with the initial yaw angle and then carry out tunneling.

[0070] It can be understood that the process of zoning control of multiple oil pumps in the shield machine in step S2 is specifically as follows:

[0071] Divide the multiple oil pumps in the shield machine into upper and lower regions with the boundary line between soft and hard strata, and divide the upper half region into a top region Y1, a top-left region Y2, and a top-right region Y3, and divide the lower half region into a bottom region Y6, a bottom-left region Y4, and a bottom-right region Y5. Among them, the number of oil pumps in the top-left region Y2, the top-right region Y3, the bottom-left region Y4, and the bottom-right region Y5 is the same, and the number of oil pumps in the top region Y1 and the bottom region Y6 is the same.

[0072] Specifically, assuming that the soil pressure remains consistent, if the oil pressures in all directions are the same during the tunneling of the shield machine, the shield machine will tunnel straight and cannot form a turn. When the shield passes through the upper-soft and lower-hard stratum, due to the smaller soil pressure above the upper-soft and lower-hard soil layer and the larger soil pressure below, a downward bending moment is easily formed during tunneling. On the other hand, if a turn is to be formed, a deflection moment in that direction is required for the shield machine. Therefore, considering that the properties of the upper and lower soil bodies are completely different in the upper-soft and lower-hard stratum, the present invention conducts zoning control of the oil pumps. On the one hand, it can well enable the shield machine to turn. On the other hand, considering the upper and lower soil bodies separately and applying different oil pressures is more in line with the actual construction situation. As Figure 3 shown, divide the multiple oil pumps in the shield machine into upper and lower regions with the boundary line between soft and hard strata, and divide the upper half region into a top region Y1, a top-left region Y2, and a top-right region Y3, and divide the lower half region into a bottom region Y6, a bottom-left region Y4, and a bottom-right region Y5. Let the number of oil pumps in region Y1 be n1, the number of oil pumps in region Y2 be n2, the number of oil pumps in region Y3 be n3, the number of oil pumps in region Y4 be n4, the number of oil pumps in region Y5 be n5, and the number of oil pumps in region Y6 be n6. Among them, n1 = n6, n2 = n3 = n4 = n5. Then the force F i = P i n i S, i = 1, 2, 3, 4, 5, 6, where P i represents the oil pressure magnitude of the oil pumps in the i-th region, S represents the contact area of the oil pumps, and n i represents the number of oil pumps in the i-th region.

[0073] It can be understood that according to the boundary line of the upper-soft and lower-hard stratum, the hydraulic pumps of the shield machine are divided into upper and lower two regions, and both the upper half region and the lower half region are further divided into three control regions, totaling six regions. Each region is controlled separately, which can not only increase the deflection torque significantly, but also enable the separate calculation of the vertical torque and the horizontal torque, greatly reducing the mutual influence between the two, facilitating the accurate control of the tunnel axis, and at the same time facilitating the improvement of the gradient.

[0074] It can be understood that in step S3, a soil pressure test is first conducted to obtain soil pressure data, and the stress-strain curves of the upper layer soil and the lower layer soil are obtained to facilitate the preliminary estimation of the vertical compensation torque and the horizontal deflection torque. Specifically, based on the Coulomb passive earth pressure formula σ p =γzK p calculate the soil pressure, where σ p represents the soil pressure, K p represents the Coulomb passive earth pressure coefficient, which is obtained by looking up the table according to the internal friction angle obtained from the soil pressure test, γ represents the unit weight of the soil, and z represents the depth from the ground surface at the position to be calculated. Since the properties of the upper layer soil and the lower layer soil in the upper-soft and lower-hard stratum are different, for the shield machine, the stress σ p1 =γ1z0K p1 , γ1 represents the unit weight of the upper layer soil, z0 represents the depth from the ground surface at the top of the shield machine, K p1 represents the Coulomb passive earth pressure coefficient of the upper layer soil, the stress σ p2 =γ1(z0+r)K p1 at the middle position of the shield, and the stress σ p3 =γ1(z0+r)K p1 +γ2rK p2 at the bottom of the shield, K p2 represents the Coulomb passive earth pressure coefficient of the lower layer soil, and γ2 represents the unit weight of the lower layer soil. Since it is in the upper-soft and lower-hard stratum, the upper side soil is soft and the lower side soil is hard. When the oil pressures on the upper and lower sides are the same during tunneling, there is a downward vertical torque on the shield machine, making it difficult to increase the gradient during tunneling, and even causing the tunneling route to deflect downward. To offset the influence of this vertical torque, the present invention provides a compensation torque by changing the oil pressures on the upper and lower sides. Assuming that the soil pressure is linearly distributed as a straight line, integrate the soil pressure on the surface of the shield machine and multiply by the moment arm length to preliminarily estimate the vertical compensation torque, and integrate the contact area of the cutter head in front of the shield machine to preliminarily estimate the vertical compensation torque as:

[0075]

[0076] where, M h represents the vertical compensation torque, γ1 and γ2 respectively represent the unit weights of the upper layer soil and the lower layer soil, r represents the radius of the shield machine body, K p1 and K p2They respectively represent the Coulomb passive earth pressure coefficients of the upper soil layer and the lower soil layer, which are obtained by referring to a table after conducting an earth pressure test. When referring to the table, the pitching angle of the shield tail is used as the inclination angle.

[0077] Meanwhile, the total length of the shield machine is denoted as L. The side arc surface is equivalent to a vertical rectangular surface. Assuming that when rotating by an angle α, the lengths of r(1 - cosα) / sinα on the left and right surfaces near the shield tail are not subjected to earth pressure, the horizontal deflection moment required when initially estimating the deflection angle to be α is as follows:

[0078]

[0079] Among them, M k represents the horizontal deflection moment, L represents the total length of the shield machine, and z0 represents the depth of the top of the shield machine from the ground surface.

[0080] It can be understood that in the step S4, taking the example of deflecting by a small radius α angle to the right, since the top region Y1 and the bottom region Y6 do not provide horizontal deflection moments, the horizontal deflection moment M k is deflected by the deflection forces provided by the regions Y2, Y3, Y4, and Y5. Therefore,

[0081] Let F2′ = F3′, F4′ = F5′, where F2′, F3′, F4′, and F5′ respectively represent the component forces exerted by the oil pressure pumps in each region in the horizontal direction. Then Therefore,

[0082] When considering the vertical compensation moment M h the horizontal moment for turning is not considered, while the effects of all six regions need to be considered. Considering the soil quality of the upper soft and lower hard strata, elevation moment compensation is required. Compared with the regions Y2, Y3, Y4, and Y5, the effects of the regions Y1 and Y6 are relatively large. To avoid excessive shear force on the shield segments due to excessive oil pressure differences among regions, let F6″ - F1″ = 2(F5″ - F3″), F2″ = F3″, F4″ = F5″, where F1″, F2″, F3″, F4″, F5″, and F6″ respectively represent the component forces exerted by the oil pressure pumps in each region in the vertical direction. Therefore,

[0083] The force difference equations for each region are obtained as follows: Thus, the oil pressure difference required for elevation moment compensation is obtained as:

[0084]

[0085]

[0086] Then, based on the oil pressure difference required for turning and the oil pressure difference required for elevation moment compensation, the overall oil pressure difference in each area is comprehensively calculated. Taking the upper right area Y3 as a reference, if the oil pressure in the upper right area Y3 is set as P3, then the oil pressure difference between the top area Y1 and the upper right area Y3 is:

[0087] The oil pressure difference between the upper left area Y2 and the upper right area Y3 is:

[0088] The oil pressure difference between the lower left area Y4 and the upper right area Y3 is:

[0089] The oil pressure difference between the lower right area Y5 and the upper right area Y3 is:

[0090] The oil pressure difference between the bottom area Y6 and the upper right area Y3 is:

[0091] Wherein, S represents the contact area of the oil pressure pump, n1 and n2 respectively represent the number of oil pressure pumps in the top area Y1 and the upper left area Y2, represents the central angle corresponding to the upper right area Y3 when performing zoned control of the shield machine oil pressure pump. It can be seen from the above oil pressure difference formula that the oil pressure differences in the Y1 area, Y2 area, and Y3 area transition evenly, that is, the oil pressure difference between the Y1 area and the Y2 area, and the oil pressure difference between the Y1 area and the Y3 area are equal, while the oil pressure differences between the Y6 area and the Y4 area, and the Y6 area and the Y5 area are also not much different, which can effectively reduce the stress mutation of the shield segment and prevent the segment from being damaged during turning.

[0092] It can be understood that in the step S5, for every measurement spacing d of tunneling, it is necessary to measure the tunneling attitude of the shield machine to ensure that the tunneling attitude meets the requirements, so as to effectively control the tunnel axis. For example, the tunneling attitude is measured every 100 mm of tunneling. When the measured tunneling attitude meets the requirements, approach is carried out. If it does not meet the requirements, the yaw angle α1 and pitch angle β1 at the shield tail at this time are measured again by a total station and replaced with the initial yaw angle and initial pitch angle, and steps S3 to S4 are repeatedly executed to calculate a new oil pressure difference, so as to achieve deviation correction adjustment. During the tunneling process, the shield attitude is continuously measured and deviation correction adjustment is carried out until tunneling reaches the specified position.

[0093] It can be understood that as Figures 4 to 6As shown in the figure, the shield attitude measuring device includes a laser transmitter 10, a laser receiver 20, an electromagnetic pushing device 30, an alarm device 40, and a normally open self-resetting switch 50. The laser transmitter 10 is arranged at the upper segment of the completed construction behind the shield machine and can continuously emit laser automatically. The laser receiver 20 is arranged at the tail of the shield machine and is on the same straight line as the laser transmitter 10 for receiving the laser emitted by the laser transmitter 10. The electromagnetic pushing device 30 is arranged at the tail of the shield machine and is electrically connected to the laser receiver 20 and an external 220V power supply to form a first series circuit. The alarm device 40 is also arranged at the tail of the shield machine and is used to give an alarm reminder when the shield attitude does not meet the requirements. The normally open self-resetting switch 50 is arranged directly below the pushing head of the electromagnetic pushing device 30 and is electrically connected to the alarm device 40 and an external 220V power supply to form a second series circuit. It can be understood that the laser receiver 20 includes a photosensitive resistor. When the photosensitive resistor is irradiated by laser, the resistance of the laser receiver 20 is very small, and when it is not irradiated by laser, the resistance of the laser receiver 20 is very large. It can be understood that the electromagnetic pushing device 30 includes an electromagnet (miniature DC sucker electromagnet ZYE1-P40 / 20) and a steel pushing head (a small steel cylinder with a diameter of 50mm, a height of 100mm, and a weight of about 1.5kg). The electromagnet and the steel pushing head are both arranged in a sleeve. Among them, the electromagnet is fixedly installed in the sleeve, and the installation method can be fixed by screw installation, bolt installation, etc. The diameter of the steel pushing head is slightly smaller than the inner diameter of the sleeve, and the steel pushing head can move up and down in the sleeve, and the electromagnet is located above the steel pushing head. The sleeve is a structure with both ends open. The circuit wire of the electromagnet extends out of the top of the sleeve and is connected to the first series circuit. After the electromagnet is powered on, it can generate a strong magnetic force of 25kg, so as to adsorb the steel pushing head and make the steel pushing head contract in the sleeve. When the electromagnet is not powered on, the magnetic adsorption effect disappears, and the steel pushing head falls under the action of gravity, so as to push the normally open self-resetting switch 50 below to close. When the electromagnet is powered on again, the magnetic adsorption effect is restored, and the electromagnet adsorbs the steel pushing head again. Among them, the sleeve is installed 2mm - 5mm above the normally open self-resetting switch 50, and the falling stroke of the steel pushing head is set between 5mm - 10mm.

[0094] During the shield tunneling construction process, when the shield attitude meets the requirements, the laser receiver 20 and the laser transmitter 10 are basically on the same horizontal straight line. The laser receiver 20 can successfully receive the laser emitted by the laser transmitter 10. The resistance of the laser receiver 20 is very small, and the first series circuit is turned on. After the electromagnetic propulsion device 30 is powered on, it generates a strong magnetic field to adsorb the magnetic pusher head. The normally open self-resetting switch 50 is in the off state, the second series circuit is disconnected, and the alarm device 40 does not work. When the shield attitude does not meet the requirements, the offset between the laser receiver 20 and the laser transmitter 10 is large. The laser receiver 20 cannot receive the laser emitted by the laser transmitter 10. The resistance of the laser receiver 20 is very large, and the first series circuit is disconnected. At this time, the electromagnetic propulsion device 30 is not powered on. The pusher head of the electromagnetic propulsion device 30 moves downward under the action of gravity and pushes the normally open self-resetting switch 50 to close. The second series circuit is turned on, and the alarm device 40 works and gives an alarm reminder.

[0095] It can be understood that the shield attitude measuring device sets the laser transmitter 10 at the upper segment ring that has been constructed, sets the laser receiver 20 at the shield tail, and forms a first series circuit by connecting the electromagnetic propulsion device 30, the laser receiver 20, and the external power supply. At the same time, a normally open self-resetting switch 50 is arranged directly below the pusher head of the electromagnetic propulsion device 30, and the normally open self-resetting switch 50, the alarm device 40, and the external power supply are electrically connected to form a second series circuit. The linkage control between the shield attitude detection and the alarm reminder is realized through the electromagnetic propulsion device 30 and the normally open self-resetting switch 50. When the shield attitude meets the requirements, the first series circuit is turned on and the second series circuit is not turned on, and the alarm device 40 does not give an alarm reminder. When the shield attitude does not meet the requirements, the first series circuit is not turned on and the second series circuit is turned on, and the alarm device 40 gives an alarm reminder, so that the construction personnel can be reminded to correct the shield attitude in time. Moreover, the accuracy requirements of the measuring instrument used are not high, which reduces the cost.

[0096] It can be understood that a temporary guide rail is laid along the shield tunneling direction on the upper segment ring that has been constructed. The laser transmitter 10 is installed in the temporary guide rail and can move along the temporary guide rail. Thus, during the shield tunneling construction process, the laser transmitter 10 moves forward as the shield tunnels, so that the distance between the laser transmitter 10 and the laser receiver 20 is always kept equal, ensuring that the laser receiver 20 can successfully receive the laser irradiation. Specifically, every time the shield machine advances a distance equal to the width of one segment ring, the laser transmitter 10 is advanced a distance equal to the width of one segment ring.

[0097] Optionally, in another embodiment of the present invention, the laser emitter 10 is fixedly installed on a rail trolley, and the rail trolley is installed on a temporary guide rail and can move along the temporary guide rail, driving the laser emitter 10 to move forward through the rail trolley.

[0098] It can be understood that the laser emitter 10 adopts a 360-degree spherical camera structure, which is convenient for adjusting the laser emission direction. During the construction of tunneling with a small turning radius, the laser emission direction of the laser emitter 10 can be adjusted through the 360-degree spherical camera structure, so as to facilitate the detection and correction of the shield attitude during the turning tunneling process.

[0099] Specifically, as Figure 7 shown, the laser emitter 10 includes a sliding wedge block 101, a first-level base 102, a second-level base 103, a spherical head 104, and a laser emission gun 105. The sliding wedge block 101 is fixedly arranged on the upper surface of the first-level base 102 and is slidably connected to the temporary guide rail. The second-level base 103 is installed below the first-level base 102 and can rotate in the horizontal direction. The spherical head 104 is installed below the second-level base 103 and can rotate in the vertical direction. The laser emission gun 105 is fixedly installed on the spherical head 104. Among them, the rotational connection methods between the second-level base 103 and the first-level base 102, and between the spherical head 104 and the second-level base 103 can be shaft connection or hinge connection. The laser emitter 10 can adjust the angle of the laser in the horizontal direction by rotating the second-level base 103, and can adjust the angle of the laser in the vertical direction by rotating the spherical head 104, and the adjustment operation is very convenient.

[0100] Optionally, as Figure 8As shown, a circular scale is provided on the front end face (i.e., the laser receiving surface) of the laser receiver 20, which is used to detect the deviation azimuth and deviation amplitude of the shield attitude. It can be understood that during shield tunneling in the soft upper and hard lower strata, in order to take into account the pressure gradient of the tunnel axis burial depth, the jacks on the shield machine are usually set such that the number of jacks in the lower half is greater than the number of jacks in the upper half, and the attitude correction is achieved by controlling the oil pressure deviation between the jacks in the upper half and the jacks in the lower half. Specifically, each area on the circular scale corresponds to a different deviation. When the laser falls within the central circular area, it indicates that the shield attitude meets the requirements and no correction is needed. When the laser falls within a certain annular area outside the central circular area, it indicates that the shield attitude has a deviation and correction is needed. Each annular area corresponds to a compensation torque, and at this time, the compensation torque corresponding to the annular area where the laser landing point is located is used for attitude adjustment. At the same time, the oil pressure deviation between the upper jacks and the lower jacks can also be judged according to the position where the laser deviates. For example, if the laser deflects downward from the central circular area, it means that the oil pressure of the lower jacks is too small or the oil pressure of the upper jacks is too large. The farther the deviation distance is, the greater the oil pressure deviation is. Then, the oil pressure of the lower side jacks is increased or the oil pressure of the upper side jacks is decreased and tunneling continues. When the alarm device 40 no longer issues an alarm reminder, it means that the correction is successful.

[0101] It can be understood that the laser receiver 20 is fixedly installed on the bracket 60, and the bracket 60 is fixedly installed on the shield tail, so as to ensure the stable installation of the laser receiver 20 and prevent it from shaking during shield tunneling.

[0102] It can be understood that the alarm device 40 includes a buzzer and / or an indicator light, so as to emit a sound alarm reminder and / or a light alarm reminder.

[0103] In addition, as Figure 9 shown, another embodiment of the present invention also provides a shield tunneling attitude control system for small-radius turning in soft upper and hard lower strata, preferably adopting the control method as described above. The system includes:

[0104] A tunneling curve design module, which is used to design a turning tunneling curve, measure the spacing and calculate the initial yaw angle of the shield tail at the beginning of tunneling, and set the initial pitch angle of the shield tail to zero;

[0105] An oil pump control module, which is used to control multiple oil pumps in the shield machine in zones;

[0106] A first calculation module, which is used to preliminarily estimate the horizontal deflection torque and the vertical compensation torque based on the initial yaw angle and the initial pitch angle;

[0107] A second calculation module, configured to calculate the oil pressure difference between the oil pressure pumps in each area based on the horizontal deflection torque and the vertical compensation torque, and start tunneling construction by using the calculated oil pressure difference;

[0108] An automatic deviation correction module, configured to detect whether the tunneling attitude of the shield machine meets the design requirements by using a shield attitude measuring device after each tunneling measurement interval. If not, measure the yaw angle and pitch angle of the shield tail at this time, and recalculate the oil pressure difference based on the yaw angle and pitch angle at this time for automatic deviation correction.

[0109] It can be understood that for the small-radius turning shield tunneling attitude control system in the soft upper and hard lower strata of this embodiment, first design a small-radius turning tunneling curve and determine the measurement interval, and then calculate the tunneling deflection angle at the start of tunneling, that is, the initial yaw angle at the shield tail, and set the initial pitch angle at the shield tail to zero. Then, the multiple oil pressure pumps in the shield machine are controlled in zones, which can not only provide a large deflection torque, but also calculate the vertical torque and the horizontal torque separately, greatly reducing the mutual influence between the two. Then, based on the initial yaw angle and the initial pitch angle, the vertical compensation torque and the horizontal deflection torque are preliminarily estimated. Among them, the horizontal deflection torque is used to realize the shield turning, and the vertical compensation torque is used to realize the elevation torque compensation to improve the shield construction slope. Then, based on the horizontal deflection torque, calculate the oil pressure difference between the areas that can provide the horizontal deflection force, and at the same time, based on the vertical compensation torque, calculate the oil pressure difference between the areas that can provide the vertical acting force. Then, based on these two types of oil pressure differences, obtain the overall oil pressure difference between the areas, and start tunneling construction. During the construction process, measure the tunneling attitude of the shield machine every time a measurement interval is tunneled. When the tunneling attitude does not meet the design requirements, measure the yaw angle and pitch angle of the shield tail at this time, and recalculate the oil pressure difference of each area to realize the automatic deviation correction of the shield attitude, so as to effectively control the tunnel axis and improve the slope at the same time.

[0110] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling the tunneling attitude of a small-radius turning shield in a soft upper and hard lower stratum, characterized in that, It includes the following contents: Design the turning tunneling curve, measure the spacing, and calculate the initial yaw angle of the shield tail at the beginning of tunneling, with the initial pitch angle of the shield tail being zero; Calculate the initial yaw angle of the shield tail at the beginning of tunneling based on the following formula: Where, α0 represents the initial yaw angle, R represents the turning radius, and d represents the measured spacing; Conduct zonal control over multiple oil pumps in the shield machine; the process of conducting zonal control over multiple oil pumps in the shield machine is specifically as follows: Divide multiple oil pumps in the shield machine into upper and lower regions with the boundary line between hard and soft strata, divide the upper half region into the top region Y1, the upper left region Y2, and the upper right region Y3, and divide the lower half region into the bottom region Y6, the lower left region Y4, and the lower right region Y5. Among them, the number of oil pumps in the upper left region Y2, the upper right region Y3, the lower left region Y4, and the lower right region Y5 is the same, and the number of oil pumps in the top region Y1 and the bottom region Y6 is the same; Based on the initial yaw angle and the initial pitch angle, preliminarily estimate the horizontal deflection moment and the vertical compensation moment; the calculation formula for the vertical compensation moment is: The calculation formula for the horizontal deflection moment is: Among them, M h represents the vertical compensation moment, γ1 and γ2 respectively represent the unit weights of the upper soil layer and the lower soil layer, r represents the radius of the shield machine body, K p1 and K p2 respectively represent the Coulomb passive earth pressure coefficients of the upper soil layer and the lower soil layer, which are obtained by referring to a table after conducting an earth pressure test, and when referring to the table, the pitching angle of the shield tail is used as the inclination angle, M k represents the horizontal deflection moment, L represents the total length of the shield machine, z0 represents the depth of the top of the shield machine from the ground surface, and α represents the deflection angle; Based on the horizontal deflection moment and the vertical compensation moment, calculate the oil pressure difference between oil pumps in each region, and start tunneling construction with the calculated oil pressure difference; Every time the tunneling distance of the measured spacing is reached, use the shield attitude measuring device to detect whether the tunneling attitude of the shield machine meets the design requirements. If not, measure the yaw angle and pitch angle of the shield tail at this time, and recalculate the oil pressure difference based on the yaw angle and pitch angle at this time for automatic deviation correction.

2. The small-radius turning shield tunneling attitude control method for the upper-soft and lower-hard stratum according to claim 1, characterized in that The process of calculating the oil pressure difference between oil pumps in each region based on the horizontal deflection moment and the vertical compensation moment is specifically as follows: The top region Y1 and the bottom region Y6 do not provide horizontal deflection moments. Let F2′ = F3′, F4′ = F5′, where F2′, F3′, F4′, and F5′ respectively represent the component forces exerted by oil pumps in each region in the horizontal direction. Based on the horizontal deflection moment, calculate the required oil pressure difference for horizontal deflection between the upper left region Y2 and the upper right region Y3, and the required oil pressure difference for horizontal deflection between the lower left region Y4 and the lower right region Y5; Let F6″ - F1″ = 2(F5″ - F3″), F2″ = F3″, F4″ = F5″, where F1″, F2″, F3″, F4″, F5″, and F6″ respectively represent the component forces exerted by oil pumps in each region in the vertical direction. Based on the vertical compensation moment, calculate the required oil pressure difference for vertical compensation between the upper left region Y2 and the lower left region Y4, the required oil pressure difference for vertical compensation between the upper right region Y3 and the lower right region Y5, and the required oil pressure difference for vertical compensation between the top region Y1 and the bottom region Y6; Based on multiple required oil pressure differences for horizontal deflection and required oil pressure differences for vertical compensation, calculate the oil pressure difference between each region.

3. The small-radius turning shield tunneling attitude control method for the upper-soft and lower-hard stratum according to claim 2, wherein Taking the upper right region Y3 as the reference, the calculation formula for the oil pressure difference between the top region Y1 and the upper right region Y3 is: P3 represents the oil pressure in the upper right area Y3; The calculation formula for the oil pressure difference between the upper left region Y2 and the upper right region Y3 is as follows: The calculation formula for the oil pressure difference between the lower left region Y4 and the upper right region Y3 is: The calculation formula for the oil pressure difference between the lower right region Y5 and the upper right region Y3 is: The calculation formula for the oil pressure difference between the bottom area Y6 and the upper right area Y3 is as follows: Where S represents the contact area of the hydraulic pump, and n1 and n2 respectively represent the number of hydraulic pumps in the top region Y1 and the upper left region Y2. It represents the central angle corresponding to the upper right region Y3 during the zoned control of the shield machine's hydraulic pump.

4. The small-radius turning shield tunneling attitude control method for the upper-soft and lower-hard stratum according to claim 1, wherein, The shield attitude measuring device includes: A laser emitter (10), which is arranged at the segment above that has been constructed and is used for continuously emitting laser; A laser receiver (20), which is arranged at the shield tail and is used for receiving the laser emitted by the laser emitter (10); An electromagnetic propulsion device (30), which is arranged at the shield tail and is electrically connected to the laser receiver (20) and an external power supply to form a first series circuit; An alarm device (40), which is arranged at the shield tail and is used for giving an alarm reminder; A normally open self-resetting switch (50), which is arranged directly below the pushing head of the electromagnetic propulsion device (30) and is electrically connected to the alarm device (40) and an external power supply to form a second series circuit; During the shield construction process, when the shield attitude meets the design requirements, the laser receiver (20) receives the laser emitted by the laser emitter (10), the first series circuit is turned on, the electromagnetic propulsion device (30) generates a strong magnetic field after being powered on to adsorb the magnetic pushing head, the second series circuit is disconnected, and the alarm device (40) does not work; when the shield attitude does not meet the design requirements, the laser receiver (20) cannot receive the laser emitted by the laser emitter (10), the first series circuit is disconnected, the electromagnetic propulsion device (30) is not powered on, the pushing head of the electromagnetic propulsion device (30) moves downward under the action of gravity and pushes the normally open self-resetting switch (50) to close, the second series circuit is turned on, and the alarm device (40) works and gives an alarm reminder.

5. The small-radius turning shield tunneling attitude control method for the upper-soft and lower-hard stratum according to claim 4, characterized in that A temporary guide rail is laid along the shield construction direction on the segment above that has been constructed, the laser emitter (10) is installed in the temporary guide rail and can move along the temporary guide rail, the laser emitter (10) includes a sliding wedge block (101), a first-level base (102), a second-level base (103), a spherical head (104) and a laser emission gun (105), the sliding wedge block (101) is fixedly arranged on the upper surface of the first-level base (102) and is slidably connected to the temporary guide rail, the second-level base (103) is installed below the first-level base (102) and can rotate in the horizontal direction, the spherical head (104) is installed below the second-level base (103) and can rotate in the vertical direction, and the laser emission gun (105) is fixedly installed on the spherical head (104).

6. The small-radius turning shield tunneling attitude control method for the upper-soft and lower-hard stratum according to claim 4, characterized in that, An annular scale is arranged on the front end face of the laser receiver (20) and is used for detecting the shield attitude offset azimuth and offset amplitude.

7. A small-radius turning shield tunneling attitude control system for soft upper and hard lower strata, which adopts the small-radius turning shield tunneling attitude control method described in any one of claims 1 to 6, and is characterized in that It includes: A tunneling curve design module, which is used for designing a turning tunneling curve, measuring the spacing and calculating the initial yaw angle of the shield tail at the beginning of tunneling, and making the initial pitch angle of the shield tail zero; An oil pump control module, which is used for controlling multiple oil pumps in the shield machine in zones; A first calculation module, which is used for preliminarily estimating the horizontal deflection moment and the vertical compensation moment based on the initial yaw angle and the initial pitch angle; A second calculation module, configured to calculate the oil pressure difference between the oil pressure pumps in each area based on the horizontal deflection torque and the vertical compensation torque, and start the tunneling construction using the calculated oil pressure difference; An automatic deviation correction module, configured to, after every tunneling measurement spacing distance, use a shield attitude measurement device to detect whether the tunneling attitude of the shield machine meets the design requirements. If not, measure the yaw angle and pitch angle of the shield tail at this time, and recalculate the oil pressure difference based on the yaw angle and pitch angle at this time for automatic deviation correction.

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