Shield attitude active adjusting device and method

Abstract

The invention discloses a shield posture active adjusting device and method, and the active adjusting device is installed in a beam shaped like a Chinese character'mi 'and is used for controlling the posture of a shield rear point; the *-shaped beam is installed on the rear portion in the middle shield and plays a role in supporting the middle shield. When the shield tunneling machine is manufactured, shield posture active adjusting devices are installed at the four positions of a middle shield *-shaped beam, and plastic mud is filled between the shield excavation inner surface and a shield body in real time along with forward tunneling of a shield. When the shield needs deviation rectification, the corresponding supporting blocks of the active adjusting device stretch out and are supported on the inner surface of the shield excavation to prevent the shield rear point posture from changing too much, and when the shield tail gap needs to be adjusted, the corresponding supporting blocks of the active adjusting device stretch out and are supported on the inner surface of the shield excavation to adjust the shield rear point posture. Therefore, the purpose of adjusting the shield tail gap is achieved.

Description

Technical Field

[0001] The invention relates to shield design and construction, and in particular to a shield attitude active adjustment device and method, the method comprising a plastic mud filling amount calculation method. Background Art

[0002] As the cutting-edge equipment in the field of international tunnel construction, shield machines have become the first choice in urban rail transit construction with their significant advantages - low safety risks, excellent tunnel forming quality, efficient construction progress and relatively low costs. The shield machine generally excavates along the center line of the designed tunnel, ensuring that the front point posture of the shield (generally the center of the frontmost point of the shield) and the rear point posture of the shield (generally the center of the rear end of the shield) are near the center line of the designed tunnel. The horizontal and vertical postures of the shield are required not to deviate from the center line of the designed tunnel by 50mm, which places high demands on the precise control of the shield posture.

[0003] The front point posture of the shield is actively controlled by the thrust of the propulsion cylinder, but the rear point posture of the shield is follow-up and cannot be actively controlled. However, when the shield is wrapped by synchronous slurry, excavating soft and hard strata, and correcting deviation, the rear point posture of the shield will change greatly. Since the shield excavation diameter is much larger than the shield diameter (the normal shield excavation diameter is larger than the middle shield diameter by 40-55mm), the rear point posture of the shield changes greatly (such as the front point posture of the shield corrects to the left, the rear point posture of the shield will deviate to the right, and in the most serious case, the right side of the shield is in direct contact with the inner surface of the shield excavation, and the limit will change by 40-55mm. When the over-excavation cutter is turned on, the change can reach 140mm), resulting in large changes in the shield tail gap (the gap between the inner diameter of the segment and the shield tail, generally 30mm) and the shield posture exceeding the limit, which affects the quality of the shield-formed tunnel. At the same time, due to the gap between the shield and the inner surface of the excavation, the synchronous slurry can easily enter the gap and flow into the soil bin, resulting in the loss of synchronous slurry and incomplete filling of slurry behind the segments. If the shield is shut down for too long, the shield will be wrapped by the synchronous slurry, making it more difficult to control the shield posture when the shield is excavated again.

[0004] Based on the above reasons, it is urgent to find an effective device or measure to control the posture of the rear point of the shield, especially in the process of shield correction, so as to prevent the shield body from being wrapped by the synchronous slurry and improve the quality of the shield-formed tunnel. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of existing equipment and technology, and provide a shield posture active adjustment device and method. The adjustment device is installed in the middle shield M-beam, and the adjustment device is supported on the inner surface of the shield excavation, and plastic mud is injected between the inner surface of the shield excavation and the shield body, so as to actively control the shield rear point posture and prevent the shield body from being wrapped by synchronous slurry.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] The shield machine attitude active adjustment device includes:

[0008] Active adjustment device, installed in the M-beam, used to control the rear point posture of the shield;

[0009] The M-beam is installed at the rear of the middle shield to support the middle shield.

[0010] As a preferred embodiment, the M-beam includes four main supporting arms;

[0011] Four circular holes are opened on the four main support arms of the M-beam at the rear end of the middle shield, and the active adjustment device is installed inside;

[0012] The active adjustment device comprises an adjustment device support, a first pin shaft, a support and jacking cylinder, a second pin shaft and a support and jacking block;

[0013] The adjusting device support is fixed to the M-shaped beam at the end of the circular hole, the adjusting device support is connected to the supporting top oil cylinder through a first pin shaft; the supporting top oil cylinder is connected to the supporting top block through a second pin shaft.

[0014] As a preferred embodiment, the end of the support block is flush with the outer surface of the middle shield and is arc-shaped when the support cylinder is not extended. This ensures that the end face of the support block is completely in contact with the inner surface of the excavation when it is extended, thereby increasing the force-bearing area.

[0015] As a preferred method, the gap between the outer surface of the support block and the inner surface of the circular hole is matched, a rectangular groove is opened at the corresponding position, a circular sealing ring is installed in the groove, and the outer surface of the support block and the inner surface of the circular hole are sealed with a circular sealing ring to prevent debris, mud or synchronous slurry in the excavated inner surface from entering the circular hole.

[0016] As a preferred method, when the supporting block is supported on the inner surface of the excavation, the supporting block and the inner surface of the excavation are in a sliding state during shield excavation. In order to prevent the supporting block from having too much forward resistance, an innovative arc-shaped transition design is adopted around the end surface of the supporting block.

[0017] A shield machine attitude active adjustment method, shield machine rear point attitude control during shield machine deviation correction:

[0018] Attitude control of the rear point of shield machine during shield deviation correction

[0019] When the shield machine corrects to the left, the posture of the rear point of the shield machine will deviate greatly to the right, and the supporting cylinder of the active adjustment device will be extended to the right, and the supporting block will be supported on the inner surface of the excavation;

[0020] When the shield machine is corrected to the right, the posture of the rear point of the shield machine will deviate greatly to the left, and the supporting cylinder of the active adjustment device will be extended to the left, and the supporting block will be supported on the inner surface of the excavation;

[0021] When the shield machine corrects downward, the rear point posture of the shield machine will deviate upward accordingly, and the supporting cylinder of the active adjustment device will be extended upward, and the supporting block will be supported on the inner surface of the excavation;

[0022] When no correction is needed, retract the support block.

[0023] A shield attitude active adjustment method: There are two situations in which the shield tail gap is not good. The first situation is that the shield corrects too quickly, resulting in a poor shield tail gap. The second situation is that the segment selection is unreasonable, resulting in a poor shield tail gap.

[0024] In view of the situation that the shield deviation is corrected too quickly, resulting in a poor shield tail gap, the method of controlling the shield rear point posture during shield deviation correction is used to solve the problem of poor shield tail gap; that is, when the shield deviation is corrected to the left, the shield rear point posture will deviate greatly to the right, and the supporting top cylinder of the active adjustment device will be extended to the right, and the supporting top block will be supported on the inner surface of the excavation; when the shield deviation is corrected to the right, the shield rear point posture will deviate greatly to the left, and the supporting top cylinder of the active adjustment device will be extended to the left, and the supporting top block will be supported on the inner surface of the excavation; when the shield deviation is corrected downward, the shield rear point posture will deviate greatly upward, and the supporting top cylinder of the active adjustment device will be extended upward, and the supporting top block will be supported on the inner surface of the excavation; when no deviation correction is needed, the supporting top block will be retracted;

[0025] In order to solve the problem of poor shield tail gap caused by unreasonable segment selection, the method of adjusting the shield rear point posture is adopted. The adjustment of the shield rear point posture must be based on the premise that the shield rear point posture does not exceed the limit; when the shield tail gap is too large on the left, right or upper side, the support cylinder of the active adjustment device needs to be extended to the right, left or downward, and the support block is supported on the inner surface of the excavation, and force is applied to move the shield rear point posture to the left, right or upward to ensure that the shield tail gap is within the normal range; wait until the segment selection is corrected, and then retract the support block.

[0026] A shield attitude active adjustment method, in which plastic mud is injected between the shield body and the inner surface of the excavation, and the injection position of the plastic mud is set at four points on the upper part of the rear end of the middle shield. As the gap between the middle shield and the inner surface of the excavation gradually decreases from the upper part to the lower part, the plastic mud gravity acts, and the lower part is easier to fill. The four points can be evenly arranged above the 3 and 9 o'clock positions on the clock, and arranged at 36°, that is, on the same plane, two adjacent points are connected to the midpoint of the shield at 36° (such as Figure 5 ). Two points at the lower front end of the shield tail. Figure 6As shown in the figure, the shield tail is generally in a suspended state due to its small weight, its own buoyancy and the buoyancy on the segments. Plastic mud needs to be injected into the lower part of the shield tail to ensure that the synchronous slurry does not penetrate into the gap between the shield tail and the inner surface of the excavation, which can effectively prevent the lower part of the shield tail from being wrapped by the synchronous slurry. The two points at the lower front end of the shield tail can be arranged at 60°, that is, on the same plane, the two adjacent points are connected to the midpoint of the shield at 60°, and plastic mud is injected through six points. By injecting plastic mud at the four points at the upper rear end of the middle shield and the two points at the lower front end of the shield tail, the gap between the inner surface of the shield excavation and the shield body can be fully filled, which can prevent the synchronous slurry from flowing into the soil bin, reduce the loss of synchronous slurry, and the shield body is wrapped by the synchronous slurry. The water seepage behind the segments flows into the soil bin to cause shield excavation gushing. In particular, the injection of plastic mud at the two points at the lower front end of the shield tail effectively prevents the phenomenon of the lower part of the shield tail being wrapped by the synchronous slurry, which often occurs. The present invention adopts the shield rear point posture active adjustment device and the shield body six-point injection plastic mud measure to accurately control the shield rear point posture and improve the shield forming tunnel quality. The filling amount of plastic mud is accurately calculated, which reduces the construction cost and improves the construction efficiency.

[0027] The injection of plastic mud can completely fill the gap between the inner surface of the shield excavation and the shield body, preventing the synchronous slurry from flowing into the soil bin, reducing the loss of synchronous slurry, the shield body being wrapped by the synchronous slurry, and the water seepage behind the segment flowing into the soil bin, causing shield excavation gushing. The shield body is not wrapped by the synchronous slurry, and the shield posture correction frequency is reduced, which reduces the frequency of use of the active adjustment device.

[0028] A shield attitude active adjustment method, there are two situations for calculating the plastic mud filling amount: one is a method for calculating the filling amount when the shield starts; the other is a method for calculating the filling amount when the shield is normally excavated.

[0029] A shield attitude active adjustment method, assuming that the outer diameters of the front shield, middle shield and tail shield are D 前 , D 中 and D 尾 , the lengths are L 前 , L 中 and L 尾 , the shield excavation diameter is D, the shield excavation distance is L, and the filling factor is K (generally 1.1~1.3).

[0030] (1) Filling volume V1 at the start of shield tunneling:

[0031]

[0032] At the beginning, there is no plastic mud between the inner surface of the shield excavation and the shield body. The volume of V1 needs to be filled to fill it fully, and a certain amount of loss is taken into account.

[0033] (2) Filling volume V2 during normal shield tunneling:

[0034]

[0035] The amount of plastic mud filled during normal shield excavation is actually the gap between the inner surface of the excavation and the shield tail.

[0036] The present invention has at least the following beneficial effects:

[0037] The shield attitude active adjustment device is installed at four positions of the middle shield M-beam, and the plastic mud is filled in real time between the inner surface of the shield excavation and the shield body as the shield advances forward. When the shield needs to be corrected, the corresponding support block of the active adjustment device is extended and supported on the inner surface of the shield excavation to prevent the shield rear point attitude from changing too much. When the shield tail gap needs to be adjusted, the corresponding support block of the active adjustment device can also be extended and supported on the inner surface of the shield excavation and force is applied to adjust the shield rear point attitude, thereby achieving the purpose of adjusting the shield tail gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only illustrate embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 This is a schematic diagram of the shield host;

[0040] Figure 2 This is a schematic diagram of the location of the shield active adjustment device;

[0041] Figure 3 This is the cross-sectional detail of the shield active adjustment device;

[0042] Figure 4 This is the detailed longitudinal section of the active adjustment device of the shield machine;

[0043] Figure 5 This is a schematic diagram of the mud injection position of Zhongdun;

[0044] Figure 6 This is a schematic diagram of the shield tail mud injection position.

[0045] In the figure, 1-cutter head, 2-front shield, 3-thrust cylinder, 4-main drive, 5-man gate, 6-middle shield, 7-M-beam, 8-assembly machine beam, 9-shield tail, 10-assembly machine, 11-shield tail brush, 12-pipe segment, 13-screw conveyor, 14-rear gate of screw conveyor, 15-belt, 16-active adjustment device, 17-articulated cylinder support, 18-reserved hole, 19-bolt hole, 20-adjustment device support, 21-circular hole, 22-first pin shaft, 23-supporting cylinder, 24-second pin shaft, 25-supporting block, 26-rectangular groove, 27-circular sealing ring, 28-excavation inner surface, 29-plastic mud, 30-middle shield mud injection hole, 31-shield tail mud injection hole. DETAILED DESCRIPTION

[0046] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0047] Hereinafter, different embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that the present disclosure is not limited to the specific form disclosed herein, but rather, the present disclosure should be interpreted as covering different changes, equivalents and / or replacements of the embodiments of the present disclosure. When describing the accompanying drawings, similar reference numerals may be used to indicate similar components.

[0048] In the present disclosure, if there is a statement "A or B", "at least one of A and / or B", or "one or more of A and / or B", it can include all possible combinations of the listed items. For example, the statement "A or B", "at least one of A and B", or "at least one of A or B" refers to all of the following situations: (1) including at least one A, (2) including at least one B, or (3) including both at least one A and at least one B.

[0049] In the present disclosure, the terms are used to describe specific embodiments and do not limit the present disclosure. As used herein, the singular form is intended to also include the plural form, unless the content clearly indicates otherwise. In the specification, it should be understood that the term "including" or "having" represents the presence of a feature, number, step, operation, structural element, component or combination thereof, without excluding in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, structural elements, components or combinations thereof.

[0050] It should be understood that certain details are provided in the following description to facilitate a complete understanding of the example embodiments. However, one of ordinary skill in the art should understand that the example embodiments can be implemented without these specific details. For example, the system can be shown in a block diagram to avoid obscuring the example with unnecessary details. In other examples, well-known processes, structures, and techniques may not be shown in unnecessary details to avoid obscuring the example.

[0051] The shield attitude active adjustment device 16 comprises:

[0052] Active adjustment device 16, installed in the M-beam 7, used to control the rear point posture of the shield;

[0053] The M-beam 7 is installed in the rear part of the middle shield 6 to support the middle shield 6.

[0054] In a preferred embodiment, the rear end of the M-beam 7 is mounted to the assembler beam 8 through the bolt hole 19, and the assembler 10 is mounted on the assembler beam 8. The M-beam 7 is a main load-bearing component of the shield machine, and mainly bears the gravity of the assembler beam 8, the assembler 10 and the front of the connecting bridge. At the same time, other components (such as the propulsion cylinder 3, the screw conveyor 13, the man gate 5) and the space for personnel to work through should also be considered.

[0055] In a preferred embodiment, the lower part of the screw conveyor 13 is placed on the M-shaped beam 7. The rear end of the screw conveyor 13 is designed with a screw conveyor rear gate 14 for closing and opening.

[0056] In a preferred embodiment, if Figure 1 As shown, the shield machine and its supporting parts include a cutter head 1, a propulsion cylinder 3, a main drive 4, a front shield 2, a middle shield 6, a shield tail 9, a man gate 5, an assembler 10, a screw conveyor 13 (with a screw conveyor rear gate 14 installed), a belt 15 and other components, and also includes a shield tail brush 11.

[0057] In a preferred embodiment, the thrust cylinder 3 passes through the reserved hole 18 and presses against the front end surface of the pipe segment 12 .

[0058] In a preferred embodiment, the middle shield 6 and the shield tail 9 are connected together by installing an articulated cylinder on an articulated cylinder support 17 .

[0059] In a preferred embodiment, the main drive 4 drives the cutter head 1 to rotate (left or right), the thrust cylinder 3 pushes against the pipe segment 12 to add thrust, and the shield advances forward. The slag cut by the cutter head 1 is transported to the slag bucket under the trolley through the cutter head 1 opening, the soil bin, the screw conveyor 13, the rear gate 14 of the screw conveyor, and the belt 15, and then transported to the shield working shaft by the battery car, and then transported to the ground slag pit, and finally loaded and transported away by the excavator. After the shield excavates the length of a ring of pipe segments 12, it stops excavating, and the pipe segment 12 assembly machine 10 assembles multiple pipe segments 12 into a ring by retracting the thrust cylinder 3 in the shield tail 9 in turn, and then excavates and assembles again. The outer surface of the pipe segment 12 and the inner diameter of the shield tail 9 are sealed by the shield tail brush 11 and filled with sealing grease to ensure that the pipe segment 12 tunnel is isolated from the stratum and ensure construction safety.

[0060] The shield excavation attitude control is controlled by the three groups of thrust cylinders. For example, when it is necessary to correct the deviation to the left, the thrust force of the three groups of thrust cylinders on the right side is greater than the thrust force of the three groups of thrust cylinders on the left side. The shield front point attitude (the front end center of the front shield 2) will deviate to the left, but at the same time, the shield rear point attitude (the rear end center of the middle shield 6) will deviate to the right (there is a gap between the outer diameter of the middle shield 6 and the inner surface 28 of the shield excavation). When strong correction is performed, the shield rear point attitude deviates more seriously to the right, which causes the shield rear point attitude to be uncontrollable. Strong correction to the left during shield excavation means that the shield does not want to deviate to the right again, but the follow-up characteristics of the shield rear point cause the shield rear point attitude to deviate to the right, which is contrary to the actual demand, resulting in the shield rear point attitude exceeding the limit. If the shield rear point attitude deviates too quickly to the right, it will also cause the gap between the right shield tail 9 to be too small, affecting the quality of the tunnel formed by the pipe segment 12. The present invention designs and installs the active adjustment device 16 in the M-beam 7, directly supports it on the excavation inner surface 28, actively controls the rear point posture of the shield, and prevents the occurrence of uncontrollable rear point posture of the shield.

[0061] In a preferred embodiment, the M-beam 7 includes four main support arms;

[0062] Four circular holes 21 are opened in the four main support arms of the M-shaped beam 7 at the rear end of the middle shield 6 and in the corresponding positions of the middle shield 6, and the active adjustment device 16 is installed therein;

[0063] The active adjustment device 16 includes an adjustment device support 20, a first pin shaft 22, a support cylinder 23, a second pin shaft 24 and a support block 25;

[0064] The adjusting device support 20 is fixed to the M-shaped beam 7 at the end of the circular hole 21 . The adjusting device support 20 is connected to the supporting cylinder 23 through a first pin shaft 22 ; the supporting cylinder 23 is connected to the supporting block 25 through a second pin shaft 24 .

[0065] In a preferred embodiment, the end of the supporting block 25 is flush with the outer surface of the middle shield 6 and is in an arc shape when the supporting cylinder 23 is not extended. This ensures that the end face of the supporting block 25 is completely in contact with the inner surface 28 of the excavation when it is extended, thereby increasing the force-bearing area.

[0066] In a preferred embodiment, a clearance fit is formed between the outer surface of the supporting block 25 and the inner surface of the circular hole 21, a rectangular groove 26 is opened on the middle shield 6 or the M-beam 7 (the rectangular groove 26 is arranged between the outer surface of the supporting block 25 and the inner surface of the circular hole 21), a circular sealing ring 27 is installed in the rectangular groove 26, and the outer surface of the supporting block 25 and the inner surface of the circular hole 21 are sealed by the circular sealing ring 27 to prevent debris, mud or synchronous slurry in the excavated inner surface 28 from entering the circular hole 21.

[0067] In a preferred embodiment, when the supporting block 25 is supported on the inner surface 28 of the excavation, the supporting block 25 and the inner surface 28 of the excavation are in a sliding state during shield excavation. In order to prevent the supporting block 25 from having too much forward resistance, an arc-shaped transition structure is adopted around the end surface of the supporting block 25.

[0068] A shield machine attitude active adjustment method:

[0069] Shield rear point posture control during shield deviation correction:

[0070] There are two main situations in which the device is used: one is that the active adjustment device 16 is needed when the shield is corrected to actively control the posture of the rear point of the shield so that it does not change too much; the other is that the gap between the shield tail 9 is not good, and the active adjustment device 16 can also be used to adjust it.

[0071] (1) Shield rear point posture control during shield deviation correction

[0072] Due to the uneven distribution of weight of the shield components, the lower part of the shield 6 in the shield under normal excavation conditions can be considered to be on the excavation inner surface 28. Therefore:

[0073] When the shield machine is corrected to the left, the rear point posture of the shield machine will deviate greatly to the right, and the supporting cylinder 23 of the active adjustment device 16 will be extended to the right, and the supporting block 25 will be supported on the inner surface 28 of the excavation;

[0074] When the shield machine is corrected to the right, the rear point posture of the shield machine will deviate greatly to the left, and the supporting cylinder 23 of the active adjustment device 16 will be extended to the left, and the supporting block 25 will be supported on the inner surface 28 of the excavation;

[0075] When the shield machine corrects its deviation downward, the rear point posture of the shield machine will deviate greatly upward, and the supporting cylinder 23 of the active adjustment device 16 will be extended upward, and the supporting block 25 will be supported on the inner surface 28 of the excavation.

[0076] When no deviation correction is needed, the supporting top block 25 is retracted.

[0077] That is, when the shield machine is corrected to the left, right and downward, the rear point posture of the shield machine will deviate greatly to the right, left and upward accordingly, and the supporting cylinder 23 of the active adjustment device 16 needs to be extended to the right, left and upward accordingly, and the supporting block 25 is supported on the inner surface 28 of the excavation to prevent the rear point posture of the shield machine from changing greatly. When no correction is needed, the supporting block 25 is retracted.

[0078] A shield machine attitude active adjustment method:

[0079] (2) Shield rear point posture adjustment when the shield tail 9 gap is not good

[0080] The gap between the shield tail 9 (between the outer surface of the segment 12 and the inner surface of the shield tail 9) is required to be controlled within the normal range. A poor gap between the shield tail 9 may be caused by too fast shield deviation correction or unreasonable selection of the segment 12.

[0081] There are two situations in which the gap at the shield tail 9 is not good. The first situation is that the shield is corrected too quickly, resulting in a poor gap at the shield tail 9. The second situation is that the segment 12 is not selected reasonably, resulting in a poor gap at the shield tail 9.

[0082] In view of the situation that the shield is corrected too quickly and the gap of the shield tail 9 is not good, the method of controlling the shield rear point posture during the shield correction is adopted to solve the problem of the poor gap of the shield tail 9; that is, when the shield is corrected to the left, the shield rear point posture will deviate greatly to the right accordingly, and the supporting top cylinder 23 of the active adjustment device 16 will be extended to the right, and the supporting top block 25 will be supported on the inner surface 28 of the excavation; when the shield is corrected to the right, the shield rear point posture will deviate greatly to the left accordingly, and the supporting top cylinder 23 of the active adjustment device 16 will be extended to the left, and the supporting top block 25 will be supported on the inner surface 28 of the excavation; when the shield is corrected downward, the shield rear point posture will deviate greatly upward accordingly, and the supporting top cylinder 23 of the active adjustment device 16 will be extended upward, and the supporting top block 25 will be supported on the inner surface 28 of the excavation; when no correction is needed, the supporting top block 25 will be retracted;

[0083] In view of the situation that the gap of the shield tail 9 is not good due to the unreasonable selection of the pipe segment 12, the method of adjusting the rear point posture of the shield is adopted to solve it. The adjustment of the rear point posture of the shield must be based on the premise that the rear point posture of the shield does not exceed the limit; when the gap on the left, right or upper side of the shield tail 9 is too large, it is necessary to extend the supporting cylinder 23 of the active adjustment device 16 to the right, left or downward, and the supporting block 25 is supported on the inner surface 28 of the excavation, and force is applied to move the rear point posture of the shield to the left, right or upward to ensure that the gap of the shield tail 9 is within the normal range; wait until the selection of the pipe segment 12 is corrected, and then retract the supporting block 25.

[0084] If the shield is corrected too much, the above (1) measures can be adopted to prevent the shield tail 9 from having a bad gap; when the segment 12 is not selected reasonably, the method of appropriately adjusting the shield rear point posture can be adopted to solve the problem. Of course, this is based on the premise that the shield rear point posture does not exceed the limit. When the gap on the left, right, and top sides of the shield tail 9 is too large, the support cylinder 23 of the active adjustment device 16 needs to be extended to the right, left, and downward accordingly, and the support block 25 is supported on the inner surface 28 of the excavation, and force is applied to move the shield rear point posture to the left, right, and upward to ensure that the shield tail 9 gap is within the normal range. After the segment 12 selection is corrected, the support block 25 can be retracted.

[0085] A shield machine attitude active adjustment method, such as Figure 1 , Figure 5 , Figure 6As shown, in order to prevent the shield from being stuck, the shield excavation diameter is larger than the shield diameter, and the diameters of the front shield 2, the middle shield 6 and the tail shield 9 are reduced in sequence. In order to prevent the formation above the shield from settling, the synchronous slurry from flowing into the soil bin, the shield from being wrapped, and the active adjustment device 16 from being wrapped by the synchronous slurry, it is necessary to inject plastic mud 29 between the shield and the inner surface 28 of the excavation; the lower part of the rear end of the middle shield 6 is generally in contact with the lower part of the inner surface 28 of the excavation (such as Figure 5 ) ; The shield tail 9 is light in weight and is generally suspended within the inner surface 28 of the excavation due to buoyancy (eg Figure 6 ). To ensure that the gap is completely filled, the injection mud 29 is set at four points on the upper rear end of the middle shield 6 and two points on the lower front end of the shield tail 9. The plastic mud 29 is injected synchronously with the shield tunneling.

[0086] A shield attitude active adjustment method, there are two cases of calculating the filling amount of plastic mud 29: one is the calculation method of the filling amount when the shield starts; the other is the calculation method of the filling amount when the shield is normally excavated.

[0087] A shield attitude active adjustment method, assuming that the outer diameters of the front shield 2, the middle shield 6 and the tail shield 9 are D 前 , D 中 and D 尾 , the lengths are L 前 , L 中 and L 尾 , the shield excavation diameter is D, the shield excavation distance is L, and the filling factor is K (generally 1.1~1.3).

[0088] (1) Filling volume V1 at the start of shield tunneling:

[0089]

[0090] At the beginning, there is no plastic mud 29 between the inner surface 28 of the shield excavation and the shield body, and the volume of V1 needs to be filled to fill it fully, and a certain amount of loss is taken into account.

[0091] (2) Filling volume V2 during normal shield tunneling:

[0092]

[0093] The filling amount of plastic mud 29 during normal shield excavation is actually the gap between the excavation inner surface 28 and the shield tail 9.

[0094] When determining the filling factor K, factors such as material production loss, material loss, compression loss, construction errors and geological conditions can be quantified.

[0095] 1. Material production loss

[0096] Generally, there will be some loss in the process of mixing, transporting, pumping and injection of plastic mud 29. The material production loss can be determined as: K 材料 =1+material loss rate=1.02.

[0097] 2. Material loss

[0098] During the injection process between the shield body and the gap between the inner surface of the excavation 28, the plastic mud 29 will flow forward to the soil bin and backward to the synchronous slurry at the rear of the shield tail 9. The loss is mainly related to the plastic mud consistency, soil bin pressure, and synchronous grouting pressure, and is usually between 5% and 10%. Assuming 7%, K 流失 =1+material loss rate=1.07. In order to prevent the plastic mud 29 from being lost seriously, the injection pressure of the plastic mud 29 should be consistent with or substantially consistent with the soil bin pressure and the synchronous grouting pressure.

[0099] 3. Compression loss

[0100] The compression ratio is about 2%, that is, K 压缩 =1+compression loss rate=1.02.

[0101] 4. Construction error

[0102] The inner surface 28 of the shield excavation cannot be an absolute arc surface. There will be unevenness when the cutter is excavating, and the volume of the injection mud will have errors. The construction error can generally be estimated within the range of 0% to 5%. Assuming 3%, K 误差 =1+construction error rate=1+0.03=1.03.

[0103] 5. Geological conditions

[0104] If the geological conditions are complex and there are cracks in the strata, plastic mud 29 will penetrate into the strata, which may have a negative impact on the losses. Assuming the geological influence coefficient is 3%, K 地质 =1+geological influence rate=1+0.03=1.03.

[0105] 6. Comprehensively determine the filling factor K

[0106] Multiply the above loss coefficients to get the final filling factor K = K 材料 ×K 流失 ×K 压缩 ×K 误差 ×K 地质 The final calculated filling amount is the actual production amount of plastic mud, that is, mixing is carried out according to this amount.

[0107] Some features and advantages of the present invention

[0108] (1) The M-beam 7 supports the equipment inside the shield body. The active adjustment device 16 is installed inside the M-beam 7 and has good strength and rigidity.

[0109] (2) The first pin 22 and the second pin 24 of the present invention are both tangent to the concentric circle of the shield body, and the force on the pins is more reasonable.

[0110] (3) The invention of the active adjustment device 16 can effectively prevent the rear point posture of the shield 6 from changing too much during the shield tunneling process, especially during the shield deviation correction process, thereby improving the quality of the formed tunnel.

[0111] (4) The periphery of the end surface of the supporting block 25 adopts an arc-shaped transition design, which can reduce the resistance of the supporting block 25 sliding forward.

[0112] (5) The extension length of the support cylinder 23 should be designed to be slightly larger than the difference between the diameter of the inner surface 28 of the excavation when the shield over-excavation cutter is opened and the outer diameter of the middle shield 6 (for example, if the shield over-excavation diameter is 6380 mm and the diameter of the middle shield 6 is 6240 mm, the extension length of the support cylinder 23 should be 160 mm).

[0113] (6) The design of the four middle shield mud injection holes 30 and the two shield tail mud injection holes 31 can ensure that the gap between the excavation inner surface 28 and the shield body is fully filled. In particular, the two shield tail mud injection holes 31 can prevent the lower part of the shield tail 9 from being easily wrapped by the synchronous slurry at this stage, thereby improving the progress of shield construction.

[0114] (7) The filling of plastic mud 29 can effectively solve many problems such as the shield body being easily wrapped by synchronous slurry, the settlement of the stratum above the shield body, the loss of synchronous slurry to the soil bin, and the gushing during shield tunneling.

[0115] (8) The present invention is applicable to shield tunneling in strata with a certain bearing capacity and the excavated inner surface 28 can withstand the top force of the active adjustment device 16.

[0116] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. The shield machine attitude active adjustment device is characterized by: include: Active adjustment device, installed in the M-beam, used to control the rear point posture of the shield; The M-beam is installed at the rear of the middle shield to support the middle shield.

2. The shield attitude active adjustment device according to claim 1 is characterized in that: The M-beam includes four main supporting arms; Four circular holes are opened on the four main support arms of the M-beam at the rear end of the middle shield, and the active adjustment device is installed inside; The active adjustment device comprises an adjustment device support, a first pin shaft, a support and jacking cylinder, a second pin shaft and a support and jacking block; The adjusting device support is fixed to the M-shaped beam at the end of the circular hole, the adjusting device support is connected to the supporting top oil cylinder through a first pin shaft; the supporting top oil cylinder is connected to the supporting top block through a second pin shaft.

3. The shield attitude active adjustment device according to claim 2 is characterized in that: The end of the supporting block is flush with the outer surface of the middle shield when the supporting cylinder is not extended.

4. The shield attitude active adjustment device according to claim 2 is characterized in that: The outer surface of the supporting top block and the inner surface of the circular hole are matched with each other in clearance, a rectangular groove is opened on the middle shield or the M-beam, and a circular sealing ring is installed in the rectangular groove.

5. The shield attitude active adjustment device according to claim 2 is characterized in that: The periphery of the end surface of the supporting top block adopts an arc-shaped transition structure.

6. A shield machine attitude active adjustment method, characterized in that: Shield rear point posture control during shield deviation correction: When the shield machine corrects to the left, the posture of the rear point of the shield machine will deviate greatly to the right, and the supporting cylinder of the active adjustment device will be extended to the right, and the supporting block will be supported on the inner surface of the excavation; When the shield machine is corrected to the right, the posture of the rear point of the shield machine will deviate greatly to the left, and the supporting cylinder of the active adjustment device will be extended to the left, and the supporting block will be supported on the inner surface of the excavation; When the shield machine corrects downward, the rear point posture of the shield machine will deviate upward accordingly, and the supporting cylinder of the active adjustment device will be extended upward, and the supporting block will be supported on the inner surface of the excavation; When no correction is needed, retract the support block.

7. A shield machine posture active adjustment method, characterized in that: There are two situations in which the shield tail gap is not good. The first situation is that the shield corrects too quickly, resulting in a poor shield tail gap. The second situation is that the segment selection is unreasonable, resulting in a poor shield tail gap. In view of the situation that the shield deviation is corrected too quickly, resulting in a poor shield tail gap, the method of controlling the shield rear point posture during shield deviation correction is used to solve the problem of poor shield tail gap; that is, when the shield deviation is corrected to the left, the shield rear point posture will deviate greatly to the right, and the supporting top cylinder of the active adjustment device will be extended to the right, and the supporting top block will be supported on the inner surface of the excavation; when the shield deviation is corrected to the right, the shield rear point posture will deviate greatly to the left, and the supporting top cylinder of the active adjustment device will be extended to the left, and the supporting top block will be supported on the inner surface of the excavation; when the shield deviation is corrected downward, the shield rear point posture will deviate greatly upward, and the supporting top cylinder of the active adjustment device will be extended upward, and the supporting top block will be supported on the inner surface of the excavation; when no deviation correction is needed, the supporting top block will be retracted; In order to solve the problem of poor shield tail gap caused by unreasonable segment selection, the method of adjusting the shield rear point posture is adopted. The adjustment of the shield rear point posture must be based on the premise that the shield rear point posture does not exceed the limit; when the shield tail gap is too large on the left, right or upper side, the support cylinder of the active adjustment device needs to be extended to the right, left or downward, and the support block is supported on the inner surface of the excavation, and force is applied to move the shield rear point posture to the left, right or upward to ensure that the shield tail gap is within the normal range; wait until the segment selection is corrected, and then retract the support block.

8. A shield machine posture active adjustment method, characterized in that: Plastic mud is injected between the shield body and the inner surface of the excavation. The injection positions of the plastic mud are set at four points on the upper part of the rear end of the middle shield and two points on the lower part of the front end of the shield tail. Plastic mud is injected through six points.

9. A shield machine attitude active adjustment method according to claim 8, characterized in that: There are two situations for calculating the filling amount of plastic mud: one is the calculation method of the filling amount when the shield starts; the other is the calculation method of the filling amount when the shield is advancing normally.

10. A shield machine posture active adjustment method according to claim 9, characterized in that: Assume that the outer diameters of the front shield, middle shield and tail shield are D 前 , D 中 and D 尾 , the lengths are L 前 , L 中 and L 尾 , the shield excavation diameter is D, the shield excavation distance is L, and the filling factor is K; (1) Filling volume V1 at the start of shield tunneling: At the beginning, there is no plastic mud between the inner surface of the shield excavation and the shield body, and the volume of V1 needs to be filled to fill it fully, and a certain amount of loss is taken into account; (2) Filling volume V2 during normal shield tunneling: The amount of plastic mud filled during normal shield excavation is actually the gap between the inner surface of the excavation and the shield tail.

Images