WO2022001621A1

WO2022001621A1 - Sealing method for shield tail sealing system for shield tunneling machine

Info

Publication number: WO2022001621A1
Application number: PCT/CN2021/099523
Authority: WO
Inventors: 陈健; 肖明清; 孙警; 李海振; 张静宇; 王承震; 历朋林; 白坤; 杜昌言; 孙文昊
Original assignee: 中铁十四局集团有限公司; 中铁第四勘察设计院集团有限公司
Priority date: 2020-07-02
Filing date: 2021-06-10
Publication date: 2022-01-06
Also published as: CN111764916A

Abstract

A sealing method for a shield tail (20) sealing system for a shield tunneling machine (50). The method comprises: step S30: applying grease to sealing brushes (10) of the shield tail (20) sealing system; step S40: making shield tail gaps (1) between the inner wall of the shield tail (20) and the outer walls of segments (30) be kept within a first preset range; and step S50, forming a sealing cavity (2) by each portion enclosed by each sealing brush (10), the inner wall of the shield tail (20) and the outer wall of each segment (30), and injecting the grease into each sealing cavity (2) to make the pressure in the sealing cavity (2) reach a preset sealing pressure value.

Description

The sealing method of the sealing system of the shield tail of the shield machine

This application claims the priority of the patent application submitted to the State Intellectual Property Office of China on July 2, 2020, the application number is 202010628958.0, and the invention title is "The sealing method of the sealing system of the shield tail of the shield machine".

technical field

The invention relates to the field of shield tail sealing, in particular to a sealing method for a shield tail sealing system of a shield machine.

Background technique

At present, the diameter of the tunnels excavated during the construction of domestic urban subways is generally 6m. The subway tunnels are buried shallowly, and the water pressure is generally lower than 3.5bar. However, for the large-diameter or super-large-diameter shield machine working under high water pressure, it is difficult to control the dynamic sealing of the shield tail during the propulsion process, which is likely to cause the breakdown of the shield tail and seriously affect the tunnel. construction.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a sealing method for the sealing system of the shield tail of the shield machine, so as to solve the problem of poor sealing performance of the shield tail of the shield machine in the prior art.

In order to achieve the above purpose, the present invention provides a sealing method for the sealing system of the shield tail of a shield machine, the sealing method includes: step S30: apply grease on the sealing brush of the sealing system of the shield tail; step S40: make the shield tail The shield tail gap between the inner wall of the shield tail and the outer wall of the segment is kept within the first preset range; step S50: the shield tail gap is surrounded by the sealing brush, the inner wall of the shield tail and the outer wall of the segment to form a sealed cavity, Grease is injected into the sealing chamber to make the pressure in the sealing chamber reach the preset sealing pressure value.

Further, step S40 includes: step S41 : adjusting the posture of the segment.

Further, a plurality of segments are arranged along the circumferential direction of the shield tail to form a segment ring, and the projection of the segment ring in the horizontal plane includes a long side and a short side extending along the axial direction of the segment ring and a connection between the long side and the segment ring. For the straight side and the oblique side between the short sides, the step of adjusting the posture of the segment includes fitting the straight side of the segment ring of the next circle with the hypotenuse of the segment ring of the previous circle.

Further, step S40 includes: step S42: adjusting the posture of the shield machine.

Further, there are multiple hydraulic rods of the hydraulic cylinder of the shield machine, and the plurality of hydraulic rods are in contact with the end face of the segment. length.

Further, after the shield machine completes the length of each segment and injects grease into the sealing cavity, the actual oil injection amount Q is compared with the theoretical oil injection amount Q _1. If the actual oil injection amount Q is not in the theoretical oil injection amount Q _{Within the range of 1} , check the oil injection pump.

Further, the sealing method further includes: step S50: controlling the grouting pressure in real time, so that the grouting pressure is within the second preset range, and if the grouting pressure is less than the minimum value of the second preset range, increase the grouting amount; If the grouting pressure is greater than or equal to the maximum value of the second preset range, the grouting is stopped.

Further, 0.75P ₁ ≤P ≤ 1.25P ₁ , where P is the grouting pressure, P ₁ is the water and soil pressure at the grouting site, and it is judged whether 1.25P ₁ is less than the grease injection pressure, if 1.25P _{1 is} less than or equal to the grease injection pressure, The second preset range is 0.75P ₁ to 1.25P ₁ , and if 1.25P _{1 is} greater than the grease injection pressure, the second preset range is 0.75P ₁ to the grease injection pressure.

Further, the sealing method further includes: step S60: manually injecting grease into the sealing cavity every predetermined time.

Further, the sealing method further includes: Step S70 : observe whether the segment is leaking water in real time, and if water leaks, inject grease into the sealing cavity corresponding to the leaking place.

Further, before step S30, the sealing method further includes: step S10: grinding the upper surface of the sealing brush and the lower surface of the shield tail in contact with the sealing brush.

Further, before step S30, the sealing method further includes: step S20: a plurality of spring steel plates behind the shield tail are sequentially crimped in a clockwise or counterclockwise direction of the shield tail to form a closed lap ring.

The application of the technical solution of the present invention ensures that the gap between the shield tail is uniform and can prevent that the gap between the shield tail and the segment is too small on one side and the gap on the other side is too large, which will lead to friction between the segment and the sealing brush. Excessive force will damage the sealing brush, thus affecting the sealing performance of the shield tail. If the gap is too large, the sealing chamber will not be tightly sealed, causing the pressure in the sealing chamber to be lower than the preset sealing pressure value, so that water, mud, mortar, etc. outside the shield machine will enter the shield tail (shield tail breakdown). The above method takes the shield tail gap between the shield tail and the segment and the pressure in the sealing cavity as the adjustment standard, which can effectively avoid the occurrence of the shield tail breakdown phenomenon, thereby improving the sealing performance of the shield tail.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

FIG. 1 shows a schematic diagram of the partial structure of the shield machine used in the sealing method of the sealing system of the shield tail of the shield machine according to the present invention;

Fig. 2 shows a partial enlarged view of the shield tail of the shield machine of Fig. 1;

FIG. 3 shows a schematic structural diagram of the segment ring when the shield machine of FIG. 1 adjusts the segment posture; and

FIG. 4 shows a schematic flowchart of the sealing method of the sealing system of the shield tail of the shield machine of FIG. 1 .

Wherein, the above-mentioned drawings include the following reference signs:

1. Shield tail gap; 2. Sealing cavity; 10. Sealing brush; 20. Shield tail; 30. Segment; 40. Segment ring; 41. Long side; 42. Short side; 43. Straight side; 44. Oblique side; 50, shield machine; 51, hydraulic cylinder; 52, hydraulic rod; 60, spring steel plate; 70, stop plate.

detailed description

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

As shown in FIG. 2 and FIG. 4 , the sealing method of the sealing system of the shield tail 20 of the shield machine 50 of the present embodiment includes: step S30: apply grease on the sealing brush of the sealing system of the shield tail; step S40: make the shield The shield tail gap between the inner wall of the tail and the outer wall of the segment is kept within the first preset range; step S50: the shield tail gap is surrounded by the sealing brush, the inner wall of the shield tail and the outer wall of the segment to form a sealed cavity , inject grease into the sealing cavity to make the pressure in the sealing cavity reach the preset sealing pressure value.

Applying the technical solution of this embodiment, ensuring the shield tail gap 1 is uniform can prevent the gap between the shield tail 20 and the segment 30 from being too small on one side and the gap on the other side being too large. The frictional force between the brushes 10 is too large and the sealing brush 10 is damaged, thereby affecting the sealing performance of the shield tail 20 . If the gap is too large, the sealing chamber 2 will not be tightly sealed, causing the pressure in the sealing chamber 2 to be lower than the preset sealing pressure value, so that the water, mud, mortar, etc. outside the shield machine 50 enter into the shield tail 20 (shield tail breakdown ). Therefore, the above method can ensure that the shield tail gap 1 between the shield tail 20 and the segment 30 is uniform, thereby improving the sealing performance of the shield tail 20 .

It should be noted that the grease can be applied manually or by machine. When applying grease, grease should be applied to the root of the sealing brush 10, between the wire bristles and between the wire bristles and the steel plate, and the entire sealing brush 10 should be covered with grease. Apply as much oil as possible to the roots. All parts of the sealing brush 10 can be lubricated with grease. If the sealing brush 10 is not pre-applied with grease, and the grease is directly injected into the sealing cavity 2, the sealing brush 10 will be partially not lubricated by grease. With the advancement of the shield machine 50, the sealing brush 10 The unlubricated positions will be severely worn, resulting in the seal chamber 2 not being tightly sealed and failing to reach the preset sealing pressure. When the sealing pressure is lower than the water pressure outside the shield machine 50, a breakdown phenomenon of the shield tail 20 will be caused.

It should also be noted that the first preset range is 30mm-50mm.

It should be further noted that the preset sealing pressure value is not a specific value, but refers to a pressure value range.

Since the shield tail gap 1 is formed by the inner wall of the shield tail 20 and the outer wall of the segment 30, the shield tail gap 1 is not uniform. On the one hand, it may be caused by the poor posture of the segment 30. caused by bad posture. Therefore, step S40 includes step S41 : adjusting the posture of the segment 30 . In the above structure, under the condition that the propulsion posture of the shield machine 50 is not deflected, the timely adjustment of the posture of the segment 30 can avoid excessive wear of the sealing brush 10 on the one hand, and on the other hand, can make the pressure in the sealing chamber 2 reach The sealing pressure value is preset, so as to ensure the sealing performance of the shield tail 20 .

Specifically, as shown in FIG. 3 , a plurality of segments 30 are arranged along the circumferential direction of the shield tail 20 to form a segment ring 40 , and the projection of the segment ring 40 in the horizontal plane includes a The long side 41 and the short side 42 and the straight side 43 and the oblique side 44 connected between the long side 41 and the short side 42, the steps of adjusting the posture of the segment 30 The beveled edges 44 of the segment ring 40 of the previous circle fit together. In the above structure, if the segment 30 is inclined to the left, the shield tail gap 1 at the left end decreases, and the shield tail gap 1 at the right end increases. At this time, when splicing the segment 30, it is necessary to make the straight side 43 of the segment ring 40 of the next circle fit with the oblique side 44 of the segment ring 40 of the previous circle, and make the long side 41 of the segment ring 40 fit. Both face to the left, and the short sides 42 face the right. After splicing several ring segments 30 in this way, the segments 30 will gradually incline to the right until the shield tail gap 1 satisfies the first preset range. Similarly, if the segment 30 is inclined to the right, the shield tail gap 1 at the right end is reduced, and the shield tail gap 1 at the left end is increased. The straight side 43 is in contact with the oblique side 44 of the segment ring 40 of the previous circle, and the long side 41 of the segment ring 40 is directed to the right, and the short side 42 of the segment ring 40 is directed to the left. After several ring segments 30 are spliced in this way, the segments 30 will gradually incline to the left until the shield tail gap 1 satisfies the first preset range. The above manner can improve the attitude adjustment efficiency of the segment 30 , thereby further ensuring the sealing performance of the shield tail 20 .

Of course, in addition to the above-mentioned way of adjusting the posture of the segment 30, when the segment 30 needs to be inclined to the left, it is only necessary to ensure that the straight side 43 of the segment ring 40 in the next circle and the oblique angle of the segment ring 40 in the previous circle are The sides 44 fit together, and most of the long sides 41 of the segment rings 40 can be at the right end. Correspondingly, when the segment 30 needs to be inclined to the right, it is only necessary to ensure that the straight edge 43 of the segment ring 40 of the latter circle is in contact with the oblique edge 44 of the segment ring 40 of the previous circle, and most of the segments The long side 41 of the sheet ring 40 may be at the left end.

In order to ensure that the shield tail gap 1 can meet the first preset range, step S40 further includes step S42 : adjusting the posture of the shield machine 50 . In the above structure, under the condition that the posture of the segment 30 is not deflected, timely adjustment of the advancing posture of the shield machine 50 can avoid excessive wear of the sealing brush 10 on the one hand, and ensure the pressure in the sealing cavity 2 on the other hand. The preset sealing pressure value is reached, thereby ensuring the sealing performance of the shield tail 20 .

Specifically, as shown in FIG. 1 , there are multiple hydraulic rods 52 of the hydraulic cylinder 51 of the shield machine 50 , and the plurality of hydraulic rods 52 are in contact with the end face of the segment 30 . The step of adjusting the posture of the shield machine 50 includes adding The length of the hydraulic rod 52 on the inclined side of the shield machine 50 . In the above structure, if the shield machine 50 is deflected to the left, the length of the left hydraulic rod 52 is increased during the advancement of the shield machine 50 . If the shield machine 50 is deflected to the right, the length of the right hydraulic rod 52 is increased during the advancement of the shield machine 50 . The above manner can improve the attitude adjustment efficiency of the shield machine 50 , thereby further ensuring the sealing performance of the shield tail 20 .

It should be noted that, after taking the measures to adjust the attitude of the segment 30 or the attitude adjustment of the shield machine 50, the shield gap is not necessarily effective as a ring, and the deviation may continue to increase, because the trend of offset still exists, The deviation has not yet reached the peak value, at this time, it is sufficient to ensure that the speed of deviation increase is reduced.

In this embodiment, after the shield machine 50 travels the length of one segment 30 forward and injects grease into the sealing cavity 2, the actual oil injection amount Q is compared with the theoretical oil injection amount Q ₁ , if the actual oil injection amount Q theoretical fill quantity Q is not within range of the injection pump ₁ is checked. In the above steps, the theoretical oil injection amount Q ₁ is calculated according to the outer diameter of the segment 30, the shield tail gap 1 and the length of the segment 30, so that the pressure in the sealing chamber 2 can reach the preset sealing pressure value. . The actual oil injection amount Q is the actual value of the oil injection amount that the shield machine 50 travels forward for the length of one segment 30 and injects into the sealing cavity 2 . The comparison of the actual oil injection amount Q and the theoretical oil injection amount Q ₁ can provide guidance for the investigation of the sealing performance. However, if the sealing performance of the system is good, the actual oil injection quantity Q due to the failure of the oil injection pump is not _{within the range of the theoretical oil injection quantity Q 1} , so that even after checking the sealing system, the actual oil injection quantity Q is still not in the theoretical range. the range of fuel injection Q ₁ ', thereby increasing the work of the staff. Therefore, when the actual oil injection amount Q is not _{within the range of the theoretical oil injection amount Q 1} , it is necessary to first check whether it is caused by the failure of the oil injection pump, so that the risk caused by the failure of the oil injection pump can be reduced to a lower level. After the failure of the oil injection pump is ruled out, the rest of the sealing system is checked, thereby reducing the workload of the staff.

In this embodiment, the sealing method further includes step S50: controlling the grouting pressure in real time, so that the grouting pressure is within the second preset range, and if the grouting pressure is less than the minimum value of the second preset range, increase the grouting amount ; If the grouting pressure is greater than or equal to the maximum value of the second preset range, stop grouting. In the above steps, the shield machine 50 may dig out the cavity in the soil layer in the process of advancing, which will cause the grouting pressure to be less than the minimum value of the second preset range. The cavity is filled to ensure that the grouting is full and dense, and the mortar flowing out of the grouting pipe will exert pressure on the spring steel plate to make it close to the outer wall of the segment 30 , thereby achieving a better sealing effect of the shield tail 20 . If the grouting pressure is greater than or equal to the maximum value of the second preset range, the grouting pressure may be too high, causing the mortar flow to break through the sealing cavity 2 and flow into the shield tail 20, or break through the stop plate 70 and flow into the shield machine. In the cutting surface of 50, the advancement of the shield machine 50 is affected.

Specifically, 0.75P ₁ ≤P ≤ 1.25P ₁ , where P is the grouting pressure, and P ₁ is the water and soil pressure at the grouting site. It is judged whether 1.25P ₁ is less than the grease injection pressure. If 1.25P _{1 is} less than or equal to the grease injection pressure, The second preset range is 0.75P ₁ to 1.25P ₁ , and if 1.25P _{1 is} greater than the grease injection pressure, the second preset range is 0.75P ₁ to the grease injection pressure. The above method can ensure that the grouting pressure is always less than or equal to the grease injection pressure, and prevent the mortar flow from breaking through the sealing cavity 2 and flowing into the inside of the shield tail 20 due to the high grouting pressure.

It should be noted that the grouting pipes are arranged inside the shell of the shield tail 20, and the grouting pipes include used pipes and spare pipes, and the used pipes and spare pipes are arranged in pairs, including 8 pairs of 16 pipes. The grouting pipeline is communicated with the mortar machine in the shield, and the mortar is automatically and continuously injected into the cavity between the outer contour of the excavated soil behind the shield tail 20 and the segment 30 through the grouting pump.

The sealing method further includes step S60: manually injecting grease into the sealing cavity 2 every predetermined time. The above method can reduce the risk of the shield tail 20 being broken down. Specifically, the method of manually replenishing grease every 8 hours is adopted. The replenishment should be carried out in the shutdown state. All grease pipes are opened, and refilling is performed for 5-10 minutes, or refilling into the sealing cavity 2 corresponding to the last sealing brush 10. The pressure value reaches 1-2bar higher than the water pressure.

The sealing method further includes: Step S70 : observe whether the segment 30 leaks water in real time, and if water leaks, inject grease into the sealing cavity 2 corresponding to the leaking place. In the above steps, the real-time observation can be performed manually to observe whether there is water leakage during the advancement of each ring segment 30 . Generally speaking, the leakage of a little clear water is a normal phenomenon, but once this happens, the grease at the leaking place needs to be injected more immediately, and as the distance increases, the actual oil injection quantity Q of each ring of grease can be appropriately increased , to reduce leakage.

In this embodiment, four sealing brushes 10 are provided, wherein the sealing brush 10 on the side close to the middle of the shield is the first sealing brush. The first three sealing brushes 10 are connected to the inner wall of the shield tail 20 by bolts, and the last sealing brush 10 is connected to the inner wall of the shield tail 20 by welding. Therefore, in order to ensure the tightness of the sealing cavity 2 , before step S30 , the sealing method further includes: step S10 : grinding the upper surface of the sealing brush 10 and the lower surface of the shield tail 20 in contact with the sealing brush 10 . The above method can remove burrs, make the connection between the sealing brush 10 and the shield tail 20 more tightly, and prevent the grease in the sealing cavity 2 from flowing out from the connection between the sealing brush 10 and the shield tail 20, so as to ensure the tightness of the sealing cavity 2.

It should also be noted that, before step S30, the sealing method further includes: step S20: the plurality of spring steel plates 60 behind the shield tail 20 are sequentially crimped in the clockwise or counterclockwise direction of the shield tail 20 to form a closed overlap. Adaptor. In the above structure, the spring steel plate 60 is arranged behind the fourth sealing brush, one end of the spring steel plate 60 is welded to the inner wall of the shield tail 20 , and the other end is inclined outward toward the segment 30 and abuts the outer wall of the segment 30 . When connecting, the spring steel plates 60 are welded sequentially in a clockwise or counterclockwise direction, so that a part of the latter spring steel plate 60 is crimped to the former spring steel plate 60, and after splicing in sequence, a lap ring closed in the circumferential direction is formed. In this way, the spring steel plates 60 are protected from each other and have the overall pressure resistance elasticity. The mortar flowing out of the grouting pipe will exert pressure on the spring steel plate 60 to make it close to the outer wall of the duct piece 30 , thereby achieving a better sealing effect of the shield tail 20 . It should be noted that the spring steel plates 60 are strictly forbidden to be out of order or partially staggered during splicing, otherwise the overall pressure resistance capability of the spring steel plates 60 will be greatly reduced.

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

Claims

A sealing method for a sealing system of a shield tail of a shield machine, characterized in that the sealing method comprises:

Step S30: apply grease on the sealing brush (10) of the sealing system of the shield tail;

Step S40: keeping the shield tail gap (1) between the inner wall of the shield tail (20) and the outer wall of the segment (30) within a first preset range;

Step S50: the shield tail gap (1) is formed by the sealing brush (10), the part enclosed by the inner wall of the shield tail (20) and the outer wall of the segment (30) to form a sealed cavity (2) , inject grease into the sealing cavity (2) to make the pressure in the sealing cavity (2) reach a preset sealing pressure value.
The sealing method according to claim 1, wherein the step S40 comprises:

Step S41: Adjust the posture of the segment (30).
The sealing method according to claim 2, characterized in that a plurality of the segments (30) are arranged along the circumferential direction of the shield tail (20) to form a segment ring (40), the segment ring (40) The projection on the horizontal plane includes a long side (41) and a short side (42) extending along the axial direction of the segment ring (40), and the long side (41) and the short side (42) connected to the long side (41) and the short side ( 42) between the straight edge (43) and the oblique edge (44), the step of adjusting the posture of the segment (30) includes connecting the straight edge (43) of the segment ring (40) of the following circle with the straight edge (43) of the segment ring (40) of the previous circle The beveled edge (44) of the segment ring (40) fits together.
The sealing method according to claim 1, wherein the step S40 comprises:

Step S42: Adjust the posture of the shield machine (50).
The sealing method according to claim 4, characterized in that there are multiple hydraulic rods (52) of the hydraulic cylinder (51) of the shield machine (50), and the multiple hydraulic rods (52) are connected to the The end faces of the segments (30) are in contact, and the step of adjusting the posture of the shield machine (50) includes increasing the length of the hydraulic rod (52) on the inclined side of the shield machine (50).
The sealing method according to claim 1, characterized in that, after the shield machine (50) travels forward the length of one segment (30) and injects grease into the sealing cavity (2), The actual oil injection amount Q is compared with the theoretical oil injection amount Q 1 , and if the actual oil injection amount Q is not within the range of the theoretical oil injection amount Q 1 , the oil injection pump is checked.
The sealing method according to claim 1, wherein the sealing method further comprises:

Step S50: Control the grouting pressure in real time, so that the grouting pressure is within the second preset range, and if the grouting pressure is less than the minimum value of the second preset range, increase the grouting amount; When the grouting pressure is greater than or equal to the maximum value of the second preset range, the grouting is stopped.
The sealing method according to claim 7, wherein 0.75P 1 ≤P ≤ 1.25P 1 , wherein P is the grouting pressure, P 1 is the water and soil pressure at the grouting place, and it is judged whether the 1.25P 1 is smaller than the grease Injection pressure, if 1.25P 1 is less than or equal to the grease injection pressure, the second preset range is 0.75P 1 to 1.25P 1 , if 1.25P 1 is greater than the grease injection pressure, the second preset range is 0.75P 1 to grease injection pressure.
The sealing method according to claim 1, wherein the sealing method further comprises:

Step S60: Manually inject grease into the sealing cavity (2) every predetermined time.
The sealing method according to claim 1, wherein the sealing method further comprises:

Step S70: Observing in real time whether the segment (30) leaks water, and if water leaks, injecting grease into the sealing cavity (2) corresponding to the leaking place.
The sealing method according to claim 1, wherein, before the step S30, the sealing method further comprises:

Step S10: Grinding the upper surface of the sealing brush (10) and the lower surface of the shield tail (20) in contact with the sealing brush (10).
The sealing method according to claim 1, wherein, before the step S30, the sealing method further comprises:

Step S20: The plurality of spring steel plates (60) behind the shield tail (20) are sequentially crimped in the clockwise or counterclockwise direction of the shield tail (20) to form a closed lap ring.