Method for installing internal cushion block and arc-shaped part of large-section shield tunnel

Abstract

The application discloses a method for installing internal cushion blocks and arc-shaped parts of a large-section shield tunnel and belongs to the technical field of large-section shield tunnel construction methods, wherein S1. The center distance of two adjacent cushion blocks is determined according to the distance between two load-bearing columns in the arc-shaped part and the width of the columns; S2. The cushion blocks are fixed at the joints of two adjacent segments; S21. The midpoint of the center line of the current segment and the next segment is taken as the center for fitting a circle with two adjacent cushion blocks; S22. The position of one of the cushion blocks is fixed, the actual installation position of the other cushion block is determined according to the center distance of the two adjacent cushion blocks and the center for fitting a circle with the two adjacent cushion blocks, and the thickness difference between the left and right cushion blocks is determined; S23. The thickness difference between the front and rear cushion blocks is determined according to the difference between the design elevation and the actual elevation of the joints of the front and rear segments; and S24. The thickness of the cushion blocks is selected according to the thickness difference between the left and right cushion blocks and the thickness difference between the front and rear cushion blocks. The thickness of the cushion blocks determined in this way can make the arc-shaped part closer to the design in the elevation and the slope and more smooth.

Description

Technical Field

[0001] This invention relates to the technical field of construction methods for large-section shield tunnels, and in particular to a method for installing internal pads and arc-shaped components in large-section shield tunnels. Background Technology

[0002] Currently, compared to the drawbacks of traditional cut-and-cover tunnels, such as poor working environment, low efficiency, and high construction risks, shield tunnels have become the preferred method for construction in densely populated urban areas. With the continuous development and progress of transportation infrastructure, the prefabrication, assembly, design, production, and construction technologies for shield tunnel segment structures have become quite mature. In recent years, with the development of prefabrication and assembly technology for underground engineering, the prefabrication of the internal structure of large-diameter shield tunnels has received increasing attention.

[0003] Based on the development history of prefabricated assembly of tunnel internal structures, the trend towards fully prefabricated internal structures is unstoppable. However, there are certain technical and construction challenges in the prefabrication of internal structures that urgently need to be addressed during application. Prefabricated tunnel structures include annular segments, arc-shaped components installed inside the segments, and central diaphragms. The installation quality of the arc-shaped components is crucial to the overall installation accuracy of the internal structure. Current technologies generally use arc-shaped component installation machines to control their installation positions. Since the actual installation position of the segments may deviate from the design, using the same size spacers at different locations will increase the installation deviation of the arc-shaped components. Therefore, the thickness of the spacers also affects the installation of the arc-shaped components, but current technologies lack research on how to set a more reasonable spacer thickness.

[0004] Therefore, how to provide an installation method for internal pads and arc-shaped components in large-section shield tunnels, so as to set a more reasonable pad thickness and thus compensate for the impact of segment installation deviation on the installation accuracy of arc-shaped components, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to address the defects and deficiencies in the prior art by providing a method for installing pads and arc-shaped components inside large-section shield tunnels. By adjusting the thickness of the pads according to the actual installation deviation of the tunnel segments, the method compensates for the impact of the tunnel segment installation deviation on the installation accuracy of the arc-shaped components, thereby improving the installation accuracy of the arc-shaped components.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for installing internal pad blocks in large-section shield tunnels, comprising the following: S1. Determine the center-to-center distance between two adjacent pads, where the center-to-center distance between two adjacent pads = the distance between the two load-bearing columns in the arc-shaped component + the width of the column; S2. Select appropriate shim size and fix the selected shims at the joint of adjacent pipe segments according to the center-to-center distance between adjacent shims determined in S1; wherein: S21. Determine the center of the circle formed by fitting two adjacent pad blocks, wherein the midpoint of the line connecting the center of this ring segment and the center of the next ring segment is the center of the circle formed by fitting two adjacent pad blocks. S22. Determine the thickness difference between the left and right pads, fix the position of one of the pads, and determine the actual installation position of the other pad based on the center distance between the two adjacent pads and the center of the circle formed by the fitting of the two adjacent pads. The thickness difference between the left and right pads = the distance between the actual installation position of the other pad and the inner surface of the segment. S23. Determine the thickness difference of the pad in the front and rear directions. The thickness difference of the front and rear pads = the difference in elevation between the designed axis and the actual axis at the two joints of a certain ring segment. S24. Select a suitable pad based on the thickness difference between the left and right pads and the thickness difference between the front and back of the pad.

[0007] Preferably, in S23, the deviation value between the axes at the bottom of the two joints in a certain ring segment is used to calculate the thickness difference of the pad in the front and rear directions.

[0008] Preferably, the thickness of the pad selected in S24 is controlled between 0.5 and 5 cm.

[0009] Preferably, the pad is fixed to the joint of adjacent segments by adhesive bonding.

[0010] This invention also provides a method for installing arc-shaped components inside a large-section shield tunnel, comprising the following: a. Measure the three-dimensional coordinates of the actual center of the tunnel segment, and calculate the optimal plane elevation position of the arc-shaped component based on the measurement results; b. Install the pads according to the installation method for the pads inside the large-section shield tunnel described above; c. Calculate the layout scheme of the arc-shaped components based on the actual planar wedge shape of the tunnel segment; d. Lay out the calculation results onto the actual tunnel segments, and the construction personnel will install the bottom arc-shaped components according to the layout results.

[0011] Preferably, the layout benchmark includes a plane layout axis and an elevation layout axis, wherein the straight segments on the plane are spaced at 5 rings and the curved segments are spaced at 2 rings, and the plane layout axis is fitted by the actual center position of the tunnel segment.

[0012] Preferably, the elevation layout axis is fitted by using two rings as intervals on the elevation, and the measured center elevation of each ring is used to fit the elevation layout axis.

[0013] Preferably, the ellipticity value of the segment used to support the arc-shaped component is controlled between 2‰ and 4‰.

[0014] Preferably, the rotation angle of the tunnel boring machine is controlled within ±1° when installing the tunnel segments.

[0015] Preferably, the deviation of the shield in plane and elevation during the installation of segments is controlled within ±50mm.

[0016] The present invention achieves the following technical effects compared to the prior art: 1. This invention determines the thickness difference between the two spacers arranged on the left and right sides and the thickness difference between the front and rear spacers based on the actual installation deviation of the tunnel segments. This is to compensate for the impact of the installation deviation of the tunnel segments on the installation accuracy of the arc-shaped components, thereby improving the installation accuracy of the arc-shaped components. Since the core of the overall installation accuracy control of the internal structure is the installation quality of the arc-shaped components, improving the installation accuracy of the arc-shaped components can further improve the overall installation accuracy of the tunnel internal structure and improve the construction quality of the tunnel. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the installation structure of the pads and curved components inside the tube segment.

[0019] Among them, 1. pad block; 2. pipe segment; 3. arc-shaped component. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, the present invention provides a method for installing internal pad blocks in a large-section shield tunnel, comprising the following: S1. Determine the center-to-center distance L between two adjacent pad blocks 1. Wherein, the center-to-center distance L between two adjacent pad blocks 1 = the distance L1 between the two load-bearing columns in the arc-shaped component 3 + the width H of the column; S2. Select a suitable size for the spacer 1, and fix the selected spacer 1 at the joint of the two adjacent pipe segments 2 according to the center-to-center distance between two adjacent spacers 1 as determined in S1; wherein: S21. Determine the center of the circle formed by fitting two adjacent pad blocks 1. The center position of the circle formed by fitting two adjacent pad blocks 1 should be determined based on the positional relationship between two consecutive pipe segments 2, and not based on the deviation of the pipe segment 2 from the actual axis. The present invention adopts a method of classifying and processing by analyzing the positional relationship between two consecutive ring pipe segments 2, that is, the positional relationship at the joint: in an ideal state, the two pipe segments 2 at the joint can be regarded as two circles, which can be regarded as the horizontal and vertical deviations X and Y of the current ring pipe segment 2 and the next ring pipe segment 2 in the cross-section. Therefore, the present invention uses the midpoint of the line connecting the centers of the current ring pipe segment 2 and the next ring pipe segment 2 as the center of the circle formed by fitting two adjacent pad blocks 1 to reduce the error; S22. Determine the thickness difference between the left and right pad blocks 1. Since the pad blocks 1 are laid with the relatively high pipe segment 2 as a reference, and the center position of pad block 1 is different from the center position of pipe segment 2, there must be a thickness difference between the left and right pad blocks 1. The method for determining the thickness difference between the left and right pad blocks 1 is as follows: First, fix the position of one pad block 1, and then determine the actual installation position of the other pad block 1 based on the center distance between the two adjacent pad blocks 1 and the center of the circle formed by fitting the two adjacent pad blocks 1. The thickness difference between the left and right pad blocks 1 = the distance between the actual installation position of the other pad block 1 and the inner surface of pipe segment 2. The actual installation position of the other pad block 1 refers to the position of the bottom surface of pad block 1 when it is installed at this location. The inner surface of pipe segment 2 referred to here is the inner surface of pipe segment 2 at the point corresponding to the line connecting the center of the circle formed by fitting the two adjacent pad blocks 1 and the actual installation position of the other pad block 1.

[0023] S23. Determine the thickness difference of pad 1 in the front and rear directions. The thickness difference of pad 1 in the front and rear directions = the difference in elevation between the designed axis and the actual axis at the two joints of a certain ring segment; S24. Select a suitable pad 1 based on the difference in thickness between the left and right sides of two adjacent pads 1 and the difference in thickness between the front and back of the pad 1.

[0024] In order to make the curved component 3 closer to the design in terms of elevation / slope and smoother, in S23, the elevation deviation between the design axis and the actual axis at the bottom of the two joints of the same ring segment 2 is compared to calculate the thickness difference of the pad block 1 in the front and rear directions. In S24, the thickness of the pad block 1 is controlled between 0.5 and 5 cm.

[0025] In S2, the fixing method between the pad 1 and the pipe segment 2 can be adhesive bonding, threaded connection, etc. As a preferred embodiment of the present invention, the pad 1 is fixed to the joint of the adjacent pipe segments 2 by adhesive bonding. Specifically, the pad 1 and the pipe segment 2 are fixed by adhesive bonding.

[0026] The present invention also provides a method for installing the arc-shaped component 3 inside a large-section shield tunnel, including the following: a. Measure the three-dimensional coordinates of the actual center of segment 2, and calculate the optimal plane elevation position of arc-shaped component 3 based on the measurement results; based on the optimal plane elevation position of arc-shaped component 3, the thickness h1 of the pad 1 that fixes its position in S22 can be calculated, and the thickness h2 of the other pad 1 is h1 + the thickness difference between the left and right pads 1.

[0027] b. According to the above-described installation method for the internal pad 1 of the large-section shield tunnel, the pad 1 is installed on the inner surface of the bottom of the segment 2. The pad 1 is made of steel and is arranged between the rings of the segment 2 in a uniform and symmetrical manner. The steel pad 1 serves to support the arc-shaped component 3 and level it. The steel pad 1 has a size of 100mm × 400mm. The required thickness of the pad 1 for each ring of arc-shaped component 3 is determined on-site by measuring the first 10 rings and the last 10 rings of the formed tunnel segment 2 during the early stages of installation and calculating the installation deviation value of the arc-shaped component 3 at the first 10 rings of segment 2. The thicknesses are 0.5cm, 2cm, 3cm, and 5cm.

[0028] c. Calculate the layout scheme of the arc-shaped component 3 based on the actual planar wedge amount of segment 2; since the component is a general type, the left and right wedge amounts are 5cm. Divide the arc-shaped component 3 layout into two types: straight segments and curved segments. In the straight segments, only staggered arrangement is required, while the curved segments can be determined according to the actual layout of segment 2: the wedge amount of segment 2 is either 68mm or 98mm. It is necessary to calculate the actual wedge amount of the arc-shaped component 3 at the corresponding height by statistically analyzing the actual layout of segment 2 and using the distribution relationship between the position of the capping block and the wedge amount of segment 2. Furthermore, the actual mileage of the arc-shaped component 3 should be checked every 100 rings to determine the placement position of special models of arc-shaped components 3, such as the arc-shaped component 3 at the distribution box, the arc-shaped component 3 at the underground transformer, etc., so as to arrange the arc-shaped component 3 in advance. Because the wedge shape of segment 2 is different from that of arc-shaped component 3, the wedge shape of segment 2 is 42mm when the turning radius is 500m. In order to ensure that the installation center of arc-shaped component 3 is consistent with the actual axis of the tunnel, the gap between adjacent arc-shaped components 3 in some areas will be greater than 10mm.

[0029] d. The calculation results are laid out onto the actual tunnel segment 2, and the construction personnel install the bottom arc-shaped component 3 according to the layout results. The layout reference includes the planar layout axis and the elevation layout axis. First, the three-dimensional coordinates of the actual center of each ring of the formed tunnel segment 2 are measured, and the installation axis is formed based on the measurement results. On the plane, straight segments are spaced at 5-ring intervals, and curved segments at 2-ring intervals. The planar layout axis is fitted using the center position of the actual tunnel segment 2. On the elevation, the elevation layout axis is fitted using the measured center elevation of each ring at 2-ring intervals. These layout axes are the layout references. The installation process of the arc-shaped component 3 is as follows: 1) The arc-shaped component 3 is transported to the working area below the shield machine's #4 frame using a double-headed flatbed truck. The overhead crane on the #4 frame slowly descends, slowly lifting the arc-shaped component 3. 2) The shield machine's #4 frame rotates the arc-shaped component 3 to the installation angle. 3) The No. 4 frame of the tunnel boring machine slowly lowers the arc-shaped component 3 to a distance of 220~30cm from the bottom surface of the segment. 4) Based on the measurement results, place steel pads of appropriate thickness 1 and fine-tune the posture of the arc-shaped component 3, and slowly lower the arc-shaped component 3 to the installation position.

[0030] Improving the installation accuracy of segment 2 is beneficial to the installation of its internal structure. Therefore, this invention controls the ellipticity of segment 2, which supports the arc-shaped component 3, to within 2‰ to 4‰, and the plane and elevation deviations of the tunnel boring machine (TBM) to within ±50mm. Considering that the rotation of the TBM will affect the positioning of the first segment 2, the relative rotation dimension between segment 2 and the shield shell should be checked before assembling each ring of segment 2. The positioning of each ring of segment 2 should be reasonably corrected to ensure the quality of tunnel construction. The rotation angle of the TBM should be controlled within ±1°, which can be adjusted in time during excavation by rotating the cutterhead forward and backward. In special cases, the rotation angle of the TBM can be adjusted by adjusting the angle of the excavation jacks. Furthermore, the perpendicularity of the annular surface of segment 2 to the tunnel design axis should be frequently measured during construction. When the advance of segment 2 exceeds the control amount, the rotation angle of segment 2 should be adjusted in time to ensure the perpendicularity of the annular surface of segment 2 to the tunnel design axis, thereby improving the installation accuracy of segment 2.

[0031] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for installing internal pad blocks in a large-section shield tunnel, characterized in that: Includes the following: S1. Determine the center-to-center distance between two adjacent pads, where the center-to-center distance between two adjacent pads = the distance between the two load-bearing columns in the arc-shaped component + the width of the column; S2. Select the size of the shim block, and fix the selected shim block at the joint of the two adjacent pipe segments according to the center-to-center distance between the two adjacent shim blocks determined in S1; wherein: S21. Determine the center of the circle formed by fitting two adjacent pad blocks, wherein the midpoint of the line connecting the center of this ring segment and the center of the next ring segment is taken as the center of the circle formed by fitting two adjacent pad blocks, so as to reduce the deviation in the horizontal and vertical directions. S22. Determine the thickness difference between the left and right pads, fix the position of one of the pads, and determine the actual installation position of the other pad based on the center distance between the two adjacent pads and the center of the circle formed by the fitting of the two adjacent pads. The thickness difference between the left and right pads = the distance between the actual installation position of the other pad and the inner surface of the segment. S23. Determine the thickness difference of the pad in the front and rear directions. The thickness difference of the front and rear pads = the difference in elevation between the designed axis and the actual axis at the two joints of a certain ring segment. S24. Select the pads based on the thickness difference between the left and right pads and the thickness difference between the front and back of the pads.

2. The method for installing internal pads in a large-section shield tunnel according to claim 1, characterized in that: S23 uses the deviation between the axes at the bottom of the two joints of a certain ring segment to calculate the thickness difference of the pad in the front and rear directions.

3. The method for installing internal pads in a large-section shield tunnel according to claim 2, characterized in that: The thickness of the pad selected in S24 is controlled between 0.5 and 5 cm.

4. The method for installing internal pads in a large-section shield tunnel according to claim 3, characterized in that: The pads are fixed to the joints of adjacent pipe segments by adhesive bonding.

5. A method for installing an arc-shaped component inside a large-section shield tunnel, characterized in that: Includes the following: a. Measure the three-dimensional coordinates of the actual center of the tunnel segment, and calculate the optimal plane elevation position of the arc-shaped component based on the measurement results; b. The method for installing the pads inside a large-section shield tunnel according to any one of claims 1 to 4; c. Calculate the layout scheme of the arc-shaped components based on the actual planar wedge shape of the tunnel segment; d. Lay out the calculation results onto the actual tunnel segments, and the construction personnel will install the bottom arc-shaped components according to the layout results.

6. The method for installing the arc-shaped component inside a large-section shield tunnel according to claim 5, characterized in that: The layout datum includes the plane layout axis and the elevation layout axis. The straight segments on the plane are spaced at 5 rings, and the curved segments are spaced at 2 rings. The plane layout axis is fitted by the actual center position of the tunnel segment.

7. The method for installing the arc-shaped component inside a large-section shield tunnel according to claim 6, characterized in that: The elevation layout axis is fitted by using two rings as intervals and the measured center elevation of each ring.

8. The method for installing the arc-shaped component inside a large-section shield tunnel according to claim 7, characterized in that: The ellipticity of the segments used to support the curved components is controlled between 2‰ and 4‰.

9. The method for installing the internal arc-shaped component of a large-section shield tunnel according to claim 8, characterized in that: When installing tunnel segments, the rotation angle of the tunnel boring machine should be controlled within ±1°.

10. The method for installing the arc-shaped component inside a large-section shield tunnel according to claim 9, characterized in that: When installing tunnel segments, the deviation of the shield's plane and elevation should be controlled within ±50mm.

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