A method for calculating over-excavation of shield machine

Abstract

The present invention belongs to the technical field of tunnel excavation, and discloses a method for calculating the over-excavation of a shield machine. The method simulates the dynamic process of the shield machine during the turning and advancing process by simulating three consecutive points in the process of the shield machine turning and advancing two rings. Based on the posture of the shield machine at three consecutive points, the cutting range of the shield machine cutter head can be obtained, and the radius R1 of the cutter head cutting range can be determined, and the sweeping range of the shield machine shell can be obtained, and the radius R2 of the sweeping range of the shield machine shell can be determined. The over-excavation RO = R1-R2. Compared with the prior art that only analyzes the static and single posture of the shield machine, the calculation result of the present invention is more accurate. In addition, the simulation of the dynamic process of the shield machine is implemented in the three-dimensional modeling software. For cases with different models and sizes of shield machines or different turning radii, only the relevant parameters need to be modified when calculating the over-excavation, which is convenient, fast and has high accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel excavation, and in particular to a method for calculating over-excavation of a shield machine. Background Art

[0002] The shield machine is an engineering machine used in urban tunnel construction. There are inevitably turning parts in the tunnel design route. Therefore, the shield machine is equipped with an articulated cylinder to enable it to carry out curved construction. When the shield machine is excavating along the curve, it is in a deviation correction state, and the imitation knife on the cutterhead is also in the open state. The actual excavation volume exceeds the theoretical excavation volume. Therefore, calculating the over-excavation volume of the shield machine during the curve turning process is extremely important for the excavation quality of the tunnel.

[0003] In the existing calculation method of over-excavation of shield machines, the dynamic process of the shield machine during advancement is usually not taken into account, and only the static and single posture of the shield machine is analyzed. It is roughly assumed that the center of the shield machine's advancement circular curve is on the center line of the shield machine's length direction. In fact, the circular curve is not like this. The over-excavation calculated by this method has a certain error. Summary of the invention

[0004] The purpose of the present invention is to provide a method for calculating the over-excavation of a shield machine, which can accurately calculate the over-excavation of the shield machine during a turning process and improve the excavation accuracy and quality of a tunnel.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A method for calculating over-excavation of a shield machine is provided, comprising the following steps:

[0007] Simulate three consecutive points in the process of the shield machine turning and advancing two rings to obtain the radius R1 of the cutting range of the shield machine cutter head and the radius R2 of the sweeping range of the shield machine shell;

[0008] Calculate the over-excavation: Over-excavation RO = R1-R2.

[0009] As a preferred solution of the shield machine overexcavation calculation method provided by the present invention, the following steps are also included:

[0010] Establish the posture model M of the shield machine when turning;

[0011] The three posture models M are used as three consecutive points in the process of the shield machine turning and advancing two rings;

[0012] Complete constraints are added between two adjacent points to simulate the process of the shield machine turning and advancing two rings.

[0013] As a preferred solution of the shield machine overexcavation calculation method provided by the present invention, the step of establishing the posture model M includes:

[0014] A front section model and a rear section model of the shield machine are established, and an inner articulated cylinder, an outer articulated cylinder and an articulated sealing structure are arranged between the front section model and the rear section model;

[0015] Add full constraints between the front and rear models to simulate the posture of the shield machine when turning.

[0016] As a preferred solution of the shield machine overexcavation calculation method provided by the present invention, the complete constraint conditions added between the front-end model and the back-end model include:

[0017] The contact conditions between the front section model and the rear section model are determined by the hinged sealing structure;

[0018] The stroke value of the inner articulated cylinder is S1;

[0019] The radius of the arc determined by three points on the center line of the front section model and the rear section model is the turning radius RT of the shield machine.

[0020] As a preferred solution of the shield machine overexcavation calculation method provided by the present invention, the three points on the center line are: two end points of the center line and the midpoint of the center line.

[0021] As a preferred solution of the shield machine overexcavation calculation method provided by the present invention, after the posture model M is established, the stroke S2 ​​of the outer articulated cylinder, the articulation angle of the posture model M and the articulation seal compression are measured.

[0022] As a preferred solution of the shield machine over-excavation calculation method provided by the present invention, the shield machine is excavated under the driving action of the propulsion cylinder, and the propulsion cylinder includes an inner propulsion cylinder and an outer propulsion cylinder;

[0023] The complete constraints added between two points include:

[0024] The axis of the thrust cylinder of the shield machine is parallel to the axis of the rear section model;

[0025] The stroke of the inner thrust cylinder is S3, where S3 is the ring width of the wedge-shaped segment;

[0026] The shield machine's posture deflection angle after advancing one ring is α, where α is the wedge angle of the wedge-shaped segment.

[0027] As a preferred solution of the shield machine overexcavation calculation method provided by the present invention, after adding a complete constraint condition between two points, the stroke S4 of the outer propulsion cylinder is measured.

[0028] As a preferred solution of the shield machine overexcavation calculation method provided by the present invention, after adding a complete constraint condition between two points, the following steps are also included:

[0029] Draw a circle A with the edge points of the cutter head at three points, and the radius of circle A is R1;

[0030] Draw a circle B concentric with circle A, and make circle B tangent to the edge of the front model at any point, and measure the radius RB of circle B;

[0031] Draw a circle C concentric with circle A, and make circle C tangent to the edge of the rear model at any point, and measure the radius RC of circle C;

[0032] The radius of the sweep range of the shield machine shell is R2=min(RB, RC).

[0033] As a preferred solution of the shield machine over-excavation calculation method provided by the present invention, the front section model, the rear section model and the posture model M are all block models established in the three-dimensional modeling software.

[0034] Beneficial effects of the present invention:

[0035] The present invention provides a method for calculating the over-excavation of a shield machine. The method simulates the dynamic process of the shield machine during the turning and advancing process by simulating three consecutive points in the process of the shield machine turning and advancing two rings. The cutting range of the shield machine cutter head can be obtained based on the posture of the shield machine at the three consecutive points, and the radius R1 of the cutter head cutting range can be determined. The sweep range of the shield machine shell can also be obtained, and the radius R2 of the shield machine shell sweep range can be determined. Then, the over-excavation RO=R1-R2 in the turning process of the shield machine can be calculated. Compared with the prior art that only analyzes the static and single posture of the shield machine, the present invention determines the sweep range of the cutter head and the shell by simulating the dynamic process of the shield machine during advancement, and the calculation result is more accurate. In addition, the simulation of the dynamic process of the shield machine in the present invention is realized in the three-dimensional modeling software, which is convenient to operate. For cases where the models and sizes of the shield machines are different or the turning radius is different, only the relevant parameters need to be modified when calculating the over-excavation, which is convenient and fast, and has a high accuracy rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the posture model M of the shield machine during the turning process in the present invention;

[0037] Figure 2 It is a schematic diagram of the shield machine turning and advancing two rings in the present invention;

[0038] Figure 3 is a schematic diagram of the process of determining the overbreak amount in the present invention;

[0039] Figure 4 yes Figure 3 A partial enlarged view of point F in the middle.

[0040] In the figure:

[0041] 1. Front section model; 2. Back section model; 3. First point; 4. Second point; 5. Third point. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0043] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0045] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0046] like Figures 1 to 4 As shown, this embodiment provides a method for calculating the over-excavation of a shield machine, which can accurately calculate the over-excavation of the shield machine during the turning process, thereby improving the excavation accuracy and quality of the tunnel. The method includes the following steps:

[0047] Simulate three consecutive points in the process of the shield machine turning and advancing two rings to obtain the radius R1 of the cutting range of the shield machine cutter head and the radius R2 of the sweeping range of the shield machine shell;

[0048] Calculate the over-excavation: Over-excavation RO = R1-R2.

[0049] By simulating three consecutive points in the process of the shield machine turning and advancing two rings, the dynamic process of the shield machine turning and advancing can be simulated. Based on the posture of the shield machine at three consecutive points, the cutting range of the shield machine cutter head can be obtained, and the radius R1 of the cutter head cutting range can be determined, and the sweep range of the shield machine shell can be obtained, and the radius R2 of the shield machine shell sweep range can be determined, and then the over-excavation RO=R1-R2 in the shield machine turning process can be calculated. Compared with the prior art that only analyzes the static and single posture of the shield machine, this embodiment determines the sweep range of the cutter head and the shell by simulating the dynamic process of the shield machine advancing, and the calculation result is more accurate.

[0050] Of course, in other embodiments, more points (more than three) may be selected during the dynamic process of the shield machine turning and advancing to determine the sweep range of the cutterhead and the shell, and then determine the over-excavation amount.

[0051] Before simulating the three consecutive points in the process of the shield machine turning and advancing two rings, it is necessary to establish the posture model M of the shield machine when turning.

[0052] The steps of establishing the posture model M include:

[0053] Step 1. See Figure 1 A front section model 1 and a rear section model 2 of the shield machine are established, and an inner articulated cylinder, an outer articulated cylinder and an articulated sealing structure are arranged between the front section model 1 and the rear section model 2.

[0054] Optionally, the front section model 1 and the rear section model 2 are block models established in a three-dimensional modeling software. Further, only the endpoints of the inner articulated cylinder and the outer articulated cylinder are established in the software, and the stroke changes of the two articulated cylinders can be known based on the distance changes between the endpoints at the two ends.

[0055] In this embodiment, the diameter of the shield machine is 10100 mm, the front section length L1 = 4504 mm, and the rear section length L2 = 4516 mm. According to these parameters, the front section model 1 and the rear section model 2 can be established.

[0056] The second step is to add complete constraints between the front model 1 and the rear model 2 to simulate the posture of the shield machine when turning.

[0057] Optionally, the above constraints are imposed by the constraint function of the sketch in the 3D modeling software. Specifically, the complete constraints added between the front-end model 1 and the back-end model 2 include:

[0058] 1. The contact conditions between the front section model 1 and the rear section model 2 are determined by the hinged sealing structure;

[0059] Specifically in this embodiment Figure 1 ,exist Figure 1 The contact condition of the front section model 1 and the rear section model 2 is added at D in the figure. The contact condition is determined by the actual hinged sealing structure between the front section and the rear section of the shield machine to simulate the actual connection between the front section and the rear section of the shield machine as realistically as possible.

[0060] 2. The stroke value S1 of the inner articulated cylinder;

[0061] When the shield machine is not turning, its inner articulated cylinder has a certain stroke value S1, which is a known value.

[0062] 3. The radius of the arc determined by the three points on the center line of the front model 1 and the rear model 2 is the turning radius RT of the shield machine.

[0063] Specifically, the three points on the center line are: the two end points of the center line and the midpoint of the center line. Figure 1 , select the front end of the front model 1 ( Figure 1 The midpoint of the left side of the center, the rear end of the rear model ( Figure 1 An arc (or circle) is made by using the midpoint of the middle point (on the right side of the center) and the midpoint of the middle position of the two models, and the radius of the arc is constrained to be the turning radius RT of the shield machine.

[0064] In this embodiment, the turning radius RT of the shield machine is 250 m, which is determined according to the design route of the tunnel.

[0065] After the constraint conditions between the front section model 1 and the rear section model 2 are added, the stroke of the outer articulated cylinder changes, and the stroke S2 ​​of the outer articulated cylinder is measured, which is greater than S1, the articulation angle of the posture model M, and the articulation seal compression. The stroke difference of the outer articulated cylinder is calculated as S2-S1. In this embodiment, the maximum articulation cylinder stroke difference is 155mm, so S2-S1 should not exceed 155mm. Similarly, the articulation angle and the articulation seal compression should not exceed the corresponding thresholds.

[0066] After determining the stroke of the outer articulated cylinder, the posture model M is made into a block model. The three block models are used as three consecutive points in the shield machine's turning process. Figure 2 , set the three points as the first point 3, the second point 4 and the third point 5 respectively.

[0067] The shield machine advances under the push of the thrust cylinder, which includes an inner thrust cylinder and an outer thrust cylinder. One end of the thrust cylinder is fixed to the shield machine, and the other end is abutted against the pipe segment. The top rod of the thrust cylinder is extended to push the shield machine forward. Every time the shield machine advances one ring (the ring width of the pipe segment), the pipe segment is attached to the inner wall of the tunnel formed behind it. In this embodiment, the shield machine reaches the second point 4 after advancing one ring at the first point 3, and reaches the third point 5 after advancing one ring at the second point 4.

[0068] Full constraints need to be added between two adjacent points to simulate the process of the shield machine turning and advancing two rings. That is, full constraints need to be added between the first point 3 and the second point 4, and between the second point 4 and the third point 5.

[0069] The complete constraints added between two points include:

[0070] 1. The axis of the thrust cylinder of the shield machine is parallel to the axis of the rear section model 2;

[0071] Specifically in this embodiment Figure 2 ,exist Figure 2 Add a parallel constraint at E in the figure to make it consistent with the situation of a real shield machine.

[0072] 2. The stroke of the inner thrust cylinder is S3, where S3 is the ring width of the wedge-shaped segment;

[0073] In the process of advancing from the first point 3 to the second point 4 and from the second point 4 to the third point 5, the stroke S3 of the inner advancing cylinder is the ring width W of the wedge-shaped segment. The wedge-shaped segment is produced according to the specific design requirements of the tunnel, and its ring width W is a known value.

[0074] 3. The attitude deflection angle α of the shield machine after advancing one ring, α is the wedge angle of the wedge segment.

[0075] Since the shield machine is advancing in a turning manner, a certain angle of posture deflection will occur after each advancement of a ring, and the posture deflection angle α is the wedge angle of the wedge-shaped segment.

[0076] In this embodiment, the ring width W is set to 1 m, then α=2arctan(W / 2 / RT), and RT=250 m is known above. Substituting the data into the calculation, α=0.23° is obtained.

[0077] Optionally, after adding a complete constraint condition between the two points, the stroke S4 of the outer propulsion cylinder is measured, S4>S3. The stroke difference of the outer propulsion cylinder is S4-S3, and this value should not exceed the set threshold.

[0078] See also Figure 3 and Figure 4After adding full constraints between the two points and measuring the stroke difference of the thrust cylinder, the following steps are also included:

[0079] Draw a circle A with the edge points of the cutter disc at three points to determine the cutting range of the cutter disc, and measure the radius of circle A, which is R1. Figure 4 As shown in;

[0080] Draw a circle B concentric with circle A, and make circle B tangent to the edge of the front section model 1 at any point to determine the sweep range of the front section of the shield machine, and measure the radius RB of circle B, such as Figure 4 As shown in;

[0081] Draw a circle C concentric with circle A, and make circle C tangent to the edge of the rear section model 2 at any point to determine the sweep range of the rear section of the shield machine, and measure the radius RC of circle C, as shown in Figure 4 as shown in .

[0082] The minimum value of RB and RC is taken as the radius of the sweep range of the shield machine shell, that is, the radius of the sweep range of the shield machine shell is R2 = min (RB, RC).

[0083] At this point, the over-excavation amount of the shield machine when turning is finally obtained as RO=R1-R2=R1-min(RB, RC).

[0084] In this embodiment, the front section model 1, the rear section model 2 and the posture model M are all block models established in the three-dimensional modeling software, which is convenient for operation. For cases with different models and sizes of shield machines or different turning radii, it is only necessary to modify the relevant parameters when calculating the over-excavation amount, which is convenient, fast and highly accurate.

[0085] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for calculating overexcavation of a shield machine, characterized in that: The following steps are involved: Simulate three consecutive points in the process of the shield machine turning and advancing two rings to obtain the radius R1 of the cutting range of the shield machine cutter head and the radius R2 of the sweeping range of the shield machine shell; Calculate the over-excavation: over-excavation RO = R1-R2; The following steps are involved: Establish the posture model M of the shield machine when turning; The three posture models M are used as three consecutive points in the process of the shield machine turning and advancing two rings; Add full constraints between two adjacent points to simulate the process of the shield machine turning and advancing two rings; The steps of establishing the posture model M include: A front section model (1) and a rear section model (2) of a shield machine are established, wherein an inner articulated oil cylinder, an outer articulated oil cylinder and an articulated sealing structure are arranged between the front section model (1) and the rear section model (2); Add full constraints between the front model (1) and the rear model (2) to simulate the posture of the shield machine when turning; The shield machine advances under the pushing action of the thrust cylinder, which includes an inner thrust cylinder and an outer thrust cylinder; The complete constraints added between two points include: The axis of the thrust cylinder of the shield machine is parallel to the axis of the rear section model (2); The stroke of the inner thrust cylinder is S3, where S3 is the ring width of the wedge-shaped segment; The attitude deflection angle α of the shield machine after advancing one ring, α is the wedge angle of the wedge segment; After adding full constraints between two points, the following steps are included: Draw a circle A with the edge points of the cutter head at three points, and the radius of circle A is R1; Construct a circle B concentric with circle A, and make circle B tangent to the edge of the front model (1) at any point, and measure the radius RB of circle B; Construct a circle C concentric with circle A, and make circle C tangent to the edge of the rear section model (2) at any point, and measure the radius RC of circle C; The radius of the sweep range of the shield machine shell is R2=min(RB, RC).

2. The shield machine overexcavation calculation method according to claim 1, characterized in that: The complete constraints added between the front-end model (1) and the back-end model (2) include: The contact conditions between the front section model (1) and the rear section model (2) are determined by the hinged seal structure; The stroke value of the inner articulated cylinder is S1; The radius of the arc determined by the three points on the center line of the front section model (1) and the rear section model (2) is the turning radius RT of the shield machine.

3. The shield machine overexcavation calculation method according to claim 2, characterized in that: The three points on the centerline are: the two endpoints of the centerline and the midpoint of the centerline.

4. The shield machine overexcavation calculation method according to claim 2, characterized in that: After the posture model M is established, the stroke S2 ​​of the outer articulated cylinder, the articulation angle of the posture model M, and the articulation seal compression are measured.

5. The shield machine overexcavation calculation method according to claim 1, characterized in that: After adding the full constraint condition between the two points, measure the stroke S4 of the outer thrust cylinder.

6. The shield machine overexcavation calculation method according to claim 1, characterized in that: The front section model (1), the back section model (2) and the posture model M are all block models established in the three-dimensional modeling software.

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