一种基于掘进机贯入指数和贯通指数的隧道围岩稳定性判识方法

Abstract

本发明提供一种基于掘进机贯入指数和贯通指数的隧道围岩稳定性判识方法，涉及隧道掘进技术领域。本发明包括以下步骤：S1、已建隧道工程掘进机掘进参数与围岩总评分参数采集；S2、计算掘进机贯入指数，统计不同隧道工程掘进机贯入指数与隧道围岩总评分的回归关系；S3、计算掘进机贯通指数，统计不同隧道工程掘进机贯通指数与隧道围岩总评分的回归关系；S4利用贯入指数和贯通指数与隧道围岩总评分的统计关系，实时判识隧道掌子面围岩的稳定性。预先判识隧道围岩稳定性、提前采取措施处置对于提升隧道施工进度、确保隧道施工安全至关重要。

Description

Technical Field

[0001] This invention relates to the field of tunnel boring technology, and in particular to a method for determining the stability of surrounding rock in tunnels based on the penetration index and the breakthrough index of the tunnel boring machine. Background Technology

[0002] The stability of the surrounding rock in a tunnel is a key factor affecting the working condition of a tunnel boring machine (TBM). Instability in the surrounding rock often leads to the TBM getting stuck or trapped, but the stability of the surrounding rock is often difficult to predict accurately in advance. Currently, methods using geophysical exploration to predict the stability of the surrounding rock in front of the TBM are not very accurate, and methods using drilling are difficult to implement. There is a potential mapping relationship between the TBM's tunneling parameters and the stability of the surrounding rock. Therefore, predicting the stability of the surrounding rock in advance based on the TBM's tunneling parameters and taking preventative measures is crucial for improving tunnel construction progress and ensuring tunnel construction safety. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for identifying the stability of surrounding rock in tunnels based on the tunnel boring machine (TBM) penetration index and breakthrough index, thereby reducing the risk of TBM getting stuck and improving the TBM construction progress.

[0004] A method for determining the stability of surrounding rock in tunnels based on the tunnel boring machine penetration index and the breakthrough index, specifically including the following steps:

[0005] S1. Collect parameters of the tunnel boring machine and the total score of the surrounding rock for the existing tunnel projects:

[0006] The tunneling data of the tunneling machine includes thrust, torque, propulsion speed, cutterhead speed, and penetration depth;

[0007] S2. Calculate the tunnel boring machine penetration index and statistically analyze the regression relationship between the tunnel boring machine penetration index and the total score of the surrounding rock for different tunnel projects:

[0008] The penetration index FPI is used to evaluate the difficulty of tunnel surrounding rock being penetrated by the cutter blade. The physical meaning of FPI is the load of a single cutter per unit penetration. The expression of the penetration index FPI is shown in Equation (1), and the unit is (kN / cutter) / (mm / r).

[0009]

[0010] In the formula, N is the number of cutters, which is determined during the design of the cutterhead; F is the thrust of the tunneling machine, in kN; and h is the penetration depth, which is the depth to which the cutters penetrate the rock per revolution of the cutterhead, in mm / r.

[0011] The regression relationship between the penetration index of tunnel boring machines and the total score of the surrounding rock of tunnels for different tunnel projects is shown in Equation (2).

[0012] FPI = 6.256e 0.025T (2)

[0013] In the formula, T represents the total score of the tunnel surrounding rock;

[0014] S3. Calculate the tunnel boring machine (TBM) breakthrough index and statistically analyze the regression relationship between the TBM breakthrough index and the total score of the surrounding rock in different tunnel projects:

[0015] The energy consumption of a TBM cutter per unit volume of rock excavation is defined as the penetration index SEI, and the expression for the penetration index SEI is shown in equation (3), with units of MJ / m. 3 .

[0016]

[0017] In the formula, F n F represents the vertical force applied to a single hob, measured in kN. r T1 is the rolling force of a single cutter head, in kN; T2 is the cutterhead torque, in kNm; R is the tunnel excavation diameter, in meters; R i Let be the installation radius of the i-th hob, in meters.

[0018] The regression relationship between the tunnel boring machine breakthrough index and the total score of the surrounding rock of different tunnel projects is shown in Equation (4).

[0019] SEI = 26.786ln(T) - 63 (4)

[0020] S4. Utilize the statistical relationship between the penetration index and the breakthrough index and the total score of the tunnel surrounding rock to determine the stability of the surrounding rock at the tunnel face in real time:

[0021] The stability of the surrounding rock at the tunnel face can be determined in real time based on the penetration index and the breakthrough index. The judgment criteria are shown in Table 1.

[0022] Table 1 Criteria for Judging the Stability of Surrounding Rock in Tunnels

[0023]

[0024] The beneficial effects of adopting the above technical solution are as follows:

[0025] This invention provides a method for identifying the stability of surrounding rock in tunnels based on the penetration index and the breakthrough index of a tunnel boring machine (TBM). This invention can identify the stability of the surrounding rock at the tunnel face in real time using the TBM's tunneling parameters. Based on this, tunnel construction can take advanced reinforcement and support measures in advance, which can effectively avoid accidents where the TBM gets stuck or trapped in unstable strata, and help to achieve safe and efficient construction of the TBM. Attached Figure Description

[0026] Figure 1 This is a flowchart of the tunnel surrounding rock stability identification method in an embodiment of the present invention.

[0027] Figure 2 This is a graph showing the fitting relationship between FPI and SEI and the total score of surrounding rock for different tunnel projects in embodiments of the present invention;

[0028] Among them, Figure (a) is a statistical analysis chart of Tunnel Project 1, and Figure (b) is a statistical analysis chart of Tunnel Project 2;

[0029] Figure 3 This is a graph showing the fitting relationship between the penetration index and the total score of the surrounding rock in an embodiment of the present invention.

[0030] Figure 4 This is a graph showing the fitting relationship between the penetration index and the total score of the surrounding rock in an embodiment of the present invention.

[0031] Figure 5 This is a diagram showing the variation of penetration index and penetration continuity index with surrounding rock stability in an embodiment of the present invention. Detailed Implementation

[0032] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0033] A method for determining the stability of surrounding rock in tunnels based on the tunnel boring machine's penetration index and breakthrough index, such as... Figure 1 As shown, the specific steps include:

[0034] S1. Collect parameters of the tunnel boring machine and the total score of the surrounding rock for the existing tunnel projects:

[0035] The tunneling data of the tunnel boring machine includes thrust, torque, propulsion speed, cutterhead speed, and penetration depth; the method for determining the total score T of the tunnel surrounding rock is given in Appendix N, Engineering Geological Classification of Surrounding Rock, of the Code for Geological Investigation of Water Conservancy and Hydropower Projects (GB 50487-2008).

[0036] S2. Calculate the tunnel boring machine penetration index and statistically analyze the regression relationship between the tunnel boring machine penetration index and the total score of the surrounding rock for different tunnel projects:

[0037] One of the necessary conditions for the cutterhead of a tunnel boring machine to break rock is that the cutterhead penetrates the rock. The field penetration index (FPI) is used to evaluate the difficulty of the tunnel surrounding rock being penetrated by the cutterhead. The physical meaning of FPI is the load per unit penetration of a single cutterhead. The expression of the field penetration index FPI is shown in the formula, and the unit is (kN / cutter) / (mm / r).

[0038]

[0039] In the formula, N is the number of cutters, which is determined during the design of the cutterhead; F is the thrust of the tunneling machine, in kN; and h is the penetration depth, which is the depth to which the cutters penetrate the rock per revolution of the cutterhead, in mm / r.

[0040] The regression relationship between the penetration index of tunnel boring machines and the total score of the surrounding rock in different tunnel projects is shown in the figure.

[0041] FPI = 6.256e 0.025T

[0042] In the formula, T represents the total score of the tunnel surrounding rock;

[0043] S3. Calculate the tunnel boring machine (TBM) breakthrough index and statistically analyze the regression relationship between the TBM breakthrough index and the total score of the surrounding rock in different tunnel projects:

[0044] The second necessary condition for TBM cutterhead cutting to break rock is that the revolution of the cutterhead drives the rotation of the cutter rollers, enabling adjacent cutter edges to penetrate and peel away rock ridges. The TBM cutter penetrates the annular rock ridges on the tunnel face, thus achieving excavation of the entire face. From an energy perspective, this is a process of multiple cutter rollers working together. Therefore, the energy consumption of the TBM cutter per unit volume of rock excavated is defined as the penetration index (SEI), used to evaluate the ease with which the surrounding rock of the tunnel can be penetrated. The expression for the penetration index SEI is shown in the formula, with units of MJ / m. 3 .

[0045]

[0046] The distribution statistics show the relationship between the penetration index (FPI) and the breakthrough index (SEI) of different tunnel boring machines and the total score (T) of the surrounding rock in different tunnel projects. Figure 2 As shown, the method for determining the total score T of the tunnel surrounding rock is found in Appendix N, Engineering Geological Classification of Surrounding Rock, of the "Code for Geological Investigation of Water Conservancy and Hydropower Projects" (GB50487-2008). Statistical analysis of different engineering data revealed that the TBM penetration index (FPI) exhibits an exponential relationship with the total score T of the tunnel surrounding rock, while the tunnel boring machine breakthrough index (ESI) exhibits a logarithmic relationship with the total score T of the tunnel surrounding rock, and the coefficient of determination R for the fitting relationship is also high. 2 All values ​​are greater than 0.7, indicating that the correlation between the fitted variables is extremely strong.

[0047] Penetration index and breakthrough index also suffer from a lack of universality, similar to that of tunneling speed. Therefore, the penetration index and breakthrough index of different tunnel projects are statistically analyzed separately. The fitting relationship between the penetration index and breakthrough index of different tunneling machines and the total score of the surrounding rock is as follows: Figure 3 , Figure 4 As shown.

[0048] The fitting results of penetration index, penetration continuity index and total surrounding rock score did not show significant separation between different engineering data, and the coefficient of determination R of the fitting relationship was [missing information]. 2 All values ​​are greater than 0.64 (when the absolute value of the correlation coefficient R is greater than 0.8, the correlation of the fitted variables is extremely strong), indicating that the tunnel boring machine penetration index, the breakthrough index and the stability of the surrounding rock of the tunnel have a very strong mapping relationship. The fitting relationship between the tunnel boring machine penetration index, the breakthrough index and the total score of the surrounding rock of the tunnel is shown in the formula.

[0049] FPI = 6.256e 0.025T

[0050] SEI = 26.786ln(T) - 63

[0051] Based on the total score of the tunnel surrounding rock, the stability of the surrounding rock is divided into 5 levels. Based on the fitting relationship between the tunnel boring machine (TBM) penetration index, breakthrough index, and the total score of the surrounding rock, the variation patterns of the TBM penetration index and breakthrough index for different surrounding rock levels are established, such as... Figure 5 As shown.

[0052] S4 uses the statistical relationship between the penetration index and the breakthrough index and the total score of the tunnel surrounding rock to determine the stability of the surrounding rock at the tunnel face in real time:

[0053] The penetration index and breakthrough index of the tunnel boring machine are calculated by using parameters such as thrust, torque and penetration depth in real time tunneling data. The established variation law of penetration index and breakthrough index with the stability of surrounding rock is used to identify the stability of the surrounding rock at the tunnel face in real time based on the penetration index and breakthrough index. The judgment criteria are shown in Table 1.

[0054] Table 1 Criteria for Judging the Stability of Surrounding Rock in Tunnels

[0055]

[0056] The tunneling parameters of the tunnel boring machine (TBM) in Tunnel Project 3 were statistically analyzed. The TBM penetration index and breakthrough index were calculated to determine the surrounding rock grade of the tunnel, and the results were compared with the actual surrounding rock grade, as shown in Table 2. The results demonstrate the effectiveness and accuracy of this method.

[0057] Table 2 Verification of Tunnel Surrounding Rock Stability Assessment

[0058]

[0059] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

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