Tunnel smooth blasting back break control method

Abstract

The invention provides a tunnel smooth blasting back break control method which is suitable for the field of tunnel smooth blasting construction and comprises the steps of making a smooth blasting scheme, dividing blasting partitions, executing the smooth blasting scheme, calculating back break, calculating back break predicted values and adjusting smooth blasting parameters in the partitions. The tunnel smooth blasting over-break and under-break control method has the advantages of being high in accuracy, high in efficiency and high in safety and can be widely applied to the field of tunnel smooth blasting construction.

Description

Technical Field

[0001] The invention relates to a tunnel smooth surface blasting over-break and under-break control method, which is applicable to the field of tunnel smooth surface blasting construction. Background Art

[0002] In tunnel construction, smooth blasting is a commonly used controlled blasting technology that achieves precise shaping of the tunnel profile by precisely controlling the blasting parameters. This technology can reduce disturbance to the surrounding rock and maintain the integrity of the surrounding rock, thereby improving the stability and safety of the tunnel. However, due to the complexity of geological conditions, inaccurate blasting parameter settings, and uncertainty in the construction process, traditional smooth blasting technology is still difficult to completely avoid over-excavation and under-excavation.

[0003] Overbreak refers to the part where the actual excavation section exceeds the designed section, while underbreak refers to the part where the actual excavation section is smaller than the designed section. At present, the general principle for tunnel overbreak and underbreak is "strictly prohibit underbreak and control overbreak"; these two phenomena will not only increase construction costs, but may also affect the structural safety and construction progress of the tunnel. Therefore, developing a method that can effectively control the overbreak and underbreak phenomenon in tunnel smooth blasting is of great significance to improving the quality and efficiency of tunnel construction.

[0004] At present, there are many novel technologies proposed for advance excavation. At the same time, laser-based scanners are mostly used for over-excavation and under-excavation detection. The cross-section obtained by scanning is compared with the designed cross-section size to calculate the over-excavation and under-excavation. However, the current control of over-excavation and under-excavation is mostly to comprehensively consider the situation of the entire cross-section and make overall adjustments. However, in fact, the distribution of rocks on the blasting face is uneven, which makes it inappropriate to adopt a unified blasting plan. Based on this, there is an urgent need for a smooth blasting over-excavation and under-excavation control method that can consider the adjustment of the blasting plan in different zones. Summary of the invention

[0005] The purpose of the present invention is to solve the current urgent need for a smooth blasting over-excavation and under-excavation control method that can consider the adjustment of blasting plans in different zones, which can be adjusted in different zones according to the smooth blasting and is more flexible and targeted.

[0006] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0007] A method for controlling over-excavation and under-excavation of smooth surface blasting in a tunnel, characterized in that the method comprises the following steps:

[0008] S101, formulate a smooth blasting plan;

[0009] The formulating of the smooth blasting plan includes setting relevant parameters according to the blasting target to form the smooth blasting plan, wherein the relevant parameters include various blast hole arrangements, blast hole length setting, charge structure selection, and detonation method selection;

[0010] S102, dividing blasting zones;

[0011] The blasting partitioning includes dividing the excavation surface of the tunnel that needs to be blasted into n equal parts according to the length of the outer arc contour line designed for the excavation surface, dividing the excavation surface to be blasted into n partitions according to the n designed outer arc contour lines, and marking the partitions from left to right from the blasting excavation surface as partition A. j , j = 1 to n;

[0012] S103, executing the smooth blasting plan;

[0013] The implementation of the smooth blasting plan includes performing blasting work on the face of the tunnel according to the smooth blasting plan. After the blasting is completed, a post-blasting inspection and risk elimination are required to ensure safety.

[0014] S104, over-excavation and under-excavation calculation;

[0015] The over-break and under-break calculation includes data collection and data processing by using a tunnel section detector after the blasting work is completed. The over-break and under-break calculation sections are planned at fixed intervals according to the blasting footage L. There are a total of m over-break and under-break calculation sections, which are marked as calculation sections D from the end farthest from the tunnel face to the end near the tunnel face. i , i = 1 ~ m, use the tunnel section detector to measure the calculated section D i Perform tunnel section detection, generate a two-dimensional image of the tunnel section, compare the two-dimensional image of the tunnel with the designed tunnel contour, and calculate the calculated section D i Each partition A i1 , A i2 , ..., A in The over-excavation correction result R i1 , R i2 , ..., R in The over-break and under-break correction results are calculated using formula (1).

[0016]

[0017] In the formula, R ij For Partition A ij The over-excavation calculation results are as follows: ij When it is positive, it is over-digging. ij When it is a negative value, it is under-digging. ij 'For partition A ij The actual excavation area, Sij For Partition A ij Design cross-sectional area;

[0018] S105, calculating the over-break and under-break prediction value;

[0019] The calculation of the over-break and under-break prediction value includes: for partition A, according to the over-break and under-break correction result, j , the over-excavation and under-excavation correction results are as follows: R 1j , R 2j , R 3j ,......,R mj , according to the over-excavation and under-excavation correction result series {R 1j , R 2j , R 3j ,......,R mj}, use the simple moving average method to analyze the data to obtain the predicted value R (m+1)j , the set of predicted value series is: {R (m+1)1 , R (m+1)2 , R (m+1)3 ,......R (m+1)n};

[0020] S106, adjusting smooth surface blasting parameters by zone;

[0021] The partition adjustment of the smooth surface blasting parameters includes: (m+1)1 , R (m+1)2 , R (m+1)3 ,......R (m+1)n}, combined with the zoning situation, the smooth blasting plan is dynamically adjusted to meet actual needs.

[0022] Furthermore, in the above S102, the method steps for dividing the blasted excavation surface into n partitions are: a) dividing the designed outer arc contour line of the excavation surface into n parts, and b) connecting the two end points of the outer arc contour line to the center of the excavation surface to which they belong, thereby completing the partitioning.

[0023] Furthermore, in the above S104, the number of over-break and under-break calculation sections is m, where m is calculated by formula (2):

[0024]

[0025] Where Floor is a function that rounds downward to an integer, L is the blasting footage in m, and a is a reduction value taken into account the unevenness of the blasting surface, with a ranging from 0.2 to 0.5 in m.

[0026] Furthermore, in the above S104, the data analysis is performed using a simple moving average method to obtain the predicted value R(m+1)j The method steps are: a) obtain partition A j , and the over-excavation and under-excavation correction results are {R 1j , R 2j , R 3j ,......,R m j}, b) determine the moving average wound size n, n is 3 to 5, c) calculate the moving average, d) predict the data value R of the next period (m+1)j .

[0027] The beneficial effects of the present invention are:

[0028] The beneficial effects of the present invention are as follows: (1) Accurately control overbreak and underbreak: By using a tunnel section detector and an overbreak and underbreak correction calculation method, the actual excavation situation of each partition can be accurately monitored and corrected, thereby effectively controlling the overbreak and underbreak phenomenon during tunnel excavation. This can ensure that the excavation surface of the tunnel is highly consistent with the designed contour and reduce unnecessary overbreak or underbreak. (2) Improve blasting effect: By adjusting the smooth surface blasting parameters by partition and dynamically adjusting the blasting plan according to the overbreak and underbreak prediction value, the blasting parameters of each partition are more adapted to the actual geological conditions and construction requirements, thereby improving the blasting effect and ensuring the safety and construction quality of tunnel construction. (3) Optimize construction efficiency: Through scientific partition blasting and real-time monitoring, the construction unit can quickly adjust and optimize the blasting plan, reduce construction delays caused by improper blasting, and improve construction efficiency. (4) Improve construction safety: Through real-time detection and precise adjustment of the tunnel section, tunnel stability problems caused by overbreak and underbreak can be effectively avoided, thereby improving the safety of the construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 : Flow chart of a tunnel smooth surface blasting over- and under-excavation control method of the present invention.

[0030] Figure 2 : A blasting zoning diagram of an embodiment of a tunnel smooth blasting over- and under-excavation control method of the present invention. DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings; it should be understood that the specific embodiments given here are only used to illustrate and explain the present invention and cannot be used to limit the present invention.

[0032] The following is a specific embodiment of a method for controlling over-excavation and under-excavation in smooth surface blasting of a tunnel.

[0033] like Figure 1 Shown is a flow chart of a tunnel smooth blasting over-excavation and under-excavation control method according to the present invention.

[0034] A method for controlling over-excavation and under-excavation of smooth surface blasting in a tunnel, characterized in that the method comprises the following steps:

[0035] The project on which this embodiment is based is: the 1# Tunnel of C2 Line, Section 8 of the East Coast Rail Link Project, Malaysia. The basic engineering overview of the tunnel is: a total length of 3595m, an import mileage of CH000+606, an export mileage of CH004+201, a line with a slope of 3‰ from the import end to CH002+400 and a slope of 6‰, a maximum burial depth of 335m, a minimum burial depth of 5m, and a ballasted composite lining structure with a standard line spacing of 4.2m. The 1# Tunnel of Sangwondan is designed with an inclined shaft auxiliary construction and rescue channel, with a length of 261m, an inclined shaft clearance section size of 5m*8m, a longitudinal slope of A1-1CH0+261-A1-1CH0+052 of 10%, and a longitudinal slope of A1-1CH0+052-A1-1CH0+000 of 1.6%. It adopts a trackless double-lane design and an anchor sprayed lining + molded lining structure.

[0036] S101, formulate a smooth blasting plan;

[0037] The formulating of the smooth blasting plan includes setting relevant parameters according to the blasting target to form the smooth blasting plan, wherein the relevant parameters include various blast hole arrangements, blast hole length setting, charge structure selection, and detonation method selection;

[0038] In this embodiment, a blasting plan is formulated, the blastholes are arranged in a circular arrangement, and the blasthole spacing is 0.5 meters; the blasthole length is set to 5 meters based on the footage L; the charge structure adopts a single charge; and the detonation method adopts millisecond delay detonation.

[0039] S102, dividing blasting zones;

[0040] The blasting partitioning includes dividing the excavation surface of the tunnel that needs to be blasted into n equal parts according to the length of the outer arc contour line designed for the excavation surface, dividing the excavation surface to be blasted into n partitions according to the n designed outer arc contour lines, and marking the partitions from left to right from the blasting excavation surface as partition A. j , j=1~n; further, in the above S102, the method steps for dividing the blasting excavation surface into n partitions are: a) dividing the designed outer arc contour line of the excavation surface into n parts, b) connecting the two end points of the outer arc contour line to the center of the excavation surface to which they belong, thereby completing the partition.

[0041] In this embodiment, the outer arc contour line is designed to be divided into 6 partitions, and the two end points of the outer arc contour line are respectively connected to the center of the tunnel to complete 6 partitions, which are marked as A1 to A6. Figure 2 shown.

[0042] S103, executing the smooth blasting plan;

[0043] The implementation of the smooth blasting plan includes performing blasting work on the face of the tunnel according to the smooth blasting plan. After the blasting is completed, a post-blasting inspection and risk elimination are required to ensure safety.

[0044] S104, over-excavation and under-excavation calculation;

[0045] The over-break and under-break calculation includes data collection and data processing by using a tunnel section detector after the blasting work is completed. The over-break and under-break calculation sections are planned at fixed intervals according to the blasting footage L. There are a total of m over-break and under-break calculation sections, which are marked as calculation sections D from the end farthest from the tunnel face to the end near the tunnel face. i , i = 1 ~ m, use the tunnel section detector to measure the calculated section D i Perform tunnel section detection, generate a two-dimensional image of the tunnel section, compare the two-dimensional image of the tunnel with the designed tunnel contour, and calculate the calculated section D i Each partition A i1 , A i2 , ..., A in The over-excavation correction result R i1 , R i2 , ..., R in The over-break and under-break correction results are calculated using formula (1).

[0046]

[0047] In the formula, R ij For Partition A ij The over-excavation calculation results are as follows: ij When it is positive, it is over-digging. ij When it is a negative value, it is under-digging. ij 'For partition A ij The actual excavation area, S ij For Partition A ij Design cross-sectional area;

[0048] Furthermore, in the above S104, the number of over-break and under-break calculation sections is m, where m is calculated by formula (2):

[0049]

[0050] Where Floor is a function that rounds downward to an integer, L is the blasting footage in m, and a is a reduction value taken into account the unevenness of the blasting surface, with a ranging from 0.2 to 0.5 in m.

[0051] Furthermore, in the above S104, the data analysis is performed using a simple moving average method to obtain the predicted value R (m+1)j The method steps are: a) obtain partition A j , and the over-excavation and under-excavation correction results are {R 1j , R 2j , R 3j ,......,R m j}, b) determine the moving average wound size n, n is 3 to 5, c) calculate the moving average, d) predict the data value R of the next period (m+1)j .

[0052] In this embodiment, for partition A1, the calculated over-break and under-break correction results are -0.1, 01, 0.05; for partition A2, the calculated over-break and under-break correction results are 0.0, 0.2, 0.15;

[0053] S105, calculating the over-break and under-break prediction value;

[0054] The calculation of the over-break and under-break prediction value includes: for partition A, according to the over-break and under-break correction result, j , the over-excavation and under-excavation correction results are as follows: R 1j , R 2j , R 3j ,......,R mj , according to the over-excavation and under-excavation correction result series {R 1j , R 2j , R 3j ,......,R mj}, use the simple moving average method to analyze the data to obtain the predicted value R (m+1)j , the set of predicted value series is: {R (m+1)1 , R (m+1)2 , R (m+1)3 ,......R (m+1)n};

[0055] In this embodiment, the predicted value obtained for A1 is The predicted value obtained for A2

[0056] S106, adjusting smooth surface blasting parameters by zone;

[0057] The partition adjustment of the smooth surface blasting parameters includes: (m+1)1 , R (m+1)2 , R (m+1)3 ,......R (m+1)n}, combined with the zoning situation, the smooth blasting plan is dynamically adjusted to meet actual needs.

[0058] In this embodiment, the next phase of blasting in the A1 zone is adjusted to reduce the blasting intensity and reduce over-excavation, and the blasting in the A2 zone is adjusted to moderately increase the intensity to control over-excavation.

[0059] In the above embodiment, the present invention discloses a method for controlling over-excavation and under-excavation in smooth surface blasting of a tunnel; the method includes formulating a smooth surface blasting plan, dividing blasting zones, executing the smooth surface blasting plan, calculating over-excavation and under-excavation, calculating over-excavation and under-excavation prediction values, and adjusting smooth surface blasting parameters by zones; the method for controlling over-excavation and under-excavation in smooth surface blasting of a tunnel proposed by the present invention has the advantages of high precision, high efficiency, and high safety, and can be widely used in the field of smooth surface blasting construction of tunnels.

[0060] The above description is a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling over-excavation and under-excavation in smooth blasting of a tunnel, characterized in that: The method for controlling over-excavation and under-excavation of smooth blasting in a tunnel comprises the following steps: 1) Formulate a smooth blasting plan; The formulating of the smooth blasting plan includes setting relevant parameters according to the blasting target to form the smooth blasting plan, wherein the relevant parameters include various blast hole arrangements, blast hole length setting, charge structure selection, and detonation method selection; 2) Divide the blasting zones; The blasting partitioning includes dividing the excavation surface of the tunnel that needs to be blasted into n equal parts according to the length of the outer arc contour line designed for the excavation surface, dividing the excavation surface to be blasted into n partitions according to the n designed outer arc contour lines, and marking the partitions from left to right from the blasting excavation surface as partition A. j , j = 1 to n; 3) Implement smooth blasting plan; The implementation of the smooth blasting plan includes performing blasting work on the face of the tunnel according to the smooth blasting plan. After the blasting is completed, a post-blasting inspection and risk elimination are required to ensure safety. 4) Calculation of over-excavation and under-excavation; The over-break and under-break calculation includes data collection and data processing by using a tunnel section detector after the blasting work is completed. The over-break and under-break calculation sections are planned at fixed intervals according to the blasting footage L. There are a total of m over-break and under-break calculation sections, which are marked as calculation sections D from the end farthest from the tunnel face to the end near the tunnel face. i , i = 1 ~ m, use the tunnel section detector to measure the calculated section D i Perform tunnel section detection, generate a two-dimensional image of the tunnel section, compare the two-dimensional image of the tunnel with the designed tunnel contour, and calculate the calculated section D i Each partition A i1 , A i2 , ..., A in The over-under excavation correction result R i1 , R i2 , ..., R in The over-break and under-break correction results are calculated using formula (1). In the formula, R ij For Partition A ij The over-excavation calculation results are as follows: ij When it is positive, it is over-digging. ij When it is a negative value, it is under-digging. ij 'For partition A ij The actual excavation area, S ij For Partition A ij Design cross-sectional area; 5) Calculate the predicted value of over-excavation and under-excavation; The calculation of the over-break and under-break prediction value includes: for partition A, according to the over-break and under-break correction result, j , the over-excavation and under-excavation correction results are as follows: R 1j , R 2j , R 3j ,......,R mj , according to the over-excavation and under-excavation correction result series {R 1j , R 2j , R 3j ,......,R mj }, use the simple moving average method to analyze the data to obtain the predicted value R (m+1)j , the set of predicted value series is: {R (m+1)1 , R (m+1)2 , R (m+1)3 ,......R (m+1)n }; 6) Adjust smooth blasting parameters by zone; The partition adjustment of the smooth surface blasting parameters includes: (m+1)1 , R (m+1)2 , R (m+1)3 ,......R (m+1)n }, combined with the zoning situation, the smooth blasting plan is dynamically adjusted to meet actual needs.

2. A tunnel smooth blasting over-break and under-break control method according to claim 1, characterized in that: In the above 2), the method steps for dividing the blasted excavation surface into n partitions are: a) dividing the designed outer arc contour line of the excavation surface into n parts, and b) connecting the two end points of the outer arc contour line to the center of the excavation surface to complete the partition.

3. A tunnel smooth blasting over-break and under-break control method according to claim 1, characterized in that: In the above 4), the number of over-excavation and under-excavation calculation sections is m, where m is calculated by formula (2): Where Floor is a function that rounds downward to an integer, L is the blasting footage in m, and a is a reduction value taken into account the unevenness of the blasting surface, with a ranging from 0.2 to 0.5 in m.

4. A tunnel smooth blasting over-break and under-break control method according to claim 1, characterized in that: In the above 4), the simple moving average method is used to perform data analysis to obtain the predicted value R (m+1)j The method steps are: a) obtain partition A j , and the over-excavation and under-excavation correction results are {R 1j , R 2j , R 3j ,......,R mj }, b) determine the moving average wound size n, n is 3 to 5, c) calculate the moving average, d) predict the data value R of the next period (m+1)j .

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