Monitoring management method for mountain tunnel supporting construction

Abstract

The invention discloses a monitoring management method for mountain tunnel support construction, which comprises the following steps: S1, arranging monitoring points in a tunnel hole, and obtaining initial monitoring data of the monitoring points; s2, in the supporting construction process, based on the initial monitoring data of the monitoring points, a three-dimensional coordinate measurement method is used for multi-measurement back measurement, so that multi-point monitoring data in the tunnel hole is obtained; and S3, drawing an accumulated deformation time curve, a deformation rate time curve and a deformation acceleration time curve according to the collected monitoring data, analyzing a data rule according to the curves, and judging the stability of the surrounding rock in the support construction process. The actual stress condition of the supporting structure is analyzed according to the monitoring data, the construction scheme can be adjusted in time, the stability and safety of the supporting structure under various construction conditions are ensured, the safety guarantee capacity of the whole project is improved, and therefore the construction efficiency and safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of construction monitoring, and particularly to a monitoring and management method for the support construction of mountain tunnels. Background Art

[0002] For the construction of mountain tunnels, the existing technology mainly still constructs based on the principle of the modern New Austrian Tunneling Method. The New Austrian Tunneling Method is a theory based on rock mechanics. It advocates using an internal and external composite lining for the lining structure, and at the same time relying on the self-bearing capacity of the surrounding rock as much as possible in terms of load-bearing to guide construction and design. For the New Austrian Tunneling Method, its core lies in the dynamic deformation of the surrounding rock. Compared with other physical and mechanical indexes, deformation has the advantages of being scientific, reliable, convenient, and timely. Therefore, deformation is often used as an important index to measure the stability of the tunnel structure system.

[0003] When constructing using the concept of the New Austrian Tunneling Method, under the action of poor geology or complex stress fields, the excavation of the tunnel will cause more serious settlement deformation and convergence deformation. Such deformations are within the safe range in the initial stage. If not properly controlled, it will lead to safety accidents beyond the limit range or even greater. Therefore, during the construction process using the New Austrian Tunneling Method, construction monitoring and dynamic management need to be carried out according to the actual on-site situation.

[0004] Therefore, this application specifically proposes a monitoring and management method for the support construction of mountain tunnels to solve the above technical problems. Summary of the Invention

[0005] The main purpose of the present invention is to provide a monitoring and management method for the support construction of mountain tunnels. According to the pre-buried components, by on-site monitoring of the dynamic change data during tunnel construction and judging the stability of the surrounding rock during the support construction process, it is used for construction adjustment to solve the above technical problems.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] A monitoring and management method for the support construction of mountain tunnels, comprising the following steps:

[0008] S1. Arrange monitoring points inside the tunnel, and obtain the initial monitoring data of the monitoring points;

[0009] S2. During the support construction process, use the three-dimensional coordinate measurement method for multiple measurements based on the initial monitoring data of the monitoring points to obtain the multi-point monitoring data inside the tunnel;

[0010] S3. Draw a cumulative deformation time curve, a deformation rate time curve, and a deformation acceleration time curve according to the collected monitoring data, and analyze the data law according to the curves to judge the stability of the surrounding rock during the support construction process.

[0011] Preferably, the specific operation process in step S1 includes:

[0012] According to the classification of surrounding rock of mountain tunnels, determine the section spacing of monitoring points, and arrange monitoring points at the crown, both arch waists and arch bottom of the tunnel section respectively;

[0013] Select a point height where the control points on both sides of the tunnel can be observed to set up a total station. After using the control points for error calibration, use the total station to measure the coordinate elevation of the monitoring points to obtain multiple groups of elevation coordinate data of the monitoring points.

[0014] Preferably, the specific operation process of multi - measurement using the three - dimensional coordinate measurement method in step S2 includes:

[0015] Establish a measurement coordinate system and set up a total station at the selected monitoring points in the tunnel;

[0016] For any two points in the tunnel, use the total station to obtain the coordinate relationship between the selected monitoring point and these two points, and use it to calculate the elevation difference and distance between these two points.

[0017] Preferably, in the measurement coordinate system, the direction parallel to the tunnel center line is defined as the X - axis, the direction perpendicular to this direction is defined as the Y - axis, and the direction perpendicular to the ground upward is the Z - axis. For any two points in the tunnel in the measurement coordinate system, the specific operation process of calculating the elevation difference and distance includes:

[0018] Use the total station to obtain the distances of these two points from the monitoring point P, the included angle of these two points with respect to the monitoring point P, and the azimuth angle of these two points, calculate the coordinates of these two points in the measurement coordinate system, and based on the coordinates of these two points, the elevation difference and distance between these two points can be calculated.

[0019] Preferably, the cumulative deformation curve drawing process in step S3 includes:

[0020] Eliminate the abnormal points in the original monitoring data obtained from each monitoring point, and calculate the cumulative deformation U measured on the i - th day i :

[0021] U i = L i - L0

[0022] In the formula, L i is the total station line reading on the i - th day, and L0 is the initial reading at the starting point;

[0023] Taking time as the horizontal axis and the cumulative deformation U i value as the vertical axis, draw a curve.

[0024] Preferably, the deformation rate - time curve drawing process in step S3 includes:

[0025] Eliminate the abnormal points in the original monitoring data obtained from each monitoring point, and calculate the deformation rate V monitored on the i-th day i :

[0026]

[0027] In the formula, ΔL is the difference in the distance of the measuring line between two adjacent times, and Δt is the time difference between two adjacent times in this section;

[0028] Taking time as the horizontal axis and the deformation rate V i as the vertical axis, draw a curve.

[0029] Preferably, the specific discrimination method for judging the stability of surrounding rock by the deformation rate-time curve in the step S3 includes:

[0030] When the deformation rate in the curve keeps decreasing, it is determined that the surrounding rock is stable at this time; when the deformation rate in the curve remains, the surrounding rock is in the continuous deformation stage, and it is determined that the surrounding rock is unstable at this time; when the deformation rate in the curve keeps increasing, it is determined that the surrounding rock is unstable at this time, and it is also determined that the surrounding rock is in a dangerous state at the same time.

[0031] Preferably, the drawing process of the deformation acceleration-time curve in the step S3 includes:

[0032] Eliminate the abnormal points in the original monitoring data obtained from each monitoring point, and calculate the deformation acceleration value a monitored on the i-th day i :

[0033]

[0034] In the formula, ΔV is the change in the deformation rate between two adjacent times, and Δt is the time difference between two adjacent times;

[0035] Taking time as the horizontal axis and the deformation acceleration value a of the deformation rate i as the vertical axis, draw a curve.

[0036] Preferably, the specific discrimination method for judging the stability of surrounding rock by the deformation acceleration-time curve in the step S3 includes:

[0037] The deformation acceleration value a i <0 When the state is reached and the deformation rate gradually decreases, it is determined that the surrounding rock of the surface tunnel gradually tends to be stable;

[0038] The deformation acceleration value a i =0 When the state is reached, if V = 0, it is determined that the surrounding rock is in the stable stage, otherwise it is determined that the surrounding rock is in the constant velocity deformation stage;

[0039] The deformation acceleration value a i >0 When the state is reached, the deformation rate continues to increase, and it is determined that the risk degree of the surrounding rock of the surface tunnel increases.

[0040] Preferably, the specific discrimination method for surrounding rock stability judgment in the step S3 further includes:

[0041] Judging according to the deformation rate: When the net clearance change rate of the surrounding rock always remains above 1 mm / d, it is judged that the surrounding rock is in a situation of intensified deformation and needs to strengthen the support; when the net clearance change rate of the surrounding rock < 0.2 mm / d, it is judged that the surrounding rock is in a stable state.

[0042] The present invention provides a monitoring and management method for the support construction of mountain tunnels. Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0043] 1. The present invention is based on the improvement of the automatic multi-observation three-dimensional coordinate measurement method, and an artificial-assisted multi-observation three-dimensional coordinate measurement method is established. This improved method makes up for the defects of the automatic three-dimensional coordinate measurement method in tunnel observation, reduces the measurement deviation caused by equipment errors or environmental factors, and thus improves the accuracy of the final measurement result.

[0044] 2. The present invention analyzes the actual stress condition of the support structure according to the monitoring data, constructs various deformation-time curves for analysis and judgment, can adjust the construction plan in a timely manner, ensure its stability and safety under various construction conditions, improve the safety guarantee of the whole project, and thus improve the construction efficiency and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The attached drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0046] Figure 1 is the overall step flow schematic diagram of the method of the present invention;

[0047] Figure 2 is the schematic diagram of the three-dimensional coordinate measurement principle of the present invention;

[0048] Figure 3 is the cumulative deformation value-time example curve graph of the present invention;

[0049] Figure 4 is the deformation rate-time example curve graph of the present invention;

[0050] Figure 5 is the deformation acceleration-time example curve graph of the present invention;

[0051] Figure 6 is the monitoring curve type rule example curve graph of the present invention;

[0052] Figure 7 is the crown settlement-time example curve graph of the present invention;

[0053] Figure 8 It is the curve graph of the vault settlement rate over time of the present invention;

[0054] Figure 9 It is the curve graph of the waist convergence time of the present invention;

[0055] Figure 10 It is the curve graph of the waist convergence rate over time of the present invention. Specific embodiments

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] In the embodiment, refer in detail to Figures 1 to 10 .

[0058] During the dynamic construction process of the tunnel, it is necessary to timely adjust the construction using informatization according to the analysis of the deformation data. Therefore, the monitored data and the subsequent data analysis become the judgment of the stability of the surrounding rock deformation.

[0059] Therefore, as Figure 1 shown, the present invention provides a monitoring and management method for the support construction of a mountain tunnel to solve the problems of the prior art, specifically including the following steps:

[0060] S1. Arrange the monitoring points in the tunnel and obtain the initial monitoring data of the monitoring points;

[0061] Its specific operation process includes:

[0062] S11. According to the classification of the surrounding rock of the mountain tunnel, determine the section spacing of the monitoring points, and arrange the monitoring points at the vault, both side waists and the arch bottom of the tunnel section respectively;

[0063] S12. Select a relatively flat and open area, select a point height where the control points on both sides of the tunnel can be observed to set up a total station. After using the control points for error calibration, use the total station to measure the coordinate elevation of the monitoring points, obtain multiple groups of elevation coordinate data of the monitoring points, and take the average value of the multiple monitoring data of the monitoring points as the final result at the monitoring point. For Class III, IV, and V surrounding rocks, the set monitoring section spacings are 10m, 20m, and 50m respectively;

[0064] In addition, for the environmental steps, it is also necessary to supplement that on the construction site, the surrounding rock state is assisted to be recorded according to the compass and the measuring crack gauge. For the surface settlement, surface settlement observation points are arranged at certain intervals, and a level, a total station and a tape measure are used for monitoring and measurement, and the vertical displacement and horizontal convergence of the surrounding rock are monitored;

[0065] S2. During the support construction process, multi-round measurements are carried out using the three-dimensional coordinate measurement method based on the initial monitoring data of the monitoring points to obtain the multi-point monitoring data in the tunnel;

[0066] Among them, the specific operation process of using the three-dimensional coordinate measurement method for multi-round measurements includes:

[0067] Establish a measurement coordinate system, as Figure 2 shown. At this time, in the measurement coordinate system, the direction parallel to the tunnel center line is defined as the X-axis, the direction perpendicular to this direction is defined as the Y-axis, and the direction perpendicular to the ground upward is the Z-axis. Then, a total station is set up at the selected monitoring points in the tunnel;

[0068] For any two points in the tunnel, use the total station to obtain the coordinate relationship between the selected monitoring points and these two points, which is used to calculate the elevation difference and distance between these two points. The specific operation process includes: Set these two points as point E and point F respectively, and use the total station to obtain: distance S PE and S PF 、the included angles α1 and α2 of point E and point F with respect to the monitoring point P, the azimuth angles β1 and β2 of point E and point F, calculate the coordinates of point E and point F in the measurement coordinate system, and based on the coordinates of point E and point F, the elevation difference h EF and the distance s EF can be calculated, and there is:

[0069] h EF =S PE sinα1 - S PF sinα2

[0070]

[0071] The artificial-assisted multi-round three-dimensional coordinate measurement method used here is a monitoring method improved on the basis of the automatic multi-round three-dimensional coordinate measurement: When performing multi-round measurements, after the measuring robot automatically searches and locates the measuring point, further manual aiming instead of automatic aiming is carried out to accurately position the center of the crosshair of the total station at the center of the crosshair of the reflector of the measuring point. After clicking the measurement, the measuring robot automatically searches and locates the next measuring point, and cycles in turn. The remaining steps are the same as those of the automatic multi-round three-dimensional coordinate measurement. This method uses the robot to find points, which improves the measurement efficiency, and manual aiming to ensure the measurement accuracy, realizes the man-machine collaborative work, takes into account the intelligence of the measuring robot and the flexibility of people at the same time, avoids the technical defects of the automatic three-dimensional coordinate measurement in the tunnel environment, and has a relatively fast measurement speed.

[0072] At this time, it can be supplemented that the advantage of multi-setting measurement is that the error is small and the accuracy is high. This application is improved on the basis of automatic multi-setting measurement. By manually assisting in multi-setting three-dimensional coordinates for point position monitoring, compared with the multi-setting measurement that requires manual calibration of the total station in the prior art, the measurement method of this application can identify and correct errors during the data processing process through multiple measurements and human judgment, thereby improving the accuracy of the final result. When facing a complex or uncertain measurement environment, this measurement method can also quickly respond and adjust the plan to adapt to different measurement requirements or emergencies.

[0073] S3. Monitoring data processing

[0074] Since direct raw data is obtained through components and instruments, and the data has a certain degree of discreteness affected by various factors, in order to use this data, corresponding processing is also required before analysis;

[0075] In the data processing process of this application, cumulative deformation time curves, deformation rate time curves, and deformation acceleration time curves are drawn based on the collected monitoring data, and the data laws are analyzed according to the curves, so as to facilitate the judgment of the surrounding rock stability during the support construction process, where:

[0076] (1) Cumulative deformation time curve

[0077] Due to the influence of various environmental and human factors, abnormal phenomena occasionally occur in the monitoring data. From the perspective of the stability of the surrounding rock and the reliability of the support structure, the deformation value of the surrounding rock is an important basis for judging whether there is intrusion, and it is also a judgment on whether the deformation of the surrounding rock affects the on-site construction safety;

[0078] Therefore, the original monitoring data obtained from each monitoring point can be plotted into a cumulative deformation time curve after removing some abnormal points, and the deformation situation of the surrounding rock at different time points can be obtained, and the stability of the tunnel can be preliminarily judged according to the development trend of the curve;

[0079] Taking the total station measurement of deformation as an example, the drawing process of the cumulative deformation time curve includes:

[0080] a1. Remove the abnormal points from the original monitoring data obtained from each monitoring point, and calculate the cumulative deformation amount U measured on the i-th day i :

[0081] U i =L i -L0

[0082] In the formula, L i is the total station measurement line reading on the i-th day, and L0 is the initial reading at the starting point;

[0083] a2. With time as the horizontal axis and the cumulative deformation amount U iThe value is taken as the vertical axis, and a curve as shown in Figure 3 is plotted to reflect the deformation state;

[0084] (2) Deformation rate-time curve

[0085] When the deformation rate exceeds the allowable deformation value, it indicates that the deformation rate of the surrounding rock and the support structure is too fast, and the surrounding rock is about to become unstable. At this time, construction at the construction site needs to be stopped immediately and corresponding reinforcement measures should be taken;

[0086] Taking the measurement of deformation by total station as an example, its plotting process includes:

[0087] Eliminate the abnormal points in the original monitoring data obtained from each monitoring point, and calculate the deformation rate V monitored on the i-th day i :

[0088]

[0089] In the formula, ΔL is the difference in the distance of the measuring line between two adjacent times, and Δt is the time difference of the adjacent times in this section;

[0090] Taking time as the horizontal axis and the deformation rate V i as the vertical axis, a curve as shown in Figure 4 is plotted to reflect the speed of deformation.

[0091] At this time, the specific discrimination method for judging the stability of the surrounding rock through the deformation rate-time curve includes: when the deformation rate in the curve keeps decreasing, it is determined that the surrounding rock is stable at this time; when the deformation rate in the curve remains, the surrounding rock is in the continuous deformation stage, and it is determined that the surrounding rock is unstable at this time; when the deformation rate in the curve keeps rising, it is determined that the surrounding rock is unstable at this time, and it is also determined that the surrounding rock is in a dangerous state at the same time.

[0092] (3) Deformation acceleration-time curve

[0093] Its plotting process includes:

[0094] Eliminate the abnormal points in the original monitoring data obtained from each monitoring point, and calculate the deformation acceleration value a monitored on the i-th day i :

[0095]

[0096] In the formula, ΔV is the change in the deformation rate between two adjacent times, and Δt is the time difference between two adjacent times;

[0097] Taking time as the horizontal axis and the deformation acceleration value a of the deformation rate i as the vertical axis, a curve as shown in Figure 5 is plotted.

[0098] At this time, the specific discrimination methods for judging the stability of surrounding rock through the deformation acceleration time curve include:

[0099] (a) The deformation acceleration value a i When in the <0 state, it indicates that the deformation of the surrounding rock is in the deceleration stage. Since the deformation rate gradually decreases, it is determined that the surface tunnel surrounding rock gradually tends to be stable;

[0100] (b) The deformation acceleration value a i When in the = 0 state, it indicates that the deformation rate is a constant value. If V = 0, it is determined that the surrounding rock is in a stable stage; otherwise, it is determined that the surrounding rock is in the stage of uniform deformation;

[0101] (c) The deformation acceleration value a i When in the > 0 state, it indicates that the surrounding rock is in the stage of accelerating deformation, and the deformation rate is still continuously increasing in this stage. The danger degree of the surface tunnel surrounding rock increases. At this time, construction at the construction site needs to be immediately stopped and corresponding reinforcement measures need to be taken to prevent further expansion of the surrounding rock deformation.

[0102] In summary, based on the cumulative deformation time curve, the deformation rate time curve, and the deformation acceleration time curve, the curve laws as shown can be summarized and obtained. And according to the curve laws as shown, they can be used to judge the stability of the surrounding rock; Figure 6 shown, and according to Figure 6 shown curve laws, it can be used to judge the stability of the surrounding rock;

[0103] In addition, it should be supplemented and explained that the specific discrimination methods for judging the stability of the surrounding rock also include: judging according to the deformation rate: when the net clearance change rate of the surrounding rock always remains above 1 mm / d, it is determined that the surrounding rock is in the situation of intensified deformation and strengthening support is required; when the net clearance change rate of the surrounding rock < 0.2 mm / d, it is determined that the surrounding rock is in a stable state.

[0104] In addition, in a specific embodiment, the stability of the surrounding rock is also judged through the crown settlement analysis and the convergence analysis of the arch waist, where:

[0105] (1) Crown settlement analysis: The value of the crown settlement of the tunnel can be used to judge the stability of the tunnel, so as to judge the safety of the construction process. Therefore, the crown settlement of the tunnel can directly reflect the dynamic stress and deformation conditions of the surrounding rock and the support structure during the tunnel excavation process. Therefore, strengthening the monitoring of the crown settlement during construction can judge whether the tunnel excavation method and the support form are reasonable.

[0106] Specifically, at the monitoring point for a certain period of time, the cumulative value of the crown settlement is obtained, the average change rate is calculated, and the crown settlement time diagram and the crown settlement rate time diagram are drawn to analyze each short-term part of the crown settlement deformation data process line. Its short-term deformation mainly has 3 forms:

[0107] Stable deformation stage: In this stage, the cumulative deformation increases steadily with time. It generally appears in the middle of the tunnel deformation monitoring period and after the influence of environmental mutations stabilizes. In this stage, the confrontation between the surrounding rock pressure and the support force is basically stable;

[0108] First increasing then slowing down stage: In this stage, the cumulative deformation increases first rapidly and then slowly with time. It generally appears in the early stage of the tunnel deformation monitoring period and when the influence of environmental mutations occurs. The entire monitoring cycle of the tunnel deformation also generally shows this curve. In the early stage of this stage, the surrounding rock pressure is significantly greater than the support force, and in the later stage, the confrontation between the surrounding rock pressure and the support force gradually stabilizes;

[0109] First slowing down then increasing stage: In this stage, the cumulative deformation increases first slowly and then rapidly with time. It generally appears before the influence of environmental mutations occurs. In the early stage of this stage, the confrontation between the surrounding rock pressure and the support force is basically stable, and in the later stage, the surrounding rock pressure is significantly greater than the support force.

[0110] As Figure 7 and Figure 8 shown, from the crown settlement time graph and the crown settlement rate time graph at monitoring points A and B, it can be seen that for the crown monitoring points at sections A and B, the development trends of their settlement deformations are basically the same; from 0 to 15 days, the crown settlement is in the rapid development stage. When this stage is completed, the crown settlement development has reached 70% - 80% of the final cumulative settlement value; from 15 to 60 days, the crown settlement deformation is in the stable development stage. In this stage, the deformation increases steadily, and the growth rate has decreased significantly compared with the previous deformation; after 70 days, the curve is basically a straight line, and the deformation tends to be stable. The change trends of the crown settlements at the two monitoring sections are basically the same. Similarly, from 0 to 15 days, the settlement rate has the characteristics of large change range, large fluctuation, and fast change, which is shown as rapid growth in the graph; from 15 to 60 days, the crown settlement rate decreases significantly, with a maximum of about 0.5 mm / d, and most of the time it is about 0.2 mm / d. At this time, it indicates that the settlement is still accumulating, but slowly; after 60 days, the settlement rate further decreases. Especially after 75 days, the settlement rate is basically 0. At this time, the crown settlement displacement remains unchanged, which is shown as an approximate straight line in the graph.

[0111] Comparing Figure 5 with the schematic diagram of the monitoring curve types, it can be seen that the monitoring curve of the tunnel example belongs to the normal type. Within 20 days before construction, it belongs to the initial deformation stage and the rapid deformation stage. The duration of the initial deformation stage of the ground settlement is very short, and the rapid deformation stage lasts for a certain time; from 20 days to 60 days, the deformation belongs to the constant speed deformation stage. In this stage, the deformation still continues to increase, but the deformation rate remains constant and fluctuates within a certain range; after 60 days, the cumulative settlement remains unchanged, basically at a certain value. At this time, the surrounding rock is in a stable stage.

[0112] (2) Analysis of the waist convergence of the arch: In addition to dynamically monitoring the ground settlement and the crown settlement during the construction process, it is also necessary to monitor the waist convergence of the tunnel. Similar to the crown settlement, the waist convergence of the arch can also intuitively reflect the stress and deformation of the surrounding rock of the tunnel, thereby judging the stability of the surrounding rock during the construction process, and further evaluating the rationality of the excavation method and the support method during the construction to ensure the safe and effective progress of the tunnel construction.

[0113] Monitor at the monitoring point for d days to obtain the waist convergence values on the left and right sides of the monitoring point, calculate the waist convergence rate, and draw the waist convergence time graph and the waist convergence rate time graph to obtain the development stage and variation characteristics of the waist convergence.

[0114] As Figure 9 and Figure 10 shown, from the waist convergence time graphs and the waist convergence rate time graphs on the left and right sides of the monitoring points A and B, it can be seen that the waist convergence trends on the left and right sides of the two cross-sections are basically the same. Overall, the cumulative convergence displacement on the left side is slightly larger than that on the right side, and the convergence displacement on both sides at B is slightly larger than that on both sides at A.

[0115] Different from the crown settlement and the ground settlement curves, the waist convergence displacement increases rapidly within the initial 0 - 10 days, reaching approximately 60% - 70% of the final displacement after reaching stability; from 10 - 30 days, the growth trend of the waist convergence displacement slows down, but there is still a certain slope, and at this time it reaches approximately 70% - 85% of the final displacement; from 30 - 60 days, the waist convergence displacement further decreases, and at this time the change curve is close to a horizontal straight line, indicating that the displacement growth is very slow at this time; after 60 days, the displacement basically does not increase, indicating that the surrounding rock is basically stable in the horizontal direction at this time; there is a maximum value of the waist convergence rate on the left side of the monitoring point A. The waist convergence rates at the four monitoring points of the two monitoring cross-sections fluctuate greatly within 0 - 10 days, which is consistent with the trend of rapid displacement growth in the waist convergence time curve within 0 - 10 days; when the convergence rate time curve is from 10 - 30 days, it decreases significantly compared with before, and basically fluctuates around 0.4 mm / d. During this stage, the displacements on the left and right sides still increase, but decrease significantly compared with before; after 30 days, the convergence rate will continue to decline, with very small fluctuations, and the overall rate is controlled at about 0.1 mm / d, and it is basically 0 in the later stage, and the waist convergence tends to be stable.

[0116] In summary, by analyzing the actual stress conditions of the support structure based on the monitoring data, constructing analysis curve models such as the cumulative deformation time curve, deformation rate time curve, and deformation acceleration time curve for analysis and determination, the stability of the surrounding rock of the construction support can be determined from multiple perspectives, thereby effectively managing and timely adjusting the construction process and the overall construction plan, facilitating the control of the overall construction progress, improving the construction efficiency, ensuring its stability and safety under various construction conditions, enhancing the safety guarantee of the entire project, and thus improving the construction efficiency and safety.

[0117] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0118] In addition, it should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0119] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, in the embodiments of the present invention, "a plurality" means two or more. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

Claims

1. A monitoring and management method for mountain tunnel support construction, characterized in that: The following steps are involved: S1. Arrange monitoring points in the tunnel and obtain initial monitoring data of the monitoring points; S2. During the support construction process, the three-dimensional coordinate measurement method is used to measure multiple times based on the initial monitoring data of the monitoring points to obtain multi-point monitoring data in the tunnel; S3. Draw the cumulative deformation time curve, deformation rate time curve and deformation acceleration time curve based on the collected monitoring data, and analyze the data rules according to the curves to determine the stability of the surrounding rock during the support construction process.

2. The monitoring and management method for mountain tunnel support construction according to claim 1, characterized in that: The specific operation process in step S1 includes: According to the surrounding rock classification of mountain tunnels, the section spacing of monitoring points is determined, and monitoring points are arranged at the arch crown, arch waists on both sides and arch bottom of the tunnel section; A total station is set up at a point height where the control points on both sides of the tunnel can be observed. After error verification using the control points, the total station is used to measure the coordinate elevation of the monitoring points to obtain multiple sets of monitoring point elevation coordinate data.

3. The monitoring and management method for mountain tunnel support construction according to claim 1, characterized in that: The specific operation process of using the three-dimensional coordinate measurement method for multiple rounds of measurement in step S2 includes: Establish a measurement coordinate system and set up total stations at selected monitoring points in the tunnel; For any two points in the tunnel, a total station is used to obtain the coordinate relationship between the selected monitoring point and the two points, which is used to calculate the height difference and distance between the two points.

4. The monitoring and management method for mountain tunnel support construction according to claim 3, characterized in that: In the measurement coordinate system, the direction parallel to the tunnel centerline is defined as the X-axis, the direction perpendicular to the direction is defined as the Y-axis, and the direction perpendicular to the ground upward is defined as the Z-axis. The specific operation process of calculating the height difference and spacing for any two points in the tunnel in the measurement coordinate system includes: Use a total station to obtain the distance between the two points and the monitoring point P, the angle between the two points about the monitoring point P, and the azimuth of the two points, calculate the coordinates of the two points in the measurement coordinate system, and based on the coordinates of the two points, calculate the height difference and spacing between the two points.

5. The monitoring and management method for mountain tunnel support construction according to claim 1, characterized in that: The cumulative deformation time curve drawing process in step S3 includes: Eliminate the abnormal points in the original monitoring data obtained from each monitoring point and calculate the cumulative deformation U monitored on the i-th day i : And i =L i -L0 Where, L i is the total station survey line reading on the ith day, and L0 is the initial reading at the starting point; With time as the horizontal axis and the cumulative deformation U i The value is the vertical axis, and the curve is drawn.

6. The monitoring and management method for mountain tunnel support construction according to claim 1, characterized in that: The deformation rate time curve drawing process in step S3 includes: Eliminate the abnormal points in the original monitoring data obtained from each monitoring point and calculate the deformation rate V monitored on the i-th day i : In the formula, ΔL is the difference in distance between the two adjacent time periods, and Δt is the time difference between the two adjacent time periods; With time as the horizontal axis and deformation rate V as the horizontal axis i Draw a curve on the vertical axis.

7. The monitoring and management method for mountain tunnel support construction according to claim 6, characterized in that: The specific determination method for determining the stability of the surrounding rock through the deformation rate time curve in step S3 includes: When the deformation rate in the curve keeps decreasing, the surrounding rock is judged to be stable; when the deformation rate in the curve remains, the surrounding rock is in a continuous deformation stage, and the surrounding rock is judged to be unstable; when the deformation rate in the curve keeps increasing, the surrounding rock is judged to be unstable and at the same time it is judged to be in a dangerous state.

8. The monitoring and management method for mountain tunnel support construction according to claim 1, characterized in that: The deformation acceleration time curve drawing process in step S3 includes: Eliminate the abnormal points in the original monitoring data obtained from each monitoring point and calculate the deformation acceleration value a monitored on the i-th day i : In the formula, ΔV is the change in deformation rate between two adjacent time periods, and Δt is the time difference between two adjacent time periods; With time as the horizontal axis, the deformation rate is the deformation acceleration value a i Draw a curve on the vertical axis.

9. The monitoring and management method for mountain tunnel support construction according to claim 8, characterized in that: The specific determination method for determining the stability of the surrounding rock through the deformation acceleration time curve in step S3 includes: Deformation acceleration value a i <0, the deformation rate gradually decreases, and it is determined that the surface tunnel surrounding rock gradually tends to be stable; Deformation acceleration value a i = 0, if V = 0, the surrounding rock is judged to be in a stable stage, otherwise it is judged to be in a constant-speed deformation stage; Deformation acceleration value a i >0, the deformation rate continues to increase, and it is determined that the danger level of the surface tunnel surrounding rock increases.

10. The monitoring and management method for mountain tunnel support construction according to claim 1, characterized in that: The specific determination method of surrounding rock stability in step S3 also includes: Determine based on the deformation rate: when the clearance change rate of the surrounding rock remains above 1mm / d, the surrounding rock is judged to be in a state of aggravated deformation and needs to be strengthened; when the clearance change rate of the surrounding rock is less than 0.2mm / d, the surrounding rock is judged to be in a stable state.

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