Measurement method and system suitable for deformation of tunnel primary support steel arch

Abstract

The invention relates to the technical field of deformation monitoring, in particular to a measurement method and system suitable for tunnel primary support steel arch deformation, and the method comprises the steps: obtaining the strain data of each strain rod at each deformation monitoring point in a to-be-measured time period relative to a waist measurement point; according to the strain data corresponding to each deformation monitoring point in the to-be-detected time period, the movement condition of each strain rod is analyzed, the deformation conditions of different strain rods at the same deformation monitoring point are analyzed in combination with the physical parameter information of the strain rods, and the deformation detection index of each strain rod at each deformation monitoring point in the to-be-detected time period is obtained; obtaining a torsion angle detection index of each deformation monitoring point in the to-be-detected time period according to the deformation detection index and distance distribution between each deformation monitoring point and the waist detection point; and the deformation detection index and the torsion angle detection index are used to determine the tunnel steel arch deformation early warning condition in the to-be-detected time period. The steel arch deformation monitoring result is more comprehensive, and the monitoring safety is improved.

Description

Technical Field

[0001] The invention relates to the technical field of deformation monitoring, and in particular to a measurement method and system suitable for deformation of an initial support steel arch of a tunnel. Background Art

[0002] Initial tunnel support refers to temporary support measures for the excavated slopes and tops during tunnel excavation to ensure the stability of the tunnel structure. Its main function is to reinforce the surrounding rock, prevent it from loosening and deforming too much, and provide safety for subsequent construction. Initial support usually includes shotcrete, anchors and steel arches, etc. These measures can effectively control the stress release and deformation of the surrounding rock, and provide a safe working environment for subsequent permanent lining.

[0003] As an important component of the initial support of the tunnel, the steel arch mainly provides support resistance for the initial support of the tunnel and limits the deformation of the surrounding rock. At the same time, it serves as the rear support point of the advance support. Therefore, the steel arch plays a vital role in the initial support of the tunnel, and its deformation is directly related to the safety and stability of the tunnel construction.

[0004] During the initial support of the tunnel, the initial surrounding rock of the tunnel will experience a certain period of change until it stabilizes under the external load pressure. During this period, continuous testing can better ensure construction safety. However, when using the traditional total station measurement method to monitor the deformation of the steel arch, there are certain requirements for the location of the total station. Long-term monitoring will affect tunnel traffic and is costly. Limited by the monitoring angle, it is impossible to better monitor the torsional deformation of the steel arch in real time. Summary of the invention

[0005] In order to solve the technical problem that the existing tunnel initial steel arch deformation monitoring method is limited by various objective factors and cannot effectively monitor the torsional deformation of the steel arch in real time, the purpose of the present invention is to provide a measurement method and system suitable for the deformation of the tunnel initial support steel arch. The technical scheme adopted is as follows: In a first aspect, the present invention provides a method for measuring deformation of an initial support steel arch of a tunnel, comprising: A waist measuring point is set at the waist of the steel arch, and a deformation monitoring point is set at a position adjacent to each waist measuring point; a strain rod is set between the waist measuring point and the deformation monitoring point; and strain data of each strain rod at each deformation monitoring point relative to the waist measuring point during the test time period is obtained; According to the strain data corresponding to each deformation monitoring point in the time period to be measured, the movement of each strain rod is analyzed, and the deformation of different strain rods at the same deformation monitoring point is analyzed in combination with the physical parameter information of the strain rod, so as to obtain the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured; According to the deformation detection index and the distance distribution between each deformation monitoring point and the waist measurement point, a torsion angle detection index of each deformation monitoring point in the time period to be measured is obtained; The deformation detection index and the torsion angle detection index are used to judge the deformation warning situation of the tunnel steel arch within the test time period.

[0006] Preferably, the strain data includes axial strain values ​​and radial strain values.

[0007] Preferably, the movement of each strain rod is analyzed according to the strain data corresponding to each deformation monitoring point in the time period to be measured, and the deformation of different strain rods at the same deformation monitoring point is analyzed in combination with the physical parameter information of the strain rod, so as to obtain the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured, which specifically includes: According to the axial strain value of each strain rod at each deformation monitoring point and the length data of the corresponding stress rod, the axial displacement data of each strain rod at each deformation monitoring point is obtained; According to the radial strain value of each strain rod at each deformation monitoring point and various physical parameters of the corresponding stress rod, the radial displacement data of each strain rod at each deformation monitoring point is obtained; According to the axial displacement data and radial displacement data of each strain rod at each deformation monitoring point in the time period to be measured, combined with the length data of the corresponding stress rod, the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured is obtained.

[0008] Preferably, the step of obtaining the axial displacement data of each strain rod at each deformation monitoring point according to the axial strain value of each strain rod at each deformation monitoring point and the length data of the corresponding stress rod specifically includes: Based on the product of the axial strain value of each strain rod at each deformation monitoring point and the length data of the corresponding strain rod, the axial displacement data of each strain rod at each deformation monitoring point is determined.

[0009] Preferably, the step of obtaining radial displacement data of each strain rod at each deformation monitoring point according to the radial strain value of each strain rod at each deformation monitoring point and various physical parameters of the corresponding stress rod specifically includes: Based on the product relationship between the radial strain value and the diameter data of each strain rod at each deformation monitoring point and the ratio relationship of the length data, a function calculation formula of the radial strain value is constructed, and the radial displacement data of each strain rod at each deformation monitoring point is solved based on the function calculation formula.

[0010] Preferably, the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured is obtained according to the axial displacement data and radial displacement data of each strain rod at each deformation monitoring point in the time period to be measured, combined with the length data of the corresponding stress rod, specifically including: For any strain rod at any deformation monitoring point, taking the waist measuring point as the origin, based on the length data of the strain rod and the initial tilt angle of the strain rod, the initial polar coordinates of the strain rod relative to the waist measuring point are obtained; Acquire the axial displacement data of the strain rod at each moment in the time period to be measured, and determine the polar coordinates of the deformation polar coordinates of the strain rod at each moment in combination with the polar coordinates of the initial polar coordinates; Acquire the radial displacement data of the strain rod at each moment in the time period to be measured, and determine the deformation angle of the strain rod at each moment by combining the axial displacement data and the length data of the strain rod at the corresponding moment; and use the sum of the deformation angle and the initial tilt angle of the strain rod as the polar angle coordinate of the deformation polar coordinate of the strain rod at each moment; Based on the distance between the deformation polar coordinates at the end time and the initial time of the time period to be measured, the deformation detection index of the strain rod at the deformation monitoring point in the time period to be measured is obtained.

[0011] Preferably, the torsion angle detection index of each deformation monitoring point in the time period to be measured is obtained according to the deformation detection index and the distance distribution between each deformation monitoring point and the waist measurement point, specifically including: For any deformation monitoring point, the actual length between the deformation monitoring point and the waist measuring point is obtained, and the difference between the deformation detection indicators of the two strain rods at the same deformation monitoring point in the time period to be measured is calculated to obtain the deformation difference value of the deformation monitoring point in the time period to be measured; the inverse tangent function value of the ratio of the deformation difference value to the actual length is used as the torsion angle detection indicator of the deformation monitoring point in the time period to be measured.

[0012] Preferably, the method of using the deformation detection index and the torsion angle detection index to judge the deformation warning situation of the tunnel steel arch within the test time period specifically includes: Obtain standard deformation data and standard torsion data of tunnel steel arch deformation; obtain early warning of tunnel steel arch deformation during the time period to be tested based on the comparison results of the deformation detection index and the standard deformation data corresponding to each deformation monitoring point during the time period to be tested, and the comparison results of the torsion angle detection index and the standard torsion data.

[0013] Preferably, the deformation warning of the tunnel steel arch in the time period to be measured is obtained according to the comparison results of the deformation detection index corresponding to each deformation monitoring point in the time period to be measured and the standard deformation data, and the comparison results of the torsion angle detection index and the standard torsion data, specifically including: When the deformation detection index corresponding to each deformation monitoring point in the time period to be tested exceeds the standard deformation data, or the torsion angle detection index exceeds the standard torsion data, an early warning of tunnel steel arch deformation in the time period to be tested is issued; when the deformation detection index corresponding to each deformation monitoring point in the time period to be tested does not exceed the standard deformation data, and the torsion angle detection index does not exceed the standard torsion data, no early warning of tunnel steel arch deformation in the time period to be tested is issued.

[0014] In a second aspect, the present invention provides a measurement system for the deformation of an initial tunnel support steel arch, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the computer program is executed by the processor, the steps of a measurement method for the deformation of an initial tunnel support steel arch are implemented.

[0015] The embodiments of the present invention have at least the following beneficial effects: The present invention firstly sets a strain rod between the waist measuring point and the deformation monitoring point during the data collection stage, converts the displacement or deformation at the deformation monitoring point into the strain of the strain rod, and provides a data basis for the subsequent analysis of the displacement deformation and torsional deformation. Then, combined with the physical parameter data of the strain rod and the distance distribution between the deformation monitoring point and the waist measuring point, the displacement deformation and torsional deformation are analyzed more specifically, and the deformation performance of the deformation monitoring point is inferred by using the geometric relationship, thereby improving the measurement accuracy. Compared with the traditional monitoring method, the present invention can realize real-time monitoring of the deformation state, does not need to occupy the tunnel space for a long time, reduces the impact on traffic, and reduces the cost. At the same time, not only the steel arch shape variable is detected, but also the torsional deformation detection of the steel arch is performed, so that the steel arch deformation monitoring results are more comprehensive and the monitoring safety is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a flow chart of the steps of the method for measuring deformation of the initial support steel arch of a tunnel provided by the present invention; Figure 2 It is a schematic diagram of the tunnel cross-section structure provided by the present invention; Figure 3 It is a structural schematic diagram of the strain rod arrangement provided by the present invention; Figure 4 It is a structural schematic diagram of the arrangement of the steel arch section strain rod provided by the present invention; Figure 5 It is a partial structural schematic diagram of the strain rod provided by the present invention; Figure 6 is a flowchart of the steps of the method for obtaining deformation detection indicators provided by the present invention; Among them, the numbers in the figure are: A, arch apex, B, left waist measuring point, C, right waist measuring point; a, first connection point, b, second connection point, c, third connection point, d, fourth connection point; 1, left strain rod, 2, right strain rod; x, axial direction, y, radial direction. DETAILED DESCRIPTION

[0018] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following, in combination with the accompanying drawings and preferred embodiments, the measurement method and system for the deformation of the initial support steel arch of the tunnel proposed by the present invention, its specific implementation method, structure, characteristics and effects are described in detail as follows.

[0019] Before introducing the specific solutions provided by the embodiments of the present application, the implementation scenarios in the present application are explained to facilitate understanding by those skilled in the art, and are not intended to limit the uses in the present application.

[0020] Tunnel primary support is a temporary or permanent structure constructed immediately after tunnel excavation, which aims to quickly stabilize the surrounding rock, prevent collapse, and provide a safe environment for subsequent construction (such as secondary lining). Its core function is to balance the surrounding rock stress and control deformation through active or passive means. Primary support is usually composed of a combination of multiple materials and technologies. The main steps include: Shotcrete: Use wet or dry spraying technology to quickly form a concrete protective layer on the excavation surface, close the cracks in the rock surface, and prevent weathering and peeling. Anchor system: Full-length bonded anchor: Combine with the surrounding rock through grouting to form a reinforcement ring. Prestressed anchor: Actively apply prestress to improve the stress state of the surrounding rock. Self-drilling anchor: Suitable for broken strata, with both drilling and anchoring functions. Steel arch (steel support): The core load-bearing component provides circumferential stiffness and forms a composite structure with shotcrete. Steel mesh: Laid between the rock surface and shotcrete to prevent concrete shrinkage and cracking and improve integrity.

[0021] The core role of the steel arch in the initial support is: Three-dimensional stress bearing: The bending stress of the surrounding rock is resisted by the section inertia moment of the steel or grid, which is especially suitable for high ground stress or shallow buried bias tunnels. Deformation coordination control: Works in conjunction with shotcrete to limit the expansion of the plastic zone of the surrounding rock. The yield strength of the steel arch can provide a certain ductile deformation capacity to avoid brittle failure. Temporary bearing during the construction period: Before the strength of the shotcrete reaches the design value, it independently bears most of the load to ensure the stability of the face. Stratum adaptability adjustment: By adjusting the arch spacing (such as 0.5m~1.2m) and cross-sectional size (such as I20~I25 steel), it can adapt to different surrounding rock grades. The broken zone can be strengthened with a double-layer arch. Spatial positioning benchmark: Provide a spatial reference system for the subsequent layout of anchor rods and steel mesh to ensure the geometric accuracy of the support system.

[0022] In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0023] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0024] The following is a detailed description of the specific scheme of the method and system for measuring deformation of a tunnel initial support steel arch provided by the present invention in conjunction with the accompanying drawings.

[0025] See also Figure 1 , which shows a flow chart of the steps of a method for measuring deformation of a tunnel initial support steel arch provided by an embodiment of the present invention, the method comprising the following steps: Step S100, setting waist measuring points at the waist of the steel arch, and setting deformation monitoring points at adjacent positions of each waist measuring point; strain rods are arranged between the waist measuring points and the deformation monitoring points; and obtaining strain data of each strain rod at each deformation monitoring point relative to the waist measuring point during a test time period.

[0026] First, in order to ensure the safety and stability of the tunnel excavation process, during the tunnel excavation process, for the tunnel sections that need to be monitored, measuring points are set at the arch waist of the section, such as Figure 2 As shown, the waist measurement points include left waist measurement point B and right waist measurement point C. Figure 2 The position of the dome apex A is also shown.

[0027] Then, a deformation monitoring point is set at the adjacent position of each waist measuring point. Specifically, after the steel arch is installed, strain rods are placed between the left waist measuring point B and the right waist measuring point C of the steel arch and the initial support steel arch connection points, respectively. The pressure between the measuring point and the steel arch connection point is measured by the strain rod to reflect the deformation of each steel arch connection point. When installing the strain rod, the two sections of the strain rod can be fixed at the welding point of the steel arch connection point. Figure 3 As shown, the first connection point a, the second connection point b, the third connection point c and the fourth connection point d are all deformation monitoring points set in this embodiment, and a strain rod is provided between each deformation monitoring point and the nearest adjacent waist measuring point.

[0028] Furthermore, since the steel material of the steel arch is usually "I" steel, the steel arch usually has a certain width. Therefore, during installation, a double strain rod can be set between the steel arch measuring point and the connection point. The double strain rod can be used to reflect the deformation and stress conditions on both sides of the steel arch to measure the torsional deformation of the steel arch. The cross-section of the steel arch is shown in the figure. Figure 4 As shown, the left waist measuring point B includes a left strain rod 1 and a right strain rod 2. It should be noted that the material of the strain rod can be selected to be consistent with the steel arch, the diameter is selected to be 15-20mm, and the full-bridge strain gauge is attached to the surface. It is connected to the stainless steel fixture and the steel arch through the universal adjustment bracket, and the positioning error is less than or equal to 1mm.

[0029] It can be seen from this that the deformation monitoring point where the connection point corresponding to each waist measuring point is located includes two strain rods. It should be understandable that subsequent characteristic analysis was carried out on the stress and deformation conditions of each strain rod between the waist measuring point on the steel arch and each deformation monitoring point.

[0030] Finally, the strain data of each strain rod relative to the waist measuring point at each deformation monitoring point in the test time period is obtained, and the strain data includes axial strain value and radial strain value. In this embodiment, the initial tilt angle of the strain rod is measured by an encoder or other angle measurement sensor.

[0031] In the above strain rod, the deformation of the strain rod mainly manifests itself in forces in two directions, one of which is the force in the axial direction of the strain rod, which mainly causes the length of the strain rod to change, which is manifested in the axial strain of the strain rod; the other is the force in the lateral direction, that is, the radial force of the strain rod, which mainly causes the strain rod to bend, which is manifested in the bending strain of the strain rod.

[0032] More specifically, in this embodiment, a full-bridge circuit is formed by strain gauges, and the resistance change rate is measured to obtain the axial strain value of each strain rod. The radial strain value of each strain rod is obtained by symmetrically arranging strain gauges on each strain rod, that is, one strain gauge on the upper surface and one strain gauge on the lower surface of the strain rod, and calculating the strain difference of the symmetrically arranged strain gauges. The method for obtaining the axial strain value and radial strain value of the strain rod is a well-known technology, and only a brief introduction is given here without further elaboration.

[0033] It can be understood that the time period to be measured refers to the unit monitoring time of the steel arch deformation during the initial support of the tunnel, reflecting the process of real-time monitoring of the steel arch deformation. Data collection operations are performed at each moment during the time period to be measured.

[0034] Step S200: Analyze the movement of each strain rod according to the strain data corresponding to each deformation monitoring point in the time period to be measured, analyze the deformation of different strain rods at the same deformation monitoring point in combination with the physical parameter information of the strain rod, and obtain the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured.

[0035] By installing strain rods between the measuring points, the strain rods are used as mechanical transmission elements to convert the displacement or deformation of the waist measuring point into the axial strain or bending strain of the corresponding connected strain rods. By measuring the strain value of the strain rods, the deformation of the associated waist measuring point is inferred in combination with the geometric relationship. Based on this, the deformation analysis of each strain rod at each deformation monitoring point is mainly divided into two dimensions, namely, axial and radial. For the sake of ease of explanation and understanding, this embodiment is described by taking a strain rod as an example. Figure 5 , which shows a schematic diagram of the local structure of a strain rod between a waist measuring point and a deformation monitoring point, where x represents the axial direction and y represents the radial direction.

[0036] More specifically, if Figure 6 As shown, the method for acquiring the deformation detection index of each strain rod at each deformation monitoring point within the test time period can be implemented by steps S201 to S203.

[0037] Step S201, obtaining axial displacement data of each strain rod at each deformation monitoring point according to the axial strain value of each strain rod at each deformation monitoring point and the length data of the corresponding stress rod.

[0038] When axial displacement occurs between the deformation monitoring point and the waist measuring point connected to the strain rod, the relative displacement between the waist measuring point and the deformation monitoring point will cause axial strain of the strain rod. That is, through the functional expression relationship between the axial strain value of the strain rod, the axial displacement of the strain rod and the length of the strain rod, the axial displacement performance of the strain rod when the axial strain phenomenon occurs can be solved.

[0039] Specifically, the axial displacement data of each strain rod at each deformation monitoring point is determined based on the product of the axial strain value of each strain rod at each deformation monitoring point and the length data of the corresponding strain rod.

[0040] More specifically, a strain rod between the left waist measuring point B and the first connection point a is used as an example for explanation. It can be understood that the deformation and displacement analysis operation can be performed at each moment in the monitoring time period. In this step, one moment is used as an example for explanation. Then, the functional relationship expression between the axial strain value of the strain rod, the axial displacement of the strain rod and the length of the strain rod can be expressed as: , represents the axial strain value of the strain bar, represents the axial displacement data of the strain bar, Represents the length data of the strain rod. The axial displacement data of the strain rod can be solved through this functional relationship expression .

[0041] It should be noted that the length data of the strain rod is the inherent physical parameter data of the strain rod and can be directly obtained. The axial displacement data of the strain rod characterizes the axial displacement performance of the relative displacement between the waist measurement point and the deformation monitoring point.

[0042] Step S202, obtaining radial displacement data of each strain rod at each deformation monitoring point according to the radial strain value of each strain rod at each deformation monitoring point and various physical parameters of the corresponding stress rod.

[0043] Based on the similar situation in the axial direction, when radial displacement occurs between the deformation monitoring point and the waist measuring point connected to the strain rod, the bending between the waist measuring point and the deformation monitoring point will cause the radial bending strain phenomenon of the strain rod. That is, through the functional expression relationship between the radial strain value of the strain rod, the physical parameter data of the strain rod and the radial displacement of the strain rod, the radial displacement performance when the strain rod bends can be solved.

[0044] Specifically, based on the product relationship between the radial strain value and the diameter data of each strain rod at each deformation monitoring point and the ratio relationship of the length data, a function calculation formula of the radial strain value is constructed, and the radial displacement data of each strain rod at each deformation monitoring point is solved based on the function calculation formula.

[0045] More specifically, a strain rod between the left waist measuring point B and the first connection point a is used as an example for explanation. It can be understood that the deformation and displacement analysis operation can be performed at each moment in the monitoring time period. In this step, one moment is used as an example for explanation. Then, the functional relationship expression between the radial strain value of the strain rod, the physical parameter data of the strain rod and the radial displacement of the strain rod, that is, the functional calculation formula of the radial strain value can be expressed as:

[0046] in, represents the radial strain value of the strain bar, represents the radial displacement data of the strain bar, represents the length data of the strain bar, Represents the cross-sectional diameter of the strain rod. The radial displacement data of the strain rod can be solved by this function calculation formula .

[0047] It should be noted that the cross-sectional diameter of the strain rod is the inherent physical parameter data of the strain rod and can be directly obtained. The radial displacement data of the strain rod characterizes the radial displacement performance of the relative bending between the waist measuring point and the deformation monitoring point.

[0048] Step S203, according to the axial displacement data and radial displacement data of each strain rod at each deformation monitoring point in the time period to be measured, combined with the length data of the corresponding stress rod, the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured is obtained.

[0049] By combining the displacement performance of the strain rod in the axial and radial directions respectively, the position data corresponding to the deformation phenomenon of the strain rod at the corresponding deformation monitoring point at each moment is determined. Furthermore, by comparing the initial position of each deformation monitoring point after the steel arch is installed with the position after the deformation phenomenon occurs, the deformation degree at the current monitoring moment is determined.

[0050] Specifically, for any strain rod at any deformation monitoring point, the waist measuring point is taken as the origin, and based on the length data of the strain rod and the initial tilt angle of the strain rod, the initial polar coordinates of the strain rod relative to the waist measuring point are obtained. In this embodiment, for a strain rod between the left waist measuring point B and the first connection point a, the length data of the strain rod is used as the polar diameter coordinate of the initial polar coordinate corresponding to the strain rod, and the initial tilt angle of the strain rod is used as the polar angle coordinate of the initial polar coordinate corresponding to the strain rod.

[0051] According to the same method as step S201, the axial displacement data of the strain rod at each moment in the time period to be measured can be obtained, and the polar radial coordinates of the deformation polar coordinates of the strain rod at each moment can be determined by combining the polar radial coordinates of the initial polar coordinates. Specifically, for any moment, the sum of the axial displacement data of the strain rod and the length data of the strain rod is used as the polar radial coordinates of the deformation polar coordinates of the strain rod, which can be expressed as , represents the axial displacement data of the strain bar, Indicates the length data of the strain bar.

[0052] According to the same method as step S202, the radial displacement data of the strain rod at each moment in the time period to be measured can be obtained, and the deformation angle of the strain rod at each moment can be determined by combining the axial displacement data and the length data of the strain rod at the corresponding moment; and the sum of the deformation angle and the initial tilt angle of the strain rod is used as the polar angle coordinate of the deformation polar coordinate of the strain rod at each moment.

[0053] Specifically, at any time, the cumulative sum of the axial displacement data and the length data of the strain rod is obtained, and the inverse tangent function of the ratio of the radial displacement data of the strain rod to the cumulative sum is calculated to obtain the deformation angle of the strain rod, which can be expressed as , represents the deformation angle of the strain bar, represents the axial displacement data of the strain bar, represents the radial displacement data of the strain bar, represents the length data of the strain bar, is the inverse tangent function. Furthermore, the polar angle coordinates of the deformation polar coordinates of the strain rod can be expressed as , represents the initial tilt angle of the strain bar.

[0054] It can be understood that the method for obtaining polar coordinates in this step is to perform data analysis by taking the data of a strain rod between the left waist measuring point B and the first connection point a at one moment as an example. According to the same method, the deformation polar coordinates of each strain rod corresponding to each waist measuring point at each moment in the measured time period can be obtained, which can be used for subsequent analysis of the deformation and torsion of the strain rod at the position of the deformation monitoring point.

[0055] Finally, based on the distance between the deformation polar coordinates at the end time and the initial time of the time period to be measured, the deformation detection index of the strain rod at the deformation monitoring point within the time period to be measured is obtained.

[0056] It can be understood that the deformation polar coordinates at the end moment of the time period to be measured represent the end position of the deformation of the deformation monitoring point that monitors the deformation process within the time period to be measured, and the deformation polar coordinates at the initial moment of the time period to be measured represent the initial position of the deformation monitoring point that monitors the deformation process within the time period to be measured. Through the distance distribution between the initial position and the end position, the deformation degree of each strain rod in the deformation monitoring process within the current time period to be measured can be calculated.

[0057] Specifically, taking a strain rod between the left waist measuring point B and the first connection point a as an example, the deformation polar coordinates of the strain rod at the initial moment and the deformation polar coordinates at the end moment in the time period to be measured are respectively converted into rectangular coordinates, and then the Euclidean distance between the two rectangular coordinates is calculated to obtain the deformation detection index of the strain rod in the time period to be measured.

[0058] At this point, the deformation detection index characterizes the deformation degree of the corresponding strain rod at the location of the deformation monitoring point.

[0059] Step S300, obtaining a torsion angle detection index of each deformation monitoring point within a test time period according to the deformation detection index and the distance distribution between each deformation monitoring point and the waist measurement point.

[0060] In the application of steel arches, in addition to direct stress, uneven force on the steel arch may also cause torsion, thus creating safety hazards. Therefore, the torsional deformation can be judged in combination with the double strain rods installed at the waist measuring point of the steel arch. The torsion amount at the deformation monitoring point of the steel arch can be judged by the deformation degree corresponding to the two different strain rods located at the same deformation monitoring point, thereby judging the torsion health of the steel arch.

[0061] like Figure 4 As shown in the figure, when the steel arch is twisted, the position information of the left strain rod 1 and the right strain rod 2 after deformation analysis will be quite different, and the corresponding displacement deformation degree of the left strain rod 1 and the right strain rod 2 will also be quite different. By analyzing the deformation difference between different strain rods at the same deformation monitoring point, combined with the actual steel arch length between the waist measuring point and the deformation monitoring point, the deformation at the deformation monitoring point is converted into a twisting condition, which is used to simultaneously monitor the twisting degree of each deformation monitoring point relative to the waist measuring point.

[0062] Specifically, for any deformation monitoring point, the actual length between the deformation monitoring point and the waist measurement point is obtained, and the difference between the deformation detection indicators of the two strain rods at the same deformation monitoring point in the time period to be measured is calculated to obtain the deformation difference value of the deformation monitoring point in the time period to be measured; the inverse tangent function value of the ratio of the deformation difference value to the actual length is used as the torsion angle detection indicator of the deformation monitoring point in the time period to be measured.

[0063] It can be understood that the actual length between the deformation monitoring point and the waist measuring point is also the actual arc length of the steel arch between the deformation monitoring point and the waist measuring point. Further, taking the strain rod between the left waist measuring point B and the deformation monitoring point corresponding to the first connection point a as an example, the torsion angle detection index of the deformation monitoring point corresponding to the first connection point a during the test time period can be expressed as: ,in It indicates the torsion angle detection index of the deformation monitoring point within the test time period. It represents the deformation detection index of the left strain rod 1 at the location of the deformation monitoring point during the test period. It represents the deformation detection index of the right strain rod 2 at the location of the deformation monitoring point during the test period, Indicates the actual length of the steel arch between the deformation monitoring point and the waist measuring point. is the inverse tangent function.

[0064] At this point, the torsion angle detection index between each deformation monitoring point and the corresponding waist measurement point during the test time period represents the torsion deformation between the deformation monitoring point and the corresponding waist measurement point.

[0065] Step S400: using the deformation detection index and the torsion angle detection index to determine the early warning situation of the tunnel steel arch deformation within the time period to be tested.

[0066] Specifically, by using the allowable deformation range and torsion angle range of the steel arch set by the tunnel engineering standards, an engineering risk warning for the initial tunnel support can be provided, thereby achieving the purpose of deformation monitoring of the steel arch for the initial tunnel support.

[0067] Based on this, the standard deformation data and standard torsion data of the tunnel steel arch deformation are obtained; according to the comparison results of the deformation detection index and the standard deformation data corresponding to each deformation monitoring point in the test time period, and the comparison results of the torsion angle detection index and the standard torsion data, the early warning of the tunnel steel arch deformation in the test time period is obtained.

[0068] It can be understood that the standard deformation data represents the maximum allowable deformation of the tunnel steel arch, that is, when the degree of deformation of the steel arch is greater than the maximum allowable deformation, the deformation of the tunnel steel arch does not meet the engineering standards. The standard torsion data represents the maximum allowable torsion angle of the tunnel steel arch, that is, when the angle of the steel arch deformation is greater than the maximum allowable deformation angle, the deformation of the tunnel steel arch does not meet the engineering standards, and both require early warnings so that relevant staff can conduct maintenance to avoid safety problems. It should be noted that the standard deformation data and standard torsion data can be directly obtained according to the engineering standards under different tunnel initial support scenarios, and will not be elaborated on here.

[0069] More specifically, when the deformation detection index corresponding to each deformation monitoring point within the time period to be tested exceeds the standard deformation data, or the torsion angle detection index exceeds the standard torsion data, an early warning of tunnel steel arch deformation within the time period to be tested is issued; when the deformation detection index corresponding to each deformation monitoring point within the time period to be tested does not exceed the standard deformation data, and the torsion angle detection index does not exceed the standard torsion data, no early warning of tunnel steel arch deformation within the time period to be tested is issued.

[0070] In summary, this embodiment improves the measurement accuracy by installing strain rods between measuring points, converting the displacement or deformation of the measuring points into the strain value of the strain rod, and inferring the deformation of the associated measuring points by combining the geometric relationship. Compared with the traditional total station measurement method, this method does not need to occupy the tunnel space for a long time, reduces the impact on traffic, and reduces the cost. At the same time, it not only detects the steel arch shape variables of key nodes, but also performs torsional deformation detection of the steel arch, improves the detection dimension of the steel arch, and improves the monitoring safety. Furthermore, by real-time monitoring of the deformation and torsion of the steel arch, the uneven force and torsion problems of the steel arch are discovered in time, which improves the safety of tunnel construction. This method has strong adaptability and is suitable for tunnels with different surrounding rock grades. By adjusting the arrangement and measurement parameters of the strain rods, it can adapt to different construction environments and requirements.

[0071] The embodiment of the present invention also provides a measurement system for deformation of steel arches in the initial support of tunnels, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the computer program is executed by the processor, the steps of a measurement method for deformation of steel arches in the initial support of tunnels are implemented. Since the embodiment of the measurement method for deformation of steel arches in the initial support of tunnels has been described in detail, it will not be described in detail here.

[0072] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for measuring deformation of initial tunnel support steel arches, characterized in that: The method comprises the following steps: A waist measuring point is set at the waist of the steel arch, and a deformation monitoring point is set at a position adjacent to each waist measuring point; a strain rod is set between the waist measuring point and the deformation monitoring point; and strain data of each strain rod at each deformation monitoring point relative to the waist measuring point during the test time period is obtained; According to the strain data corresponding to each deformation monitoring point in the time period to be measured, the movement of each strain rod is analyzed, and the deformation of different strain rods at the same deformation monitoring point is analyzed in combination with the physical parameter information of the strain rod, so as to obtain the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured; According to the deformation detection index and the distance distribution between each deformation monitoring point and the waist measurement point, a torsion angle detection index of each deformation monitoring point in the time period to be measured is obtained; The deformation detection index and the torsion angle detection index are used to judge the deformation warning situation of the tunnel steel arch within the test time period.

2. The method for measuring deformation of initial tunnel support steel arch according to claim 1, characterized in that: The strain data includes an axial strain value and a radial strain value.

3. The method for measuring deformation of initial tunnel support steel arch according to claim 2, characterized in that: The method analyzes the movement of each strain rod according to the strain data corresponding to each deformation monitoring point in the time period to be measured, and analyzes the deformation of different strain rods at the same deformation monitoring point in combination with the physical parameter information of the strain rod, so as to obtain the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured, which specifically includes: According to the axial strain value of each strain rod at each deformation monitoring point and the length data of the corresponding stress rod, the axial displacement data of each strain rod at each deformation monitoring point is obtained; According to the radial strain value of each strain rod at each deformation monitoring point and various physical parameters of the corresponding stress rod, the radial displacement data of each strain rod at each deformation monitoring point is obtained; According to the axial displacement data and radial displacement data of each strain rod at each deformation monitoring point in the time period to be measured, combined with the length data of the corresponding stress rod, the deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured is obtained.

4. The method for measuring deformation of initial tunnel support steel arch according to claim 3 is characterized in that: The method of obtaining the axial displacement data of each strain rod at each deformation monitoring point according to the axial strain value of each strain rod at each deformation monitoring point and the length data of the corresponding stress rod specifically includes: Based on the product of the axial strain value of each strain rod at each deformation monitoring point and the length data of the corresponding strain rod, the axial displacement data of each strain rod at each deformation monitoring point is determined.

5. The method for measuring deformation of initial tunnel support steel arch according to claim 3, characterized in that: The radial displacement data of each strain rod at each deformation monitoring point is obtained according to the radial strain value of each strain rod at each deformation monitoring point and various physical parameters of the corresponding stress rod, specifically including: Based on the product relationship between the radial strain value and the diameter data of each strain rod at each deformation monitoring point and the ratio relationship of the length data, a function calculation formula of the radial strain value is constructed, and the radial displacement data of each strain rod at each deformation monitoring point is solved based on the function calculation formula.

6. The method for measuring deformation of initial tunnel support steel arch according to claim 3, characterized in that: The deformation detection index of each strain rod at each deformation monitoring point in the time period to be measured is obtained according to the axial displacement data and radial displacement data of each strain rod at each deformation monitoring point in the time period to be measured, combined with the length data of the corresponding stress rod, specifically including: For any strain rod at any deformation monitoring point, taking the waist measuring point as the origin, based on the length data of the strain rod and the initial tilt angle of the strain rod, the initial polar coordinates of the strain rod relative to the waist measuring point are obtained; Acquire the axial displacement data of the strain rod at each moment in the time period to be measured, and determine the polar coordinates of the deformation polar coordinates of the strain rod at each moment in combination with the polar coordinates of the initial polar coordinates; Acquire the radial displacement data of the strain rod at each moment in the time period to be measured, and determine the deformation angle of the strain rod at each moment by combining the axial displacement data and the length data of the strain rod at the corresponding moment; and use the sum of the deformation angle and the initial tilt angle of the strain rod as the polar angle coordinate of the deformation polar coordinate of the strain rod at each moment; Based on the distance between the deformation polar coordinates at the end time and the initial time of the time period to be measured, the deformation detection index of the strain rod at the deformation monitoring point in the time period to be measured is obtained.

7. The method for measuring deformation of initial tunnel support steel arch according to claim 3, characterized in that: The method of obtaining the torsion angle detection index of each deformation monitoring point in the time period to be measured according to the deformation detection index and the distance distribution between each deformation monitoring point and the waist measurement point specifically includes: For any deformation monitoring point, the actual length between the deformation monitoring point and the waist measuring point is obtained, and the difference between the deformation detection indicators of the two strain rods at the same deformation monitoring point in the time period to be measured is calculated to obtain the deformation difference value of the deformation monitoring point in the time period to be measured; the inverse tangent function value of the ratio of the deformation difference value to the actual length is used as the torsion angle detection indicator of the deformation monitoring point in the time period to be measured.

8. The method for measuring deformation of initial tunnel support steel arch according to claim 7, characterized in that: The method of using the deformation detection index and the torsion angle detection index to judge the deformation warning situation of the tunnel steel arch within the time period to be tested specifically includes: Obtain standard deformation data and standard torsion data of tunnel steel arch deformation; obtain early warning of tunnel steel arch deformation during the time period to be tested based on the comparison results of the deformation detection index and the standard deformation data corresponding to each deformation monitoring point during the time period to be tested, and the comparison results of the torsion angle detection index and the standard torsion data.

9. The method for measuring deformation of initial tunnel support steel arch according to claim 1, characterized in that: The deformation warning of the tunnel steel arch in the time period to be tested is obtained according to the comparison results of the deformation detection index and the standard deformation data corresponding to each deformation monitoring point in the time period to be tested, and the comparison results of the torsion angle detection index and the standard torsion data, specifically including: When the deformation detection index corresponding to each deformation monitoring point in the time period to be tested exceeds the standard deformation data, or the torsion angle detection index exceeds the standard torsion data, an early warning of tunnel steel arch deformation in the time period to be tested is issued; when the deformation detection index corresponding to each deformation monitoring point in the time period to be tested does not exceed the standard deformation data, and the torsion angle detection index does not exceed the standard torsion data, no early warning of tunnel steel arch deformation in the time period to be tested is issued.

10. A system for measuring deformation of a tunnel initial support steel arch, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the computer program is executed by the processor, the steps of the method for measuring deformation of a steel arch for initial support of a tunnel as described in any one of claims 1 to 9 are implemented.

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