Displacement monitoring device and monitoring method

Abstract

The invention relates to the technical field of rock-soil body displacement monitoring, in particular to a displacement monitoring device and a monitoring method. The device comprises a protective sleeve, the protective sleeve is fixedly installed in a supporting body, and the two ends of the protective sleeve are flush with the two sides of the supporting body respectively; the first measuring rod is inserted into the protective sleeve in a sliding manner along the axial direction of the protective sleeve; one end of the first measuring rod is located in the protective sleeve, and the other end is located in the rock-soil body; the sealing cover is detachably connected with one end, far away from the rock-soil body, of the protective sleeve; the first displacement sensor is installed on the sealing cover, and a measuring head of the first displacement sensor abuts against the end, located in the protection sleeve, of the first measuring rod. On one hand, the displacement condition of the rock-soil body on the outer side of the supporting body can be reflected more accurately, and on the other hand, it can be ensured that the monitoring device is not damaged in the construction process of the underground building in the foundation pit.

Description

Technical Field

[0001] The present invention relates to the technical field of rock and soil displacement monitoring, and in particular to a displacement monitoring device and a monitoring method. Background Art

[0002] Before constructing the underground building in the excavated foundation pit, the side walls of the foundation pit need to be supported. In order to ensure the safety of the construction of the underground building, it is necessary to monitor the rock and soil around the foundation pit, and then grasp the dynamic information of the rock and soil in real time, and according to the dynamic information of the rock and soil, timely strengthen the support of the area with significant displacement of the rock and soil.

[0003] However, the existing monitoring methods using displacement sensors usually install monitoring points on the support surface or are buried inside the support body, and do not penetrate into the rock and soil. The monitoring data cannot reflect the displacement of the rock and soil in a timely manner. Moreover, the monitoring points exposed on the surface of the support body have no protection measures and are easily damaged during the construction of underground buildings, resulting in discontinuous monitoring data and unable to truly reflect the deformation process and displacement of the rock and soil. It can be seen that the existing monitoring methods are difficult to truly reflect the dynamic process of the displacement of the rock and soil around the foundation pit, resulting in a large safety hazard in the construction of underground buildings. Summary of the invention

[0004] The object of the present invention is to provide a displacement monitoring device and a monitoring method, which can at least partially overcome the above-mentioned technical problems. On the one hand, it can more accurately reflect the displacement of the rock and soil body outside the support body. On the other hand, it can also ensure that the monitoring device will not be damaged during the construction of the underground building in the foundation pit.

[0005] On the one hand, the present invention provides a displacement monitoring device, which can be used to monitor the displacement of a rock and soil body outside a support body. Specifically, the displacement monitoring device includes: a protective sleeve, which is fixedly installed in the support body, and the two ends of the protective sleeve are respectively flush with the two sides of the support body; a first measuring rod, which is inserted into the protective sleeve along the axial direction of the protective sleeve; one end of the first measuring rod is located inside the protective sleeve, and the other end is located inside the rock and soil body; a cover, which is detachably connected to one end of the protective sleeve away from the rock and soil body; and a first displacement sensor, which is installed on the cover, and the probe of the first displacement sensor abuts against one end of the first measuring rod located inside the protective sleeve.

[0006] Furthermore, the first measuring rod is a hollow rod, and the displacement monitoring device also includes a second measuring rod, and a pointed head is provided at one end of the second measuring rod; the second measuring rod is inserted into the first measuring rod along the axial direction of the first measuring rod, and the pointed head faces the rock and soil body; an abutment plate is detachably installed at the end of the first measuring rod away from the rock and soil body, and the measuring head of the first displacement sensor abuts against the abutment plate.

[0007] Furthermore, the displacement monitoring device also includes a plurality of sub-monitoring components, each of the sub-monitoring components is evenly distributed along the circumference of the axis of the second measuring rod, each of the sub-monitoring components is slidably connected to the first measuring rod, and the sliding direction is perpendicular to the axis direction of the second measuring rod; for any sub-monitoring component, a slider is fixedly installed on the side of the sub-monitoring component facing the second measuring rod, a wedge-shaped platform is provided on the side of the second measuring rod facing the sub-monitoring component, and a sliding groove cooperating with the slider is provided on the wedge surface of the wedge-shaped platform.

[0008] Furthermore, during the process of inserting the first measuring rod and the second measuring rod into the rock and soil body, the pointed head is exposed on the end face of the first measuring rod facing the rock and soil body, and each of the sub-monitoring components is located inside the first measuring rod; during the process of the pointed head retracting between the two end faces of the first measuring rod, each of the sliding grooves causes the corresponding sub-monitoring component to slide toward the outside of the first measuring rod.

[0009] Furthermore, the sub-monitoring assembly includes a mounting tube, a second displacement sensor and a contact plate; the mounting tube is slidably connected to the first measuring rod, and the slider is fixedly mounted on the side of the mounting tube facing the second measuring rod; the second displacement sensor is fixedly mounted on the mounting tube, and the measuring head of the second displacement sensor faces the rock and soil body, and the contact plate is fixedly mounted on the measuring head of the second displacement sensor.

[0010] Preferably, the displacement monitoring device also includes a mounting seat; a plurality of slide rails are arranged inside the side of the protective sleeve away from the rock and soil body, and each of the slide rails is parallel to the axial direction of the protective sleeve; the mounting seat and each of the slide rails are slidably connected, and the sliding direction is parallel to the axial direction of the protective sleeve; the first displacement sensor is fixedly mounted on the mounting seat, and a threaded hole is opened on the side of the mounting seat away from the rock and soil body; an adjusting screw threadedly connected to the threaded hole is rotatably mounted on the cover.

[0011] On the other hand, the present invention provides a displacement monitoring method, which is based on the above-mentioned displacement monitoring device. Specifically, the displacement monitoring method includes: installing the displacement monitoring device at multiple preset monitoring points, and continuously collecting output data of each displacement monitoring device after installation; for any displacement monitoring device, the output data includes a first displacement output by a first displacement sensor, and multiple second displacements output by each of the second displacement sensors; when there is a change in the first displacement and / or the second displacement, it is determined that the rock and soil body has shifted.

[0012] Furthermore, the point where the rock mass first acts on the support body after displacement occurs is defined as the failure point; when the first displacements of multiple displacement monitoring devices change, the changed first displacements are compared, and if the following conditions are met: ,in, X max is the maximum value among the first displacements that have changed, X min is the minimum value of the first displacements that have changed, is the average value of the first displacements that have changed, R is the preset coefficient; then it is considered that the failure point is located at X max The location of the corresponding displacement monitoring device; otherwise, it is deemed that the rock and soil mass has undergone overall displacement.

[0013] Furthermore, for any displacement monitoring device, the number of the sub-monitoring components is four; the displacement monitoring devices are distributed in a rectangular array and the horizontal and vertical spacings of the array are both d ; The point where the rock mass first acts on the support body after displacement occurs is defined as the failure point; the displacement monitoring method also includes: when only the first displacement corresponding to one displacement monitoring device and the four second displacements all change, comparing the magnitude relationship of the four second displacements; when there is only one maximum value among the four second displacements, establishing a plane rectangular coordinate system on the outer side of the support body with the position of the displacement monitoring device as the origin, and the sub-monitoring component corresponding to the maximum value is located at x On the positive half axis of the axis; if y If the second displacements of the two sub-monitoring components on the axis are equal, it is considered that the failure point is located at x The positive half axis of the axis, and the distance between the destruction point and the origin is less than ; If located y If the second displacements of the two sub-monitoring components on the axis are larger, it is considered that the failure point is located at x The positive half axis of the axis is oriented toward the quadrant where the sub-monitoring component corresponding to the larger value is located, and the damage point and x axis, yThe distance between the axes is less than ; When there are two maximum values ​​among the four second displacements, and the sub-monitoring components corresponding to the two maximum values ​​are adjacent, it is determined that the failure point is located on the side of the perpendicular midline connecting the sub-monitoring components corresponding to the two maximum values, far away from the other two sub-monitoring components, and the distance between the failure point and the position where the displacement monitoring device is located is less than When the four second displacements are equal, it is determined that the failure point is located at the position where the displacement monitoring device is located.

[0014] Furthermore, the change in the first displacement amount per unit time is defined as a displacement rate, and the displacement monitoring method also includes: for any displacement monitoring device, determining the safety state of the rock and soil body according to the displacement rate, including: when the displacement rate is equal to zero, it is determined that the rock and soil body at the location of the displacement monitoring device is in a stable state; when the displacement rate is greater than zero, it is determined that the rock and soil body at the location of the displacement monitoring device is in a continuous displacement state; when the displacement rate continues to increase, it is determined that the rock and soil body at the location of the displacement monitoring device is in an unstable state.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The displacement of the measuring rod of a displacement monitoring device provided by the embodiment of the present disclosure can represent the actual displacement of the rock and soil body, and the displacement transmitted by the measuring rod to the displacement sensor is not interfered by other components. In addition, the entire displacement monitoring device has no "protruding" part exposed inside the support body, and only the end faces of the sleeve and the cover away from the rock and soil body may be collided during the construction of the underground building body in the foundation pit, which greatly reduces the possibility of damage to the displacement monitoring device; 2. A displacement monitoring device provided by an embodiment of the present disclosure, by providing a first measuring rod and a second measuring rod, can use the pointed tip of the second measuring rod to reduce the resistance of the two during the insertion process of the first measuring rod, thereby facilitating the insertion; after being inserted to the target depth, the second measuring rod is retracted to a state where the pointed tip is not exposed, so that the first measuring rod and the second measuring rod can jointly form a concave front end structure, so that the displaced rock and soil body will act on a larger action surface, thereby ensuring that the displacement of the rock and soil body is reliably transmitted to the first displacement sensor, thereby ensuring the accuracy of monitoring; 3. A displacement monitoring method provided by the embodiment of the present disclosure can keenly determine whether the rock and soil mass has been displaced, thereby facilitating early warning and ensuring the safe construction of the underground building in the foundation pit; and can also determine whether the displaced rock and soil mass is an overall displacement or a local displacement, thereby enabling targeted reinforcement of the support body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings: Figure 1 A schematic diagram of the installation of a displacement monitoring device according to an embodiment of the present invention; Figure 2 A schematic diagram of the three-dimensional structure of a displacement monitoring device drawn according to an embodiment of the present invention; Figure 3 Based on Figure 2 A cross-sectional view of the displacement monitoring device is drawn; Figure 4 Based on Figure 3 A partial magnified view of the drawn A area; Figure 5 Another three-dimensional structural schematic diagram of a displacement monitoring device drawn according to an embodiment of the present invention; Figure 6 Based on Figure 5 A cross-sectional view of the displacement monitoring device is drawn; Figure 7 Based on Figure 6 A partial magnified view of the drawn B area; Figure 8 It is a schematic diagram of a three-dimensional structure in which a sub-monitoring assembly is arranged around a second measuring rod according to an embodiment of the present invention; Fig. 9 Based on Figure 8 A magnified partial view of region C is drawn.

[0017] Marks and corresponding parts names in the attached drawings: 1-support body; 2-rock body; 3-protective sleeve; 31-cover; 32-slide rail; 41-first measuring rod; 42-first displacement sensor; 43-abutment plate; 51-second measuring rod; 511-tip; 52-wedge platform; 521-slide groove; 6-sub-monitoring assembly; 61-slider; 62-mounting tube; 63-second displacement sensor; 64-contact plate; 71-mounting seat; 72-threaded hole; 73-adjusting screw. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and drawings. The schematic implementation modes and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention. It should be noted that the present invention is already in the actual development and use stage.

[0019] Before constructing the underground building in the excavated foundation pit, the side walls of the foundation pit need to be supported. In order to ensure the safety of the construction of the underground building, it is necessary to monitor the rock and soil around the foundation pit, and then grasp the dynamic information of the rock and soil in real time, and according to the dynamic information of the rock and soil, timely strengthen the support of the area with significant displacement of the rock and soil.

[0020] However, the existing monitoring methods using displacement sensors usually install monitoring points on the support surface or are buried inside the support body, and do not penetrate into the rock and soil. The monitoring data cannot reflect the displacement of the rock and soil in a timely manner. Moreover, the monitoring points exposed on the surface of the support body have no protection measures and are easily damaged during the construction of underground buildings, resulting in discontinuous monitoring data and unable to truly reflect the deformation process and displacement of the rock and soil. It can be seen that the existing monitoring methods are difficult to truly reflect the dynamic process of the displacement of the rock and soil around the foundation pit, resulting in a large safety hazard in the construction of underground buildings.

[0021] In order to overcome the difficulty of existing monitoring means in accurately feeding back the real displacement of rock and soil bodies and to prevent the monitoring device from being damaged during the construction of underground buildings in foundation pits, the present invention provides a displacement monitoring device and a monitoring method, which are used to at least partially overcome the above technical problems and achieve the above beneficial effects.

[0022] Embodiment 1: like Figure 1 As shown, this embodiment provides a displacement monitoring device for monitoring the displacement of the rock and soil body 2 outside the support body 1. The displacement monitoring device includes: A protective sleeve 3, wherein the protective sleeve 3 is fixedly installed in the support body 1, and two ends of the protective sleeve 3 are respectively flush with two sides of the support body 1; A first measuring rod 41, which is inserted into the protective sleeve 3 in an axially sliding manner along the protective sleeve 3; one end of the first measuring rod 41 is located inside the protective sleeve 3, and the other end is located inside the rock mass 2; A sealing cover 31, wherein the sealing cover 31 is detachably connected to an end of the protective sleeve 3 away from the rock and soil body 2; The first displacement sensor 42 is mounted on the cover 31 , and the probe of the first displacement sensor 42 abuts against one end of the first measuring rod 41 located inside the protective sleeve 3 .

[0023] Preferably, the protective sleeve 3 is pre-buried before the support body 1 is formed, and the pre-buried protective sleeve 3 abuts against the surface of the rock and soil body 2 on the side facing the rock and soil body 2, and the pre-buried protective sleeve 3 is fixedly connected to at least one of the anchor rods, steel frames and steel bars in the support body 1 (referring to the location where the support body 1 to be formed is located) by welding or other means.

[0024] Preferably, the distance between the end of the first measuring rod 41 located inside the rock mass 2 and the outside of the supporting body 1 is greater than 200 mm. It should be understood that the first measuring rod 41 is inserted into the rock mass 2 along the protective sleeve 3 after the supporting body 1 is formed and before the monitoring starts, thereby ensuring that the end of the first measuring rod 41 located inside the rock mass 2 is in reliable contact with the rock mass 2 when the monitoring starts.

[0025] Preferably, the sealing cap 31 is detachably connected to the protective sleeve 3 by a threaded connection; specifically, an internal thread is provided at one end of the protective sleeve 3 away from the rock and soil body 2, and an external thread is provided on the outer peripheral surface of the sealing cap 31; more preferably, after the sealing cap 31 is screwed into the protective sleeve 3 to complete the connection, the end of the sealing cap 31 away from the rock and soil body 2 is flush with the end of the protective sleeve 3 away from the rock and soil body 2. Therefore, after the connection between the cover 31 and the protective sleeve 3 is completed, the end of the displacement monitoring device away from the rock and soil body 2 is flush with the inner side of the support body 1. During the construction of the underground building in the foundation pit, only the end faces of the protective sleeve 3 and the cover 31 of the entire displacement monitoring device away from the rock and soil body 2 may be collided, which greatly reduces the possibility of damage to the displacement monitoring device during the construction of the underground building in the foundation pit; and after the cover 31 and the protective sleeve 3 are connected, there is no exposed thread, which avoids the situation where the threads connecting the two are damaged during the construction of the underground building, and then it is difficult to remove the cover 31 (in fact, it is to avoid damage to the connection structure of the two, which makes it impossible to remove the cover 31), which is conducive to the removal of the displacement monitoring device after the monitoring work is completed, and is conducive to the maintenance and replacement of the parts of the displacement monitoring device during the monitoring period.

[0026] Based on this, in the displacement monitoring device provided in this embodiment, the protective sleeve 3 and the support body 1 form a reliable fixed connection, and the sliding movement of the first measuring rod 41 located inside it will not be affected by the support body 1, thereby ensuring that the "displacement" represented by the sliding movement of the first measuring rod 41 is not disturbed; inserting the first measuring rod 41 to a depth of at least 200 mm inside the rock and soil body 2 can ensure that the sliding movement of the first measuring rod 41 truly represents the displacement movement of the rock and soil body 2.

[0027] Preferably, if Figure 2 , Figure 3 , Figure 6 As shown, the displacement monitoring device further includes a mounting seat 71; a plurality of slide rails 32 are provided inside the side of the protective sleeve 3 away from the rock and soil body 2, and each of the slide rails 32 is parallel to the axial direction of the protective sleeve 3; the mounting seat 71 is slidably connected to each of the slide rails 32, and the sliding direction is parallel to the axial direction of the protective sleeve 3; The first displacement sensor 42 is fixedly mounted on the mounting seat 71 , and a threaded hole 72 is provided on a side of the mounting seat 71 away from the rock and soil body 2 ; an adjusting screw 73 threadably connected to the threaded hole 72 is rotatably mounted on the cover 31 .

[0028] Therefore, after the first measuring rod 41 is inserted into the rock and soil body 2, the connection between the cover 31 and the protective sleeve 3 is completed. At this time, the mounting seat 71 can be slid along the slide rail 32 by rotating the adjusting screw 73, so that the measuring head of the first displacement sensor 42 and the end of the first measuring rod 41 located inside the protective sleeve 3 can be reliably abutted. Compared with directly installing the first displacement sensor 42 on the cover 31, the relative positions of the two can be adjusted to ensure that the measuring head of the first displacement sensor 42 and the end of the first measuring rod 41 located inside the protective sleeve 3 are reliably abutted after the cover 31 is installed, and the adjustment process is simpler.

[0029] Embodiment 2: like Figures 2 to 9 As shown, this embodiment is based on Embodiment 1, except that, in this embodiment: The first measuring rod 41 is a hollow rod, and the displacement monitoring device further comprises a second measuring rod 51, and a pointed tip 511 is provided at one end of the second measuring rod 51; The second measuring rod 51 is inserted into the first measuring rod 41 by sliding along the axial direction of the first measuring rod 41, and the pointed head 511 faces the rock and soil body 2; An abutment plate 43 is detachably mounted on one end of the first measuring rod 41 away from the rock and soil body 2 , and a measuring head of the first displacement sensor 42 abuts against the abutment plate 43 .

[0030] It should be understood that the cross-sectional area of ​​the pointed tip 511 decreases in the direction toward the rock mass 2 .

[0031] The installation process of the displacement monitoring device in this embodiment is as follows: first, the second measuring rod 51 is inserted into the first measuring rod 41 and the pointed end 511 is exposed (such as Figure 3 As shown in the figure), the first measuring rod 41 and the second measuring rod 51 are then inserted together toward the rock mass 2 to the target depth (the distance between the end of the first measuring rod 41 located inside the rock mass 2 and the outside of the support body 1 is greater than 200 mm), and then the second measuring rod 51 is withdrawn to a state where the tip 511 is not exposed (as shown in the figure). Figure 6As shown in the figure, the abutment plate 43 is installed, and finally the cover 31 is installed on the protective sleeve 3 and the probe of the first displacement sensor 42 is abutted against the abutment plate 43 by adjusting the screw 73. Obviously, in the process of inserting the first measuring rod 41 and the second measuring rod 51 toward the rock and soil body 2 together, the relative positions of the first measuring rod 41 and the second measuring rod 51 should be maintained. For example, a shaft with a shoulder can be used, so that the front end of the shaft is abutted against the end of the second measuring rod 51 away from the rock and soil body 2, and the shoulder of the shaft is abutted against the end of the first measuring rod 41 away from the rock and soil body 2, and then the first measuring rod 41 and the second measuring rod 51 can be inserted into the rock and soil body 2 synchronously by pushing the shaft.

[0032] Obviously, if only the first measuring rod 41 is set, and one wants to contact the rock and soil body 2 through one end of the first measuring rod 41 located inside the rock and soil body 2 and then transmit the displacement of the rock and soil body 2, the cross-sectional area of ​​this end cannot be too small (if the cross-sectional area of ​​this end is too small, the displaced rock and soil body 2 will be "punctured", and then the displacement can only be partially transmitted to the first measuring rod 41, resulting in a smaller monitoring result); but in the case where the cross-sectional area of ​​this end is larger, if the inserted front end is a "tip" with a reduced cross-sectional area toward the rock and soil body 2, although it is conducive to the insertion of the first measuring rod 41, during the monitoring process after the setting is completed, the displaced rock and soil body 2 will be "punctured" by the "tip", which will also cause the monitoring result to be smaller. If the end is a flat or concave structure, the insertion resistance is larger, which increases the difficulty of installation.

[0033] In comparison, in this embodiment, by providing the first measuring rod 41 and the second measuring rod 51, during the insertion of the first measuring rod 41, the pointed tip 511 of the second measuring rod 51 is conducive to reducing the resistance of the two during the insertion process, thereby facilitating the insertion; after being inserted to the target depth, the second measuring rod 51 is retracted to a state where the pointed tip 511 is not exposed, so that the first measuring rod 41 and the second measuring rod 51 together form a concave front end structure (such as Figure 5 , Figure 6 As shown in FIG. 4 ), the displaced rock and soil body 2 will act on a larger action surface, thereby ensuring that the displacement of the rock and soil body 2 is reliably transmitted to the first displacement sensor 42, thereby ensuring the accuracy of monitoring.

[0034] Furthermore, if Figures 2 to 9 As shown, the displacement monitoring device further includes a plurality of sub-monitoring components 6, each of which is evenly distributed along the circumference of the axis of the second measuring rod 51, and each of the sub-monitoring components 6 is slidably connected to the first measuring rod 41, and the sliding direction is perpendicular to the axis direction of the second measuring rod 51; For any of the sub-monitoring components 6, a slider 61 is fixedly installed on the side of the sub-monitoring component 6 facing the second measuring rod 51, a wedge-shaped platform 52 is provided on the side of the second measuring rod 51 facing the sub-monitoring component 6, and a sliding groove 521 cooperating with the slider 61 is provided on the wedge surface of the wedge-shaped platform 52.

[0035] Specifically, during the process of inserting the first measuring rod 41 and the second measuring rod 51 into the rock and soil body 2, the pointed head 511 is exposed on the end surface of the first measuring rod 41 facing the rock and soil body 2, and each of the sub-monitoring components 6 is located inside the first measuring rod 41; When the pointed tip 511 retracts between the two end surfaces of the first measuring rod 41 , each of the sliding grooves 521 enables the corresponding sub-monitoring assembly 6 to slide toward the outside of the first measuring rod 41 .

[0036] The sub-monitoring assembly 6 includes a mounting tube 62, a second displacement sensor 63 and a contact plate 64; The mounting tube 62 is slidably connected to the first measuring rod 41, and the slider 61 is fixedly mounted on the side of the mounting tube 62 facing the second measuring rod 51; the second displacement sensor 63 is fixedly mounted on the mounting tube 62, and the measuring head of the second displacement sensor 63 faces the rock and soil body 2, and the contact plate 64 is fixedly mounted on the measuring head of the second displacement sensor 63.

[0037] Based on this, during the process of the first measuring rod 41 and the second measuring rod 51 being synchronously inserted into the rock and soil body 2, each of the sub-monitoring components 6 is not exposed on the side wall of the first measuring rod 41 (such as Figures 2 to 4As shown), no resistance will be caused during the insertion process; after the first measuring rod 41 is inserted to a preset depth, by retracting the second measuring rod 51 to a state where the pointed tip 511 is not exposed, each sub-monitoring component 6 can be simultaneously extended toward the outside of the first measuring rod 41 (it should be understood that the size of the sub-monitoring component 6 is much smaller than the size of the first measuring rod 41, and thus the sub-monitoring component 6 will not encounter too much resistance during the process of extending toward the outside of the first measuring rod 41, and the first measuring rod 41 will not be unable to slide due to the resistance caused by the cross-section of each sub-monitoring component 6 under the action of the displacement of the rock and soil body 2). Based on this, by setting up sub-monitoring components 6, it is possible to judge the direction of the displaced part of the rock and soil body 2 relative to the displacement monitoring device according to the monitoring results of each sub-monitoring component 6; in addition, a "corner" is formed between the sub-monitoring component 6 extending to the outside of the first measuring rod 41 and the outer wall of the first measuring rod 41. When the displacement direction of the rock and soil body 2 is not parallel to the axial direction of the first measuring rod 41, it is difficult for the first measuring rod 41 to perceive the displacement (the first measuring rod 41 perceives the displacement component of the displacement in the axial direction of the first measuring rod 41), but the displaced rock and soil body 2 will gather at the "corner" formed between the sub-monitoring component 6 and the outer wall of the first measuring rod 41, and then the corresponding sub-monitoring component 6 can keenly perceive this displacement that is not parallel to the axial direction of the first measuring rod 41.

[0038] Embodiment 3: This embodiment provides a displacement monitoring method, based on the above-mentioned displacement monitoring device, specifically, the displacement monitoring method includes: Install the displacement monitoring devices at a plurality of preset monitoring points, and continuously collect output data of each displacement monitoring device after installation; For any displacement monitoring device, the output data includes a first displacement amount output by the first displacement sensor 42 and a plurality of second displacement amounts output by each of the second displacement sensors 63; When there is a change in the first displacement amount and / or the second displacement amount, it is determined that the rock and soil body 2 has been displaced.

[0039] It should be understood that the first displacement refers to the difference between the displacement currently fed back by the first displacement sensor 42 and the displacement at the initial moment, that is, the net displacement of the first measuring rod 41; the second displacement refers to the difference between the displacement currently fed back by the second displacement sensor 63 and the displacement at the initial moment, that is, the net displacement of the contact plate 64.

[0040] Accordingly, the displacement monitoring method provided in this embodiment can keenly determine whether the rock and soil body 2 is displaced, which is conducive to early warning and ensures the safe construction process of the underground building in the foundation pit.

[0041] Furthermore, the point where the rock mass 2 first acts on the support body 1 after displacement is defined as the failure point; When the first displacements of the plurality of displacement monitoring devices change, the first displacements that have changed are compared, and if: ,in, X max is the maximum value among the first displacements that have changed, X min is the minimum value of the first displacements that have changed, is the average value of the first displacements that have changed, R is the preset coefficient; The failure point is considered to be located at X max The corresponding displacement monitoring device is located at the location; otherwise, it is determined that the rock and soil body 2 has undergone overall displacement.

[0042] Based on this, the displacement monitoring method can determine whether the displacement of the rock and soil body 2 is an overall displacement or a local displacement (i.e., the failure point is located at X max The corresponding displacement monitoring device is located at the location), and the support body 1 can be reinforced accordingly.

[0043] Furthermore, for any displacement monitoring device, the number of the sub-monitoring components 6 is four; each of the displacement monitoring devices is distributed in a rectangular array and the horizontal and vertical spacings of the array are both d The point where the rock mass 2 first acts on the support body 1 after displacement is defined as the failure point; The displacement monitoring method further comprises: When only one displacement monitoring device corresponds to a first displacement amount and four second displacement amounts, the magnitude relationship of the four second displacement amounts is compared; When there is only one maximum value among the four second displacements, a plane rectangular coordinate system is established on the outer side of the support body 1 with the position of the displacement monitoring device as the origin, and the sub-monitoring component 6 corresponding to the maximum value is located at x On the positive half axis of the axis; if y If the second displacements of the two sub-monitoring components 6 on the axis are equal, it is determined that the failure point is located at x The positive half axis of the axis, and the distance between the destruction point and the origin is less than ; If located y If the second displacement corresponding to the two sub-monitoring components 6 on the axis is larger, it is determined that the damage point is located at x The positive half axis of the axis is toward the quadrant where the sub-monitoring component 6 corresponding to the larger value is located, and the damage point and x axis,y The distance between the axes is less than ; In the case where there are two maximum values ​​among the four second displacements, and the sub-monitoring components 6 corresponding to the two maximum values ​​are adjacent, it is determined that the failure point is located on the side of the perpendicular midline connecting the sub-monitoring components 6 corresponding to the two maximum values, which is far away from the other two sub-monitoring components 6, and the distance between the failure point and the position where the displacement monitoring device is located is less than ; When the four second displacement amounts are equal, it is determined that the failure point is located at the position where the displacement monitoring device is located.

[0044] Accordingly, the displacement monitoring method provided in this embodiment can more accurately determine the position of the displacement failure point of the rock and soil body 2 (specifically, it is accurate to within the range of a rectangle formed by the horizontal and vertical spacings of the displacement monitoring devices distributed in a rectangular array) in the initial stage of displacement of the rock and soil body 2 (when only the first displacement amount and the four second displacement amounts corresponding to one displacement monitoring device have changed), thereby reducing the workload of targeted reinforcement of the support body 1.

[0045] Furthermore, the change amount of the first displacement amount per unit time is defined as a displacement rate, and the displacement monitoring method further includes: For any displacement monitoring device, determining the safety state of the rock and soil body 2 according to the displacement rate includes: When the displacement rate is equal to zero, it is determined that the rock and soil body 2 where the displacement monitoring device is located is in a stable state; When the displacement rate is greater than zero, it is determined that the rock mass 2 at the location of the displacement monitoring device is in a continuous displacement state; When the displacement rate continues to increase, it is determined that the rock and soil body 2 where the displacement monitoring device is located is in an unstable state.

[0046] It should be understood that the aforementioned term "stable state" means that the rock mass 2 and the displacement monitoring device are in a relatively static state; the aforementioned term "continuous displacement state" means that the rock mass 2 is continuously displacing relative to the displacement monitoring device; the aforementioned term "instability state" means that the displacement of the rock mass 2 is increasing rapidly and the rock mass 2 is about to "slide".

[0047] Accordingly, the displacement monitoring method provided in this embodiment can judge the safety and stability of the rock and soil body 2 according to the first displacement amount fed back in real time by the displacement monitoring device, especially after the rock and soil body 2 is displaced, it can intuitively characterize the displacement development process of the rock and soil body 2, thereby facilitating timely changes in the type of alarm.

[0048] It should be understood that in the present application, the monitored object "rock and soil body" is not limited to the rock and soil body outside the foundation pit support body, it can also be the surrounding rock outside the tunnel support body, the slope inside the slope support body, etc. The present application is not limited to this, that is, the displacement monitoring device can also be used to monitor the displacement of the surrounding rock outside the tunnel support body, monitor the displacement of the slope outside the slope protection, etc.

[0049] It should be understood that in the present application, "rotational installation" means that the two can only rotate relative to each other, such as the rotational setting of the hole and the shaft rod, and the axial relative movement can be restricted by setting a shoulder on the shaft and a limit groove in the hole; the terms "sliding insertion" and "sliding connection" mean that the two can only slide relative to each other, such as dovetail grooves, T-slots and other structures.

[0050] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A displacement monitoring device for monitoring the displacement of a rock mass (2) outside a support body (1), characterized in that: include: A protective sleeve (3), the protective sleeve (3) being fixedly mounted in the support body (1), with two ends of the protective sleeve (3) respectively being flush with two sides of the support body (1); a first measuring rod (41), the first measuring rod (41) being inserted into the protective sleeve (3) by sliding along the axial direction of the protective sleeve (3); one end of the first measuring rod (41) is located inside the protective sleeve (3), and the other end is located inside the rock mass (2); A sealing cover (31), wherein the sealing cover (31) is detachably connected to an end of the protective sleeve (3) away from the rock and soil body (2); A first displacement sensor (42), the first displacement sensor (42) being mounted on the cover (31), the probe of the first displacement sensor (42) being in contact with one end of the first measuring rod (41) located inside the protective sleeve (3).

2. The displacement monitoring device according to claim 1, characterized in that: The first measuring rod (41) is a hollow rod, and the displacement monitoring device further comprises a second measuring rod (51), wherein one end of the second measuring rod (51) is provided with a pointed head (511); The second measuring rod (51) is inserted into the first measuring rod (41) by sliding along the axial direction of the first measuring rod (41), and the pointed head (511) faces the rock and soil body (2); An abutment plate (43) is detachably mounted on one end of the first measuring rod (41) away from the rock and soil body (2), and a measuring head of the first displacement sensor (42) abuts against the abutment plate (43).

3. The displacement monitoring device according to claim 2, characterized in that: The displacement monitoring device further comprises a plurality of sub-monitoring components (6), each of the sub-monitoring components (6) being evenly distributed along the circumference of the axis of the second measuring rod (51), each of the sub-monitoring components (6) being slidably connected to the first measuring rod (41), and the sliding direction being perpendicular to the axis direction of the second measuring rod (51); For any of the sub-monitoring components (6), a slider (61) is fixedly mounted on a side of the sub-monitoring component (6) facing the second measuring rod (51), a wedge-shaped platform (52) is provided on a side of the second measuring rod (51) facing the sub-monitoring component (6), and a slide groove (521) cooperating with the slider (61) is provided on a wedge surface of the wedge-shaped platform (52).

4. The displacement monitoring device according to claim 3, characterized in that: During the process of inserting the first measuring rod (41) and the second measuring rod (51) into the rock and soil body (2), the pointed head (511) is exposed on the end surface of the first measuring rod (41) facing the rock and soil body (2), and each of the sub-monitoring components (6) is located inside the first measuring rod (41); During the process of the pointed head (511) retracting to between the two end surfaces of the first measuring rod (41), each of the sliding grooves (521) enables the corresponding sub-monitoring assembly (6) to slide toward the outside of the first measuring rod (41).

5. The displacement monitoring device according to claim 3, characterized in that: The sub-monitoring assembly (6) comprises a mounting cylinder (62), a second displacement sensor (63) and a contact plate (64); The mounting tube (62) is slidably connected to the first measuring rod (41), and the sliding block (61) is fixedly mounted on a side of the mounting tube (62) facing the second measuring rod (51); the second displacement sensor (63) is fixedly mounted on the mounting tube (62), and the measuring head of the second displacement sensor (63) faces the rock and soil body (2), and the contact plate (64) is fixedly mounted on the measuring head of the second displacement sensor (63).

6. The displacement monitoring device according to any one of claims 1 to 5, characterized in that: The displacement monitoring device further comprises a mounting seat (71); a plurality of slide rails (32) are arranged inside a side of the protective sleeve (3) away from the rock and soil body (2), and each of the slide rails (32) is parallel to the axial direction of the protective sleeve (3); the mounting seat (71) and each of the slide rails (32) are slidably connected, and the sliding direction is parallel to the axial direction of the protective sleeve (3); The first displacement sensor (42) is fixedly mounted on the mounting seat (71), and a threaded hole (72) is provided on a side of the mounting seat (71) away from the rock body (2); an adjusting screw (73) threadably connected to the threaded hole (72) is rotatably mounted on the cover (31).

7. A displacement monitoring method, based on the displacement monitoring device according to claim 5, characterized in that: include: Install the displacement monitoring devices at a plurality of preset monitoring points, and continuously collect output data of each displacement monitoring device after installation; For any displacement monitoring device, the output data includes a first displacement amount output by the first displacement sensor (42), and a plurality of second displacement amounts output by each of the second displacement sensors (63); When there is a change in the first displacement amount and / or the second displacement amount, it is determined that the rock and soil body (2) has been displaced.

8. The displacement monitoring method according to claim 7, characterized in that: The point where the rock mass (2) first acts on the support body (1) after displacement is defined as the failure point; When the first displacements of the plurality of displacement monitoring devices change, the first displacements that have changed are compared, and if: ,in, X max is the maximum value among the first displacements that have changed, X min is the minimum value of the first displacements that have changed, is the average value of the first displacements that have changed, R is the preset coefficient; The failure point is considered to be located at X max The corresponding displacement monitoring device is located at the location; otherwise, it is determined that the rock and soil body (2) has undergone overall displacement.

9. The displacement monitoring method according to claim 7, characterized in that: For any displacement monitoring device, the number of the sub-monitoring components (6) is four; the displacement monitoring devices are distributed in a rectangular array and the horizontal and vertical spacings of the array are both d ; The point where the rock mass (2) first acts on the supporting body (1) after displacement is defined as the failure point; The displacement monitoring method further comprises: When only one displacement monitoring device corresponds to a first displacement amount and four second displacement amounts, the magnitude relationship of the four second displacement amounts is compared; When there is only one maximum value among the four second displacements, a plane rectangular coordinate system is established on the outer side surface of the support body (1) with the position of the displacement monitoring device as the origin, and the sub-monitoring component (6) corresponding to the maximum value is located at x On the positive half axis of the axis; if y If the second displacements of the two sub-monitoring components (6) on the axis are equal, it is determined that the failure point is located at x The positive half axis of the axis, and the distance between the destruction point and the origin is less than ; If located y If the second displacements corresponding to the two sub-monitoring components (6) on the axis are larger, it is determined that the failure point is located at x The positive half axis of the axis is oriented toward the quadrant where the sub-monitoring component (6) corresponding to the larger value is located, and the damage point and x axis, y The distance between the axes is less than ; In the case where there are two maximum values ​​among the four second displacement amounts, and the sub-monitoring components (6) corresponding to the two maximum values ​​are adjacent, it is determined that the failure point is located on the side of the perpendicular midline connecting the sub-monitoring components (6) corresponding to the two maximum values, which is far away from the other two sub-monitoring components (6), and the distance between the failure point and the position where the displacement monitoring device is located is less than ; When the four second displacement amounts are equal, it is determined that the failure point is located at the position where the displacement monitoring device is located.

10. The displacement monitoring method according to claim 7, characterized in that: The change amount of the first displacement amount per unit time is defined as a displacement rate, and the displacement monitoring method further includes: For any displacement monitoring device, determining the safety state of the rock mass (2) according to the displacement rate includes: When the displacement rate is equal to zero, it is determined that the rock mass (2) at the location of the displacement monitoring device is in a stable state; When the displacement rate is greater than zero, it is determined that the rock mass (2) at the location of the displacement monitoring device is in a continuous displacement state; When the displacement rate continues to increase, it is determined that the rock and soil body (2) at the location of the displacement monitoring device is in an unstable state.

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