A displacement monitoring device and a monitoring method

Abstract

The present invention relates to the technical field of geotechnical displacement monitoring, and particularly relates to a displacement monitoring device and a monitoring method. The device includes a protective sleeve fixedly installed in a support body, with both ends of the protective sleeve flush with both sides of the support body; a first measuring rod slidably inserted axially into the protective sleeve along the axis 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 geotechnical body; a cover detachably connected to the end of the protective sleeve away from the geotechnical body; a first displacement sensor 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. On the one hand, it can more accurately reflect the displacement of the geotechnical 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 underground buildings in the foundation pit.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical displacement monitoring, and particularly relates to a displacement monitoring device and a monitoring method. Background Art

[0002] Before constructing an underground building in an excavated foundation pit, it is necessary to support the side wall of the foundation pit. To ensure the safety of the construction operation of the underground building, it is necessary to monitor the geotechnical body around the foundation pit, and then timely master the dynamic information of the geotechnical body, and strengthen the support for the area where the geotechnical displacement is significant according to the dynamic information of the geotechnical body.

[0003] However, in the existing monitoring means using displacement sensors, the monitoring points are usually installed on the surface of the support or buried inside the support body, and do not penetrate deep into the geotechnical body. The monitoring data cannot timely reflect the displacement of the geotechnical body; moreover, the monitoring points exposed on the surface of the support body have no protection measures and are extremely easy to be damaged during the construction operation of the underground building, resulting in discontinuous monitoring data and unable to truly reflect the deformation process and displacement of the geotechnical body. It can be seen that the existing monitoring means are difficult to truly reflect the dynamic process of the displacement of the geotechnical body around the foundation pit, resulting in relatively large potential safety hazards during the construction operation of the underground building. Summary of the Invention

[0004] The purpose of the present invention is to provide a displacement monitoring device and a monitoring method, which can at least partially overcome the above technical problems. On the one hand, it can more accurately reflect the displacement of the geotechnical body outside the support body, and 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 the geotechnical body outside the support body. Specifically, the displacement monitoring device includes: a protective sleeve, the protective sleeve is fixedly installed in the support body, and both ends of the protective sleeve are flush with both sides of the support body; a first measuring rod, the first measuring rod is slidably 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 geotechnical body; a cover, the cover is detachably connected to the end of the protective sleeve away from the geotechnical body; a first displacement sensor, the first displacement sensor 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] Further, the first measuring rod is a hollow rod, and the displacement monitoring device further includes a second measuring rod with a pointed tip at one end. The second measuring rod is slidably inserted into the first measuring rod along the axial direction of the first measuring rod, with the pointed tip facing the rock and soil mass. A contact plate is detachably installed at the end of the first measuring rod away from the rock and soil mass, and the probe of the first displacement sensor abuts against the contact plate.

[0007] Further, the displacement monitoring device further includes a plurality of sub-monitoring components, which are circumferentially and evenly distributed along the axis of the second measuring rod. Each sub-monitoring component 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 one of the sub-monitoring components, 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 chute for cooperating with the slider is provided on the inclined surface of the wedge-shaped platform.

[0008] Further, during the process of inserting the first measuring rod and the second measuring rod into the rock and soil mass, the pointed tip is exposed outside the end face of the first measuring rod facing the rock and soil mass, and each sub-monitoring component is located inside the first measuring rod. During the process of the pointed tip retracting between the two end faces of the first measuring rod, each chute causes the corresponding sub-monitoring component to slide towards the outside of the first measuring rod.

[0009] Further, the sub-monitoring component includes an installation cylinder, a second displacement sensor, and a contact plate. The installation cylinder is slidably connected to the first measuring rod, and the slider is fixedly installed on the side of the installation cylinder facing the second measuring rod. The second displacement sensor is fixedly installed on the installation cylinder, and the probe of the second displacement sensor faces the rock and soil mass, and the contact plate is fixedly installed on the probe of the second displacement sensor.

[0010] Preferably, the displacement monitoring device further includes a mounting seat. A plurality of slide rails are provided inside the protection sleeve on the side away from the rock and soil mass, and each slide rail is parallel to the axial direction of the protection sleeve. The mounting seat is slidably connected to each slide rail, and the sliding direction is parallel to the axial direction of the protection sleeve. The first displacement sensor is fixedly installed on the mounting seat, and a threaded hole is provided on the side of the mounting seat away from the rock and soil mass. An adjusting screw threadedly connected to the threaded hole is rotatably installed on the cover.

[0011] On the other hand, the present invention provides a displacement monitoring method, which is based on the aforementioned displacement monitoring device. Specifically, the displacement monitoring method includes: installing the displacement monitoring device at a plurality of preset monitoring points, and continuously collecting the output data of each displacement monitoring device after installation; for any displacement monitoring device, the output data includes the first displacement amount output by the first displacement sensor and a plurality of second displacement amounts output by each second displacement sensor; in the case where the first displacement amount and / or the second displacement amount changes, it is determined that the rock and soil mass has a displacement.

[0012] Further, the point where the rock and soil mass first acts on the support after displacement is defined as the failure point; in the case where the first displacement amounts of a plurality of displacement monitoring devices change, compare the changed first displacement amounts. If the following conditions are met: , where X max is the maximum value among the changed first displacement amounts, X min is the minimum value among the changed first displacement amounts, is the average value of the changed first displacement amounts, R is a preset coefficient; then it is determined that the failure point is located at X max the position where the corresponding displacement monitoring device is located; otherwise, it is determined that the rock and soil mass has an overall displacement.

[0013] Further, for any displacement monitoring device, the number of sub-monitoring components is four; each displacement monitoring device is distributed in a rectangular array and the horizontal and vertical spacings of the array are both d ; the point where the rock and soil mass first acts on the support after displacement is defined as the failure point; the displacement monitoring method further includes: in the case where only the first displacement amount and the four second displacement amounts corresponding to one displacement monitoring device change, compare the magnitude relationship of the four second displacement amounts; in the case where there is only one maximum value among the four second displacement amounts, establish a plane rectangular coordinate system on the outer side of the support with the position of this displacement monitoring device as the origin, and the sub-monitoring component corresponding to this maximum value is located on x the positive half-axis of the y axis; if the second displacement amounts corresponding to the two sub-monitoring components located on the x axis are equal, it is determined that the failure point is located on the positive half-axis of the y axis, and the distance between the failure point and the origin is less than x ; if there is a larger value among the second displacement amounts corresponding to the two sub-monitoring components located on the x axis, it is determined that the failure point is located in the quadrant of the positive half-axis of the yThe distances between the shafts are all less than ; when there are two maximum values among the four second displacement amounts, and the sub-monitoring components corresponding to the two maximum values are adjacent, it is determined that the damage point is located on the perpendicular bisector of the line connecting the sub-monitoring components corresponding to the two maximum values and on the side far from the other two sub-monitoring components, and the distance between the damage 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 damage point is located at the position where the displacement monitoring device is located.

[0014] Further, the change amount of the first displacement amount per unit time is defined as the displacement rate. The displacement monitoring method further includes: for any displacement monitoring device, determining the safety state of the rock and soil mass according to the displacement rate, including: when the displacement rate is equal to zero, it is determined that the rock and soil mass at the position 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 and soil mass at the position where the displacement monitoring device is located is in a continuous displacement state; when the displacement rate continuously increases, it is determined that the rock and soil mass at the position where the displacement monitoring device is located is in an unstable state.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] 1. The displacement of the measuring rod of the displacement monitoring device provided by the embodiment of the present disclosure can represent the real displacement of the rock and soil mass, and the displacement transmitted by the measuring rod to the displacement sensor is not interfered by other components. In addition, there is no "protruding" part of the entire displacement monitoring device exposed inside the support. Only the end faces of the protection sleeve and the cover away from the rock and soil mass may be collided during the construction of the underground building in the foundation pit, greatly reducing the possibility of damage to the displacement monitoring device;

[0017] 2. The displacement monitoring device provided by the embodiment of the present disclosure, by setting the first measuring rod and the second measuring rod, can use the pointed head of the second measuring rod to reduce the resistance during the insertion process of the two during the insertion of the first measuring rod, facilitating insertion; after being inserted to the target depth, retracting the second measuring rod to a state where the pointed head is not exposed can enable the first measuring rod and the second measuring rod to jointly form an inwardly concave front-end structure. Furthermore, the displaced rock and soil mass will act on a larger acting surface, and thus it can ensure that the displacement of the rock and soil mass is reliably transmitted to the first displacement sensor, thereby guaranteeing the monitoring accuracy;

[0018] 3. The displacement monitoring method provided by the embodiment of the present disclosure can sensitively determine whether the rock and soil mass has displacement, which is beneficial for early warning and ensuring the safe progress of the construction of the underground building in the foundation pit; and it can also determine whether the displaced rock and soil mass is in overall displacement or local displacement, and thus can carry out targeted reinforcement of the support accordingly. Description of the Drawings

[0019] The accompanying drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the accompanying drawings:

[0020] Figure 1 is an installation schematic diagram of a displacement monitoring device drawn according to an embodiment of the present invention;

[0021] Figure 2 is a three-dimensional structure schematic diagram of a displacement monitoring device drawn according to an embodiment of the present invention;

[0022] Figure 3 is according to Figure 2 a sectional view of the displacement monitoring device drawn;

[0023] Figure 4 is according to Figure 3 a partial enlarged view of area A drawn;

[0024] Figure 5 is a three-dimensional structure schematic diagram of another displacement monitoring device drawn according to an embodiment of the present invention;

[0025] Figure 6 is according to Figure 5 a sectional view of the displacement monitoring device drawn;

[0026] Figure 7 is according to Figure 6 a partial enlarged view of area B drawn;

[0027] Figure 8 is a three-dimensional structure schematic diagram of a sub-monitoring component arranged around a second measuring rod drawn according to an embodiment of the present invention;

[0028] Figure 9 is according to Figure 8 a partial enlarged view of area C drawn.

[0029] Reference numerals in the accompanying drawings and corresponding component names:

[0030] 1 - Support body; 2 - Rock and soil body; 3 - Protection sleeve; 31 - Sealing cover; 32 - Slide rail; 41 - First measuring rod; 42 - First displacement sensor; 43 - Abuttment plate; 51 - Second measuring rod; 511 - Tip; 52 - Wedge table; 521 - Chute; 6 - Sub-monitoring component; 61 - Slide block; 62 - Installation cylinder; 63 - Second displacement sensor; 64 - Contact plate; 71 - Installation base; 72 - Threaded hole; 73 - Adjusting screw. Detailed implementation manners

[0031] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. The illustrative embodiments 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 has been in the actual R & D and use stage.

[0032] Before constructing an underground building in an excavated foundation pit, it is necessary to support the side walls of the foundation pit. To ensure the safe progress of the construction operation of the underground building, it is necessary to monitor the rock and soil around the foundation pit, so as to timely master the dynamic information of the rock and soil, and based on the dynamic information of the rock and soil, strengthen the support for the areas with significant displacement of the rock and soil in a timely manner.

[0033] However, in the existing monitoring means using displacement sensors, the monitoring points are usually installed on the surface of the support or buried inside the support, and do not penetrate deep into the rock and soil. The monitoring data cannot timely reflect the displacement of the rock and soil; and the monitoring points exposed on the surface of the support have no protection measures and are extremely easy to be damaged during the construction operation of the underground building, 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 means are difficult to truly reflect the dynamic process of the displacement of the rock and soil around the foundation pit, resulting in relatively large potential safety hazards during the construction operation of the underground building.

[0034] In order to overcome the situation that the existing monitoring means are difficult to accurately feedback the true displacement of the rock and soil; and to avoid the damage of the monitoring device during the construction of the underground building in the foundation pit. 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.

[0035] Embodiment 1:

[0036] As Figure 1 shown, this embodiment provides a displacement monitoring device for monitoring the displacement of the rock and soil 2 outside the support 1. The displacement monitoring device includes:

[0037] A protective sleeve 3, the protective sleeve 3 is fixedly installed in the support 1, and both ends of the protective sleeve 3 are flush with both sides of the support 1;

[0038] A first measuring rod 41, the first measuring rod 41 is slidably inserted into the protective sleeve 3 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 and soil 2;

[0039] A cover 31, the cover 31 and the end of the protective sleeve 3 away from the rock and soil 2 are detachably connected;

[0040] 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.

[0041] Preferably, the protective sleeve 3 is pre-embedded before the formation of the support body 1. One side of the pre-embedded protective sleeve 3 facing the rock and soil body 2 abuts against the surface of the rock and soil body 2, and the pre-embedded protective sleeve 3 is fixedly connected to at least one of the anchor rod, steel frame and steel bar inside the support body 1 (referring to the position where the upcoming support body 1 is located) by means of welding or the like.

[0042] Preferably, the distance between one end of the first measuring rod 41 located inside the rock and soil body 2 and the outside of the support body 1 is greater than 200 mm. It should be understood that the first measuring rod 41 is inserted into the rock and soil body 2 along the protective sleeve 3 after the formation of the support body 1 and before the start of monitoring. Thus, it can be ensured that when the monitoring starts, one end of the first measuring rod 41 located inside the rock and soil body 2 is in reliable contact with the rock and soil body 2.

[0043] Preferably, the cover 31 is detachably connected to the protective sleeve 3 in a threaded connection form; specifically, internal threads are provided at one end of the protective sleeve 3 away from the rock and soil body 2, and external threads are provided on the outer peripheral surface of the cover 31; more preferably, after the cover 31 is screwed into the protective sleeve 3 to complete the connection, one end of the cover 31 away from the rock and soil body 2 is flush with one end of the protective sleeve 3 away from the rock and soil body 2. Thus, after the cover 31 and the protective sleeve 3 are connected, 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 body in the foundation pit, only the end faces of the protective sleeve 3 and the cover 31 away from the rock and soil body 2 of the entire displacement monitoring device may be collided, greatly reducing the possibility of damage to the displacement monitoring device during the construction of the underground building body in the foundation pit; and after the cover 31 and the protective sleeve 3 are connected, no threads are exposed, avoiding damage to the threads of their connection during the construction of the underground building body, and thus making it difficult to remove the cover 31 (substantially avoiding damage to the connection structure of the two resulting in the inability to remove the cover 31), which is beneficial to the removal of the displacement monitoring device after the monitoring work is completed, and is also beneficial to the maintenance and replacement of the components of the displacement monitoring device during the monitoring period.

[0044] 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 amount" represented by the sliding movement of the first measuring rod 41 is not disturbed; inserting the first measuring rod 41 into the rock and soil body 2 to a depth of at least 200 mm can ensure that the sliding movement of the first measuring rod 41 truly represents the displacement movement of the rock and soil body 2.

[0045] Preferably, as Figure 2 , Figure 3 , Figure 6 shown, the displacement monitoring device further includes a mounting base 71; a plurality of sliding rails 32 are arranged inside the side of the protective sleeve 3 away from the rock and soil body 2, and each of the sliding rails 32 is parallel to the axial direction of the protective sleeve 3; the mounting base 71 is slidably connected to each of the sliding rails 32, and the sliding direction is parallel to the axial direction of the protective sleeve 3;

[0046] The first displacement sensor 42 is fixedly installed on the mounting base 71, and a threaded hole 72 is formed on the side of the mounting base 71 away from the rock and soil body 2; an adjusting screw 73 threadedly connected to the threaded hole 72 is rotatably installed on the cover 31.

[0047] Thus, 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 base 71 can be slid along the sliding rail 32 by rotating the adjusting screw 73, so that the probe of the first displacement sensor 42 and the end of the first measuring rod 41 located inside the protective sleeve 3 are reliably abutted; compared with directly installing the first displacement sensor 42 on the cover 31 and ensuring the reliable abutment between the probe of the first displacement sensor 42 and the end of the first measuring rod 41 located inside the protective sleeve 3 by adjusting the relative positions of the two, the adjustment process is simpler.

[0048] Embodiment 2:

[0049] As Figures 2 to 9 shown, this embodiment is based on Embodiment 1, and the difference is that in this embodiment:

[0050] The first measuring rod 41 is a hollow rod, and the displacement monitoring device further includes a second measuring rod 51, and a pointed head 511 is arranged at one end of the second measuring rod 51;

[0051] The second measuring rod 51 is slidably inserted into the first measuring rod 41 along the axial direction of the first measuring rod 41, and the pointed head 511 faces the rock and soil body 2;

[0052] A contact plate 43 is detachably installed at the end of the first measuring rod 41 away from the rock and soil body 2, and the probe of the first displacement sensor 42 abuts against the contact plate 43.

[0053] It should be understood that the cross-sectional area of the pointed head 511 decreases in the direction towards the rock and soil body 2.

[0054] The installation process of the displacement monitoring device in this embodiment is as follows: First, insert the second measuring rod 51 into the first measuring rod 41 and keep the pointed head 511 exposed (as Figure 3As shown in the figure), then insert the first measuring rod 41 and the second measuring rod 51 together into the geotechnical body 2 to the target depth (the distance between the end of the first measuring rod 41 inside the geotechnical body 2 and the outside of the support body 1 is greater than 200 mm), and then retract the second measuring rod 51 until the tip 511 is not exposed (as Figure 6 shown), and install the abutting plate 43. Finally, install the cover 31 on the protective sleeve 3 and make the probe of the first displacement sensor 42 abut against the abutting plate 43 by adjusting the screw rod 73. Obviously, during the process of inserting the first measuring rod 41 and the second measuring rod 51 together into the geotechnical body 2, the relative positions of the first measuring rod 41 and the second measuring rod 51 should be maintained. For example, a shaft rod with a shoulder can be used, so that the front end of the shaft rod abuts against the end of the second measuring rod 51 away from the geotechnical body 2, and the shoulder of the shaft rod abuts against the end of the first measuring rod 41 away from the geotechnical body 2. Then, by pushing the shaft rod, the first measuring rod 41 and the second measuring rod 51 can be inserted into the geotechnical body 2 synchronously.

[0055] Obviously, if only the first measuring rod 41 is set, and it is desired to transfer the displacement of the geotechnical body 2 by the end of the first measuring rod 41 inside the geotechnical 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 displacing geotechnical body 2 will be "pierced", and then only part of the displacement can be transferred to the first measuring rod 41, resulting in a smaller monitoring result); but when the cross-sectional area of this end is relatively large, if the front end inserted is a "tip" with a reduced cross-sectional area towards the geotechnical body 2, although it is beneficial for the insertion of the first measuring rod 41, during the subsequent monitoring process after installation, the displacing geotechnical body 2 will be "pierced" by this "tip", which will also result in a smaller monitoring result. If this end is a flat or concave structure, the insertion resistance will be greater, increasing the installation difficulty.

[0056] In contrast, in this embodiment, by setting the first measuring rod 41 and the second measuring rod 51, during the insertion process of the first measuring rod 41, the tip 511 of the second measuring rod 51 is beneficial to reducing the resistance during the insertion of the two, facilitating the insertion; after inserting to the target depth, retract the second measuring rod 51 until the tip 511 is not exposed, so that the first measuring rod 41 and the second measuring rod 51 jointly form a concave front-end structure (as Figure 5 、 Figure 6 shown), and then the displacing geotechnical body 2 will act on a relatively large acting surface, and then it can ensure that the displacement of the geotechnical body 2 is reliably transferred to the first displacement sensor 42, thereby ensuring the monitoring accuracy.

[0057] Furthermore, as Figures 2 to 9As shown, the displacement monitoring device further includes a plurality of sub-monitoring components 6, and the sub-monitoring components 6 are circumferentially and evenly distributed along the axis of the second measuring rod 51. 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;

[0058] For any one 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 chute 521 matching the slider 61 is provided on the inclined surface of the wedge-shaped platform 52.

[0059] Specifically, during the process of inserting the first measuring rod 41 and the second measuring rod 51 into the rock and soil mass 2, the pointed head 511 is exposed outside the end face of the first measuring rod 41 facing the rock and soil mass 2, and each of the sub-monitoring components 6 is located inside the first measuring rod 41;

[0060] During the process of the pointed head 511 retracting between the two end faces of the first measuring rod 41, each of the chutes 521 causes the corresponding sub-monitoring component 6 to slide towards the outside of the first measuring rod 41.

[0061] The sub-monitoring component 6 includes an installation cylinder 62, a second displacement sensor 63, and a contact plate 64;

[0062] The installation cylinder 62 is slidably connected to the first measuring rod 41, and the slider 61 is fixedly installed on the side of the installation cylinder 62 facing the second measuring rod 51; the second displacement sensor 63 is fixedly installed on the installation cylinder 62, and the probe of the second displacement sensor 63 faces the rock and soil mass 2, and the contact plate 64 is fixedly installed on the probe of the second displacement sensor 63.

[0063] Based on this, during the process of synchronously inserting the first measuring rod 41 and the second measuring rod 51 into the rock and soil mass 2, each of the sub-monitoring components 6 is not exposed outside the side wall of the first measuring rod 41 (such as Figures 2 to 4As shown, there will be no resistance during the insertion process. After the first measuring rod 41 is inserted to the 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 made to extend outward from the outside of the first measuring rod 41 at the same time (it should be understood that the size of the sub-monitoring component 6 is much smaller than that of the first measuring rod 41. Therefore, during the process of the sub-monitoring component 6 extending outward from the outside of the first measuring rod 41, there will be no excessive resistance, and the movement of the first measuring rod 41 sliding along the protective sleeve 3 under the action of the displacement of the rock and soil mass 2 will not be unable to slide due to the resistance caused by the cross-section of each sub-monitoring component 6). Based on this, by setting the sub-monitoring component 6, it is possible to judge the direction of the displaced part of the rock and soil mass 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 mass 2 is not parallel to the axial direction of the first measuring rod 41, it is difficult for the first measuring rod 41 to sense this displacement (what the first measuring rod 41 senses is the displacement component of this displacement in the axial direction of the first measuring rod 41), but the displaced rock and soil mass 2 will gather at the "corner" formed between the sub-monitoring component 6 and the outer wall of the first measuring rod 41. Accordingly, the corresponding sub-monitoring component 6 can keenly sense this displacement that is not parallel to the axial direction of the first measuring rod 41).

[0064] Embodiment 3:

[0065] This embodiment provides a displacement monitoring method. Based on the aforementioned displacement monitoring device, specifically, this displacement monitoring method includes:

[0066] Install the displacement monitoring device at multiple preset monitoring points, and continuously collect the output data of each displacement monitoring device after installation;

[0067] For any displacement monitoring device, the output data includes the first displacement amount output by the first displacement sensor 42 and multiple second displacement amounts output by each second displacement sensor 63;

[0068] In the case where there is a change in the first displacement amount and / or the second displacement amount, it is determined that the rock and soil mass 2 has undergone displacement.

[0069] It should be understood that the first displacement amount refers to the difference between the displacement amount currently fed back by the first displacement sensor 42 and the displacement amount at the initial moment, that is, the net displacement amount of the first measuring rod 41; the second displacement amount refers to the difference between the displacement amount currently fed back by the second displacement sensor 63 and the displacement amount at the initial moment, that is, the net displacement amount of the contact plate 64.

[0070] Accordingly, the displacement monitoring method provided in this embodiment can keenly determine whether the rock and soil mass 2 has undergone displacement, which is conducive to early warning and ensures the safe construction process of the underground building in the foundation pit.

[0071] Further, the point where the rock and soil mass 2 first acts on the support body 1 after displacement is defined as the failure point;

[0072] In the case where the first displacement amounts of multiple displacement monitoring devices change, compare the changed first displacement amounts. If the following conditions are met:

[0073] , where X max is the maximum value among the changed first displacement amounts, X min is the minimum value among the changed first displacement amounts, is the average value of the changed first displacement amounts, R is a preset coefficient;

[0074] then it is determined that the failure point is located at X max the position where the corresponding displacement monitoring device is located; otherwise, it is determined that the rock and soil mass 2 has undergone overall displacement.

[0075] Based on this, the displacement monitoring method can determine whether the displaced rock and soil mass 2 has undergone overall displacement or local displacement (i.e., the case where the failure point is located at the position where the corresponding displacement monitoring device is located), and thus can reinforce the support body 1 accordingly. X max the position where the corresponding displacement monitoring device is located), and can thus reinforce the support body 1 accordingly.

[0076] Further, 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 and soil mass 2 first acts on the support body 1 after displacement is defined as the failure point;

[0077] The displacement monitoring method further includes:

[0078] In the case where only the first displacement amount corresponding to one displacement monitoring device and the four second displacement amounts have changed, compare the magnitude relationship of the four second displacement amounts;

[0079] In the case where there is only one maximum value among the four second displacement amounts, establish a plane rectangular coordinate system 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 on x the positive half-axis of the yIf the second displacement amounts corresponding to the two sub-monitoring components 6 on the shaft are equal, it is determined that the failure point is located at x the positive semi-axis of the shaft, and the distance between the failure point and the origin is less than ; if it is located at y the shaft, and there is a larger value among the second displacement amounts corresponding to the two sub-monitoring components 6, it is determined that the failure point is located at x the quadrant of the positive semi-axis of the shaft towards the sub-monitoring component 6 corresponding to the larger value, and the distances between the failure point and x the shaft, y the shaft are both less than ;

[0080] If 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 perpendicular bisector of the line connecting the two sub-monitoring components 6 corresponding to the two maximum values, on the side far 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 ;

[0081] If 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.

[0082] Accordingly, the displacement monitoring method provided in this embodiment can more accurately determine the position of the displacement failure point of the geotechnical body 2 in the initial stage of displacement of the geotechnical body 2 (specifically, accurate to within the range of the rectangle formed by the horizontal and vertical spacings of the displacement monitoring devices arranged in a rectangular array), thereby reducing the workload of the targeted reinforcement support 1.

[0083] Furthermore, defining the change amount of the first displacement amount per unit time as the displacement rate, the displacement monitoring method further includes:

[0084] For any displacement monitoring device, determining the safety state of the geotechnical body 2 according to the displacement rate, including:

[0085] When the displacement rate is equal to zero, it is determined that the geotechnical body 2 at the position where the displacement monitoring device is located is in a stable state;

[0086] When the displacement rate is greater than zero, it is determined that the geotechnical body 2 at the position where the displacement monitoring device is located is in a continuous displacement state;

[0087] When the displacement rate continues to increase, it is determined that the geotechnical body 2 at the position where the displacement monitoring device is located is in an unstable state.

[0088] It should be understood that the foregoing term "steady state" means that the geotechnical body 2 and the displacement monitoring device are in a relatively stationary state; the foregoing term "continuous displacement state" means that the geotechnical body 2 is continuously displacing relative to the displacement monitoring device; the foregoing term "unstability state" means that the displacement amount of the geotechnical body 2 is increasing rapidly, and the geotechnical body 2 is about to "landslide".

[0089] Accordingly, the displacement monitoring method provided in this embodiment can determine the safety and stability degree of the geotechnical body 2 according to the first displacement amount real-time feedback by the displacement monitoring device. Especially after the geotechnical body 2 is displaced, it can intuitively characterize the displacement development process of the geotechnical body 2, and then facilitate timely changing the type of warning.

[0090] It should be understood that in this application, the monitoring object "geotechnical body" is not limited to the geotechnical body outside the foundation pit support body. It can also be the surrounding rock outside the tunnel support body, the slope body inside the slope support body, etc. This application is not limited thereto. That is to say, this displacement monitoring device can also be used to monitor the displacement of the surrounding rock outside the tunnel support body, the displacement of the slope body outside the slope protection, etc.

[0091] It should be understood that in this application, "rotationally installed" means that the two can only rotate relative to each other. For example, the rotational setting of a hole and a shaft rod can be realized by setting a shaft shoulder on the shaft and a limiting groove in the hole to restrict the relative axial movement; the terms "sliding insertion" and "sliding connection" mean that the two can only slide relative to each other, such as dovetail grooves, T-shaped grooves and other structures.

[0092] The above-mentioned specific implementation manners have further detailed the purpose, technical solution and beneficial effects of the present invention. It should be understood that the above-mentioned are only the specific implementation manners of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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) 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) and an end of the protective sleeve (3) away from the rock and soil body (2) are detachably connected; 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); 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); 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); 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).

2. The displacement monitoring device according to claim 1, 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).

3. The displacement monitoring device according to claim 1 or 2, 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).

4. A displacement monitoring method, based on the displacement monitoring device according to claim 2, 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.

5. The displacement monitoring method according to claim 4, 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.

6. The displacement monitoring method according to claim 4, 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.

7. The displacement monitoring method according to claim 4, 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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