Surrounding rock displacement sleeve type measuring device and measuring method thereof

Abstract

The invention relates to a surrounding rock displacement sleeve type measuring device and a measuring method thereof, which are mainly used for measuring surrounding rock deformation in tunnels and underground engineering. The device is composed of a plurality of sleeves, a concentrator, a measuring line, a counter weight, a grouting pipeline, an exhaust pipeline, a tail end back shore and the like. Partition devices are arranged at the two ends of each casing pipe, the adjacent casing pipes are connected in a bell and spigot mode to form an integral structure, and the partition devices are used for separating poured cement paste. The concentrators are fixedly installed in the sleeves, the counter weights are hung through the measuring lines, and the hanging height change of the counter weights can reflect the deformation displacement of the surrounding rock. The device injects cement paste into the drill hole through the grouting pipeline and the exhaust pipeline and exhausts air, and it is guaranteed that the grouting process is conducted smoothly. The tail end back shore is used for protecting the casing pipe and providing pushing force. According to the invention, large-range and multi-point dynamic displacement measurement of the surrounding rock around the tunnel can be realized, the method has the advantages of high precision, strong reliability, simple and convenient construction and the like, and an effective safety monitoring means is provided for tunnel construction and operation.

Description

Technical Field

[0001] The invention relates to a surrounding rock displacement measurement technology, in particular to a casing type displacement measurement device and a measurement method thereof for measuring deformation displacement of surrounding rocks in tunnels and underground projects. Background Art

[0002] As an engineering structure buried in the ground, tunnels are widely used in the development and utilization of underground space. It usually refers to a tunnel with a cross-sectional area of ​​more than 2m2 built in various ways in the underground according to the specified shape and size. 2 As a key structure in many major infrastructure projects such as transportation engineering, water conservancy and hydropower engineering, municipal engineering and mining, tunnels play an important role and have irreplaceable significance for the national economy and people's livelihood.

[0003] Surrounding rock refers to the rock mass within the range of stress redistribution around the tunnel after excavation. It is also the part of the rock mass that affects the stability of the tunnel after excavation. Its stability directly affects the construction process and operational safety of the tunnel. The stress and deformation of the tunnel structure are closely related to the surrounding rock. The support structure and the surrounding rock interact with each other to form a system with common stress. Therefore, in tunnel construction, in addition to improving excavation efficiency, it is also necessary to do a good job in surrounding rock support and lining, especially to control the deformation of the surrounding rock around the tunnel to ensure the construction safety of the tunnel and the stability of the subsequent operation.

[0004] The deformation displacement inside the surrounding rock is a manifestation of the dynamic change of the surrounding rock. It not only reflects the degree of relaxation inside the surrounding rock, but also reveals the changes in the relaxation range of the surrounding rock. The deformation displacement of the surrounding rock is one of the important reference indicators for evaluating its stability. By dynamically measuring the deformation displacement inside the surrounding rock around the tunnel, its temporal and spatial evolution law is revealed, which can provide scientific guidance for decision-making on construction and operation plans and timely emergency response measures. However, due to the complex influence of factors such as lithology, geological structure, and groundwater, the geological conditions at the tunnel construction site are often changeable, resulting in smaller deformation displacement in the hard rock area and larger deformation displacement in the soft rock area.

[0005] In addition, the measurement of surrounding rock deformation and displacement during tunnel construction often requires a long time and high frequency. Especially in complex geological environments, the required deformation and displacement measurement device needs to have the characteristics of large range, high accuracy, strong reliability, good durability, easy installation, and low cost. However, the current surrounding rock deformation and displacement measurement technology still has many limitations, especially for the measurement of surrounding rock deformation and displacement in a large (deep) range around the tunnel.

[0006] The existing tunnel surrounding rock deformation displacement measuring devices mainly include mechanical, electrical and grouting anchoring types. These devices are composed of positioning devices, displacement transmission devices, orifice fixing devices, dial indicators or reading instruments and other components. The mechanical displacement measuring device has a simple structure, convenient installation, high durability and stability, and low comprehensive use cost. Although its accuracy is slightly inferior, it can meet actual needs and is widely used in engineering practice. The electrical displacement measuring device is equipped with a reading instrument, signal transmission and receiving equipment, with high measurement accuracy and automation, and can be remotely measured and convenient to use. However, its structure is complex, its stability is poor, it is easily affected by the external environment, and it is expensive, resulting in high use costs. The grouting anchoring displacement measuring device injects slurry or anchoring agent with coagulation and hardening properties into the annular gap between the borehole and the measuring device, and bonds it to the borehole rock wall to achieve anchoring. Its construction is simple and the cost is low, but because it is invisible in the borehole and the diffusion range of the slurry is uncontrollable, the actual anchoring effect is difficult to accurately control.

[0007] Although the existing displacement measurement devices can measure the deformation and displacement of the surrounding rock in a small range around the tunnel, the products on the market generally have the problems of fewer measuring points and smaller measurement range, which makes it difficult to meet the measurement needs of deformation and displacement in a larger (deep) range of the surrounding rock around the tunnel. As the requirements for safety and stability in tunnel construction continue to increase, it is urgent to develop a technical solution that can solve these problems and adapt to the large-scale surrounding rock deformation and displacement measurement needs under complex geological conditions. Summary of the invention

[0008] The present invention relates to a casing-type measuring device for surrounding rock displacement and a method thereof, aiming to provide a high-precision, large-range, multi-measuring-point, reliable and durable surrounding rock deformation displacement measuring device, so as to solve the problems of insufficient precision, limited range, few measuring points and narrow application scope in the prior art for surrounding rock deformation displacement measurement.

[0009] The present invention is achieved through the following technical solutions:

[0010] A casing-type measuring device for surrounding rock displacement includes a plurality of casings, a plurality of hubs, a plurality of measuring lines and a plurality of counterweights. A spacer device is provided at both ends of each casing, and two adjacent casings are connected by a socket connection to form an integral casing structure. The spacer device is used to separate the poured cement slurry outside the integral casing structure into a plurality of sections. A hub is fixedly installed at one end of each casing, and the hub is connected to a counterweight through a measuring line, and the counterweight is suspended outside one end of the integral casing structure. The deformation position and displacement of the surrounding rock are detected by measuring the change in the hanging height of the counterweight.

[0011] The key technical features of the surrounding rock displacement casing measurement device are as follows:

[0012] Casing structure: The casing includes a first section casing and multiple intermediate sections casing. The first section casing consists of a conical guide head and a casing body, which is easy to install in the borehole around the tunnel. Each intermediate section casing consists of a small diameter pipe body and a large diameter pipe body. The small diameter pipe body of the intermediate section casing is inserted into the casing body of the first section casing, and a stable overall structure is formed by the head and tail socket connection.

[0013] Hub structure: The hub is a cylindrical structure with several through holes in the middle for threading, which is used to bundle or pass through the measuring lines. The hub is combined with the positioning concave ring on the inner wall of the small-diameter pipe body and fixed by screws to ensure the stability of the hub in the casing.

[0014] Spacer device: The spacer device includes a main support ring and a secondary support ring. The main support ring and the secondary support ring have the same profile shape, and their inner diameter matches the outer diameter of the casing. The main support ring is nested on the casing body or the large diameter pipe body, and the secondary support ring is connected to the main support ring by screws, realizing a stable spacer function, ensuring the effective separation of cement slurry, and at the same time, used to support the grouting pipe and exhaust pipe.

[0015] Grouting pipeline and exhaust pipeline: The grouting pipeline consists of the first section of grouting pipe, several intermediate sections of grouting pipes and several grouting pipe joints. The first section of grouting pipe and the intermediate sections of grouting pipes and the intermediate sections of grouting pipes are all connected by grouting pipe joints, which are used to inject slurry with coagulation and hardening properties into the annular gap between the borehole and the casing. The exhaust pipeline consists of the first section of exhaust pipe, several intermediate sections of exhaust pipes and exhaust pipe joints. The first section of exhaust pipe and the intermediate sections of exhaust pipes and the intermediate sections of exhaust pipes are all connected by exhaust pipe joints, which are used to exhaust the air in the borehole to ensure the smooth progress of grouting.

[0016] Sealing device: The sleeves are sealed by sealing rings, which are installed in the annular grooves on the inner walls of the sleeves to prevent slurry leakage and ensure the sealing effect.

[0017] End support: The end support is a hollow tubular structure with a socket slot and an end cover. It is used to protect the end of the casing during installation, increase the area of ​​action of the jacking force, and ensure that the casing is pushed into the borehole smoothly.

[0018] In addition, the present invention also provides a surrounding rock displacement measurement method based on the surrounding rock displacement casing type measurement device. The method comprises the following steps:

[0019] 1. According to the deformation displacement position, direction, depth, lithology and geological structure of the surrounding rock to be measured, select appropriate drilling equipment and supporting machinery and tools to drill a linear measuring hole of appropriate diameter and depth.

[0020] 2. Assemble the casing-type surrounding rock displacement measuring device of the required length and push the device into the measuring hole.

[0021] 3. Inject cement slurry into the drilled hole through the grouting pipeline until the annular gap is filled and the air in the hole is exhausted.

[0022] 4. After the injected cement slurry solidifies, complete the installation of the surrounding rock displacement casing measuring device.

[0023] 5. Measure the deformation displacement of the surrounding rock by observing the changes in the hanging height of the counterweight at regular or irregular intervals.

[0024] 6. According to the change of the counterweight suspension height, draw the relationship curve between the internal deformation displacement of the surrounding rock and time, revealing the temporal and spatial evolution law of the surrounding rock deformation displacement.

[0025] The present invention can effectively solve various problems in the prior art by providing a surrounding rock displacement measuring device with simple structure, convenient installation, high measurement accuracy and wide adaptability, and provide a scientific basis for the safety and stability of tunnel construction and operation.

[0026] The working principle of the present invention is based on the joint action of casing, hub, measuring line and counterweight. By monitoring the change of the hanging height of the counterweight, the deformation and displacement of the surrounding rock around the tunnel can be accurately measured. First, each section of casing is inserted into the measuring hole drilled during the tunnel excavation process in sequence, and the casings are connected by sockets to form an overall casing structure. After the installation is completed, cement slurry is injected into the measuring hole through the grouting pipeline. After the cement slurry solidifies, due to the presence of the barrier device, multiple sections of cement stone bodies are formed, and each section of cement slurry is firmly bonded to the corresponding casing, so that the outer wall of each section of casing is stably fixed and bonded to the hole wall of the borehole. When the surrounding rock is deformed, the displacement of the surrounding rock (borehole wall) will drive the surrounding cement stone bodies and the bonded casing to move toward the hole mouth. A hub is fixedly installed at one end of each casing, and the hub is connected to the casing by fixing screws and the like. A threading hole is provided in the middle of the hub for tying the measuring line. One end of the measuring line is fixed on the hub, and the other end is hung with a counterweight. As the casing moves, the hanging height of the counterweight changes. The hanging height of the counterweight is proportional to the displacement of the casing. Therefore, by measuring the change in the hanging height of the counterweight, the deformation of the surrounding rock at the measuring point can be directly obtained.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] By regularly or in real time monitoring the changes in the counterweight suspension height, the present invention can obtain dynamic data on surrounding rock deformation. Each change in the counterweight suspension height indicates the size and displacement position of the surrounding rock deformation at the corresponding measuring point. By synchronously monitoring multiple measuring points, recording and drawing the relationship curve between surrounding rock deformation and time, the temporal and spatial evolution of the surrounding rock can be fully reflected, thereby providing a basis for safety assessment during tunnel construction and operation. Since the present invention adopts a multi-point measurement method, it can accurately monitor the deformation of the surrounding rock around the tunnel, thereby realizing the measurement of surrounding rock displacement over a larger range, meeting the high-precision and high-frequency requirements for dynamic measurement of surrounding rock deformation and displacement during tunnel construction.

[0029] In summary, the present invention can monitor the deformation and displacement of the tunnel surrounding rock in real time through the comprehensive layout of multiple casings, hubs, measuring lines and counterweights, and accurately reflect the deformation of the surrounding rock through the change data of the counterweight's suspension height, providing important dynamic measurement data for tunnel construction and operation, and ensuring the safety and stability of the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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:

[0031] Figure 1 A three-dimensional assembly diagram of the present invention as a whole;

[0032] Figure 2 An exploded view of a partially assembled version of the present invention;

[0033] Figure 3 It is a schematic diagram of a three-dimensional model of the first section of the casing of the present invention;

[0034] Figure 4 A three-dimensional isometric perspective view of the first section of the casing of the present invention;

[0035] Figure 5 It is an axonometric view of a three-dimensional model of the intermediate section casing of the present invention;

[0036] Figure 6 It is an axonometric perspective view of a three-dimensional model of the intermediate section casing of the present invention;

[0037] Figure 7 is an axonometric view of a three-dimensional model of the hub of the present invention;

[0038] Figure 8 It is an axonometric perspective view of a three-dimensional model of the hub of the present invention;

[0039] Fig. 9 A front view of a three-dimensional model of the secondary support ring of the present invention;

[0040] Fig.10It is an axonometric perspective view of a three-dimensional model of the secondary support ring of the present invention;

[0041] Fig.11 It is an exploded view of assembling two adjacent grouting pipes of the present invention;

[0042] Fig.12 It is an exploded view of the assembly of two adjacent exhaust pipes of the present invention;

[0043] Fig.13 It is a schematic axonometric perspective diagram of a three-dimensional model of the end support of the present invention.

[0044] Reference numerals and corresponding component names:

[0045] 1-first section of casing, 11-conical guide head, 12-through hole, 13-first section of casing body, 14-annular groove, 15-socket protrusion;

[0046] 2-middle section casing, 21-small diameter pipe body, 211-positioning hole, 212-positioning concave ring, 22-large diameter pipe body, 23-reducing joint, 24-socket groove;

[0047] 31-main supporting ring, 311-main supporting top surface, 312-connecting screw hole, 32-secondary supporting ring, 321-secondary supporting top surface, 322-connecting through hole, 33-screw;

[0048] 4-hub, 41-threading hole, 42-positioning screw hole, 43-screw, 44-measuring line, 45-counterweight;

[0049] 5- Sealing ring;

[0050] 61-first section grouting pipe, 611-grouting hole, 612-thread, 62-grouting pipe joint, 63-middle section grouting pipe;

[0051] 71-first section exhaust pipe, 711-thread, 72-exhaust pipe joint, 73-middle section exhaust pipe;

[0052] 8-end support, 81-socket long groove, 82-end cover. DETAILED DESCRIPTION

[0053] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0054] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details are not necessarily employed to practice the present invention. In other instances, well-known structures, circuits, materials, or methods are not specifically described in order to avoid obscuring the present invention.

[0055] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0056] In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the scope of protection of the present invention.

[0057] Example

[0058] like Figure 1 and Figure 2 As shown, a casing type measuring device for surrounding rock displacement of the present invention comprises a plurality of casings, a plurality of hubs 4, a plurality of measuring lines 44 and a plurality of counterweights 45. A spacer device is provided at both ends of each casing, and two adjacent casings are connected by a socket connection to form an integral casing structure. The spacer device is used to separate the poured cement slurry outside the integral casing structure into a plurality of sections. A hub 4 is fixedly installed at one end of the inner pipe of each casing, and the hub 4 is connected to a counterweight 45 through a measuring line 44, and the counterweight 45 is suspended outside one end of the integral casing structure. The deformation position and displacement of the surrounding rock are detected by measuring the change in the hanging height of the counterweight 45.

[0059] like Figure 3 to Figure 13Specifically, the plurality of casings include a first casing section 1 and a plurality of middle casing sections 2, the first casing section 1 is connected with the middle casing section 2 by means of spigots and sockets, and the middle casing section 2 is connected with the middle casing section 2 by means of spigots and sockets, and the first casing section 1 is composed of a conical guide head 11 and a first casing section body 13. Among them, the conical guide head 11 is a structure designed to facilitate insertion and installation into a borehole in the surrounding rock of the tunnel; the first section casing body 13 is a hollow tube, which is fixedly connected to the conical guide head 11 and is arranged at a lower middle part of the conical guide head 11; a through hole 12 for passing the first section exhaust pipe 71 is provided at the upper part of the conical guide head 11 and above the first section casing body 13; two socket protrusions 15 connected to the socket groove 24 are symmetrically arranged at the upper and lower ends of the first section casing body 13; on the inner wall of the first section casing body 13, near the socket protrusion 15, two annular grooves 14 for installing the sealing ring 5 are arranged at intervals;

[0060] The middle section casing 2 is mainly composed of a hollow tubular small-diameter pipe body 21 and a large-diameter pipe body 22. Among them, a positioning concave ring 212 with the same length as the thickness of the hub 4 is provided on the inner wall of the left end of the small-diameter pipe body 21, which is used to place the hub 4; a positioning hole 211 for inserting the top screw 43 is provided in the middle above the positioning concave ring 212; a reducer 23 is provided at the right end of the small-diameter pipe body 21, the left end of the reducer 23 is fixedly connected to the right end of the small-diameter pipe body 21, the specification of the right end of the reducer 23 is equivalent to the inner diameter of the large-diameter pipe body 22, the right side of the reducer 23 is inserted into the left end of the large-diameter pipe body 22 by 10 to 60 cm, and then the reducer 23 is inserted into the outer wall of the left end of the large-diameter pipe body 22 and fixedly connected to the inner wall of the left end of the large-diameter pipe body 22; two socket grooves 24 connected to the socket protrusion 15 are symmetrically provided at the left end of the large-diameter pipe body 22. Similar to the structure at the end of the first section casing body 13, two socket protrusions 15 are symmetrically arranged at the upper and lower ends of the large diameter pipe body 22; on the inner wall of the large diameter pipe body 22, and near the portion of the socket protrusion 15 at the rear end thereof, two annular grooves 14 for accommodating the sealing ring 5 are arranged at intervals. The sealing structure is combined with the sealing rubber sleeve at the joint between the socket protrusion 15 and the socket groove 24 of the adjacent first section casing body 13 right end and the small diameter pipe body 21 left end after the socket connection, and the socket protrusion 15 and the socket groove 24 of the right end of the large diameter pipe body 22 of the adjacent two intermediate section casings 2, so as to ensure that when grouting is performed at the orifice into the annular gap between the present invention and the borehole, the slurry is prevented from flowing into the interior of the first section casing 1 and the intermediate section casing 2 from the joint;

[0061] The barrier device adopts a main supporting ring 31 and a secondary supporting ring 32, both of which have the same contour shape and are both hollow structures shaped like a "cat's head". The specification (inner diameter) of the through hole located in the middle of them is the same as the outer diameter of the first section casing body 13 and the large diameter pipe body 22, and two "cat ears" shaped structures are symmetrically arranged above them. The "W" shaped area between the pair of "cat ears" structures is the main supporting top surface 311 and the secondary supporting top surface 321 respectively. The contours of the main supporting top surface 311 and the secondary supporting top surface 321 are suitable for well placing and supporting the grouting pipe (the first section grouting pipe 61 and the middle section grouting pipe 63) and the exhaust pipe (the first section exhaust pipe 71 and the middle section exhaust pipe 73). Among them, the main supporting ring 31 is first inserted to the left from the right end of the first section casing body 13 and the right end of several large-diameter tube bodies 22 to 10 to 80 cm, and then fixedly connected to the outer walls of the first section casing body 13 and several large-diameter tube bodies 22; the secondary supporting ring 32 is an independent structure, and is fixedly connected to the corresponding main supporting ring 31 by screws 33. Taking into account the friction and wear between the present invention and the borehole rock wall when the present invention is pushed into the borehole during installation, as well as the heavy weight of the first section casing 1 and the plurality of intermediate section casings 2, the material of the main support ring 31 is the same as that of the first section casing 1 and the intermediate section casing 2, and stainless steel, aluminum alloy, nickel alloy, titanium alloy, carbon fiber material, basalt fiber material, etc. with good strength, wear resistance and corrosion resistance can be selected; and the auxiliary support ring 32 mainly assists the main support ring 31 in grouting the first section casing 1, the plurality of intermediate section casings 2, the grouting pipes (the first section grouting pipe 61 and the intermediate section grouting pipe 63) and the exhaust pipe (the first section exhaust pipe 71 and the intermediate section exhaust pipe 73). Support, and considering reducing the weight and manufacturing cost of the present invention as much as possible, the material of the secondary supporting ring 32 can be selected from nylon, polyamide, polyester fiber, polypropylene, polyethylene, etc., which are lighter in weight, have better wear resistance and corrosion resistance, and are cheaper; in addition, the thickness of the main supporting ring 31 and the secondary supporting ring 32 can be the same or different, but the thickness of the secondary supporting ring 32 is not less than that of the main supporting ring 31, so as to achieve reliable support for the first section casing 1, several intermediate section casings 2, grouting pipes (first section grouting pipe 61 and intermediate section grouting pipe 63) and exhaust pipes (first section exhaust pipe 71 and intermediate section exhaust pipe 73) under the condition of increasing the weight and manufacturing cost of the present invention as little as possible. In order to realize reliable connection between the main supporting ring 31 and the auxiliary supporting ring 32, two connecting screw holes 312 with internal threads are symmetrically provided at the square "cat ear" structure on the main supporting ring 31, and two connecting through holes 322 without threads are symmetrically provided at the same position of the auxiliary supporting ring 32, so that the main supporting ring 31 and the auxiliary supporting ring 32 can be fixedly connected by two screws 33. A main supporting ring 31 is provided on the outer wall of the large diameter pipe body 22 and at a position 10 to 80 cm away from the right end of the large diameter pipe body 22.A main support ring 31 is provided on the outer wall of the first section casing body 13 and is fixedly connected to the secondary support ring 32 by screws 33 at a position 10 to 80 cm away from the end of the first section casing body 13. The main support ring 31 is a hollow structure shaped like a "cat's head". The through hole specification in the middle is the same as the outer diameter of the first section casing body 13 and the large diameter pipe body 22. The main support ring 31 is inserted from one end of the first section casing 1 and the large diameter pipe body 22 and is fixedly connected to the outer wall of the first section casing 1 and the large diameter pipe body 22. The bottom of the main support ring 31 contacts the bottom rock wall of the borehole, so that the first section casing body 13 It is suspended from several large-diameter pipe bodies 22 without direct contact with the borehole rock wall; two "cat ear" shaped structures are symmetrically provided on the upper part of the main support ring 31, and two connecting screw holes 312 with internal threads are symmetrically provided here; the top of the main support ring 31, that is, the "W" shaped area between the top sides of the two "cat ear" shaped structures is the main support top surface 311, and the two sides of the main support top surface 311 are respectively used to place grouting pipes (the first section grouting pipe 61 and the middle section grouting pipe 63) and exhaust pipes (the first section exhaust pipe 71 and the middle section exhaust pipe 73).

[0062] The hub 4 is a cylindrical structure with an outer diameter equivalent to the inner diameter of the small-diameter tube body 21. A plurality of through-shaped threading holes 41 for tying and passing a plurality of measuring lines 44 are provided at intervals in the middle of the hub 4, and a positioning screw hole 42 with an internal thread is provided at the top of the hub 4; when the hub 4 is placed in the positioning concave ring 212 inside the left end of the small-diameter tube body 21, the positioning screw hole 42 is aligned with the positioning hole 211, and the top screw 43 is inserted downward from the positioning hole 211 and screwed into the positioning screw hole 42, thereby realizing the fixed connection between the hub 4 and the inner wall of the small-diameter tube body 21. All measuring lines 44 need to be numbered in advance so as to match them with the corresponding threading holes 41; for the hub 4 placed inside the left end of the first small-diameter pipe body 21, the first measuring line 44 passes through the first threading hole 41 set in the middle of the hub 4, and one end of the measuring line is firmly tied to the threading hole, and the other end of the measuring line passes through the first threading holes 41 in the middle of all the subsequent small-diameter pipe bodies 21 placed inside the left ends of the hubs 4, and then a small counterweight 45 is tied to the other end of the measuring line. The measuring line 44 is straightened by the deadweight of the counterweight 45, and the purpose of measuring the deformation displacement at the first measuring point inside the surrounding rock around the tunnel can be achieved by observing the elongation of the measuring line; accordingly, the second measuring line passes through the second threading hole 41 in the middle of the hub 4 placed inside the left end of the second small-diameter pipe body 21, and one end of the measuring line is firmly tied to the threading hole, and the other end of the measuring line passes through the first threading holes 41 in the middle of all the subsequent small-diameter pipe bodies 21 placed inside the left ends of the hubs 4, and then one end of the measuring line is firmly tied to the threading hole, and the other end of the measuring line passes through the first threading holes 41 in the middle of all the subsequent small-diameter pipe bodies 21 placed inside the left ends of the hubs 4, and then a small counterweight 45 is tied to the other end of the measuring line. After passing through the second threading hole 41 in the middle of the hub 4 inside the left end of the third small-diameter pipe body 21, a small counterweight 45 is tied to the other end of the measuring line to straighten it. By observing the elongation of the measuring line, the purpose of measuring the deformation displacement at the second measuring point inside the surrounding rock around the tunnel can be achieved; the third measuring line passes through the third threading hole 41 in the middle of the hub 4 installed inside the left end of the third small-diameter pipe body 21, and one end of the measuring line is firmly tied in the threading hole, and the other end of the measuring line passes through all the third threading holes 41 in the middle of the hub 4 installed inside the left ends of other subsequent small-diameter pipe bodies 21 in turn, and then a small counterweight 45 is tied to the other end of the measuring line to straighten it. By observing the elongation of the measuring line, the purpose of measuring the deformation displacement at the third measuring point inside the surrounding rock around the tunnel can be achieved; and so on, the binding and threading of all measuring lines 44 can be completed, thereby realizing dynamic monitoring and measurement of deformation displacement at all measuring points inside the surrounding rock around the tunnel.

[0063] The grouting pipeline is formed by a first section grouting pipe 61 and a plurality of intermediate sections grouting pipes 63 connected by threads, and is a channel for injecting slurry with coagulation and hardening properties from the orifice to the annular gap between the first section casing 1 and the plurality of intermediate sections casing 2 and the borehole rock wall. The first section grouting pipe 61 and the subsequent plurality of intermediate sections grouting pipes 63 are threadedly connected as a whole through a grouting pipe joint 62. On the first section grouting pipe 61 and the plurality of intermediate sections grouting pipes 63, a plurality of grouting holes 611 for slurry to flow out are arranged at intervals and staggered. Among them, the first section grouting pipe 61 is fixedly connected to the outer wall of the first section casing body 13, and the left end of the first section grouting pipe 61 is 2 to 40 cm away from the rear end of the conical guide head 11, and the distance is suitable for the slurry to flow out smoothly from the left end of the central through hole of the first section grouting pipe 61 and the plurality of grouting holes 611 arranged thereon. After being threadedly connected with the first grouting pipe 61 and the intermediate grouting pipe 63 in sequence, a plurality of intermediate grouting pipes 63 are placed on the main support top surface 311 and the secondary support top surface 321 at the top of the main support ring 31 and the secondary support ring 32 .

[0064] The exhaust pipeline, which is formed by a first exhaust pipe 71 and a plurality of intermediate exhaust pipes 73 connected by threads, is a passage for exhausting air from the hole to the outside during grouting. The first exhaust pipe 71 and the subsequent intermediate exhaust pipes 73 are connected as a whole by threads through an exhaust pipe joint 72. When grouting is performed from the orifice into the annular gap between the borehole and the first casing 1 and the intermediate casing 2 through the above-mentioned grouting pipeline, the presence of air in the borehole will hinder the smooth implementation of grouting. Therefore, by setting up the exhaust pipeline, the original air in the borehole can be discharged from the exhaust pipeline to the outside of the hole while injecting the slurry, thereby ensuring the smooth progress of grouting.

[0065] The end support 8 is a hollow tubular structure with an open left end and a socket long groove 81, and an end cover 82 at the right end. It is an auxiliary component that is socket-connected with the two socket protrusions 15 of the last intermediate section casing 2 when the present invention is pushed and placed in the borehole section by section. It can play three roles: ① It can effectively protect the socket protrusions 15 from being damaged when the present invention is pushed forward with force; ② It can effectively increase the area of ​​action of the force when pushing the present invention. In addition to providing the pushing force manually, other auxiliary machines and tools that are convenient to obtain at the tunnel construction site, such as jacks and excavators, can also be used for pushing operations; ③ When the present invention is installed in place, the end support 8 can be fixedly connected to the end of the last intermediate section casing 2, thereby effectively protecting the end of the last intermediate section casing 2, as well as the internal cavities of the first section casing 1 and several intermediate section casings 2, several measuring lines 44 and counterweights 45. In addition, the length of the socket long groove 81 is slightly larger than the length of the socket protrusion 15. When the end support 8 is socket-connected with the socket protrusion 15 of the middle section casing 2, the socket protrusion 15 cannot completely resist the end of the socket long groove 81, and there is a certain gap between the two. The gap is used as a channel for the ends of several measuring lines 44 and the counterweight 45 to be thrown out from the internal cavity of the first section casing 1 and several middle section casings 2. It can effectively avoid the risk of accidentally cutting the measuring line 44 when pushing hard during the placement of the present invention, and play a good protective role; on the other hand, it can also serve as a channel for all measuring lines 44 and counterweights 45 to be thrown out from the internal cavity of the first section casing 1 and several middle section casings 2 after the present invention is installed in place section by section, so that the technicians carrying out the measurement work on site can grasp the deformation displacement at the corresponding measuring points inside the surrounding rock around the tunnel by observing the elongation change of different measuring lines 44, that is, the hanging height of the counterweight 45.

[0066] When the present invention is used to carry out dynamic measurement of deformation and displacement inside the surrounding rock of a tunnel, it is first necessary to determine and prepare in advance the required first section casing 1, middle section casing 2, auxiliary support ring 32, hub 4, measuring line 44, counterweight 45, sealing ring 5, first section grouting pipe 61, grouting pipe joint 62, middle section grouting pipe 63, first section exhaust pipe 71, exhaust pipe joint 72, middle section exhaust pipe 73 and end top support 8 components according to the depth and number of measuring points at which the deformation and displacement measurement inside the surrounding rock is to be carried out. In order to facilitate the statistics of the length of the displacement measuring device installed in the borehole at the tunnel construction site, the length of the first section casing body 13 can be set to 1m. At the same time, when the small diameter pipe body 21 is inserted into the right end of the first section casing body 13, and the socket groove 24 is fully in contact with the socket protrusion 15 to realize the socket connection, the length of the exposed part (i.e., the large diameter pipe body 22) is also set to 1m. The first section casing 1 and each intermediate section casing 2 are a measuring point. Therefore, on site, it is only necessary to determine the required number of components such as the first section casing 1, the intermediate section casing 2, the auxiliary support ring 32, the hub 4, the measuring line 44, the weight 45, the sealing ring 5, the first section grouting pipe 61, the grouting pipe joint 62, the intermediate section grouting pipe 63, the first section exhaust pipe 71, the exhaust pipe joint 72, the intermediate section exhaust pipe 73 and the end top support 8 according to the required measurement and number of measuring points of the internal deformation displacement of the surrounding rock around the tunnel.

[0067] Secondly, since the space on the tunnel site is limited and the measurement of the deformation and displacement of the surrounding rock cannot interfere with the normal tunnel construction work, the rapid installation of the present invention can only be carried out by making full use of the intermittent shift time of the normal tunnel construction work. In order to effectively improve the installation efficiency of the present invention, and considering the limited space available for operation on the tunnel site, the several hubs 4 and several measuring lines 44 of the present invention need to be tied and threaded in advance outside the tunnel. The specifications and structures of all hubs 4 are the same, and they do not need to be numbered when used, but the threading holes 41 thereon need to be numbered; in addition, since different measuring lines 44 need to correspond to different measuring points, that is, the left ends of different measuring points 44 need to be tied to different threading holes 41 of different hubs 4, all measuring lines 44 also need to be numbered to prevent mistakes or confusion. The first measuring line 44 passes through the first threading hole 41 of the first hub 4, and its left end is tied to the threading hole 41, and its right end passes through the first threading hole 41 of the second hub 4, and then passes through the first threading hole 41 of the third hub 4... until it passes through the first threading hole 41 of the last hub 4, and leaving enough margin; the second measuring line 44 passes through the second threading hole 41 of the second hub 4, and its left end is tied to the threading hole 41, and its right end passes through the second threading hole 41 of the third hub 4, and then passes through the second threading hole 41 of the fourth hub 4... until it passes through the second threading hole 41 of the last hub 4, and leaving enough margin; and so on, the last measuring line 44 passes through the last threading hole 41 of the last hub 4, and its left end is tied to the threading hole 41, and leaving enough margin. Subsequently, the corresponding hubs 44 are sequentially placed in the positioning concave rings 212 at the left ends of the corresponding intermediate sleeves 2, and the positioning screw holes 42 are aligned with the positioning holes 211, and the hubs 44 are fixed with the top screws 43. In addition, since the specifications and structures of all the secondary support rings 32 are the same, they do not need to be numbered. According to the number of intermediate sleeves 2, the corresponding number of secondary support rings 32 are used, and they are respectively inserted from the right ends of the large diameter tube bodies 22 of the corresponding intermediate sleeves 2 until they are in contact with the main support rings 31, and then the secondary support rings 32 are fixedly connected with the main support rings 31 with screws 33. Then all the first-section casings 1 and the middle-section casings 2 are arranged in order. They can be arranged into a long straight line according to the situation on site, or several adjacent groups of first-section casings 1 and middle-section casings 2 can be connected by sockets to form a small whole. Then, the next group of adjacent middle-section casings 2 of the same number can also be socketed to form a small whole. The present invention can be divided into several groups of such small wholes. Small wholes of different groups can be placed together in parallel in an "S" shape to save transportation and space. In this process, special attention should be paid to the fact that all measuring lines cannot be entangled or knotted.At the same time, considering that the injected slurry should be prevented from flowing into the first section casing 1 and the plurality of intermediate section casings 2 along the joints between the adjacent socket projections 15 and the socket grooves 24 during the subsequent grouting, a thin-walled rubber sleeve with good elasticity can be put on the joints between the adjacent socket projections 15 and the socket grooves 24. Then, the first section grouting pipe 61 and the plurality of intermediate section grouting pipes 63 are respectively connected as a whole with the grouting pipe joint 62, and the first section exhaust pipe 71 and the plurality of intermediate section exhaust pipes 73 are respectively connected as a whole with the exhaust pipe joint 72, and they are all placed on the corresponding main support top surface 311 and the secondary support top surface 321 in sequence; considering that the present invention is installed in the borehole in sections, the connection length of the grouting pipe and the exhaust pipe should match the length of the installation in sections of the present invention, that is, they are also connected in sections and enter the borehole in sections along with the first section casing 1 and the intermediate section casing 2 in sequence.

[0068] Then, according to the position, direction, depth, rock type and geological structure of the surrounding rock deformation displacement to be measured, suitable drilling equipment and supporting machinery are selected, and a suitable drilling process is used to drill a linear borehole of the required specification and depth at the corresponding surrounding rock. If the surrounding rock is relatively hard and has good stability, conventional rotary drilling or impact drilling can be used for drilling operations. After the desired borehole is drilled, the hole wall is stable without collapse, block drop, shrinkage and other undesirable phenomena. Compressed air, clean water or special tools are then used to clean the hole, and the rock cuttings remaining in the hole are cleaned out of the hole, providing the necessary conditions for the subsequent installation of the present invention in the borehole. If the surrounding rock is relatively soft and has poor stability, a follow-up drilling process is required, that is, when drilling, the steel casing follows the drill bit and the drill rod column into the hole. When the drilling is completed, the drill bit and the drill rod column are removed from the hole, and the steel casing is left behind. The hole wall is supported in the hole to prevent the hole wall from collapsing, falling off, shrinking in diameter, and other problems. The present invention is then pushed into the steel casing section by section until it is installed in place. A pulling machine such as a jack is used at the hole mouth to pull the steel casing out of the borehole, leaving only the present invention in the hole. If the surrounding rock is relatively broken, a slurry with coagulation and hardening properties (such as cement slurry) can be injected into the hole after the drilling operation is completed to fill the borehole. After the cement slurry coagulates and hardens, the borehole wall is effectively reinforced and becomes sufficiently stable. Then a hole is drilled into the cement stone body again at the original hole mouth until a stable borehole that meets the installation requirements of the present invention is drilled. Then, the present invention is pushed into the borehole section by section starting from the conical guide head 11 of the first section of the casing 1. Manpower can be used for pushing, or an excavator, jack or other suitable equipment and tools that are convenient to use on site can be used to provide the required force. Each time the pushing is performed, the end support 8 needs to be connected with the two socket protrusions 15 at the end of the large-diameter pipe body 22 of the last intermediate section of the casing 2, and all the measuring lines 44 involved are thrown outward from the side socket long grooves 81 to avoid accidentally cutting off the measuring lines during the pushing process. This cycle is repeated and pushed section by section until the present invention is completely pushed into the borehole.

[0069] Again, outside the hole, grouting equipment and machines such as mixers, high-pressure hoses, grouting pumps, and grouting plugs are used to inject slurry with coagulation and hardening properties (such as cement slurry, cement mortar, etc.) into the annular gap formed by the outer wall of the first section casing 1, several intermediate sections casing 2, and the borehole wall through the end of the last intermediate section grouting pipe 63 along the entire grouting pipeline. As the grouting proceeds, the air originally remaining in the borehole is discharged out of the hole along the exhaust pipe. The grouting operation is terminated after the grouting operation continues for a period of time to allow the slurry to better fill the annular gap. Depending on the coagulation and hardening of the slurry on site, the slurry is allowed to solidify for several hours until a better bonding between the present invention and the borehole wall is achieved. At this time, the portion of the large-diameter pipe body 22 of each intermediate section casing 2 exposed outside can be used as a fixed measuring point for measuring the deformation and displacement of the surrounding rock.

[0070] Finally, the end support 8 is connected with the socket projection 15 at the end of the last intermediate section casing 2 by socket connection, and they are fixed together. A counterweight 45 of appropriate weight is tied at the end of all measuring lines 44, so that the corresponding measuring lines 44 are all in a straight state. The surrounding rock around the tunnel will deform and displace over time. When the deformation and displacement occur, the borehole wall will drive the large-diameter pipe body 22 at the corresponding measuring point to move, and the length of the corresponding measuring line 44 extending outside the borehole will change to a certain extent. By repeatedly observing the length changes of all measuring lines 44, that is, the changes in the hanging height of the counterweight 45, recording them in time, and drawing them into a curve of the relationship between the deformation and displacement of the surrounding rock around the tunnel and time, the temporal and spatial changes of the deformation and displacement at different measuring points (depths) inside the surrounding rock can be indirectly grasped.

[0071] 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 casing type measuring device for surrounding rock displacement, characterized in that: It comprises a plurality of casings, a plurality of hubs, a plurality of measuring lines and a plurality of counterweights, one end of each casing is provided with a spacer, two adjacent casings among the plurality of casings are connected by socket connection to form an integral casing structure, the spacer is used to separate the poured cement slurry outside the integral casing structure into a plurality of sections; a hub is fixedly installed at one end of the inner pipe of each casing, a counterweight is suspended from each hub through a measuring line, and the counterweight is suspended outside one end of the integral casing structure; the deformation position and displacement of the surrounding rock are detected by measuring the change in the hanging height of each counterweight.

2. A casing type measuring device for surrounding rock displacement according to claim 1, characterized in that: The plurality of casings include a first section casing and a plurality of intermediate section casings, wherein the plurality of intermediate section casings are connected by socket joints at the head and tail ends and are socketed in the first section casing to form an integral casing structure; the first section casing is composed of a conical guide head and a casing body, and the conical guide head is used for inserting and installing into a surrounding rock borehole around the tunnel; each intermediate section casing is composed of a small diameter pipe body and a large diameter pipe body; the small diameter pipe body of the intermediate section casing is inserted into the casing body of the first section casing, and the small diameter pipe body of one intermediate section casing is inserted into the large diameter pipe body of another intermediate section casing.

3. A casing type measuring device for surrounding rock displacement according to claim 2, characterized in that: The hub is a cylindrical structure with radial positioning screw holes; the inner wall of the small-diameter tube body of the middle section sleeve is provided with a positioning recessed ring for accommodating the hub, and the positioning recessed ring is radially provided with positioning holes for inserting screws; the hub is placed in the positioning recessed ring and fixedly connected to the inner wall of the small-diameter tube body by screws.

4. A casing type measuring device for surrounding rock displacement according to claim 3, characterized in that: A plurality of through-going threading holes are provided in the middle of the cylindrical end surface of the hub, and the threading holes are used for binding or passing the measuring lines.

5. The casing type measuring device for surrounding rock displacement according to claim 4 is characterized in that: It also includes a sealing ring. Two annular grooves for installing the sealing ring are provided at intervals on the inner wall of the first section casing body; two annular grooves for accommodating the sealing ring are provided at intervals on the inner wall of the large-diameter tube body of the middle section casing; the first section casing and the middle casing, and the middle casing and the middle casing are connected by sockets and connected by sealing rings to prevent slurry from entering the interior of the overall casing structure.

6. A casing type measuring device for surrounding rock displacement according to claim 5, characterized in that: The spacer device includes a main supporting ring and a secondary supporting ring. The main supporting ring and the secondary supporting ring have the same contour shape, and their inner diameters match the outer diameters of the first section casing body or the large diameter pipe body; the main supporting ring is nested in the first section casing body or the large diameter pipe body; the secondary supporting ring is nested in the first section casing body or the large diameter pipe body, and is connected to the corresponding main supporting ring by screws.

7. A casing type measuring device for surrounding rock displacement according to any one of claims 1 to 6, characterized in that: It also includes a grouting pipeline, which includes a first-section grouting pipe, several middle-section grouting pipes and several grouting pipe joints. The first-section grouting pipe and the middle-section grouting pipes are provided with several grouting holes for slurry to flow out at intervals and staggered. The first-section grouting pipe and the middle-section grouting pipes, and the middle-section grouting pipes and the middle-section grouting pipes are connected by grouting pipe joints to form a grouting pipeline. The grouting pipeline is placed on the main support top surface of the main support ring, the top of the secondary support ring and the top surface of the secondary support, in parallel with the overall casing structure, and is used to inject slurry with coagulation and hardening characteristics. The first-section grouting pipe of the grouting pipeline is 2 to 40 cm away from the rear end of the conical guide head of the first-section casing in the axial direction.

8. The casing type measuring device for surrounding rock displacement according to claim 7 is characterized in that: It also includes an exhaust pipeline, which is composed of a first-section exhaust pipe, several middle-section exhaust pipes and several exhaust pipe joints. The first-section exhaust pipe and the middle-section exhaust pipe, as well as the middle-section exhaust pipes and the middle-section exhaust pipes are all connected through exhaust pipe joints; the exhaust pipeline is placed on the main support top surface of the main support ring, the top of the secondary support ring and the secondary support top surface, and is connected in parallel with the overall casing structure to discharge the air in the borehole during the grouting process.

9. The casing type measuring device for surrounding rock displacement according to claim 8, characterized in that: It also includes an end support, which is a hollow tubular structure with a long socket groove at one end and an end cover at the other end; the end support is connected to the end of the middle section of the sleeve at the end of the integral sleeve structure for jacking installation.

10. A method for measuring surrounding rock displacement, characterized in that: The casing type measuring device for surrounding rock displacement according to claims 1 to 9 is used, and the steps include: Step 1: According to the location, direction, depth, lithology and geological structure of the surrounding rock deformation displacement to be measured, select the corresponding drilling equipment and supporting machinery and tools, and use the corresponding drilling process to drill a linear measuring hole of the required diameter and depth at the corresponding surrounding rock; Step 2: According to the required depth of the surrounding rock measurement hole, assemble the surrounding rock displacement casing measuring device of the required length, and push the surrounding rock displacement casing measuring device into the linear measurement hole section by section; Step 3: Inject cement slurry into the measuring hole through the grouting pipeline of the surrounding rock displacement casing type measuring device until the entire measuring hole gap is filled, and the air inside the measuring hole is discharged through the exhaust pipeline of the surrounding rock displacement casing type measuring device; Step 4: After the injected cement slurry solidifies, the installation of the surrounding rock displacement casing measuring device is completed; Step 5: regularly or irregularly measure the hanging height of each counterweight hung outside the surrounding rock displacement casing type measuring device; Step 6: By observing the length changes of all counterweight suspensions multiple times, recording them in a timely manner, and drawing a curve of the relationship between the deformation displacement inside the surrounding rock and time, the changing pattern of the deformation displacement at different measuring points inside the surrounding rock can be obtained.

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