Thin-wall composite lining tunnel osmometer post-installation structure and construction method thereof

Abstract

The invention discloses a thin-wall composite lining tunnel osmometer post-installation structure and a construction method thereof, the thin-wall composite lining tunnel osmometer post-installation structure comprises a lining structure, an anchoring groove is formed in the concrete surface of the lining structure, and an installation hole is drilled in the groove bottom wall perpendicular to the anchoring groove in the lining structure direction; the sleeve is embedded in the mounting hole, and a pipe orifice at one end of the sleeve is detachably connected with a wire outlet terminal; the outgoing line terminal is located in the anchoring groove. A drainage hole is drilled between the sleeve and the drainage cushion layer, and the drainage hole is communicated with an inner cavity of the sleeve; the protection cover is buckled with the wire outlet terminal; the osmometer is located in the sleeve, and a cable of the osmometer penetrates through the wire outlet terminal and the protective cover; the epoxy mortar is filled in the anchoring groove; and the polyurea layer covers the epoxy mortar and the concrete surface corresponding to the circumferential direction of the anchoring groove. According to the method, the osmometer can be installed in the groove formed in the existing concrete, damage to the stress structure of the tunnel is reduced, and adverse effects of the tunnel environment and grouting on the osmometer can be avoided to the maximum extent.

Description

Technical Field

[0001] This invention relates to the field of safety monitoring technology for water conservancy and hydropower projects, and more specifically to a post-installation structure and construction method for a thin-walled composite lining tunnel piezometer. Background Technology

[0002] Installing piezometers for real-time monitoring and early warning of water pressure in the drainage cushion layer is crucial. Timely drainage and pressure relief when the water pressure reaches the warning value is extremely important. Furthermore, as operating time increases, the instruments gradually become ineffective due to the underwater environment of the tunnel and their own lifespan, necessitating the periodic installation and replacement of piezometers.

[0003] However, the existing piezometer installation methods are not suitable for retrofitted piezometers. The construction work is extensive and there is a risk of damaging the tunnel's stress structure. During the installation of the instrument, the piezometer may be encased in cement slurry during the concrete pouring process, causing the measurement value to be distorted. After the instrument is installed, there is a lack of special waterproofing treatment, which may create new leakage channels and damage the anti-seepage system. If the piezometer fails, it is difficult to replace the retrofitted piezometer and the construction must be redone.

[0004] Chinese invention patent application No. 201810877876.2 discloses a single-hole multi-pore water pressure gauge installation structure and method. This method involves pre-drilling a hole or embedding a casing with a diameter smaller than the predetermined location of the soil layer to be measured, filling the embedded pipe with fine sand, and finally sealing the hole with clay. However, this method is only suitable for downward drilling and detection where the water pressure is low and there is no upward seepage. It is not suitable for tunnels with severe seepage, as filling the voids inside the pipe with only clay and gravel is insufficient to stop seepage under conditions of high and constant water flow.

[0005] Utility model patent application number 202121002978.3 discloses an installation structure for a piezometer in a water conveyance tunnel, including a tunnel lining; a blind hole is provided at the top of the tunnel lining, with the opening of the blind hole facing downwards, and a grout-sealing and permeable bag is inserted into the blind hole, with a piezometer installed inside the grout-sealing and permeable bag; cotton yarn is filled into the blind hole at the bottom of the grout-sealing and permeable bag, and a wooden cover is provided at the opening of the blind hole. However, the wrapping materials used in this structure, such as the grout-sealing and permeable bag, cotton yarn, and wooden cover, are all traditional materials, which may create new leakage channels and damage the seepage prevention system.

[0006] Therefore, how to provide a post-installation structure for piezometers that can be installed by slotting in existing concrete, reducing damage to the stress structure of the tunnel, and minimizing the adverse effects of the tunnel environment and grouting on the piezometers, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a post-installation structure and construction method for a piezometer in a thin-walled composite lining tunnel, which enables the installation of the piezometer in grooves on existing concrete, reducing damage to the tunnel's stress structure and minimizing the adverse effects of the tunnel environment and grouting on the piezometer. At the same time, a complete sealing system is adopted to prevent the post-installed piezometer from damaging the seepage prevention system, and replacement is also relatively convenient if the post-installed piezometer fails.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A post-installation structure for a piezometer in a thin-walled composite-lined tunnel includes:

[0010] The lining structure has anchoring grooves on its concrete surface and mounting holes drilled perpendicular to the bottom wall of the anchoring grooves and along the direction of the lining structure.

[0011] A sleeve is fitted into the mounting hole, and one end of the sleeve is detachably connected to a terminal; the terminal is located in the anchoring groove; a drainage hole is drilled between the sleeve and the drainage pad, and the drainage hole communicates with the inner cavity of the sleeve.

[0012] Protective cover, which fastens to the outgoing terminal;

[0013] A piezometer, the piezometer being located inside the casing, the piezometer's cable passing through the outlet terminal and the protective cover;

[0014] Epoxy mortar, the epoxy mortar being filled into the anchoring groove;

[0015] A polyurea layer covering the epoxy mortar and the concrete surface corresponding to the circumference of the anchoring groove.

[0016] The beneficial effects of the technical solution of this invention are as follows: by installing the piezometer through anchoring grooves and drilling installation holes, the damage to the stress structure of the tunnel is reduced, and the instrument can be installed on the thin-walled composite lining structure in the later stage; the piezometer is installed in the casing, which can effectively avoid the influence of the underwater environment on the piezometer, prevent silt from affecting the piezometer readings, and also prevent the piezometer from being encased in cement slurry during concrete pouring, causing measurement distortion; by sealing the anchoring groove with epoxy mortar and polyurea layer, the installation of the instrument is prevented from damaging the tunnel's seepage prevention system.

[0017] Preferably, a rebar adhesive is provided between the outer wall of the sleeve and the inner wall of the mounting hole. The rebar adhesive has strong bonding properties and can firmly bond the outer wall of the sleeve to the inner wall of the mounting hole.

[0018] Preferably, a temporary plug is bonded to the outer wall of the end of the sleeve furthest from the outlet terminal. During the insertion of the sleeve into the mounting hole, the temporary plug seals the sleeve opening to prevent the anchoring adhesive from entering the sleeve and causing distortion in the piezometer measurement.

[0019] Preferably, the concrete surface is further provided with a cable groove, which connects to the anchoring groove; the end of the cable away from the piezometer is located inside the cable groove. The cable is contained by the cable groove to prevent cable leakage.

[0020] Preferably, the cable trough is filled with epoxy mortar, and both the epoxy mortar and the concrete surface corresponding to the circumference of the cable trough are covered with the polyurea layer. This ensures the cable trough is sealed and leak-proof.

[0021] Preferably, it also includes a waterproof connector; both the outlet terminal and the side wall of the protective cover have outlet holes for the cable to pass through, and the waterproof connector is bolted to the outlet hole. Passing the cable through the waterproof connector ensures the cable routing and secure fixation to the outlet terminal and protective cover, thus ensuring the stable operation of the piezometer.

[0022] Preferably, a flange is fixed to the outer wall of the sleeve, and the flange is pressed tightly against the bottom wall of the anchoring groove; the protective cover is bolted to the flange. The flange connects the protective cover and the sleeve into a single unit, and the detachable connection facilitates the maintenance and replacement of the piezometer.

[0023] Preferably, the inner diameter of the drainage hole is smaller than the inner diameter of the mounting hole.

[0024] This invention also provides a method for post-installation construction of a piezometer in a thin-walled composite-lined tunnel. The construction of the post-installation structure for a piezometer in a thin-walled composite-lined tunnel, as described above, includes the following steps:

[0025] S1. Cut anchoring grooves on the concrete surface of the lining structure and drill installation holes perpendicular to the bottom wall of the anchoring groove.

[0026] S2. Pour anchoring adhesive into the mounting hole and insert the sleeve into the mounting hole;

[0027] S3. Drill drainage holes along the direction of the drainage pad in the inner cavity of the casing;

[0028] S4. After the drainage hole is formed, a water pressure test is performed.

[0029] S5. Install the piezometer inside the casing, record the depth of the piezometer in the casing according to the markings on the cable, and put the cable leading out of the piezometer into the cable groove.

[0030] S6. Fill the anchor groove and cable groove with epoxy mortar;

[0031] S7. After the epoxy mortar has solidified, a polyurea coating is sprayed onto its surface to form a polyurea layer.

[0032] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a post-installation structure and construction method for a piezometer in a thin-walled composite lining tunnel. This allows for the installation of the piezometer within existing concrete grooves, reducing damage to the tunnel's stress structure and minimizing the adverse effects of the tunnel environment and grouting on the piezometer. Furthermore, a complete sealing system is employed to prevent damage to the seepage prevention system caused by the post-installed piezometer, and replacement is relatively convenient if the post-installed piezometer fails. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the rear installation structure of the piezometer provided by the present invention;

[0035] Figure 2 This is a schematic diagram of the sleeve structure provided by the present invention.

[0036] Among them, 1-lining structure; 2-anchoring groove; 3-cable trough; 4-rebar adhesive; 5-sleeve; 6-outlet terminal; 7-flange; 8-protective cover; 9-waterproof joint; 10-temporary plug; 11-piezometer; 12-cable; 13-drainage pad; 14-drainage hole; 15-epoxy mortar; 16-polyurea layer. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] like Figure 1 and 2As shown, a post-installation structure for a thin-walled composite lining tunnel piezometer according to an embodiment of the present invention includes a lining structure 1, a sleeve 5, a protective cover 8, a piezometer 11, epoxy mortar 15, and a polyurea layer 16; an anchoring groove 2 is formed on the concrete surface of the lining structure 1, and an installation hole is drilled perpendicular to the bottom wall of the anchoring groove 2 and along the direction of the lining structure 1; the sleeve 5 is embedded in the installation hole, and one end of its pipe is detachably connected to an outlet terminal 6; the outlet terminal 6 is located in the anchoring groove 2; the sleeve 5 A drainage hole 14 is drilled between the drainage pad 13 and the inner cavity of the sleeve 5; the inner diameter of the drainage hole 14 is smaller than the inner diameter of the installation hole; the protective cover 8 is fastened to the outlet terminal 6; the piezometer 11 is located inside the sleeve 5, and the cable 12 of the piezometer 11 passes through the outlet terminal 6 and the protective cover 8; epoxy mortar 15 is filled in the anchoring groove 2; the polyurea layer 16 covers the epoxy mortar 15 and the corresponding concrete surface around the anchoring groove 2; the thickness of the polyurea layer 16 is not less than 3mm.

[0040] This embodiment installs the piezometer by slotting and drilling into the concrete surface of the lining structure, minimizing damage to the tunnel's stress structure and minimizing the adverse effects of the tunnel environment and grouting on the piezometer. Simultaneously, placing the piezometer inside the casing effectively avoids the influence of silt and sand, as well as the adverse effects of backfilling and grouting on the instrument. A drainage hole connects the inner cavity of the casing to the drainage cushion layer, allowing water from the drainage cushion layer to permeable stone into the casing without affecting the piezometer's accurate measurement of water pressure within the cushion layer. Sealing the anchoring groove using epoxy mortar and polyurea waterproofing ensures that the overall anti-seepage system of the tunnel is not damaged, preventing the creation of new leakage channels during instrument installation and thus preventing any impact on the tunnel's structural safety.

[0041] To further optimize the above technical solution and ensure that the sleeve 5 is firmly and stably installed in the mounting hole, a rebar adhesive 4 is provided between the outer wall of the sleeve 5 and the inner wall of the mounting hole.

[0042] In some other specific embodiments, in order to prevent the anchoring adhesive 4 from entering the inner cavity of the sleeve 5, a temporary plug 10 is bonded to the outer wall of the end of the sleeve 5 away from the outgoing terminal 6.

[0043] To further optimize the above technical solution, the cable 12 of the piezometer 11 is concealed, and a cable groove 3 is also opened on the concrete surface, which is connected to the anchoring groove 2; the end of the cable 12 away from the piezometer 11 is located in the cable groove 3.

[0044] In this embodiment, in order to waterproof and seal the cable tray 3, the cable tray 3 is filled with epoxy mortar 15, and both the epoxy mortar 15 and the corresponding circumferential concrete surface of the cable tray 3 are covered with a polyurea layer 16.

[0045] To further optimize the above technical solution, a waterproof connector 9 is also included; both the outlet terminal 6 and the protective cover 8 have outlet holes for the cable 12 to pass through, and the waterproof connector 9 is bolted to the outlet hole.

[0046] The cable is run through a waterproof connector and secured with screws at the connector. The piezometer is then suspended inside the casing by the cable, and the suspension depth of the piezometer inside the casing can be determined by the markings on the cable.

[0047] In some other specific embodiments, to facilitate the maintenance and replacement of the piezometer 11, a flange 7 is fixed to the outer wall of the sleeve 5, and the flange 7 is pressed tightly against the bottom wall of the anchoring groove 2; the protective cover 8 is bolted to the flange 7.

[0048] Example 2

[0049] This embodiment describes a post-installation structure for a thin-walled composite lining tunnel piezometer in Construction Embodiment 1. Before construction, all materials must undergo water pressure resistance testing: the protective cover and outgoing terminals are made of 304 stainless steel, and the overall airtightness and water pressure resistance must reach above 1 MPa. The process includes the following steps:

[0050] S1. Cut anchoring groove 2 and wire groove 3 on the concrete surface of lining structure 1, and drill installation holes perpendicular to the bottom wall of anchoring groove 2; anchoring groove 2 is a square groove with a length, width and height of 15cm×15cm×10cm; wire groove 3 has a width and height of 2cm×2cm; the installation hole has a hole size of Φ30mm×30cm.

[0051] Before drilling, install M6×15 expansion bolts around the pre-set opening of the anchoring groove 2 according to the hole size on the flange 7. After drilling the installation hole, inject anchoring adhesive 4 into the hole.

[0052] S2. Pour anchoring adhesive 4 into the mounting hole and insert sleeve 5 into the mounting hole; before inserting sleeve 5, use epoxy to bond a temporary plug 10 of PVC material to the outer wall of the end of sleeve 5 away from the terminal 6; during the process of inserting sleeve 4 into the mounting hole, the anchoring adhesive will be squeezed out of the mounting hole, the anchoring adhesive 4 in the anchoring groove 2 will be removed, and the flange 7 will be connected to the expansion bolt, so that the flange 7 is pressed against the bottom wall of the anchoring groove 2.

[0053] After the sleeve 5 is inserted into the installation hole, it should be left to stand for at least 24 hours to allow the anchoring adhesive 4 to solidify.

[0054] S3. Drill a drainage hole 14 in the inner cavity of the casing 5 along the direction of the drainage pad 13; use an M16 drill bit to probe into the casing, and drill from the pipe end with the temporary plug 10 bonded on it. After breaking the PVC temporary plug 10 at the pipe end, continue drilling until you reach the drainage pad 13. When approaching the drainage pad 13, slow down the drilling speed, and stop immediately after pulling out the fabric inside the drainage pad 13 to prevent over-drilling from damaging the outer lining.

[0055] S4. After the drainage hole 14 is formed, a water pressure test is carried out; only after the drainage pad 13 is confirmed to have good permeability can the piezometer 11 be installed.

[0056] S5. Install the piezometer 11 inside the sleeve 5. Record the depth of the piezometer 11 in the sleeve 5 according to the markings on the cable 12. Place the cable 12 leading out from the piezometer 11 into the cable groove 3. Install the waterproof connector 9 and fix the cable 12 to the waterproof connector 9 with screws, so that the piezometer 11 is suspended inside the sleeve 5. At the same time, pull the cable 12 into the cable groove 3.

[0057] S6. Fill the anchoring groove 2 and the wire groove 3 with epoxy mortar 15;

[0058] S7. After the epoxy mortar 15 solidifies, a polyurea coating is sprayed onto its surface to form a polyurea layer 16.

[0059] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0060] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A post-installation structure for a piezometer in a thin-walled composite-lined tunnel, characterized in that, include: Lining structure (1), the concrete surface of the lining structure (1) is provided with anchoring groove (2), and installation holes are drilled perpendicular to the bottom wall of the anchoring groove (2) and along the direction of the lining structure (1). A sleeve (5) is embedded in the mounting hole, and one end of the sleeve is detachably connected to a terminal (6); the terminal (6) is located in the anchoring groove (2); a drainage hole (14) is drilled between the sleeve (5) and the drainage pad (13), and the drainage hole (14) communicates with the inner cavity of the sleeve (5); A protective cover (8) is attached to the outgoing terminal (6); A piezometer (11) is located inside the sleeve (5), and the cable (12) of the piezometer (11) passes through the outlet terminal (6) and the protective cover (8); Epoxy mortar (15) is filled in the anchoring groove (2); A polyurea layer (16) covers the epoxy mortar (15) and the concrete surface corresponding to the anchor groove (2) in the circumferential direction.

2. The post-installation structure for a thin-walled composite lining tunnel piezometer according to claim 1, characterized in that, Rebar adhesive (4) is provided between the outer wall of the sleeve (5) and the inner wall of the mounting hole.

3. The post-installation structure for a thin-walled composite lining tunnel piezometer according to claim 2, characterized in that, A temporary plug (10) is bonded to the outer wall of the end of the sleeve (5) away from the outlet terminal (6).

4. The post-installation structure for a thin-walled composite lining tunnel piezometer according to claim 1, characterized in that, The concrete surface is also provided with a wire groove (3), which is connected to the anchor groove (2); the end of the cable (12) away from the piezometer (11) is located in the wire groove (3).

5. The post-installation structure for a thin-walled composite lining tunnel piezometer according to claim 4, characterized in that, The groove (3) is filled with epoxy mortar (15), and the epoxy mortar (15) and the concrete surface corresponding to the circumference of the groove (3) are covered with the polyurea layer (16).

6. The post-installation structure for a thin-walled composite lining tunnel piezometer according to claim 1, characterized in that, It also includes a waterproof connector (9); both the outlet terminal (6) and the protective cover (8) have outlet holes for the cable (12) to pass through, and the waterproof connector (9) is bolted to the outlet hole.

7. The post-installation structure for a thin-walled composite lining tunnel piezometer according to claim 1, characterized in that, The outer wall of the sleeve (5) is fixed with a flange (7), which is pressed against the bottom wall of the anchoring groove (2); the protective cover (8) is bolted to the flange (7).

8. The post-installation structure for a thin-walled composite lining tunnel piezometer according to claim 1, characterized in that, The inner diameter of the drainage hole (14) is smaller than the inner diameter of the mounting hole.

9. The post-installation structure for a thin-walled composite lining tunnel piezometer according to claim 1, characterized in that, The thickness of the polyurea layer (16) is not less than 3 mm.

10. A construction method for a post-installation structure of a thin-walled composite lining tunnel piezometer as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Cut out the anchoring groove (2) on the concrete surface of the lining structure (1) and drill the installation hole perpendicular to the bottom wall of the anchoring groove (2). S2. Pour anchoring adhesive (4) into the mounting hole and insert the sleeve (5) into the mounting hole; S3. Drill a drainage hole (14) in the inner cavity of the sleeve (5) along the direction of the drainage pad (13); S4. After the drainage hole (14) is formed, a water pressure test is performed; S5. Install the piezometer (11) inside the sleeve (5), record the depth of the piezometer (11) in the sleeve (5) according to the marking on the cable (12), and put the cable (12) led out from the piezometer (11) into the cable groove (3). S6. Fill the anchoring groove (2) and the wire groove (3) with epoxy mortar (15); S7. After the epoxy mortar (15) solidifies, a polyurea coating is sprayed onto its surface to form a polyurea layer (16).

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