Tunnel support pressure testing device

Abstract

The utility model relates to the technical field of tunnel support pressure testing, in particular to a tunnel support pressure testing device, which comprises a pressure box body and a bearing structure, and is characterized in that the pressure box body comprises a first pressure box body embedded between a surrounding rock and a primary support and a second pressure box body embedded between the primary support and a secondary lining; the bearing structure comprises a first bearing frame installed at the position of the first pressure box body, a second bearing frame installed at the position of the second pressure box body and a limiting rod located between the first bearing frame and the second bearing frame. Pressure testing structures are arranged between the surrounding rock and the primary support and between the primary support and the secondary lining, the pressure testing structures and the primary support are integrally designed, overall installation and management of pressure testing can be achieved, and meanwhile the pressure box can be tightly attached to the surface of the secondary lining and the surface of the surrounding rock on the premise that the pressure box is not damaged.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel support pressure testing, in particular to a tunnel support pressure testing device. Background Art

[0002] At present, my country's railway construction has entered an unprecedented high-speed development stage. With the rapid advancement of railway construction in the western region of my country, the construction of many long and deep tunnels has to be put on the agenda. However, the western region is full of high mountains and deep gullies, the terrain and geology are complex, and it has experienced many strong tectonic movements. In the construction of tunnel engineering, it is inevitable to encounter problems such as high ground stress, blasting disturbance, and soft surrounding rock fragmentation. Such tunnels are often difficult to construct, and are prone to rock bursts and large deformation of soft rocks, which cause great difficulties to tunnel construction. When encountering complex geological conditions in underground projects such as tunnels, a composite lining structure is generally used, that is, steel support + sprayed anchor as the primary support, and cast reinforced concrete as the secondary lining. However, the traditional tunnel support method for such tunnels is difficult to meet the construction needs. Therefore, in order to study the support structure that meets the high ground stress soft rock tunnel, it is very necessary to carry out research on the force characteristics between the support structures under complex geological conditions.

[0003] The measurement of contact pressure between the secondary lining and the primary support of a tunnel is usually done by welding a pressure box directly to the secondary lining steel bars. By default, the pressure box can be close to the primary support, and the pressure box measurement value can approximately reflect the contact pressure between the primary support and the secondary lining. However, the welding fixation form causes the calibration coefficient of the pressure box to change after being subjected to the high temperature of welding, which in turn leads to errors in the monitoring results. In addition, this method destroys the integrity of the secondary lining, which can easily cause cracks in the secondary lining and cause tunnel leakage. Drilling holes at various locations around the tunnel is difficult to construct, has great safety hazards, and has high installation costs.

[0004] At the same time, in order to carry out key support or support reinforcement in a special area with complex geological conditions, it is necessary to focus on the design and improvement of the support structure on both sides. However, the existing pressure box device needs to install pressure test boxes on both sides for this situation, which increases the construction process and cannot be designed in a coordinated manner.

[0005] Therefore, developing a tunnel support pressure testing device not only has urgent research value, but also has good economic benefits and industrial application potential, which is the driving force and basis for the completion of the utility model. Summary of the invention

[0006] In order to overcome the above-mentioned defects of the prior art, the inventors conducted in-depth research and completed the present invention after paying a lot of creative work.

[0007] Specifically, the technical problem to be solved by the utility model is to provide a tunnel support pressure testing device to solve the technical problems that the support pressure in the existing composite lining structure is inaccurately measured and the measurement is easy to damage the integrity of the secondary lining.

[0008] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0009] A tunnel support pressure testing device includes a pressure box body and a bearing structure, characterized in that: the pressure box body includes a first pressure box body buried between the surrounding rock and the primary support and a second pressure box body buried between the primary support and the secondary lining, the bearing structure includes a first bearing frame installed at the first pressure box body, a second bearing frame installed at the second pressure box body and a limiting rod located between the first bearing frame and the second bearing frame, the first bearing frame is a flat plate, and a receiving groove embedded in the first pressure box body is opened on the side of the plate body facing the first pressure box body.

[0010] In the utility model, as an improvement, the second support frame includes a base plate and a fixing member installed on the upper and lower sides of the second pressure box body, wherein the fixing member has a leg bent toward the base plate and surrounded by the outside of the second pressure box body, and the end of the leg has a mounting portion parallel to the base plate, and the mounting portion and the base plate have matching screw holes, and the mounting portion and the base plate are connected by bolts.

[0011] In the present utility model, as an improvement, the fixing member is a cross-shaped frame composed of two strip steel plates, and the mounting portion and the frame are an integrated structure.

[0012] In the utility model, as an improvement, the limit rod includes an adjusting rod fixedly connected to the first carrier frame or the base plate and a sleeve coaxially sleeved on the outside of the adjusting rod, the sleeve is correspondingly installed on the base plate or the first carrier frame, and the sleeve and the adjusting rod both have matching limit holes, and several holes are arranged along the axial direction.

[0013] In the present invention, as an improvement, a protection unit is arranged on the outer side of the second carrier frame, and the protection unit includes a detachable protection layer arranged on the lower side of the fixing member, and a detachable outer sealing layer is wrapped around the bottom plate, the fixing member and the outer side of the protection unit.

[0014] In the present utility model, as an improvement, the first bearing frame and the second bearing frame are located outside the primary supporting steel cage.

[0015] In the present utility model, as an improvement, the pressure box body measuring line is arranged in the pre-embedded protective sleeve of the primary support steel bar.

[0016] Compared with the prior art, the beneficial effects of the utility model are:

[0017] (1) In this application, pressure test structures are provided between the surrounding rock and the primary support and between the primary support and the secondary lining. The integrated design of the two can realize the coordinated installation and management of the pressure test. At the same time, under the premise of not damaging the pressure box, the pressure box can be closely fitted to the surface of the secondary lining and the surrounding rock, avoiding the change of the pressure box calibration coefficient due to the high temperature of welding.

[0018] (2) The pressure box and the conductor are wrapped and protected by the protective layer, the outer sealing layer and the protective sleeve, ensuring that the pressure box and the conductor are not corroded or damaged by the concrete during the shotcrete operation and the construction of the secondary lining. At the same time, the monitoring device can obtain the data of all contact pressures between the supporting structures at the same monitoring point after a one-time installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the specific implementation or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, each element or part is not necessarily drawn according to the actual scale.

[0020] Figure 1 It is a structural schematic diagram of the test device of the utility model;

[0021] Figure 2 It is a schematic diagram of the structure of the pressure testing device of the utility model after the primary support shotcrete operation is completed and the protection unit is removed;

[0022] Figure 3 for Figure 2 Schematic diagram of the structure in the AA direction.

[0023] 1. first pressure box body, 2. first bearing frame, 3. adjusting rod, 4. fixing pin, 5. bottom plate, 6. second pressure box body, 7. fixing part, 8. protection unit, 9. sleeve, 71. supporting leg, 72. bolt, 81. protection layer, 82. outer sealing layer. DETAILED DESCRIPTION

[0024] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0025] A tunnel support pressure testing device, which includes a pressure box body and a bearing bracket, wherein the pressure box body is installed in the bearing bracket, and the bearing bracket is installed in the lining support structure, the pressure box body includes a first pressure box body 1 buried between the surrounding rock and the primary support and a second pressure box body 6 buried between the primary support and the secondary lining, and the bearing structure is installed between the two pressure box bodies.

[0026] The bearing structure includes a first bearing frame 2 for supporting the first pressure box body 1 and a second bearing frame for supporting the second pressure box body 6, and also includes a limit rod connected between the first bearing frame 2 and the second bearing frame. The limit rod is a telescopic adjustment structure. The first bearing frame 2 is a square steel plate with a groove on one side. The outer end of the first pressure box body 1 is installed in the groove on the first bearing frame 2, and the inner end of the first pressure box body 1 is set in contact with the surrounding rock plane.

[0027] The second supporting frame has a frame protected on the outside of the second pressure box body 6, including a bottom plate 5 and a fixing member 7, the bottom plate 5 is located on the side facing the first supporting bracket 2, the fixing member 7 is located on the other side of the second pressure box body 6, and the fixing member 7 has a leg 71 bent toward the bottom plate 5 and surrounded on the outside of the second pressure box body 6, the leg 71 extends to the bottom plate 5, and the end of the leg 71 has a mounting portion parallel to the bottom plate 5, the mounting portion and the bottom plate 5 have matching screw holes, and the mounting portion and the bottom plate 5 are connected by bolts 72, so that the second pressure box body 6 is located in the protective frame composed of the bottom plate 5 and the fixing member 7.

[0028] The fixing part 7 is a cross-shaped frame composed of two strip steel plates. The mounting part and the frame are an integrated structure. In order to extend the service life, galvanized steel plates can be used. The width is 30mm-40mm, specifically, the width can be 35mm, and the thickness is 1.0mm-2.0mm, specifically, the thickness can be 2mm. The bolts 72 are preferably high-foot bolts for easy adjustment and control.

[0029] The limiting rod includes an adjusting rod 3 fixedly connected to the first supporting frame 2 or the base plate 5 and a sleeve 9 coaxially sleeved on the outside of the adjusting rod 3. The sleeve 9 is correspondingly installed on the base plate 5 or the first supporting frame 2. The sleeve 9 and the adjusting rod 3 both have matching limiting holes. Several holes are arranged along the axial direction. By relatively moving the sleeve 9 and the adjusting rod 3, the limiting holes on the side walls of the two are overlapped, and the fixing pin 4 is inserted to limit the distance between the two supporting frames.

[0030] A protection unit 8 is arranged on the outside of the second supporting frame, and the protection unit 8 includes a detachable protection layer 81 arranged on the lower side of the fixing member 7, preferably a hard square foam block 81, which is approximately larger than the second bottom plate 5, with a width of 40cm-50cm, specifically, a width of 4cm, and a thickness of 5mm-10mm, specifically, a thickness of 8mm, and a detachable outer sealing layer 82 wrapped around the bottom plate 5, the fixing member 7 and the outer side of the protection unit 8, and the outer sealing layer 82 is a colloid plastic layer.

[0031] The method of burying this pressure test device in the tunnel support is:

[0032] Place the second pressure box body 6 for monitoring the contact pressure between the primary support and the secondary lining on the bottom plate 5, buckle the fixing piece 71 on the outside of the second pressure box body 6, connect the fixing piece 71 and the bottom plate 5 through the fixing bolt 72, and adjust the height of the fixing bolt 72 to fix the second pressure box body 6;

[0033] After the fixing is completed, the square hard protective layer 81 is placed outside the fixing member 71 and is completely wrapped around the bottom plate 5 through the outer sealing layer 82, so that the protective unit 8, the fixing member 7, the second pressure box body 6 and the bottom plate 5 form a whole;

[0034] Place the first pressure box body 1 for monitoring the contact pressure between the surrounding rock and the primary support in the groove of the first bearing frame 2, and move the entire testing device so that the outer end surface of the first pressure box body 1 is in close contact with the surrounding rock;

[0035] By adjusting the length of the limit rod, ensure that the first pressure box 1 for monitoring the contact pressure between the surrounding rock and the primary support can be close to the surrounding rock, and at the same time, the outer side of the second pressure box 6 for monitoring the contact pressure between the primary support and the secondary lining can just exceed the primary support shotcrete surface by 10mm-20mm. After determining the length, weld the adjustable limit rod to the steel cage of the initial support;

[0036] Before the initial support shotcrete operation, the pressure box measuring lines are integrated into a bundle, tied with the annular steel bars of the initial support by means of wire tying, and a protective sleeve is pre-buried at the steel bar. The measuring lines are located in the protective sleeve. After the initial support shotcrete operation, the measuring lines are taken out of the protective sleeve to avoid damage during the construction of the secondary lining. After the tunnel support structure is completely constructed, the contact pressure data between the support structures can be collected by the conductor.

[0037] The initial support is shotcrete-worked. When the shotcrete reaches the designed inner surface of the initial support (which is flush with the initial support surface of the previous construction section), the initial support construction is completed.

[0038] After marking the monitoring points, wait for the tunnel to continue blasting forward. At this time, the monitoring device is completely buried in the primary support concrete and is less affected by the tunnel blasting impact.

[0039] When the secondary lining of the tunnel is applied to the monitoring section, the concrete scum on the surface of the measuring point is removed, and the foam protection unit 8 is removed, and the outer contour of the second pressure box body 6 is completely exposed to the outside, waiting for the construction of the secondary lining of the tunnel;

[0040] After the second lining of the tunnel is constructed, the pressure box measuring line is taken out to carry out real-time monitoring of the contact pressure between the tunnel support linings.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A tunnel support pressure testing device, comprising a pressure box and a bearing structure, characterized in that: The pressure box body comprises a first pressure box body (1) buried between the surrounding rock and the primary support, and a second pressure box body (6) buried between the primary support and the secondary lining; the bearing structure comprises a first bearing frame (2) installed at the first pressure box body (1), a second bearing frame installed at the second pressure box body (6), and a limit rod located between the first bearing frame (2) and the second bearing frame; the first bearing frame (2) is a flat plate, and a receiving groove for embedding the first pressure box body (1) is provided on a side of the plate body facing the first pressure box body (1).

2. The tunnel support pressure testing device according to claim 1, characterized in that: The second support frame comprises a bottom plate (5) and a fixing member (7) mounted on the upper and lower sides of the second pressure box body (6), wherein the fixing member (7) has a leg (71) bent toward the bottom plate (5) and arranged around the outside of the second pressure box body (6), and the end of the leg (71) has a mounting portion parallel to the bottom plate (5), and the mounting portion and the bottom plate (5) have matching screw holes, and the mounting portion and the bottom plate (5) are connected by bolts (72).

3. The tunnel support pressure testing device according to claim 2, characterized in that: The fixing member (7) is a cross-shaped frame composed of two strip steel plates, and the mounting portion and the frame are an integrated structure.

4. The tunnel support pressure testing device according to claim 1, characterized in that: The limiting rod comprises an adjusting rod (3) fixedly connected to the first supporting frame (2) or the bottom plate (5) and a sleeve (9) coaxially sleeved on the outside of the adjusting rod (3); the sleeve (9) is correspondingly mounted on the bottom plate (5) or the first supporting frame (2); the sleeve (9) and the adjusting rod (3) are both provided with matching limiting holes, and a plurality of holes are provided along the axial direction.

5. The tunnel support pressure testing device according to claim 1, characterized in that: A protection unit (8) is arranged on the outer side of the second carrier frame, and the protection unit (8) comprises a detachable protection layer (81) arranged on the lower side of the fixing member (7), and a detachable outer sealing layer (82) wrapped around the bottom plate (5), the fixing member (7) and the outer side of the protection unit (8).

6. The tunnel support pressure testing device according to claim 1, characterized in that: The first bearing frame (2) and the second bearing frame are located outside the primary support steel cage.

7. The tunnel support pressure testing device according to claim 1, characterized in that: The pressure box body measuring line is arranged in the pre-embedded protective sleeve of the primary steel bar.

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