Excavation supporting structure for sand shale large-section tunnel
By using a combined support solution of supporting columns, pressure bearing parts and anchor structures in gravel tunnels, the loosening and collapse problems caused by the loss of self-stability of surrounding rocks is solved, and more efficient support effect and construction safety are achieved.
Patent Information
- Application Number
- CN202421975326.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-13
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-08-13
AI Technical Summary
In the excavation of gravel tunnels, especially in the excavation areas of large sections, the surrounding rocks tend to lose their self-stability, resulting in loosening and collapse, difficulty in initial support, and high construction safety risks.
A support structure consisting of two support columns and one pressure bearing member is adopted. The support column and the pressure bearing member are provided with an anchor structure. The distance between the support column and the pressure bearing member is adjusted through the adjustment component, providing a top holding force and reverse thrust to avoid loosening and collapse.
It effectively improves the support effect of large-section tunnels of sand and mudstone, reduces the risk of loosening and collapse of surrounding rocks, and improves construction safety.
Smart Images
Figure CN222962866U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of tunnel excavation support, and particularly relates to an excavation support structure for a large-section tunnel in sandy mudstone. Background Technique
[0002] With the development of water conservancy and hydropower undertakings, the development of water conservancy and hydropower projects has gradually expanded to the western plateau and canyon basins. The dam construction conditions are becoming more and more complex, with high mountains and deep valleys, thick overburden layers, and complex geological conditions. In the excavation of many gravel tunnels, especially in the sections with larger excavation cross-sections, the surrounding rock stability is poor. Due to the increase in the excavation cross-section and the free face at the junction of the gravel tunnel and its affiliated chambers, the gravel layer is easily disturbed by external forces and loosens and collapses. The initial support is difficult and the construction safety risk is high. Therefore, it is particularly important to take scientific and reasonable measures to timely support and protect the excavation of affiliated chambers.
[0003] Stable rock masses have self-stabilizing capabilities and do not generate loads, while unstable rock masses may collapse and require a support structure to support them. The loss of stability of unstable surrounding rock is a process. If necessary assistance or restrictions are provided during this process, the surrounding rock can still enter a stable state. For the excavation of gravel tunnels, the excavated surrounding rock needs to be supported in a timely manner, especially in large-section excavation areas such as affiliated chambers and intersections. The surrounding rock of the gravel layer is prone to losing self-stability and causing collapses, and the construction safety risk is high. Therefore, only by taking fast and efficient measures to support in a timely manner can it be more beneficial to the stability and safe construction of affiliated chambers. Content of the Utility Model
[0004] The purpose of the utility model is to provide an excavation support structure for a large-section tunnel in sandy mudstone, which can solve the problems raised in the above background technique in view of the deficiencies of the prior art.
[0005] The technical solution of the utility model is realized as follows:
[0006] The utility model provides an excavation support structure for a large-section tunnel in sandy mudstone, which includes two support columns erected in the tunnel excavation cross-section. A pressure-bearing member adapted to the top of the tunnel excavation cross-section is arranged between the two support columns. An adjusting component for adjusting the relative distance between the two is arranged between the two support columns. Anchor structures penetrating into the sandy mudstone are arranged on both the support columns and the pressure-bearing member.
[0007] In some technical solutions of the utility model, guide groove members are arranged at the ends of the support columns along the tunnel excavation direction. Guide bars connected to the pressure-bearing member are slidably arranged in the guide groove members. A plurality of mounting holes are opened on the outer side walls of the guide groove members, and screw rods threadedly connected thereto are penetrated in the mounting holes. The ends of the screw rods are partially embedded in the guide bars.
[0008] In some technical solutions of the present utility model, the adjusting assembly includes crossbeams respectively arranged on the opposite side walls of two support columns. An installation beam is slidably arranged between the two crossbeams, and hydraulic push rods connected to the crossbeams are arranged on both sides of the installation beam.
[0009] In some technical solutions of the present utility model, the anchoring structure includes a plurality of installation openings respectively opened on the support columns and the pressure-bearing members. Guide tubes are all penetrated in the installation openings, and anchoring rods placed in the sandy mudstone are penetrated in the guide tubes.
[0010] In some technical solutions of the present utility model, a plurality of through holes are opened on the outer side wall of the guide tube, limiting rods are all penetrated in the through holes, limiting springs are sleeved on the inner and outer walls of the guide tube, and the end of the limiting rod abuts against the outer wall of the anchoring rod.
[0011] In some technical solutions of the present utility model, a support plate abutting against the inner wall of the tunnel excavation section is arranged on the outer wall of the guide tube.
[0012] In some technical solutions of the present utility model, the guide tube shell is detachably arranged in the installation opening.
[0013] Compared with the prior art, the embodiments of the present utility model have at least the following advantages or beneficial effects:
[0014] The adjusting assembly can move the support columns closer to the side walls of the tunnel excavation section, thereby applying a jacking force to the side walls of the tunnel excavation section; and when the adjusting assembly pushes the support columns closer to the side walls of the tunnel excavation section, the distance between the two ends of the pressure-bearing member connected to the support columns increases, providing a reverse thrust to the top of the tunnel, thereby further avoiding the occurrence of loosening and collapse caused by the sandy gravel layer being easily disturbed by external forces; both the support columns and the pressure-bearing members are provided with an anchoring structure penetrated in the sandy mudstone, and during the process of the support columns and the pressure-bearing members supporting the tunnel, the anchoring structure can be driven into the sandy gravel layer to realize the organic connection of the support columns and the pressure-bearing members, thereby improving the supporting effect of this structure on the sandy mudstone and avoiding the occurrence of loosening and collapse caused by the sandy gravel layer being easily disturbed by external forces. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.
[0016] Figure 1 It is a schematic installation structure diagram of the present utility model;
[0017] Figure 2Schematic three-dimensional structure diagram after the combination of the support column and the pressure-bearing member of the present utility model;
[0018] Figure 3 Schematic sectional combination diagram of the guide cylinder of the present utility model;
[0019] Figure 4 Schematic installation structure diagram of the cross beam and the installation beam in the present utility model.
[0020] Icon: 1, pressure-bearing member; 2, support column; 3, guide cylinder; 4, guide groove member; 5, guide strip; 6, screw; 7, cross beam; 8, installation beam; 9, anchor rod; 10, baffle; 11, limit rod; 12, limit spring; 13, hydraulic push rod. Specific embodiments
[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and illustrated herein can be arranged and designed in various different configurations.
[0022] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the present utility model to be protected, but merely represents the selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0023] Embodiment 1
[0024] Please refer to Figures 1-4 as shown.
[0025] The present utility model provides a support structure for the excavation of large-section sandstone and mudstone tunnels, such as Figure 1 , Figure 2As shown in the figure, it mainly solves the problem in the prior art that due to the increase in the excavation section and the free face at the junction of the tunnel in the gravel layer and its auxiliary chambers, the gravel layer is prone to loosening and caving under external force disturbance. To solve the above problems, in this technical solution, two support columns 2 erected in the tunnel excavation section support both sides of the tunnel excavation section. The two support columns 2 are made of I-shaped steel structures, and after being appropriately bent, they fit with the side walls of the tunnel, improving the support and blocking ability of the support columns 2 for the tunnel. A pressure-bearing member 1 adapted to the top of the tunnel excavation section is provided between the two support columns 2. The pressure-bearing member 1 is formed by splicing multiple sections of I-shaped steel into an arc-shaped structure, and any two ends of the I-shaped steel are connected by a plurality of high-strength bolts, increasing the overall structural strength of the pressure-bearing member 1. And the pressure-bearing member 1 and the support column 2 can also be fastened by bolts for easy disassembly in the later stage. An adjusting assembly for adjusting the relative distance between the two is provided between the two support columns 2, which can move the support columns 2 closer to the side walls of the tunnel excavation section, thereby applying a jacking force to the side walls of the tunnel excavation section. And when the adjusting assembly pushes the support columns 2 closer to the side walls of the tunnel excavation section, the distance between the two ends of the pressure-bearing member 1 connected to the support columns 2 increases, providing a reverse thrust to the top of the tunnel, further avoiding the situation that the gravel layer is prone to loosening under external force disturbance and causing caving. Anchor structures penetrating into the sandy mudstone are provided on both the support columns 2 and the pressure-bearing member 1. During the process of the support columns 2 and the pressure-bearing member 1 supporting the tunnel, the anchor structures can be driven into the gravel layer to realize the organic connection of the support columns 2 and the pressure-bearing member 1, thereby improving the support effect of this structure on the sandy mudstone and avoiding the situation that the gravel layer is prone to loosening under external force disturbance and causing caving.
[0026] Preferably, multiple groups of the above structures can be set up to support the gravel layer during the actual support process.
[0027] In some technical solutions of the present utility model, guide groove members 4 are provided at the ends of the support columns 2 along the tunnel excavation direction. The guide groove members 4 are steel frames with a wedge-shaped channel in cross-section, which are bent by mechanical equipment, and the guide groove members 4 are fixed on the opposite side walls of the two support columns 2 by bolts. A guide bar 5 connected to the pressure-bearing member 1 is slidably arranged in the guide groove member 4, and the guide bar 5 and the end of the pressure-bearing member 1 are also fixed by bolts. A plurality of mounting holes are opened on the outer side wall of the guide groove member 4, and screw rods 6 threadedly connected therewith are inserted into the mounting holes. The end part of the screw rod 6 is partially embedded in the guide bar 5. In this way, when the pressure-bearing member 1 is fixed in the guide groove member 4 arranged on the support column 2 through the guide bar 5, it is prevented that the support column 2 and the pressure-bearing member 1 have relative displacement, resulting in the failure of the support capacity of the support structure formed by the above structure for the gravel layer and causing the sudden problem of the collapse of the gravel layer.
[0028] In some technical solutions of the present utility model, the adjusting assembly includes cross beams 7 respectively arranged on the opposite side walls of two support columns 2. An installation beam 8 is slidably arranged between the two cross beams 7. Hydraulic push rods 13 connected to the cross beams 7 are arranged on both sides of the installation beam 8. The arranged cross beams 7 are also of I-shaped steel structure, and the cross beams 7 are fixed on the support columns 2 through bracket columns. The installation beam 8 is a frame structure with a "C" - shaped cross - section, and limit plates are arranged on both vertical sections of the installation beam 8. The limit plates are integrally formed with the installation beam 8, which can prevent the separation problem between the cross beam 7 and the installation beam 8 during their assembly. Moreover, the number of the liquid push rods is two, and the bodies of the two hydraulic push rods 13 are rotatably arranged in the installation beam 8 through pin shafts. The pushing ends of the liquid push rods are also connected to the side walls of the cross beams 7 through pin shaft sleeves. In this way, when the pushing ends of the two hydraulic rods gradually extend out of the bodies of the hydraulic rods, the support columns 2 are pushed closer to the side walls of the tunnel excavation section, and the distance between the two ends of the pressure - bearing member 1 connected to the support columns 2 is increased, providing a reverse thrust for the top of the tunnel, thereby further avoiding the occurrence of the situation that the gravel layer is easily disturbed by external forces and loosens, resulting in collapse.
[0029] In some technical solutions of the present utility model, the anchoring structure includes a plurality of installation openings respectively opened on the support columns 2 and the pressure - bearing members 1. Guide cylinders 3 are inserted into the installation openings. Anchor rods 9 placed in the sandy mudstone are inserted into the guide cylinders 3. The arranged guide cylinders 3 can be driven into the gravel layer from the installation openings arranged on the support columns 2. And a breakable sealing layer is arranged at the end of the guide cylinder 3 entering the gravel layer. The sealing layer is a rubber plug, which is used to prevent the gravel layer from entering the guide cylinder 3 and causing blockage, resulting in the problem that the anchor rod 9 cannot be driven into the gravel layer. The above - mentioned structure can realize the organic connection between the support columns 2 and the pressure - bearing members 1 when the anchor rods 9 are driven into the gravel layer, thereby improving the support effect of this structure on the sandy mudstone and avoiding the occurrence of the situation that the gravel layer is easily disturbed by external forces and loosens, resulting in collapse.
[0030] Preferably, cement mortar can also be injected into the gravel layer through the guide cylinder 3 to increase the connection strength between the anchor rod 9 and the gravel layer.
[0031] In some technical solutions of the present utility model, a plurality of through holes are opened on the outer side wall of the guide cylinder 3. Limit rods 11 are inserted into the through holes, and there is a gap between them. Limit springs 12 are sleeved on the limit rods 11 on the inner and outer walls of the guide cylinder 3, and the ends of the limit rods 11 are in contact with the outer wall of the anchor rod 9. When the anchor rod 9 is inserted into the guide cylinder 3, the anchor rod 9 squeezes the limit rods 11 installed on the guide cylinder 3, forcing the limit rods 11 to gradually withdraw from the through holes until the limit rods 11 are inserted into the gravel layer, increasing the connection strength between the guide cylinder 3 and the gravel layer, thereby stably fixing the guide cylinder 3 and the anchor rod 9 in the gravel layer. When cement mortar is injected into the gravel layer through the guide cylinder 3 subsequently, the cement mortar will enter the gravel layer from the through holes, increasing the connection strength between the anchor rod 9 and the gravel layer.
[0032] Preferably, the through hole can be inclinedly arranged on the outer side wall of the cylinder, and the inclination angle is between 0 degree and 180 degrees.
[0033] In some technical solutions of the present utility model, a support plate abutting against the inner wall of the tunnel excavation section is provided on the outer wall of the guide cylinder 3. The support plate is sleeved on the sleeve and fixed to the sleeve by two bolts. Therefore, an external thread is provided on the outer wall of the guide cylinder 3 on the side close to the support column 2, so that it is convenient to adjust the distance between the support plate and the tunnel excavation section, and it can also play a role of mutual pulling with the anchor rod 9 embedded in the gravel layer and the guide cylinder 3, further improving the support effect of the equipment on the gravel layer.
[0034] In some technical solutions of the present utility model, the guide cylinder 3 can be detachably arranged in the installation opening. Notches communicating with the installation opening are formed on the side walls of the support rod or the pressure-bearing member 1. The guide cylinder 3 and the installation opening are connected by welding. Later, the spot welding position of the two can be cut by a grinding wheel to realize the separation of the guide cylinder 3 from the support column 2, and the guide cylinder 3 is permanently placed in the gravel layer to provide continuous support for the gravel layer.
[0035] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A sand-mudstone large-section tunnel excavation support structure, characterized in that: It includes two support columns erected in the tunnel excavation section, a pressure-bearing piece adapted to the top of the tunnel excavation section is provided between the two support columns, an adjustment component for adjusting the relative distance between the two support columns is provided between the two support columns, and the support columns and the pressure-bearing piece are provided with anchoring structures penetrating into the sandstone and mudstone.
2. The sand-mudstone large-section tunnel excavation support structure according to claim 1, characterized in that: The ends of the support columns are provided with guide grooves along the tunnel excavation direction, and guide strips connected to the pressure-bearing parts are slidably provided in the guide grooves. A plurality of mounting holes are provided on the outer wall of the guide grooves, and screws threadedly connected to the mounting holes are passed through the mounting holes, and the ends of the screws are partially embedded in the guide strips.
3. The sand-mudstone large-section tunnel excavation support structure according to claim 1, characterized in that: The adjustment assembly comprises cross beams respectively arranged on opposite side walls of two support columns, a mounting beam is slidably arranged between the two cross beams, and hydraulic push rods connected to the cross beams are arranged on both sides of the mounting beams.
4. The sand-mudstone large-section tunnel excavation support structure according to claim 1, characterized in that: The anchoring structure comprises a plurality of installation openings respectively opened on the support column and the pressure bearing member, guide tubes are passed through the installation openings, and anchoring rods placed in sandstone and mudstone are passed through the guide tubes.
5. The sand-mudstone large-section tunnel excavation support structure according to claim 4, characterized in that: A plurality of through holes are provided on the outer wall of the guide cylinder, and limit rods are inserted in the through holes. The limit rods are placed on the inner and outer walls of the guide cylinder and sleeved with limit springs, and the ends of the limit rods abut against the outer wall of the anchor rod.
6. The sand-mudstone large-section tunnel excavation support structure according to claim 4, characterized in that: A supporting plate abutting against the inner wall of the tunnel excavation section is provided on the outer wall of the guide cylinder.
7. The sand-mudstone large-section tunnel excavation support structure according to claim 4, characterized in that: The guide tube housing is detachably arranged in the installation opening.