CN113236286B - Construction method for controlling large deformation of tunnel face of soft rock tunnel - Google Patents
Construction method for controlling large deformation of tunnel face of soft rock tunnel Download PDFInfo
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- CN113236286B CN113236286B CN202110121749.1A CN202110121749A CN113236286B CN 113236286 B CN113236286 B CN 113236286B CN 202110121749 A CN202110121749 A CN 202110121749A CN 113236286 B CN113236286 B CN 113236286B
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- 238000010276 construction Methods 0.000 title claims abstract description 51
- 239000011435 rock Substances 0.000 title claims abstract description 36
- 230000007246 mechanism Effects 0.000 claims abstract description 31
- 230000003014 reinforcing effect Effects 0.000 claims description 24
- 229910000831 Steel Inorganic materials 0.000 claims description 20
- 239000010959 steel Substances 0.000 claims description 20
- 239000002689 soil Substances 0.000 claims description 13
- 238000006073 displacement reaction Methods 0.000 claims description 12
- 238000009412 basement excavation Methods 0.000 claims description 6
- 230000009471 action Effects 0.000 claims description 4
- 239000003365 glass fiber Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 11
- 230000008569 process Effects 0.000 abstract description 10
- 238000005516 engineering process Methods 0.000 abstract description 4
- 238000001125 extrusion Methods 0.000 description 12
- 230000000694 effects Effects 0.000 description 2
- 230000002787 reinforcement Effects 0.000 description 2
- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/14—Lining predominantly with metal
- E21D11/18—Arch members ; Network made of arch members ; Ring elements; Polygon elements; Polygon elements inside arches
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Lining And Supports For Tunnels (AREA)
Abstract
The invention discloses a construction method for controlling large deformation of a tunnel face of a soft rock tunnel, which comprises the following steps: step one, excavating a concave tunnel face; step two, installing an anchor rod; and step three, installing a flexible supporting mechanism. The invention can prevent and treat large tunnel face deformation disasters in the construction process of the soft rock tunnel, ensure the safety in the tunnel construction process, shorten the construction period and further improve the design level and construction technology of the soft rock tunnel.
Description
Technical Field
The invention relates to the technical field of tunnel construction, in particular to a construction method for controlling large deformation of a tunnel face of a soft rock tunnel.
Background
Soft rock refers to rock mass with weak rock property, low bearing capacity, relatively developed joint cracks and broken structure. If the tunnel is built in the soft rock stratum, the surrounding rock structure is extremely easy to generate larger deformation and even collapse and other risks due to construction disturbance in the building process, the safety of site operators and construction equipment is threatened, the construction progress is seriously influenced, and a series of problems such as construction cost increase, construction period delay and the like are caused. And as soft rock stratum tunnel engineering projects are more and more, the risk of large deformation of the face and even instability and damage of surrounding rock structures in the construction process is increased.
According to the construction concept of the new method, the root cause of the large deformation disease of the tunnel face of the soft rock tunnel is extrusion deformation of soil body in front of the tunnel face, so that the control of the extrusion deformation of the tunnel face is a key for preventing and controlling the large deformation of the tunnel face. At present, when the reinforcing mesh and the anchor rod are used for supporting a soft rock tunnel, the displacement of the tunnel face is controlled through rigid constraint, and the self-stabilization capability of surrounding rock is not fully exerted. The large deformation control technology of the tunnel face of the soft rock tunnel needs to be continuously optimized and innovated.
Disclosure of Invention
The invention aims to provide a construction method for controlling the large deformation of the tunnel face of a soft rock tunnel, which can prevent and treat the large deformation disaster of the tunnel face of the soft rock tunnel in the construction process, ensure the safety in the tunnel construction process, shorten the construction period and further improve the design level and the construction technology of the soft rock tunnel.
In order to achieve the above purpose, the construction method for controlling the large deformation of the tunnel face of the soft rock tunnel provided by the invention comprises the following steps:
firstly, excavating a concave tunnel face, namely excavating an initial straight tunnel face into a curved concave tunnel face which is concave towards the excavation direction;
installing an anchor rod, wherein the anchor rod is installed in a core soil body in front of the concave tunnel face, and the anchor rod is arranged along the tunnel construction direction;
and thirdly, installing a flexible supporting mechanism, wherein the flexible supporting mechanism is installed on the front surface of the concave tunnel face and is connected with the inner wall of the tunnel and the bottom surface of the tunnel at the near end of the curved tunnel face.
Preferably, the flexible supporting mechanism comprises a reinforcing mesh, a spring and a steel arch, wherein the steel arch is deformed along the arc shape of the tunnel wall, the outer side of the steel arch is connected with the inner wall of the tunnel, one end of the spring is connected with the inner side of the steel arch, and the other end of the spring is connected with the outer edge of the reinforcing mesh.
Further, one end of the spring is detachably connected with the inner side of the steel arch, and the other end of the spring is detachably connected with the outer edge of the reinforcing mesh.
Preferably, the anchor rod is a glass fiber anchor rod.
Preferably, the distal end of the concave tunnel face is spaced 0.5m from the flexible support mechanism.
Preferably, the flexible support mechanism is located at the position of the initial straight face.
Preferably, the concave palm face is an ellipsoid.
Preferably, the size of the flexible supporting mechanism corresponds to the size of the straight tunnel face.
Preferably, the maximum deformation of the flexible supporting mechanism to the outside is 0.08m.
Preferably, the anchor rod is connected with the arc-shaped tunnel face through an anchor rod sleeve ring.
Compared with the prior art, the invention has the following technical effects:
1. the invention can prevent and treat large tunnel face deformation disasters in the construction process of the soft rock tunnel, and ensure the safety in the tunnel construction process;
2. the invention can shorten the construction period and save manpower and material resources;
3. the invention further improves the design level and construction technology of the soft rock tunnel.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic view of a longitudinal section of an excavated initial state tunnel according to an embodiment;
fig. 2 is a schematic view of a longitudinal section of a tunnel when the excavated curved tunnel face is just contacted with a flexible supporting mechanism after being deformed by stress;
FIG. 3 is a schematic view of a longitudinal section of a tunnel when a curved tunnel face is deformed under stress and the flexible supporting mechanism reaches a maximum deformation amount after excavation according to an embodiment;
icon: 1-flexible supporting mechanism, 2-anchor rod, 3-arc face, 4-front core soil body, 5-straight face and 6-convex face.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.
It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the embodiments of the present application, it should be noted that, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship that is conventionally put when the product of the application is used, or the orientation or positional relationship that is conventionally understood by those skilled in the art, or the orientation or positional relationship that is conventionally put when the product of the application is used, which is merely for convenience of describing the application and simplifying the description, and is not indicative or implying that the device or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the application. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
In the description of the embodiments of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.
Examples
A construction method for controlling large deformation of a tunnel face of a soft rock tunnel comprises the following steps:
firstly, excavating a concave tunnel face 3, namely excavating an initial straight tunnel face 5 into a curved concave tunnel face 3 which is concave towards the excavation direction;
installing an anchor rod 2, wherein the anchor rod 2 is installed in a core soil body 4 in front of the concave tunnel face 3, and the anchor rod 2 is arranged along the tunnel construction direction;
and thirdly, installing a flexible supporting mechanism 1, installing the flexible supporting mechanism 1 on the front surface of the concave tunnel face 3, and connecting the flexible supporting mechanism 1 with the inner wall and the bottom surface of the tunnel at the near end of the curved tunnel face 3.
The flexible supporting mechanism 1 comprises a reinforcing mesh, a spring and a steel arch, wherein the steel arch is deformed along the arc shape of the tunnel wall, the outer side of the steel arch is connected with the inner wall of the tunnel, one end of the spring is connected with the inner side of the steel arch, and the other end of the spring is connected with the outer edge of the reinforcing mesh.
One end of the spring is detachably connected with the inner side of the steel arch, and the other end of the spring is detachably connected with the outer edge of the reinforcing mesh.
The anchor rod 2 is a glass fiber anchor rod.
The distal end of the concave tunnel face 3 is spaced 0.5m from the flexible support means 1.
The flexible support means 1 is located at the position of the initial straight tunnel face 5.
The concave face 3 is an ellipsoid.
The size of the flexible supporting mechanism 1 corresponds to the size of the straight tunnel face 5.
The maximum deformation of the flexible supporting mechanism 1 to the outside is 0.08m.
The anchor rod 2 is connected with the arc-shaped tunnel face 3 through an anchor rod sleeve ring.
The specific implementation process comprises the following steps:
as shown in fig. 1, after the construction of the straight tunnel face 5 is finished, the shape of the straight tunnel face 5 is excavated into a curved concave tunnel face 3 by adopting a manual excavation mode, the maximum depth of the concave tunnel face is 0.5m, the concave tunnel face 3 can form a bearing arch in front of the tunnel and around the tunnel, the stability of the tunnel face 3 is improved, after the excavation of the concave tunnel face 3 is finished, under the stress action of a core soil body in front of the concave tunnel face 3, the concave tunnel face 3 continuously performs extrusion displacement, and the concave tunnel face 3 is filled in an inwards concave part, so that the concave tunnel face 3 gradually becomes the straight tunnel face 5, and as shown in fig. 2, the stress of surrounding rocks is effectively released, and the self-bearing capacity of the surrounding rocks is effectively exerted.
After the concave tunnel face 3 is excavated, firstly, an anchor rod 2 is constructed and installed in the concave tunnel face 3, the anchor rod 2 is connected with the concave tunnel face 3 by adopting an anchor rod sleeve ring, and the anchor rod 2 has the function of applying a certain prestress to the concave tunnel face 3 to strengthen a core soil body in front of the concave tunnel face 3. The flexible supporting mechanism 1 consists of a reinforcing mesh, a spring and a steel arch, and the reinforcing mesh is characterized in that local load can be transferred to the periphery, so that the load bearing capacity of the whole mechanism can be improved. The steel bar net is connected with the steel arch by a spring, and the steel arch is clung to the near end of the concave tunnel face 3. The larger the displacement of the reinforcing mesh under the action of external force, the larger the constraint acting force of the reinforcing mesh is, so that the displacement of the front core soil body 4 is limited. After the reinforcement mesh is pretensioned, the reinforcement mesh can be clung to the bottom of the concave tunnel face 3.
The shape of the concave tunnel face 3 is changed according to the magnitude of the stress applied by the tunnel face extrusion displacement. If the extrusion displacement of the tunnel face is not increased before or just before the concave tunnel face 3 becomes the straight tunnel face 5, the extrusion displacement of the tunnel face is relatively small, surrounding rocks around the tunnel are in a relatively stable state, and the flexible supporting mechanism 1 only serves as a safety reserve and does not play a practical role; if the extrusion deformation of the concave tunnel face 3 is not converged after the tunnel face is changed into the straight tunnel face 5, at this time, the straight tunnel face 5 is gradually changed into the convex tunnel face 6, under the action of the spring, the greater the extrusion displacement of the convex tunnel face 6 is, the greater the restraint effect of the reinforcing mesh on the convex tunnel face 6 is, and the reinforcing mesh is tightly attached to the front core soil body of the convex tunnel face 6 and the anchor rod collar, and a certain acting force is applied to the front core soil body of the convex tunnel face 6 and the anchor rod collar to restrain the front core soil body of the convex tunnel face 6 and prevent the front core soil body of the convex tunnel face 6 from continuing to displace outwards. When the extrusion displacement of the tunnel face reaches the maximum deformation of the flexible supporting mechanism 1 to the outside of 0.08m, the extrusion displacement of the convex tunnel face 6 is constrained by the flexible supporting mechanism 1, namely, the stretching length of the spring and the deformation of the reinforcing mesh reach the maximum, and the constraint force of the reinforcing mesh to the convex tunnel face 6 reaches the maximum.
After the flexible reinforcing mesh is used, the reinforcing mesh can be separated from the steel arch by using the cutting tool, so that the reinforcing mesh can be quickly taken down and can be continuously reused in the subsequent stage of tunnel construction, and meanwhile, due to poor shearing resistance of the anchor rod, the flexible reinforcing mesh is easily treated by using a construction machine in the subsequent construction process, so that the subsequent construction of the tunnel cannot be influenced.
The flexible supporting mechanism 1 can furthest allow extrusion deformation of the tunnel face, exerts self-supporting capability of surrounding rock, simultaneously controls the extrusion deformation within a reasonable range, is convenient to dismantle in the later stage and can be recycled, and safety construction of the tunnel face is ensured.
Of course, the present invention is capable of other various embodiments and its several details are capable of modification and variation in light of the present invention by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (8)
1. The construction method for controlling the large deformation of the tunnel face of the soft rock tunnel is characterized by comprising the following steps:
firstly, excavating a concave tunnel face (3), and excavating an initial straight tunnel face (5) into a concave tunnel face (3) with a curved surface concave towards the excavation direction;
installing an anchor rod (2), wherein the anchor rod (2) is installed in a core soil body (4) in front of the concave tunnel face (3), and the anchor rod (2) is arranged along the tunnel construction direction;
installing a flexible supporting mechanism (1), wherein the flexible supporting mechanism (1) is installed on the front surface of the concave tunnel face (3), and the flexible supporting mechanism (1) is connected with the inner wall of the tunnel and the bottom surface of the near end of the curved concave tunnel face (3); the flexible supporting mechanism (1) comprises a reinforcing mesh, a spring and a steel arch, wherein the steel arch is deformed along the arc shape of the tunnel wall, the outer side of the steel arch is connected with the inner wall of the tunnel, one end of the spring is connected with the inner side of the steel arch, and the other end of the spring is connected with the outer edge of the reinforcing mesh; the flexible supporting mechanism (1) is located at the initial straight face (5), and the larger the spring can enable the displacement of the reinforcing mesh to be under the action of external force, the larger the constraint acting force applied to the reinforcing mesh is, so that the displacement of the core soil body in front is limited.
2. The construction method for controlling large deformation of the tunnel face of a soft rock tunnel according to claim 1, wherein the construction method comprises the following steps: one end of the spring can be detachably connected with the inner side of the steel arch, and the other end of the spring can be detachably connected with the outer edge of the reinforcing mesh.
3. The construction method for controlling large deformation of the tunnel face of a soft rock tunnel according to claim 1, wherein the construction method comprises the following steps: the anchor rod (2) is a glass fiber anchor rod.
4. The construction method for controlling large deformation of the tunnel face of a soft rock tunnel according to claim 1, wherein the construction method comprises the following steps: the distance between the far end of the concave tunnel face (3) and the flexible supporting mechanism (1) is 0.5m.
5. The construction method for controlling large deformation of the tunnel face of a soft rock tunnel according to claim 1, wherein the construction method comprises the following steps: the concave tunnel face (3) is an ellipsoid.
6. The construction method for controlling large deformation of the tunnel face of a soft rock tunnel according to claim 1, wherein the construction method comprises the following steps: the size of the flexible supporting mechanism (1) corresponds to the size of the straight tunnel face (5).
7. The construction method for controlling large deformation of the tunnel face of a soft rock tunnel according to claim 1, wherein the construction method comprises the following steps: the maximum deformation of the flexible supporting mechanism (1) to the outside is 0.08m.
8. The construction method for controlling large deformation of the tunnel face of a soft rock tunnel according to claim 1, wherein the construction method comprises the following steps: the anchor rod (2) is connected with the concave tunnel face (3) through an anchor rod sleeve ring.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110121749.1A CN113236286B (en) | 2021-01-28 | 2021-01-28 | Construction method for controlling large deformation of tunnel face of soft rock tunnel |
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| CN202110121749.1A CN113236286B (en) | 2021-01-28 | 2021-01-28 | Construction method for controlling large deformation of tunnel face of soft rock tunnel |
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| CN113236286A CN113236286A (en) | 2021-08-10 |
| CN113236286B true CN113236286B (en) | 2024-03-05 |
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Citations (5)
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|---|---|---|---|---|
| CN104314585A (en) * | 2014-10-15 | 2015-01-28 | 中国神华能源股份有限公司 | Pre-reinforcement method and pre-reinforcement structure for full section of tunnel |
| CN207080233U (en) * | 2017-08-10 | 2018-03-09 | 中铁十七局集团有限公司 | The hard and soft bow member of large-deformation tunnel in soft rock supporting |
| CN109826657A (en) * | 2019-03-08 | 2019-05-31 | 西南交通大学 | One kind being used for soft rock tunnel solidifying of the working face device and its construction method |
| CN209818093U (en) * | 2019-03-08 | 2019-12-20 | 西南交通大学 | Be used for soft rock tunnel face reinforcing apparatus |
| CN111487147A (en) * | 2020-03-31 | 2020-08-04 | 河海大学 | Device and method for testing damage of concrete-surrounding rock interface under different vibration source distances |
-
2021
- 2021-01-28 CN CN202110121749.1A patent/CN113236286B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104314585A (en) * | 2014-10-15 | 2015-01-28 | 中国神华能源股份有限公司 | Pre-reinforcement method and pre-reinforcement structure for full section of tunnel |
| CN207080233U (en) * | 2017-08-10 | 2018-03-09 | 中铁十七局集团有限公司 | The hard and soft bow member of large-deformation tunnel in soft rock supporting |
| CN109826657A (en) * | 2019-03-08 | 2019-05-31 | 西南交通大学 | One kind being used for soft rock tunnel solidifying of the working face device and its construction method |
| CN209818093U (en) * | 2019-03-08 | 2019-12-20 | 西南交通大学 | Be used for soft rock tunnel face reinforcing apparatus |
| CN111487147A (en) * | 2020-03-31 | 2020-08-04 | 河海大学 | Device and method for testing damage of concrete-surrounding rock interface under different vibration source distances |
Non-Patent Citations (1)
| Title |
|---|
| 彭立敏、王薇、张运良.《隧道工程 铁道工程方向》.武汉大学出版社,2014,第235-237页. * |
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