A protective framework for improving the safety performance of water diversion tunnel structure

Abstract

The present invention belongs to the technical field of water diversion tunnel structure safety and stability, and specifically relates to a protective frame for improving the safety performance of the water diversion tunnel structure, including a pipeline main body, an inner steel ring layer and an epoxy resin layer. The present invention is mainly used for a pipeline main body formed by splicing prefabricated reinforced concrete pipe segments in a water diversion tunnel. The structure is unique and novel, and the stability effect is good. The pipeline is spliced ​​by multiple groups of hexagonal prefabricated reinforced concrete pipe segments. An epoxy resin layer is added between the pipeline and the inner steel ring layer as an adhesive, so that the epoxy resin layer fills the gap between the inner steel ring layer and the pipeline. The epoxy resin layer can also play a certain buffering role on the inner steel ring, and prevent the inner steel ring layer and the prefabricated reinforced concrete pipe segment from being displaced, affecting the integrity and stability of the overall structure, and effectively solves the problem of structural instability caused by cracks between pipe segments when the existing water diversion tunnel passes through a large buried depth, poor geology and surrounding rock materials.

Description

Technical Field

[0001] The invention belongs to the technical field of safety and stability of water diversion tunnel structures, and in particular relates to a protective frame for improving the safety performance of water diversion tunnel structures. Background Art

[0002] Since my country has abundant water resources but the distribution is uneven between the north and south, long-distance water diversion and water transfer projects are increasingly playing an important role in human life. Water diversion tunnels are widely used in water diversion and water transfer projects, but there are many problems with water diversion tunnels in practice. Among them, the problem of high ground stress caused by the large burial depth needs to be paid special attention to. Therefore, solving the problem of water diversion tunnels overcoming high ground stress and ensuring that water diversion tunnels can safely and normally transfer water is an important engineering measure. It can bring huge benefits in water supply, power generation, irrigation, flood control, etc., and plays an important role in improving national economic development and overcoming the safety hazards of water diversion tunnels. With the rapid economic development of my country, the number of water diversion projects using water diversion tunnels is increasing, and the research on improving the structural stability of water diversion tunnels and prefabricated reinforced concrete pipes is particularly important.

[0003] During the excavation of the water diversion tunnel, the prefabricated reinforced concrete pipe must withstand the surrounding rock pressure and external water pressure at the top of the pipe. Due to the large excavation depth of the tunnel or the poor properties of the surrounding rock materials, the water diversion tunnel often collapses, causing the prefabricated reinforced concrete pipe to withstand large compressive stress. Cracks may appear in local locations inside the pipe, resulting in internal water seepage during water filling operation. Therefore, during the construction process, relevant measures need to be taken to reduce the compressive stress that the prefabricated reinforced concrete pipe can withstand and improve the safety and stability of the overall structure.

[0004] At present, the project improves the safety and stability of the water diversion tunnel structure by adopting measures such as taking a second lining concrete inside the pipeline or using a full steel plate pipeline. In the process of deep buried tunnel excavation, if the ground stress is not released, the effect of the method of using a second lining concrete is not very obvious, and it will also increase the self-weight load of the overall structure, which will also increase the stability of the structure itself, and will be detrimental to the safety of the internal pipelines in the deep buried area water diversion tunnel. The method of using a full steel plate pipeline has a significant effect on reducing the compressive stress of the pipeline, but this solution is not very economical and has a long construction period. In order to ensure that the normal operation of the prefabricated reinforced concrete pipeline under the original design conditions is not affected, and that the pipeline will not crack when the external pressure load is the largest, so as to achieve economic benefits and shorten the construction period, it is necessary to improve and innovate the existing reinforced concrete pressure pipeline structure. Based on this, it is necessary to study a protective structure that improves the safety performance of the water diversion tunnel structure. Summary of the invention

[0005] In view of the defects and problems existing in the existing equipment, the present invention provides a protective frame for improving the safety performance of the water diversion tunnel structure. The frame has a unique structure, good pressure resistance, short construction period and low cost. It effectively solves the problem that during the excavation of deep buried tunnels, when the ground stress is not released, the compressive stress value borne by the prefabricated reinforced concrete pipe exceeds the specification range, and the opening and misalignment between the pipe segments are too large, which endangers the stability of the overall structure of the prefabricated reinforced concrete pipe.

[0006] The solution adopted by the present invention to solve its technical problems is: a protective frame for improving the safety performance of a water diversion tunnel structure, comprising a pipeline body, an inner tensioned steel ring layer and an epoxy resin layer, wherein the pipeline body and the inner tensioned steel ring layer are concentrically arranged, the pipeline body is formed by splicing a plurality of groups of hexagonal prefabricated reinforced concrete segments, the annular seams of adjacent segments are connected by positioning pins, and each segment joint surface is provided with two positioning pins, the inner tensioned steel ring layer is installed inside the pipeline body, and its shape is a staggered jigsaw shape, the epoxy resin layer is arranged between the inner tensioned steel ring layer and the pipeline body, and plays a role of bonding reinforcement, rivets are embedded in the outer surface of the inner tensioned steel ring layer, and the bottom of the rivets is embedded in the pipeline body, and the pipeline body, the epoxy resin layer and the inner tensioned steel ring layer are connected, a reinforcement component is arranged on the top of the pipeline body, and the reinforcement component includes a grouting layer, the pipeline body is installed in the surrounding rock body, and a filling gap is arranged between the pipeline body and the surrounding rock body, and the filling gap is filled with a grouting layer.

[0007] Furthermore, the prefabricated reinforced concrete pipe segment is a hexagonal and longitudinally concave-convex ball-and-socket structure.

[0008] Furthermore, the width of the prefabricated reinforced concrete segments is 1.4 m, and high-resistance nylon locating pins are used between the segments.

[0009] Furthermore, each ring of segments of the pipeline body is divided into four pieces, one bottom segment, one top segment, and two side segments.

[0010] Furthermore, when the prefabricated reinforced concrete segments are assembled, a segment installer is used to install the segments radially along the hole, first installing the top and bottom segments, and then installing the side segments.

[0011] Furthermore, the curvature of the jagged parts of the inner tension steel ring layer is not greater than 0.01 or is trapezoidal.

[0012] Furthermore, the inner tension steel ring layer is made of Q235 steel with a thickness of 2 to 5 cm.

[0013] Furthermore, the inner tension steel ring layer is composed of a steel ring and a connecting steel plate. The width of the steel ring is 0.6m, the width of the connecting steel plate is 0.8m, and the connecting steel plate and the steel ring are connected as a whole by full welding, and a steel cage is formed after the connection.

[0014] Furthermore, when laying the inner steel ring, one steel ring is fully laid every 0.8m, and adjacent steel rings are welded by connecting steel plates of the same material. The laying area of ​​the connecting steel plates within every 1.4m accounts for 2 / 3 of the area of ​​the steel ring, and the angle between two adjacent connecting steel plates is 30º.

[0015] Furthermore, the epoxy resin layer is between the pipe body and the inner steel ring layer, and its minimum thickness is 1 cm.

[0016] Furthermore, the rivets are chemical rivets, which are arranged 10 cm from the edge of the inner tension steel ring layer. 24 rivets are clamped into one circle of the steel ring, a rubber ring is arranged between the rivets and the inner tension steel ring layer, and prestressed tension ropes are arranged on the 24 rivets.

[0017] Furthermore, the wall thickness of the pipeline body is a, and the wall thickness of the reinforcement component on the top of the pipeline is b, where b is the maximum diameter of the TBM excavation.

[0018] The beneficial effects of the present invention are as follows: the present invention is mainly used for the pipe body formed by splicing prefabricated reinforced concrete segments in the water diversion tunnel. The structure is unique and novel, and the stabilizing effect is good. The inner steel ring layer is not embodied in the conventional circular form inside the pipe body, but in the form of up and down unevenness, and the curvature is not greater than 1 / 100. When the water flows into the pipe, the head loss along the way and the local head loss may increase. However, the hole diameter of the pipe is too large, and the head loss caused by the uneven place is not much different from the head loss caused by the traditional form. In addition, when the inner steel ring layer is laid inside the pipe, it can be reinforced with a half ring or a full ring, and laid inside the pipe layer, and an epoxy resin layer is added between the pipe and the inner steel ring layer as a binder, so that the epoxy resin layer fills the gap between the inner steel ring layer and the pipe, and the epoxy resin layer also It can play a certain buffering role on the inner tensioned steel ring, and prevent the inner tensioned steel ring layer and the prefabricated reinforced concrete segments from large displacements, affecting the integrity and stability of the overall structure; adding high-resistance nylon locating pins between the prefabricated reinforced concrete segments can effectively limit the displacement between the segments when subjected to large internal and external pressures; a grouting layer is wrapped around the outside of the pipeline, and the grouting layer is made of concrete, which has good stability, wear resistance, and erosion resistance. The outside of the grouting layer is the surrounding rock mass. For Class V surrounding rock, the structure itself is not very stable, and soil collapse will occur during excavation. To avoid such a phenomenon during excavation, it is necessary to first strengthen the properties of the surrounding rock outside the pipeline. In addition, the grouting layer can also reduce the influence of stress transmitted to the pipeline by other factors, resist the erosion of the external environment, protect the pipeline, and further protect the safety and stability of the water diversion tunnel.

[0019] When the inner steel ring layer is laid along the direction of the tunnel excavation, a steel ring is fully laid every 0.8m, and the adjacent steel rings are welded by connecting steel plates of the same material. The laying area of ​​the connecting steel plate within every 1.4m accounts for 2 / 3 of the steel ring area, and the angle between the adjacent connecting steel plates is 30º. The connecting steel plate and the steel ring are connected as a whole by full welding. After the connection, a steel cage will be formed, thereby further improving the steel cage's ability to share the pipeline stress; the bottom of the rivet is embedded in the pipeline, and the outer end contacts the steel cage through a rubber ring, and 24 rivets are clamped on a circle of the steel ring and evenly distributed on the steel ring, and the connecting steel plate needs to be embedded with rivets at the four corners. The cooperation between the steel ring, the connecting steel plate and the rivet can not only make the three more compact and become an integral component, but also play a supporting role inside the pipeline, making it more stable under water operation conditions.

[0020] Therefore, the present invention has a novel and unique structure, good compression resistance, economical and practical, and simple construction, and effectively solves the problem that when the existing water diversion tunnel passes through a large buried depth, high ground stress, poor geology and surrounding rock materials, cracks appear in the pipeline, causing structural instability, causing large deformation of the prefabricated reinforced concrete segments, causing leakage of the pipeline body, and endangering the stability of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the cross section of the pipeline body in the present invention;

[0022] Figure 2 for Figure 1 A schematic diagram of the enlarged structure at A in the middle;

[0023] Figure 3 It is a schematic diagram of the unfolded structure of the inner tension steel ring layer in the present invention;

[0024] Figure 4 It is a schematic diagram of the cross-sectional structure of the longitudinal section of the pipeline body in the present invention;

[0025] Figure 5 This is a schematic diagram of the expanded structure of the pipeline body in the present invention.

[0026] The numbers in the figure are: 1 is the pipeline body, 2 is the inner tension steel ring layer, 3 is the epoxy resin layer, 4 is the rivet, 5 is the surrounding rock mass, 6 is the grouting layer, 7 is the steel ring, 8 is the connecting steel plate, 9 is the rubber ring, 10 is the prefabricated reinforced concrete segment, and 11 is the positioning pin. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0028] Embodiment 1: This embodiment aims to provide a protective frame for improving the structural safety performance of a water diversion tunnel, and is mainly used for a pipe body formed by splicing prefabricated reinforced concrete segments in a water diversion tunnel, so as to solve the problem that during the excavation of a deep buried tunnel, when the high ground stress is not released, the compressive stress value borne by the prefabricated reinforced concrete segments exceeds the specification range, and the pipe body is deformed too much and cracks appear, thereby endangering the stability of the overall structure of the water diversion tunnel. Based on this, this embodiment mainly aims at the protective frame, and an inner tension steel ring layer 2 and an epoxy resin layer 3 are arranged.

[0029] In specific structures, such as Figure 1-5 As shown in the figure, a protective framework for improving the safety performance of the water diversion tunnel structure includes a grouting layer 6 arranged inside the surrounding rock mass 5, and also includes an inner tension steel ring layer 2 at the innermost part of the overall structure. The pipeline body 1 is spliced ​​by prefabricated reinforced concrete hexagonal segments 10, and the outside is wrapped with concrete grouting materials. The outside of the grouting layer 6 is the surrounding rock mass 5 with poor physical and mechanical indicators. When the grade of the surrounding rock mass 5 is high, the grouting layer 6 can be appropriately omitted. The pipeline body 1 also includes a steel ring 7 and a connecting steel plate 8. The connecting steel plate 8 and the steel ring 7 are connected as a whole by full welding. After the connection, a steel cage will be formed. Shape - inner tensioned steel ring layer 2, the material of steel has good pressure resistance, shock resistance, wear resistance, corrosion resistance and other characteristics, the inner tensioned steel ring layer 2 and the pipe body 1 are bonded by an epoxy resin layer 3, and the epoxy resin material has good adhesion, shock resistance, corrosion resistance and other characteristics, and is mainly filled in the gap between the inner tensioned steel ring layer 2 and the pipe body 1. At the same time, in order to strengthen the overall structure of the inner tensioned steel ring layer 2 in the pipeline, rivets 4 are embedded in the outer surface of the inner tensioned steel ring layer 2, and the bottom of the rivet 4 is deeply embedded in the pipe body 1, and the outside is connected to the inner tensioned steel ring layer 2, and the two are in contact through a rubber ring 9.

[0030] When the excavation is at a high burial depth or the surrounding rock material properties are poor, the pipeline body 1 has to bear the pressure of the unreleased ground stress, which can easily cause the compressive stress of the pipeline body 1 to exceed the corresponding standard value, and the vertical pipeline deformation also exceeds the specified value. In order to prevent the pipeline body 1 from having cracks, the protective frame of the present invention is adopted to share part of the surrounding rock pressure with the help of the mechanical properties of the grouting layer 6, and to avoid the phenomenon of soil collapse during excavation, which can indirectly improve the safety and stability of the surrounding rock. The connecting steel plate 8 and the steel ring 7 are used to improve the compressive performance of the pipeline body 1, thereby avoiding the phenomenon of internal water seepage in the pipeline body 1 during construction and operation conditions.

[0031] There are uneven areas in the inner steel ring layer 2, and the curvature here is related to the diameter of the steel ring 7. The diameter of the steel ring 7 is c. This design is a trapezoidal structure, such as Figure 1As shown, the wall thickness of the pipeline body is a, the height of the trapezoid is a / 100, the thickness of the steel ring 7 and the connecting steel plate 8 is controlled within 2cm~5cm, and the length of the two along the pipe diameter direction is 1m, the laying area of ​​the connecting steel plate within every 2m accounts for 2 / 3 of the steel ring area, and the angle between two adjacent connecting steel plates is 30º. In addition, the minimum thickness of the epoxy resin layer 3 is guaranteed to be 1cm, and the position with the steel plate must be filled with epoxy resin. The pipeline body and the inner steel ring layer are arranged according to this standard, which can improve the structural strength of the inner steel ring layer 2, can ensure safe operation while ensuring the bonding effect, and also avoid material waste and excess performance.

[0032] Embodiment 2: This embodiment is basically the same as Embodiment 1, except that this embodiment further describes the specific structure of the inner tension steel ring layer 2.

[0033] In specific structures, such as Figure 1 As shown in the figure, the inner steel ring layer 2 contains rivets 4 and rubber rings 9. After the epoxy resin layer 3 bonds the pipeline body 1 to the inner steel ring layer 2, the rivet 4 is embedded in the edge of the connecting steel plate 8 and the steel ring 7, so that the pipeline body 1, the epoxy resin layer 3 and the inner steel ring layer 2 are connected as a whole again, and the outer bolt cap and the inner steel ring are isolated by the rubber ring 9 to prevent the rivet 4 from being corroded under the water operation condition, and avoid a series of troubles when the damaged material is replaced later. Compared with Example 1, this embodiment is equivalent to treating the pipeline body 1, the epoxy resin layer 3 and the inner steel ring layer 2 as a whole, so as to promote the joint bearing of "inner steel ring layer 2-pipeline body 1-surrounding rock mass 5", improve the compressive resistance of the water diversion tunnel, and use the epoxy resin layer 3 as a buffer layer to avoid the inner steel ring layer 2 directly bearing the pressure brought by the pipeline.

[0034] Embodiment 3: This embodiment is basically the same as Embodiment 1, and the difference is that this embodiment further describes the specific structure of the rivet 4.

[0035] In specific structures, such as Figure 2As shown in the figure, when the device is in use, water flows through the pipe to generate outward prestress, which will impact the rivet 4 and the inner tension steel ring layer 2, thereby causing the device to be unstable. Each rivet 4 is provided with a through hole spanning the rivet 4, and prestressed tension ropes are inserted in the through holes in sequence. The prestressed tension ropes are connected end to end to form a prestressed tension ring, and the prestressed tension ring is connected to the outer protrusion of the inner tension steel ring layer 2; through the setting of the prestressed tension rope, when in use, the inner tension steel ring layer 2 is first fixed with the rivet 4, and then the prestressed tension rope is used to pass through the through holes in sequence. Through all the rivets 4, a prestressed tensioning ring is formed. The prestressed tensioning ring has a supporting and tightening effect on the rivets 4. At this time, the inward prestress generated by the prestressed tensioning ring and the traction force of the rivets 4 fixed in the pipeline body 1 and the impact force generated by the water flow from the inside of the pipeline to the outside offset each other. At the same time, the prestressed tensioning ring is connected to the outer protrusion of the inner tension steel ring layer 2. The inward prestress generated by it can offset the pressure of the water flow impacting the inner tension steel ring layer 2, thereby further improving the fixing stability of the equipment and increasing the service life of the equipment.

Claims

1. A protective framework for improving the safety performance of a water diversion tunnel structure, comprising a pipeline body, an inner steel ring layer and an epoxy resin layer, wherein the pipeline body and the inner steel ring layer are concentrically arranged, wherein the inner steel ring layer is composed of a steel ring and a connecting steel plate, wherein the connecting steel plate and the steel ring are connected as a whole by full welding, and a steel cage is formed after the connection; the pipeline is formed by splicing a plurality of groups of hexagonal prefabricated reinforced concrete segments, wherein the circumferential seams of adjacent segments are connected by positioning pins, wherein each segment joint surface is provided with two positioning pins, wherein the inner steel ring layer is installed inside the pipeline body, and its shape is a staggered jigsaw pattern, wherein the epoxy resin layer is provided with a plurality ... wherein the inner steel ring layer is provided with a staggered jigsaw pattern, wherein the epoxy resin layer is provided with a plurality of hexagonal prefabricated reinforced concrete segments, wherein the circumferential seams of adjacent segments are connected by positioning pins, wherein the circumferential seams of adjacent segments are connected by positioning pins, wherein the circumferential seams of adjacent segments are connected by positioning pins, wherein the circumferential seam surface of each segment is provided with two positioning pins, wherein the inner steel ring layer is installed inside the pipeline body, and wherein the inner steel ring layer is provided with a staggered jigsaw pattern, wherein the epoxy resin layer is provided with a plurality of hexagonal prefabr The resin layer is arranged between the inner tension steel ring layer and the pipeline body to play the role of bonding and reinforcement. The curvature of the inner tension steel ring layer at the jagged part is not more than 0.01 or is trapezoidal. It is made of Q235 steel with a thickness of 2 to 5 cm. Rivets are embedded in the outer surface of the inner tension steel ring layer, and the bottom of the rivet is embedded in the pipeline body to connect the pipeline body, the epoxy resin layer and the inner tension steel ring layer. A reinforcement component is arranged on the top of the pipeline body, and the reinforcement component includes a grouting layer. The pipeline body is installed in the surrounding rock body. A filling gap is arranged between the pipeline body and the surrounding rock body, and the filling gap is filled with a grouting layer.

2. The protective framework for improving the safety performance of the water diversion tunnel structure according to claim 1 is characterized in that: The prefabricated reinforced concrete pipe segment is a hexagonal and longitudinally concave-convex ball-and-socket structure.

3. The protective framework for improving the safety performance of the water diversion tunnel structure according to claim 1 is characterized in that: The width of the prefabricated reinforced concrete segments is 1.4m, and high-resistance nylon locating pins are used between the segments.

4. The protective framework for improving the safety performance of the water diversion tunnel structure according to claim 1 is characterized in that: Each ring of segments of the pipeline body is divided into four pieces, one bottom segment, one top segment, and two side segments; when the prefabricated reinforced concrete segments are assembled, a segment installer is used to install the segments radially along the hole, first installing the top and bottom segments, and then installing the side segments.

5. The protective framework for improving the safety performance of the water diversion tunnel structure according to claim 1 is characterized in that: The width of the steel ring is 0.6m and the width of the connecting steel plate is 0.8m.

6. The protective framework for improving the safety performance of the water diversion tunnel structure according to claim 4 is characterized in that: When laying the inner steel ring, one steel ring is fully laid every 0.8m, and adjacent steel rings are welded by connecting steel plates of the same material. The laying area of ​​the connecting steel plates within every 1.4m accounts for 2 / 3 of the area of ​​the steel ring, and the angle between two adjacent connecting steel plates is 30º.

7. The protective framework for improving the safety performance of the water diversion tunnel structure according to claim 1 is characterized by: The epoxy resin layer is between the pipe body and the inner steel ring layer, and its minimum thickness is 1 cm.

8. The protective framework for improving the safety performance of a water diversion tunnel structure according to claim 1 is characterized in that: The rivets are chemical rivets, which are set at 10 cm from the edge of the inner steel ring layer. 24 rivets are clamped into one circle of the steel ring, a rubber ring is set between the rivets and the inner steel ring layer, and prestressed tension ropes are set on the 24 rivets.

9. The protective framework for improving the safety performance of a water diversion tunnel structure according to claim 1 is characterized in that: The wall thickness of the pipeline body is a, and the wall thickness of the reinforcement component on the top of the pipeline is b, where b is the maximum diameter of the TBM excavation.

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