A structure, method and construction method for resisting floor heave deformation of a tunnel

Abstract

The present invention relates to the technical field of railway tunnel engineering construction, and particularly relates to a structure, method and construction method for resisting floor heave deformation of a tunnel. The structure includes a pressure relief well, and the pressure relief well includes a cavity structure located in the inverted arch filling layer. The bottom of the pressure relief well penetrates through the inverted arch, and the top is located below the track. A plurality of the pressure relief wells are arranged longitudinally along the tunnel. By adopting this structure, a certain space is reserved through the pressure relief well to provide a release area for the floor heave deformation of the tunnel. At the same time, the contact area between the tunnel bottom structure and the rock mass is reduced, the deformation pressure of the rock mass is reduced from being transmitted to the tunnel bottom structure, and the upward deformation of the rock mass is induced to develop towards the free face of the pressure relief well. At the same time, the contact area between the tunnel bottom structure and the rock mass is reduced, and the rock mass deformation pressure transmitted to the tunnel bottom structure is reduced, so that the floor heave deformation of the tunnel is controlled and a good anti-bottom deformation effect is achieved. The construction is convenient and easy to implement.

Description

Technical Field

[0001] The present invention relates to the technical field of railway tunnel engineering construction, and particularly relates to a structure, method and construction method for resisting floor heave deformation of a tunnel. Background Art

[0002] The arching of the ballastless track in the tunnel is mainly caused by the floor heave deformation of the tunnel. The floor heave deformation of the tunnel is a complex physical and mechanical phenomenon. After years of research, there are mainly three reasons: groundwater, swelling rock mass and in-situ stress. Among them, the mechanism of in-situ stress causing floor heave deformation of the tunnel is the most complex, the action time is the longest, and the rectification difficulty is the greatest. For example, since a certain tunnel on the Shanghai-Chengdu Railway was put into operation in 2009, the floor heave deformation of the tunnel has lasted for 12 years. After multiple rounds of rectification, although the deformation has been suppressed, there is still no sign of stopping.

[0003] At present, the technical ideas for controlling the arching of the ballastless track in the tunnel are mainly of four categories: (1) improving the stiffness of the tunnel bottom structure to inhibit the floor heave deformation of the tunnel, and then controlling the arching of the ballastless track. This idea mainly adopts adjusting the curvature and thickness of the tunnel invert structure, strengthening the filling layer between the ballastless track and the invert and the reinforcement of the invert structure; (2) improving the stiffness of the rock mass at the bottom of the tunnel to reduce the floor heave deformation of the tunnel, and then controlling the arching of the ballastless track. This idea mainly adopts prestressed long bolts or cables to anchor the rock mass at a certain depth at the bottom of the tunnel, and at the same time grouting reinforcement is carried out to improve the strength of the rock mass; (3) absorbing and isolating deformation. This idea mainly adopts setting materials or structures for absorbing deformation outside the invert at the bottom of the tunnel or between the invert and the ballastless track, or setting pile foundations under the ballastless track, isolating the pile body from the tunnel structure, and embedding the bottom of the pile into the stable and non-deforming stratum; (4) releasing in-situ stress. This idea mainly adopts setting pressure relief holes or pressure relief grooves around the tunnel to reduce the in-situ stress level at the bottom of the tunnel to achieve reducing floor heave deformation. The main problems existing in these four ideas are: (1) improving the stiffness of the tunnel bottom structure. In the closed thin-walled statically indeterminate structure of the tunnel, it is easy to cause the imbalance of the overall structure stiffness, stress concentration will occur at the bottom, and the greater the stress, the greater the difficulty of deformation control, so the effect is very limited; (2) improving the stiffness of the rock mass at the bottom of the tunnel is controlled by geological factors such as rock joints and fissures and rock creep. At the same time, the dispersion effect of prestress also causes the anchoring effect on the deep rock mass to be always poor, it is difficult to achieve the expected purpose, and there is also a risk of loosening of the prestressed structure; (3) it is difficult to accurately set the reserved deformation amount in the limited space for absorbing and isolating deformation. The materials and structures for absorbing deformation also have deformation limits. It is difficult to accurately determine the stable and non-deforming rock stratum when isolating deformation. When the pile foundation is too long, it will affect the dynamic stability of the ballastless track; (4) releasing in-situ stress is difficult to accurately control the magnitude and direction of the release, and it is easy to cause damage to the bearing structure in the surrounding rock mass of the tunnel.

[0004] Therefore, there is an urgent need for a technical solution to solve the technical problems that the existing tunnel floor heave deformation is difficult to control and the good anti-floor heave deformation effect cannot be achieved. Summary of the Invention

[0005] The purpose of the present invention is to provide a structure, method and construction method for tunnel anti-floor heave deformation in view of the technical problems that the existing tunnel floor heave deformation is difficult to control and the good anti-floor heave deformation effect cannot be achieved.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A structure for tunnel anti-floor heave deformation includes a pressure relief well. The pressure relief well includes a cavity structure located in the inverted arch filling layer. The bottom of the pressure relief well penetrates through the inverted arch, and the top is located below the track. A number of the pressure relief wells are arranged longitudinally along the tunnel.

[0008] In the structure for tunnel anti-floor heave deformation of the present invention, through the setting of the pressure relief well, a certain space is reserved as the release area for tunnel floor heave deformation, providing space for the deformation of the rock mass under the inverted arch, and inducing the upward deformation of the rock mass to develop towards the free surface of the pressure relief well. At the same time, the contact area between the tunnel bottom structure and the rock mass is reduced, the rock mass deformation pressure received by the tunnel bottom structure is reduced, so that the tunnel floor heave deformation is controlled and a good anti-bottom deformation effect is achieved.

[0009] As a preferred scheme of the present invention, the width of the pressure relief well along the transverse direction of the tunnel is the same as the width of the track, and the cross-section of the pressure relief well is circular or polygonal.

[0010] As a preferred scheme of the present invention, the height of the pressure relief well is at least equal to 1 times the predicted maximum floor heave deformation amount. The inverted arch provided with the pressure relief well can withstand the floor heave deformation amount = predicted maximum floor heave deformation amount * [1 - (2 * pressure relief well width / tunnel width)]. So that the pressure relief well can meet the predicted maximum floor heave deformation amount and has a certain design redundancy.

[0011] As a preferred scheme of the present invention, a cover plate is arranged in the filling layer. A vertical support plate is arranged at the bottom of the cover plate. The vertical support plate is connected to the top surface of the inverted arch. The cover plate includes a top plate and a vertical support plate arranged at the bottom of the top plate. The vertical support plate is integrated with the inverted arch. The top plate and the vertical support plate enclose the pressure relief well. The cover plate is used to disperse the loads of the upper track and the filling layer along the side surface of the pressure relief well to the inverted arch through the vertical support plate. The bottom surface of the cover plate is far from the rock mass at the bottom of the inverted arch, so that the bottom surface of the cover plate does not bear the floor heave deformation load. The inverted arch is stressed through its own arc structure, transfers the tunnel floor heave deformation load to the rock masses on both sides of the tunnel, and controls the tunnel floor heave deformation through its own stiffness, improving the overall ability of the tunnel to resist floor heave deformation.

[0012] As a preferred embodiment of the present invention, a keel beam is arranged below the central drainage ditch of the tunnel. The keel beam is arranged longitudinally through the tunnel, and the bottom of the keel beam is integrally connected with the inverted arch; a longitudinal beam is arranged below the side wall of the tunnel. The longitudinal beam is arranged longitudinally through the tunnel, and the longitudinal beam is embedded in the inverted arch. The keel beam and the longitudinal beam are both arranged longitudinally through the tunnel and are both rectangular beams. Among them, the longitudinal beam is used to convert the transverse force of the tunnel into a longitudinal force, and the keel beam is used to transfer the floor heave deformation load of the tunnel longitudinally.

[0013] As a preferred embodiment of the present invention, cross braces are arranged below the side walls of the tunnel. A plurality of the cross braces are arranged longitudinally along the tunnel. The cross braces and the pressure relief wells are arranged alternately longitudinally along the tunnel. One side of the cross braces along the transverse direction of the tunnel is located in the filling layer, and the other side is located in the side rock mass of the tunnel. The cross braces are integrally connected with the inverted arch; the top surface of the cross braces is attached to the longitudinal beam, and a reaction pier is attached to the side of the longitudinal beam close to the rock mass. The reaction pier is arranged on the top of the cross braces. The cross braces are embedded in the rock mass, and are used to fully transfer the lateral horizontal force of the inverted arch caused by the floor heave deformation of the tunnel to the rock mass at the arch foot position, and transfer most of the vertical force to the rock mass through the reaction pier, and a small part of the vertical force is directly transferred to the longitudinal beam.

[0014] As a preferred embodiment of the present invention, anti-pull piles are connected to the bottom of the keel beam and / or the cross braces. A plurality of the anti-pull piles are arranged longitudinally along the tunnel. The tops of the anti-pull piles pass through the inverted arch, and the bottoms extend into the rock mass at the bottom of the tunnel. The anti-pull piles include steel pipe piles and / or prestressed anchor rods. The anti-pull piles include an anchor structure extending into the rock mass, and are used to transmit the floor heave deformation load back to the rock mass.

[0015] A method for preventing floor heave deformation of a tunnel adopts the structure for preventing floor heave deformation of a tunnel as described above.

[0016] A method for resisting floor heave deformation of a tunnel. Due to adopting the above-mentioned structure for resisting floor heave deformation of a tunnel, it has the following advantages: First, by reserving a certain space in the pressure relief well, a release area for the floor heave deformation of the tunnel is provided, inducing the upward deformation of the rock mass to develop towards the free face of the pressure relief well, reducing the contact area between the tunnel floor structure and the rock mass, and reducing the rock mass deformation pressure received by the tunnel floor structure, so that the deformation of the tunnel floor structure is controlled; Second, when the inverted arch is connected to the cross brace and the reaction pier structure, the lateral horizontal force of the inverted arch caused by the floor heave deformation of the tunnel is fully transmitted to the rock mass at the tunnel side wall position, and most of the vertical forces are transmitted to the rock mass at the tunnel side wall position through the reaction pier, transferring the rock mass deformation pressure received by the tunnel floor structure, and further controlling the deformation of the tunnel floor structure; Third, when the inverted arch is connected to the keel beam, longitudinal beam, cross brace and anti-pulling pile, the vertical force of the inverted arch caused by the floor heave deformation of the tunnel is transmitted to the deep rock mass at the bottom of the tunnel through the anti-pulling pile, transferring the rock mass deformation pressure received by the tunnel floor structure, and further controlling the deformation of the tunnel floor structure; Fourth, when the keel beam and the anti-pulling pile structure are arranged in the middle of the inverted arch, a stress anchor point can be formed in the middle of the tunnel inverted arch structure, reducing the span of the tunnel bottom structure, and further controlling the deformation of the tunnel floor structure; According to the actual situation, during the construction of a new tunnel, the above-mentioned structure for resisting floor heave deformation of a tunnel can be adopted continuously or intermittently along the longitudinal direction of the tunnel, or the above-mentioned structure for resisting floor heave deformation of a tunnel can be reconstructed and set in an existing tunnel.

[0017] A construction method for resisting floor heave deformation of a tunnel, which is applied to the forming of the above-mentioned structure for resisting floor heave deformation of a tunnel. When tying the steel bars of the inverted arch, holes and connecting steel bars are reserved at the designed position of the pressure relief well; after pouring the inverted arch concrete, the steel bars of the cover plate are tied and connected to the connecting steel bars at the reserved holes, and the pressure relief well penetrating the inverted arch at the bottom is poured and formed, and the inverted arch structure with a rectangular wave-shaped longitudinal section is formed.

[0018] A construction method for resisting floor heave deformation of a tunnel according to the present invention realizes the smooth transmission of the floor heave deformation load of the tunnel upward and the dispersion of the load in the upper track and filling layer to the inverted arch by connecting the cover plate and the inverted arch, and the construction is convenient and easy to implement.

[0019] As a preferred embodiment of the present invention, the following steps are included: S1. At the position of the tunnel sidewall, excavate the rock mass transversely along the tunnel to form a chamber for setting cross braces and reaction piers. The part of the chamber exceeding the tunnel sidewall is supported by shotcrete with wire mesh and bolts. The initial support at the position where the chamber passes through the sidewall is temporarily propped up. After excavating and completing the initial support and temporary propping of the chamber on one side of the tunnel, then excavate the chamber on the other side; S2. Excavate the invert filling layer and the rock mass at the invert position; S3. Arrange and set anti-pulling pile structures longitudinally along the tunnel center and both sides of the tunnel, and reserve connecting steel bars at the top of the anti-pulling piles; S4. Bind the steel bars of the keel beam and pour concrete, and reserve connecting steel bars for connecting the invert on both sides; S5. Bind the steel bars of the cross braces and reaction piers, and then pour concrete, and reserve connecting steel bars for connecting the invert; S6. Bind the steel bars of the invert and pour concrete, open a hole at the designed position of the pressure relief well and reserve connecting steel bars; S7. Bind the steel bars of the longitudinal beam and pour concrete; S8. Bind the steel bars of the cover plate and connect them with the connecting steel bars reserved at the opening position of the pressure relief well, and then pour concrete to form the cover plate; S9. Pour and form the invert filling layer, tunnel cable trench and central water channel; S10. Pour the sidewall and arch crown of the secondary lining of the tunnel; S11. Pour the ballastless track.

[0020] In summary, due to the adoption of the above technical solutions,

[0021] The beneficial effect of a tunnel anti-floor heave deformation structure of the present invention is that: through the setting of the pressure relief well, a certain space is reserved as the release area for the floor heave deformation of the tunnel, providing space for the deformation of the rock mass under the invert, and inducing the upward deformation of the rock mass to develop towards the free face of the pressure relief well. At the same time, the contact area between the tunnel bottom structure and the rock mass is reduced, and the rock mass deformation pressure received by the tunnel bottom structure is reduced, so that the tunnel floor heave deformation is controlled and a good anti-bottom deformation effect is achieved;

[0022] The beneficial effect of a tunnel anti-floor heave deformation method of the present invention is that: due to the adoption of the above-mentioned tunnel anti-floor heave deformation structure, by reducing the contact area between the tunnel bottom structure and the rock mass, adopting the pressure relief well structure, reserving a certain space, providing a release area for the tunnel floor heave deformation, and reducing the transfer of the rock mass deformation pressure to the tunnel bottom structure; by adopting the cross brace and reaction pier structures, transferring the rock mass deformation pressure at the tunnel bottom to the rock masses on both sides of the tunnel sidewall position, realizing the transfer of the rock mass deformation pressure received by the tunnel bottom structure; by adopting the keel beam and anti-pulling pile structures, transferring the rock mass deformation pressure at the tunnel bottom to the deep rock mass at the tunnel bottom, reducing the transfer of the rock mass deformation pressure to the tunnel bottom structure; at the same time, by adopting the keel beam and anti-pulling pile structures, reducing the span of the tunnel bottom structure, forming a force anchor point in the middle of the tunnel invert structure, and reducing the deformation of the tunnel bottom structure caused by the rock mass deformation pressure. The combination of the above three methods or any one of them controls the tunnel floor heave deformation and achieves a good anti-bottom deformation effect;

[0023] The beneficial effects of a construction method for preventing floor heave deformation of a tunnel in the present invention are as follows: By connecting the cover plate to the inverted arch and pouring the pressure relief well into shape, the cover plate and the inverted arch are connected as a whole, making full use of the space under the track, saving the amount of concrete used in the inverted arch filling layer, achieving the smooth transfer of the floor heave deformation load upward, and the dispersion of the load in the upper track and filling layer to the inverted arch. The construction is convenient and easy to implement, and the construction method is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a schematic elevational structure diagram of a structure for preventing floor heave deformation of a tunnel (at the position of the I-I section);

[0025] FIG. 2 is a schematic elevational structure diagram of a structure for preventing floor heave deformation of a tunnel (at the position of the II-II section);

[0026] FIG. 3 is a schematic side structure diagram of a structure for preventing floor heave deformation of a tunnel (at the position of the III-III section);

[0027] FIG. 4 is a schematic plan view of a structure for preventing floor heave deformation of a tunnel (at the position of the IV-IV section);

[0028] Figure 5 is a schematic side structure diagram of a structure for preventing floor heave deformation of a tunnel (at the position of the V-V section);

[0029] Figure 6 is a diagram of the stress state of the inverted arch in the present invention at the position of the I-I section;

[0030] Figure 7 is a diagram of the stress state of the inverted arch in the present invention at the position of the II-II section.

[0031] ICON:

[0032] 1 - Pressure relief well, 2 - Cover plate, 21 - Top plate, 22 - Vertical support plate, 3 - Inverted arch, 4 - Longitudinal beam, 5 - Keel beam, 6 - Cross brace, 7 - Reaction pier, 8 - Uplift pile, 9 - Filling layer, 10 - Track, 11 - Drainage and cable trench, 12 - Side wall, 13 - Arch crown, 14 - Central drainage ditch. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The present invention will be described in detail below with reference to the accompanying drawings.

[0034] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] Embodiment 1

[0036] As Figures 1 - 7As shown in the figure, a structure for resisting floor heave deformation of a tunnel includes a pressure relief well 1. The pressure relief well 1 includes a cavity structure located in the filling layer 9 of the inverted arch 3. The bottom of the pressure relief well 1 penetrates through the inverted arch 3, and the top is located below the track 10. A number of the pressure relief wells 1 are arranged longitudinally along the tunnel.

[0037] For the structure for resisting floor heave deformation of a tunnel in this embodiment, by opening holes in the inverted arch 3 directly below the two ballastless tracks 10 of the tunnel, in the filling layer 9 of the inverted arch 3 above the holes, by arranging a cover plate 2 including a top plate 21 and a vertical support plate 22, the vertical support plate 22 is integrally connected with the inverted arch 3 to form a cavity structure located in the filling layer 9. By arranging the pressure relief well 1, on the one hand, a certain space is reserved to provide a release area for the floor heave deformation of the tunnel, inducing the upward deformation of the rock mass to develop towards the free face of the pressure relief well 1. On the other hand, the contact form between the tunnel bottom structure and the surrounding rock is changed, from the complete surface contact between the inverted arch 3 and the bottom rock mass to local surface contact, greatly reducing the contact area between the tunnel bottom structure and the rock mass, thereby reducing the rock mass deformation pressure received by the tunnel bottom structure. During use, the top plate 21 disperses the loads of the upper track 10 and the filling layer 9 along the side wall of the pressure relief well 1 through the vertical support plate 22 to the inverted arch 3. The bottom surface of the cover plate 2 does not bear the floor heave deformation load, while the inverted arch 3 is stressed through its own arc structure, transferring the tunnel floor heave deformation load to the rock masses on both sides of the tunnel, and controlling the tunnel floor heave deformation through its own stiffness, so that the tunnel floor heave deformation is controlled, achieving a better anti-bottom deformation effect, forming an anti-floor heave deformation structure with a reserved deformation space, and improving the overall ability of the tunnel to resist floor heave deformation.

[0038] Preferably, the width of the pressure relief well 1 along the transverse direction of the tunnel is the same as the width of the track 10, and the cross-section of the pressure relief well 1 is rectangular.

[0039] Preferably, the height of the pressure relief well 1 is at least equal to 1 times the predicted maximum floor heave deformation amount, so that the pressure relief well 1 can at least meet the predicted maximum floor heave deformation amount and has a certain design redundancy.

[0040] Preferably, the inverted arch 2 provided with the pressure relief well 1 can bear the floor heave deformation amount = predicted maximum floor heave deformation amount * [1 - (2 * pressure relief well width / tunnel width)].

[0041] Preferably, for the pressure relief well 1 below the ballastless track 10 of a double-track tunnel, the longitudinal length is 3 m, the transverse width is 2 m, the net clear height is 1.25 m, the longitudinal spacing between two pressure relief wells 1 is 3 m, the transverse spacing is 2.5 m, and they are arranged symmetrically in the transverse direction. The construction is relatively convenient, and a good anti-floor heave deformation effect can be achieved. Each data can be adjusted within a certain range according to the actual construction.

[0042] Specifically, the wall thickness of the cover plate 2 is 35 cm. A filling layer 9 with a thickness of 30 cm is reserved above the top cover plate 2 of the pressure relief well 1. The well wall and the cover plate 2 of the pressure relief well 1 are made of reinforced concrete, and the reinforcement of the cover plate 2 is adjusted according to the upper train load.

[0043] Embodiment 2

[0044] As Figures 1 - 7 shown, for a structure for resisting floor heave deformation of a tunnel in this embodiment, on the basis of Embodiment 1, a keel beam 5 is arranged below the central drainage ditch 14 of the tunnel. The keel beam 5 is arranged longitudinally through the tunnel, and the bottom of the keel beam 5 is integrally connected with the inverted arch 3; a longitudinal beam 4 is arranged below the side wall 14 of the tunnel. The longitudinal beam 4 is arranged longitudinally through the tunnel, and the longitudinal beam 4 is embedded in the inverted arch 3.

[0045] For a structure for resisting floor heave deformation of a tunnel in this embodiment, both the keel beam 5 and the longitudinal beam 4 are reinforced concrete structural members, and either one can be arranged, preferably both are arranged. And both are rectangular beams. Among them, the keel beam 5 is located directly below the central drainage ditch 14 of the tunnel, is transversely connected to the inverted arch 3, and longitudinally runs through the tunnel longitudinally, and is used to transfer the deformation load at the bottom of the tunnel to the longitudinal direction of the tunnel. The longitudinal beam 4 is located below the position of the side wall 14 of the tunnel, runs through the tunnel longitudinally, and is used to convert the transverse force of the tunnel into a longitudinal force, and cooperate with the pressure relief well 1 in Embodiment 1, so that part of the tunnel bottom load at the position of the pressure relief well 1 is transversely transmitted to the rock mass through the inverted arch 3 at this position, and the other part is transmitted to both ends of the pressure relief well 1 through the longitudinal beam 4 and the keel beam 5.

[0046] Preferably, the width of the keel beam 5 is 1 m, the height is 1 m, and main longitudinal reinforcement is provided. The width of the longitudinal beam 4 is 0.75 m, the height is 1 m, and main longitudinal reinforcement is provided. The construction is relatively convenient, and a good effect of resisting floor heave deformation can be achieved. Each data can be adjusted within a certain range according to the actual construction.

[0047] Embodiment 3

[0048] As Figures 1 - 7 shown, for a structure for resisting floor heave deformation of a tunnel in this embodiment, on the basis of Embodiment 1 or Embodiment 2, cross braces 6 are arranged below the side wall 14 of the tunnel. A plurality of the cross braces 6 are arranged longitudinally along the tunnel. The cross braces 6 are arranged longitudinally and alternately with the pressure relief well 1 along the tunnel. One side of the cross braces 6 along the transverse direction of the tunnel is located in the filling layer 9, and the other side is located in the side rock mass of the tunnel. The cross braces 6 are integrally connected with the inverted arch 3; the top surface of the cross braces 6 is attached to the longitudinal beam 4, and a reaction pier 7 is attached to the side of the longitudinal beam 4 close to the rock mass. The reaction pier 7 is arranged on the top of the cross braces 6.

[0049] A structure for resisting floor heave deformation of a tunnel in this embodiment. The cross brace 6 is a reinforced concrete structure located below the longitudinal beam 4 of the tunnel, outside the inverted arch 3, and horizontally inserted into the rock mass. It is used to fully transfer the horizontal force of the inverted arch 3 caused by the floor heave deformation of the tunnel to the rock mass at the arch foot position of the inverted arch 3, transfer a small part of the vertical force to the longitudinal beam 4, and transfer most of the vertical force to the reaction pier 7. The reaction pier 7 is a reinforced concrete structure arranged outside the longitudinal beam 4, inside the rock mass, and above the cross brace 6. It is used to strengthen the contact between the rock mass and the structure, provide sufficient reaction force support, and transfer the floor heave deformation load of the tunnel to the rock masses on both sides.

[0050] Preferably, the length of the cross brace 6 along the longitudinal direction of the tunnel is 3 m, the width along the transverse direction of the tunnel is 3.8 m, and the height is 1 m. The length of the reaction pier 7 along the longitudinal direction of the tunnel is 3 m, the width along the transverse direction of the tunnel is 1.5 m, and the height is 1 m. The construction is relatively convenient, and a good effect of resisting floor heave deformation can be achieved. Each data can be adjusted within a certain range according to the actual construction.

[0051] Embodiment 4

[0052] As Figures 1 - 7 shown, a structure for resisting floor heave deformation of a tunnel in this embodiment, on the basis of Embodiment 2 and Embodiment 3, anti-pulling piles 8 are respectively connected to the bottom of the keel beam 5 and the longitudinal beam 4. A number of the anti-pulling piles 8 are arranged in a row along the longitudinal direction of the tunnel. The top of the anti-pulling pile 8 passes through the inverted arch 3, and the bottom extends into the rock mass at the bottom of the tunnel. The anti-pulling pile 8 includes a steel pipe pile and / or a prestressed anchor rod.

[0053] A structure for resisting floor heave deformation of a tunnel in this embodiment. The anti-pulling pile 8 is a steel pipe pile in the rock mass at the positions of the cross braces 6 on both sides of the bottom of the tunnel and at the position of the keel beam 5 at the center of the bottom of the tunnel, forming an anchor pulling structure extending into the rock mass, and forming a stress anchor pulling point in the middle of the tunnel bottom structure. It is used to transmit the floor heave deformation load of the tunnel back to the rock mass. When in use, a part of the deformation load borne by the keel beam 5 is transmitted downward to the bottom rock mass through the connected anti-pulling pile 8, and the other part is transmitted horizontally to the rock masses on both sides through the inverted arch 3. A part of the deformation load borne by the longitudinal beam 4 is transmitted to the bottom rock mass through the connected cross brace 6 and anti-pulling pile 8, and the other part is transmitted to the rock masses on both sides through the connected cross brace 6 and reaction pier 7. The reaction force provided by the reaction pier 7 and the anti-pulling force provided by the anti-pulling pile 8 are used to resist the development of deformation. At the same time, the keel beam 5 and the anti-pulling pile 8 are arranged at the center of the bottom of the tunnel, which plays a role in reducing the span of the tunnel bottom structure and also reduces the structural deformation amount. The effect of resisting floor heave deformation is good, forming a structure for resisting floor heave deformation that can resist the development of deformation. In cooperation with the structure for resisting floor heave deformation with a reserved deformation space, the anti-floor heave deformation ability of this structure is maximally improved.

[0054] Preferably, the uplift resistance pile 8 is a φ42 steel pipe pile, arranged with a lateral spacing of 0.5 m and a longitudinal spacing of 0.5 m, extending 8 m into the rock mass. By opening grouting holes around the steel pipe and using cement slurry for perfusion molding, each data can be adjusted within a certain range according to the actual construction.

[0055] Embodiment 5

[0056] A method for resisting floor heave deformation of a tunnel, adopting the structure for resisting floor heave deformation of a tunnel described above.

[0057] For the method for resisting floor heave deformation of a tunnel in this embodiment, according to the actual situation, the structure for resisting floor heave deformation of a tunnel described in any one of Embodiments 1 - 4 can be adopted.

[0058] Specifically, taking the structure for resisting floor heave deformation of a tunnel in Embodiment 4 as an example for illustration, through a variety of structural combinations, the ability of the tunnel to resist floor heave deformation is improved. Among them, by reserving a certain space in the pressure relief well 1, a release area for the floor heave deformation of the tunnel is provided, inducing the upward deformation of the rock mass to develop towards the free face of the pressure relief well 1, and reducing the contact area between the tunnel floor structure and the rock mass, reducing the rock mass deformation pressure received by the tunnel floor structure, so that the deformation of the tunnel floor structure is controlled; then, through the inverted arch 3 connecting the cross brace 6 and the reaction pier 7 structures, the lateral horizontal force of the inverted arch 3 caused by the floor heave deformation of the tunnel is fully transmitted to the rock mass at the tunnel side wall position, and most of the vertical forces are transmitted to the rock mass at the tunnel side wall position through the reaction pier 7, transferring the rock mass deformation pressure received by the tunnel floor structure, and further controlling the deformation of the tunnel floor structure; furthermore, by connecting the inverted arch 3 with the keel beam 5, longitudinal beam 4, cross brace 6 and uplift resistance pile 8, the vertical force of the inverted arch 3 caused by the floor heave deformation of the tunnel is transmitted to the deep rock mass at the bottom of the tunnel through the uplift resistance pile 8, transferring the rock mass deformation pressure received by the tunnel floor structure, and further controlling the deformation of the tunnel floor structure; at the same time, the keel beam 5 and uplift resistance pile 8 structures arranged in the middle of the inverted arch 3 can form a force anchoring point in the middle of the tunnel inverted arch structure, reducing the span of the tunnel bottom structure, and further controlling the deformation of the tunnel floor structure.

[0059] Specifically, according to the actual situation, during the construction of a new tunnel, the above-mentioned structure for resisting floor heave deformation of a tunnel can be adopted continuously or intermittently along the longitudinal direction of the tunnel, or the above-mentioned structure for resisting floor heave deformation of a tunnel can also be retrofitted in an existing tunnel.

[0060] Specifically, for a method of resisting floor heave deformation of a tunnel in this embodiment, compared with the existing technical solutions of adjusting the curvature of the tunnel invert 3 and increasing the thickness of the invert 3, the present invention reduces the contact between the structure and the rock mass, reduces the transfer of deformation load to the structure, realizes leaving the deformation in the rock mass, improves the deformation resistance ability of the structure, and at the same time reduces the amount of concrete used; compared with the existing technical solutions of anchoring the rock mass at the bottom of the tunnel with prestressed long bolts or cables, the present invention has high safety and does not pose a risk of the loosening and failure of the prestressed structure threatening the operation safety of high-speed railways; compared with the existing technical solutions of in-situ stress release, the present invention does not require large cavity structures such as pressure relief holes to be arranged around the tunnel, will not cause the tunnel lining structure to be stressed due to in-situ stress adjustment, and has strong controllability.

[0061] Embodiment 6

[0062] A construction method for resisting floor heave deformation of a tunnel is applied to the forming of the structure for resisting floor heave deformation of a tunnel in any one of Embodiments 1-4. Taking the construction of the structure for resisting floor heave deformation of a tunnel in Embodiment 4 as an example, the construction method specifically includes the following steps: S1, at the position of the side wall of the tunnel, excavate the rock mass transversely along the tunnel to form a chamber for setting the cross brace 6 and the reaction pier 7. The part of the chamber exceeding the tunnel side wall 14 is supported by shotcrete with wire mesh and bolts. The initial support at the position where the chamber passes through the side wall 14 is temporarily propped up; S2, excavate the rock mass at the positions of the invert 3 and the invert filling layer 9; S3, arrange the uplift piles 8 longitudinally along the tunnel at the center and both sides of the tunnel, and reserve connecting steel bars at the top of the uplift piles 8; S4, bind the steel bars of the keel beam 5 and pour concrete, and reserve connecting steel bars for connecting the invert 3 on both sides; S5, bind the steel bars of the cross brace 6 and the reaction pier 7, and then pour concrete, and reserve connecting steel bars for connecting the invert 3; S6, bind the steel bars of the invert 3 and pour concrete, open a hole at the designed position of the relief well 1 and reserve connecting steel bars; S7, bind the steel bars of the longitudinal beam 4 and pour concrete; S8, bind the steel bars of the cover plate 2 and connect them with the connecting steel bars reserved at the opening position of the relief well 1, and then pour concrete to form the cover plate 2; S9, pour and form the invert filling layer 9, the tunnel cable trench 11 and the central water channel 14; S10, pour the side wall 14 and the arch crown 13 of the secondary lining of the tunnel; S11, pour the ballastless track 10.

[0063] The construction method for resisting floor heave deformation of a tunnel in this embodiment provides a complete construction process for the structure resisting floor heave deformation of the tunnel. The construction process is coordinated with the structure for resisting floor heave deformation of the tunnel to form an invert 3 structure with a rectangular wave-shaped longitudinal section. With the settings of the keel beam 5, the cross brace 6, the reaction pier 7, and the uplift piles 8, the tunnel structure formed by construction has good ability to resist floor heave deformation.

[0064] Preferably, in S1, after the excavation of the chamber on one side of the tunnel and the completion of the initial support and temporary propping, the excavation of the chamber on the other side is carried out.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A structure for resisting floor heave deformation of a tunnel, characterized in that It includes a pressure relief well (1), and the pressure relief well (1) includes a cavity structure located in the filling layer (9) of the inverted arch (3). The bottom of the pressure relief well (1) penetrates through the inverted arch (3), and the top is located below the track (10). A number of the pressure relief wells (1) are arranged longitudinally along the tunnel. A cover plate (2) is arranged in the filling layer (9). The cover plate (2) includes a top plate (21) and a vertical support plate (22) arranged at the bottom of the top plate (21). The vertical support plate (22) is integrally connected with the inverted arch (3). The top plate (21) and the vertical support plate (22) enclose the pressure relief well (1). A keel beam (5) is arranged below the central drainage ditch (14) of the tunnel. The keel beam (5) is arranged longitudinally through the tunnel. The bottom of the keel beam (5) is integrally connected with the inverted arch (3). A longitudinal beam (4) is arranged below the tunnel side wall (12). The longitudinal beam (4) is arranged longitudinally through the tunnel. The longitudinal beam (4) is embedded in the inverted arch (3). A cross brace (6) is arranged below the tunnel side wall (12). A number of the cross braces (6) are arranged longitudinally along the tunnel. The cross braces (6) and the pressure relief wells (1) are arranged alternately longitudinally along the tunnel. One side of the cross brace (6) along the tunnel transverse direction is located in the filling layer (9), and the other side is located in the tunnel side rock mass. The cross brace (6) is integrally connected with the inverted arch (3). The top surface of the cross brace (6) is in contact with the longitudinal beam (4). A reaction pier (7) is arranged in contact with one side of the longitudinal beam (4) close to the rock mass. The reaction pier (7) is arranged at the top of the cross brace (6).

2. The structure for resisting floor heave deformation of a tunnel according to claim 1, wherein The width of the pressure relief well (1) along the tunnel transverse direction is the same as the width of the track (10). The cross section of the pressure relief well (1) is circular or polygonal.

3. The structure for resisting floor heave deformation of a tunnel according to claim 1, wherein The height of the pressure relief well (1) is at least equal to 1 times the predicted maximum floor heave deformation amount. The inverted arch (3) provided with the pressure relief well (1) can withstand the floor heave deformation amount = predicted maximum floor heave deformation amount * [1 - (2 * pressure relief well width / tunnel width)].[[]END]] 4. A structure for resisting floor heave deformation of a tunnel according to claim 1, characterized in that, The bottom of the keel beam (5) and / or the cross brace (6) is connected with a pull - out resistance pile (8). A number of the pull - out resistance piles (8) are arranged longitudinally along the tunnel. The top of the pull - out resistance pile (8) passes through the inverted arch (3), and the bottom extends into the tunnel bottom rock mass. The pull - out resistance pile (8) includes a steel pipe pile and / or a prestressed anchor rod.

5. A construction method for tunnel anti-floor heave deformation, characterized in that, It includes a tunnel anti - floor heave deformation structure as described in claim 4. When binding the steel bars of the inverted arch (3), holes and connecting steel bars are reserved at the designed position of the pressure relief well (1). After pouring the concrete of the inverted arch (3), the steel bars of the cover plate (2) are bound and connected with the connecting steel bars at the reserved hole positions, and the pressure relief well (1) with the bottom penetrating through the inverted arch (3) is formed, and the inverted arch (3) structure with a longitudinal section in a rectangular wave shape is formed, and the following steps are included: S1. At the position of the tunnel sidewall, excavate the rock mass transversely along the tunnel to form a chamber for setting the cross strut (6) and the reaction pier (7). The part of the chamber exceeding the tunnel sidewall (12) is supported by shotcrete with wire mesh and bolts. The initial support at the position where the chamber passes through the tunnel sidewall (12) is temporarily propped up. After the excavation and completion of the initial support and temporary propping of the chamber on one side of the tunnel, the excavation of the chamber on the other side is carried out. S2. Excavate the filling layer (9) of the inverted arch (3) and the rock mass at the position of the inverted arch (3). S3. Arrange and set the anti-pulling pile (8) structures longitudinally along the tunnel center and both sides of the tunnel. Connecting steel bars are reserved at the top of the anti-pulling pile (8). S4. Bind the steel bars of the keel beam (5) and pour concrete, and reserve connecting steel bars on both sides for connecting with the inverted arch (3). S5. Bind the steel bars of the cross strut (6) and the reaction pier (7), and then pour concrete, and reserve connecting steel bars for connecting with the inverted arch (3). S6. Bind the steel bars of the inverted arch (3) and pour concrete, drill holes at the designed position of the pressure relief well (1) and reserve connecting steel bars. S7. Bind the steel bars of the longitudinal beam (4) and pour concrete. S8. Bind the steel bars of the cover plate (2), connect them with the connecting steel bars reserved at the drilled hole position of the pressure relief well (1), and then pour concrete to form the cover plate (2). S9. Pour and form the filling layer (9) of the inverted arch (3), the tunnel cable trench (11) and the central water channel (14). S10. Pour the tunnel sidewall (12) and the arch crown (13) of the secondary lining of the tunnel. S11. Pour the ballastless track (10).

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