A beam-slab tunnel bottom structure and its anti-bottom heave deformation method and treatment construction method

Abstract

The present invention relates to the technical field of railway tunnel engineering construction, and in particular to a beam-slab type tunnel bottom structure and its anti-bottom drum deformation method and treatment construction method, wherein the beam-slab type tunnel bottom structure comprises a rock mass groove at the bottom of the tunnel and a beam-slab structure, wherein the beam-slab structure is arranged in the rock mass groove, the top of the beam-slab structure is connected to the tunnel side wall, a force transmission support structure is arranged at the bottom, the force transmission support structure is connected to the bottom surface of the rock mass groove, and a reserved deformation space is formed between the beam-slab structure and the rock mass groove. By inducing the tunnel bottom drum deformation to develop toward the free surface of the reserved deformation space, the influence of the bottom drum deformation on the upper track is reduced; the contact form between the tunnel bottom structure and the rock mass is changed, and the way in which the rock mass deformation pressure is transmitted to the tunnel bottom structure is reduced; stress concentration is formed at the bottom of the force transmission support structure, and effective guidance and control of the tunnel bottom drum disease are achieved, the tunnel bottom drum disease can be effectively treated, the smoothness of the track in the tunnel is ensured, and the safe and stable operation of the train is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of railway tunnel engineering construction, and particularly relates to a beam-slab type tunnel bottom structure, a method for resisting floor heave deformation thereof, and a rectification construction method. 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, and there are three main reasons: groundwater, expansive tunnel bottom 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, its action time is the longest, and the rectification difficulty is the greatest.

[0003] At present, there are mainly four categories of methods for rectifying the floor heave disease of the tunnel: (1) improving the stiffness of the tunnel bottom structure: mainly by 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, so as to improve the stiffness of the tunnel bottom structure, inhibit the floor heave deformation of the tunnel, and then control the arching of the ballastless track; (2) improving the stiffness of the tunnel bottom rock mass: mainly using prestressed long bolts or cables to anchor the tunnel bottom rock mass at a certain depth of the tunnel bottom, and at the same time grouting and strengthening to improve the strength of the tunnel bottom rock mass, so as to reduce the floor heave deformation of the tunnel, and then control the arching of the ballastless track; (3) setting materials or structures for absorbing deformation on the outside of the tunnel bottom invert 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-deformable stratum; (4) setting pressure relief holes or pressure relief grooves around the tunnel to release the in-situ stress and reduce the in-situ stress level at the tunnel bottom, so as to reduce the floor heave deformation.

[0004] The main problems existing in the above four categories of methods are as follows: (1) For the measures to improve the stiffness of the tunnel bottom structure, in the closed thin-walled hyperstatic structure of the tunnel, it is easy to cause the overall stiffness imbalance of the tunnel structure, stress concentration will occur at the bottom, and as the stress increases, the deformation control difficulty increases, so the effect is very limited; (2) For the measures to improve the stiffness of the tunnel bottom rock mass, it is restricted by geological factors such as the joints and fissures of the tunnel bottom rock mass and the creep of the tunnel bottom rock mass. At the same time, the dispersion effect of prestress is also likely to cause poor anchoring effect on the deep tunnel bottom rock mass, and it is difficult to achieve the expected purpose, and there is also a risk of loosening of the prestress structure; (3) For the measures of setting deformation absorption and isolation, it is difficult to accurately set the reserved deformation amount in a limited space, and the materials and structures for absorbing deformation also have deformation limits; if pile foundations are used for isolation, it is difficult to accurately determine the stable and non-deformable rock stratum; and when the pile foundation is too long, it will affect the dynamic stability of the ballastless track; (4) For the pressure relief measures of setting pressure relief holes or pressure relief grooves, it is difficult to accurately control the magnitude and direction of the released in-situ stress, and it is easy to cause damage to the bearing structure in the tunnel bottom rock mass around the tunnel.

[0005] With the development of railway construction in China, the number of railway tunnels put into operation is increasing continuously. The probability of tunnel floor heave disease is increasing, the rectification difficulty is rising continuously, but the rectification effect is not satisfactory, which seriously affects the safety of railway operation.

[0006] Therefore, there is an urgent need for a technical solution at present to effectively rectify the tunnel floor heave disease, reduce the influence of the tunnel floor heave disease on the track elevation, and ensure the safety of railway operation. Summary of the Invention

[0007] The purpose of the present invention is to provide a beam-slab type tunnel floor structure, its anti-floor heave deformation method and rectification construction method for the technical problem that the existing tunnel floor heave disease cannot be effectively rectified and affects the safety of railway operation.

[0008] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] A beam-slab type tunnel floor structure includes a rock mass groove at the tunnel floor and a beam-slab structure body. The beam-slab structure body is arranged in the rock mass groove. The top of the beam-slab structure body is connected to the tunnel side wall, and a force transmission support structure is arranged at the bottom. The force transmission support structure is connected to the bottom surface of the rock mass groove. A reserved deformation space is formed between the beam-slab structure body and the rock mass groove. A filling layer for supporting the track is arranged above the beam-slab structure body, and a number of manholes are arranged in the reserved deformation space.

[0010] For the beam-slab type tunnel floor structure of the present invention, by adopting a beam-slab structure body to replace the traditional inverted arch structure, a reserved deformation space is formed below the beam-slab structure body, inducing the tunnel floor heave deformation to develop towards the free surface of the reserved deformation space, reducing the influence of the floor heave deformation on the upper track. At the same time, through the setting of the force transmission support structure, most of the beam-slab structure body is suspended, changing the contact form between the tunnel floor structure and the rock mass, optimizing from the traditional surface contact to local point contact, reducing the contact area between the tunnel floor structure and the surrounding rock, thereby reducing the transfer of the rock mass deformation pressure to the tunnel floor structure. At the same time, the beam-slab structure body transfers the surrounding rock load of the tunnel arch, the self-weight loads of structures such as the tunnel lining and the ballastless track, and the train load to the tunnel floor rock mass through the force transmission support structure, forming stress concentration at the bottom of the force transmission support structure, applying a load to resist the floor heave deformation to the rock mass, reducing the upward floor heave deformation amount at the position of the force transmission support structure, reducing the influence of the tunnel floor heave disease on the track elevation, realizing the effective guidance and control of the tunnel floor heave disease, ensuring the safety of railway operation. When in use, the operating personnel enter the reserved deformation space through the manhole to monitor the floor heave deformation condition of the rock mass.

[0011] As a preferred embodiment of the present invention, a number of induced deformation grooves are provided at the bottom of the rock mass groove. The induced deformation grooves are arranged longitudinally through the tunnel. The shape of the induced deformation grooves in the cross-section of the tunnel is trapezoidal with a larger upper part and a smaller lower part. The included angle between the top edge and the inclined edge of the induced deformation groove is (45º + M / 2), where M is the internal friction angle of the rock mass. The induced deformation grooves are used to expand the deformation space of the rock mass below the tunnel bottom structure, and induce the upward deformation of the rock mass and the failure deformation of the upper structure to the rock mass to develop towards the free face of the groove, so as to realize the two-way induction effect of the upward deformation of the lower rock mass and the downward deformation of the upper structure.

[0012] As a preferred embodiment of the present invention, the tunnel bottom structure further includes a deformation adjustment tie rod. The bottom of the deformation adjustment tie rod is anchored in the tunnel bottom rock mass, and the top vertically passes through the beam and slab structure body. The deformation adjustment tie rod is connected to a reaction plate, and the reaction plate is arranged on the top of the beam and slab structure body. The deformation adjustment tie rod is connected to a tensioning mechanism. When the deformation adjustment tie rod adjusts the deformation, it is connected to the tensioning mechanism. The tensioning force is applied through the tensioning mechanism, and the reaction force is applied to the beam and slab structure body through the reaction plate, so as to apply a downward adjustment load to the tunnel bottom structure, form a stress concentration artificially at the bottom of the force transmission and support structure, damage the rock mass at the bottom of the tunnel, cause the active settlement of the tunnel structure, and use the active settlement to counteract the floor heave deformation, so as to realize the active control of the deformation of the tunnel bottom structure and lock the ballastless track elevation at the normal level. During use, the operator enters the reserved deformation space from the manhole to repair and maintain the anchored end of the deformation adjustment tie rod, so as to realize the precise control of the structural displacement when the deformation adjustment load is applied.

[0013] As a preferred embodiment of the present invention, a cutting edge member is provided at the lower end of the force transmission and support structure in a wrapped manner. The cutting edge member is embedded in the bottom surface of the rock mass groove. The shape of the cutting edge member in the cross-section of the tunnel is trapezoidal with a larger upper part and a smaller lower part. The cutting edge member includes a steel plate structure member. The cutting edge member of the steel plate structure member is in direct contact with the rock mass below the tunnel bottom structure, forms a stress concentration with the rock mass, transmits the load of the upper structure to the lower rock mass, and cuts the rock mass through its trapezoidal structure to form a downward displacement.

[0014] As a preferred embodiment of the present invention, the force transmission and support structure includes force transmission piers. The force transmission piers are arranged within the tunnel bottom projection plane of the track. The force transmission piers are arranged longitudinally through the tunnel. The force transmission piers include reinforced concrete structure members. The shape of the force transmission piers in the cross-section of the tunnel is an inverted trapezoidal structure with a wider upper part and a narrower lower part. The force transmission piers are used for the transmission of the structural load and the adjustment load between the beam and slab structure body and the rock mass, are arranged below the track, form a stress concentration to resist deformation, and directly reduce the deformation amount at the track position.

[0015] As a preferred solution of the present invention, the force transmission support structure includes a wall toe, which is arranged in the tunnel bottom projection surface of the tunnel side wall, and is arranged to penetrate the tunnel longitudinally, and the wall toe includes a reinforced concrete structural member. The shape of the wall toe in the tunnel cross section is an inverted trapezoidal structure that is wide at the top and narrow at the bottom. The wall toe has the same function as the force transmission pier and is arranged below the side wall to form stress concentration to resist deformation, thereby indirectly reducing the deformation of the track position.

[0016] As a preferred solution of the present invention, the beam-slab structure includes a bottom plate, a plurality of cross beams and a plurality of longitudinal beams; the cross beams are arranged transversely along the tunnel, and a plurality of the cross beams are arranged longitudinally along the tunnel; the longitudinal beams are arranged longitudinally through the tunnel, and a plurality of the longitudinal beams are arranged transversely along the tunnel; the cross beams and the longitudinal beams are staggered to form a grid body, and the bottom plate is arranged in the grid of the grid body. The cross beams and longitudinal beams are mainly used to uniformly transfer the deformation adjustment load to the force transmission support structure along the transverse and longitudinal directions of the tunnel, and at the same time, realize the uniform transfer of the tunnel structure load such as the ballastless track and the ditch above to the force transmission support structure.

[0017] As a preferred solution of the present invention, the tunnel bottom structure also includes a rock wall support structure, which includes a support frame and a plurality of support anchors, wherein the top surface of the support frame is connected to the tunnel side wall; the support frame includes a first vertical support, a second vertical support and a cross support; a plurality of first vertical supports are erected against the rock mass, wherein the first vertical supports are arranged at intervals along the longitudinal direction of the tunnel, and the first vertical supports are positioned and fixed by support anchors; a plurality of second vertical supports are erected adjacent to the inner side of the tunnel, wherein the second vertical supports are arranged at intervals along the longitudinal direction of the tunnel, and the second vertical supports are positioned and fixed by support anchors; the cross support is arranged at the top of the first vertical support and the second vertical support along the longitudinal direction of the tunnel. The cross support includes a plurality of I-beams welded side by side, wherein the support anchors are anchored and connected to the side walls of the rock mass trough, and the support anchors are connected to steel mesh to form an anchor mesh spray support structure. To improve the overall stability of the structure, the second vertical supports occupy part of the space at the toe of the wall and are removed during the construction of the toe structure.

[0018] As a preferred solution of the present invention, the beam-slab structure comprises horizontal and vertical staggered transverse beams and longitudinal beams, a bottom plate is arranged in the grid formed by the horizontal beams and longitudinal beams, and a deformation adjustment rod is vertically penetrated at the intersection of the horizontal beams and longitudinal beams; the force transmission support structure comprises a force transmission pier and a wall toe, the two force transmission piers are arranged symmetrically in the tunnel transversely, an induced deformation groove is arranged in the middle between the two force transmission piers, the top width of the induced deformation groove is 1 / 3 of the center distance between the two force transmission piers, an induced deformation groove is arranged between the force transmission pier and the wall toe, the induced deformation groove is arranged biased towards the wall toe, and the top width is 2 / 3 of the center distance between the force transmission pier and the wall toe; a blade foot piece is covered on the lower end of the force transmission support structure.

[0019] A method for resisting floor heave deformation of a beam-slab type tunnel floor structure, comprising: reconstructing and installing the above-mentioned beam-slab type tunnel floor structure in the section for treating tunnel floor heave diseases, or continuously or intermittently installing the above-mentioned beam-slab type tunnel floor structure during tunnel construction, and the beam-slab type tunnel floor structure provides a reserved deformation space to induce floor heave deformation and / or provides a settlement adjustment load to resist floor heave deformation.

[0020] In the method for resisting floor heave deformation of the beam-slab type tunnel floor structure of the present invention, by adopting the above-mentioned beam-slab type tunnel floor structure, a release area for the floor heave deformation of the tunnel floor can be provided through the reserved deformation space, inducing the development of deformation, and reducing the contact area between the tunnel floor structure and the surrounding rock, reducing the rock mass deformation pressure transmitted to the structure, and reducing floor heave deformation. At the same time, the structural load can be transmitted to the rock mass through the beam-slab structure body and the force transmission and support structure, inducing the development of deformation and reducing floor heave deformation. At the same time, by artificially applying an adjustment load, active settlement of the structure can be realized, and the active settlement is used to counteract the floor heave deformation, realizing the active guidance and control of the deformation of the tunnel floor structure, and realizing locking the ballastless track at a fixed elevation. Through this method, the tunnel floor heave diseases can be effectively treated, the smoothness of the track in the tunnel can be ensured, and the safe and stable operation of the train can be guaranteed.

[0021] As a preferred solution of the present invention, the settlement adjustment load includes the structural load composed of the surrounding rock load of the tunnel arch above the beam-slab structure body, the self-weight load of the tunnel structure and the train load, and / or the active adjustment load applied to the beam-slab structure body by tensioning the deformation adjustment tie rod through a tensioning mechanism. The bottom of the deformation adjustment tie rod is anchored in the tunnel floor rock mass, the top vertically passes through the beam-slab structure body, and the deformation adjustment tie rod is connected to a reaction plate, and the reaction plate is arranged on the top of the beam-slab structure body. When the structural load is applied, the tunnel floor structure realizes induced deformation through its own structure, reducing floor heave deformation; when the adjustment load is applied, stress concentration is artificially formed in the rock mass through the force transmission and support structure to realize active settlement of the structure, and realize locking the ballastless track at a fixed elevation.

[0022] As a preferred solution of the present invention, the settlement adjustment load forms stress concentration at the bottom of the force transmission and support structure, and the stress concentration coefficient = the transverse width of the beam-slab structure body along the tunnel / the sum of the transverse widths of the force transmission and support structures along the tunnel; when the structural load * the stress concentration coefficient < the tensile strength of the rock mass, the tunnel floor structure is in the stage of induced deformation development; when (structural load + active adjustment load) * the stress concentration coefficient > the tensile strength of the rock mass, the force transmission and support structure cuts the rock mass, and the tunnel floor structure is in the stage of active adjustment deformation, and the stage of active adjustment deformation is carried out in a timely manner according to the monitoring situation of floor heave deformation. After the tunnel undergoes induced deformation and / or active adjustment deformation, it adapts to the deformation, and the track elevation returns to the original elevation. According to the actual situation, the overall structure of the beam-slab type tunnel floor structure can be adjusted to realize the cyclic process of adapting to deformation - inducing deformation - actively adjusting deformation correction - adapting to deformation, and realize the dynamic locking of the ballastless track elevation.

[0023] A construction method for rectifying a beam - slab type tunnel bottom structure, which is used to transform and set up a beam - slab type tunnel bottom structure as described above in the section for rectifying the tunnel floor heave disease. The transformation and setting up includes the following steps:

[0024] S1: Cut off the high - speed railway rails, remove the ballastless track, the water channel and the cable trough, and construct a number of locking foot bolts at the top of the tunnel side wall. The number of the locking foot bolts is arranged in an array;

[0025] S2: Remove the secondary lining and the primary support above the bottom surface of the ballastless track and below the top surface of the side wall on one side of the tunnel, and use non - blasting construction to excavate the rock mass and set up the first support structure; then remove the inverted arch and the filling layer below the bottom surface of the ballastless track on this side and above the designed bottom surface of the rock mass trough, and use non - blasting construction to excavate the rock mass and set up the second support structure. The first support structure and the second support structure are vertically connected to form a rock wall support structure;

[0026] S3: Repeat S2 to carry out the excavation and support of the other side tunnel side area;

[0027] S4: Remove the tunnel center water channel, the remaining inverted arch filling layer and the inverted arch, and use non - blasting construction to excavate the rock mass to the designed bottom surface of the rock mass trough to form the bottom surface structure of the rock mass trough;

[0028] S5: According to the design position of the force - transferring support structure, bind the steel bars and set up the formwork to cast and form the force - transferring support structure in - situ;

[0029] S6: Bind the steel bars of the beam - slab structure body, set up the formwork and cast in - situ to form the beam - slab structure body;

[0030] S7: Set up the joint steel bars and isolation parts at the tunnel side wall position, and pour the concrete at the side wall position to realize the isolation of the beam - slab structure body and the arch top structure in the vertical displacement;

[0031] S8: Pour at least 30 cm thick plain concrete on the beam - slab structure body as the filling layer, then form the ballastless track, the center water channel and the cable trough, restore the pipeline connection, weld the rails, and resume the operation of the high - speed railway.

[0032] The construction method for rectifying a beam - slab type tunnel bottom structure of the present invention transforms and sets up the above - mentioned beam - slab type tunnel bottom structure in the section for rectifying the tunnel floor heave disease, has a good rectifying effect on the tunnel floor heave disease, has relatively high construction feasibility, and realizes the rapid, economical and effective rectification of the tunnel floor heave disease.

[0033] As a preferred scheme of the present invention, in S2, the single - time replacement length along the tunnel longitudinal direction does not exceed 4 m. The rock wall support structure includes an I - steel support frame, a number of threaded steel support bolts and a number of steel meshes, and the thickness of the shotcrete is not less than 5 cm. It realizes the stable rectification of each section along the tunnel longitudinal direction.

[0034] As a preferred embodiment of the present invention, step S4 further includes: drilling installation holes for the deformation adjustment tie rods on the bottom surface of the rock mass groove, and installing the rock - penetrating part of the deformation adjustment tie rods; the bottom of the rock - penetrating part is anchored with an anchoring agent, and a joint is reserved at the top.

[0035] As a preferred embodiment of the present invention, step S5 further includes: installing a cutting edge member on the bottom surface of the rock mass groove.

[0036] As a preferred embodiment of the present invention, step S6 specifically includes: tying the steel bars of the cross beam, longitudinal beam and bottom plate, embedding steel pipes at the intersection positions of the cross beam and the longitudinal beam, then setting up formwork and casting in - situ to form a beam - slab structure body, forming a passing channel for the deformation adjustment tie rods, setting a steel plate as a reaction plate at the top of the passing channel, and then installing the free - standing part of the deformation adjustment tie rods, and connecting the free - standing part with the reserved joint of the rock - penetrating part. The adjustment load applied by the deformation adjustment tie rods is applied to the intersection positions of the cross beam and the longitudinal beam, ensuring the structural stability of the beam - slab structure body under the adjustment load and realizing the smooth and uniform transmission of the adjustment load.

[0037] As a preferred embodiment of the present invention, after the deformation adjustment tie rods are installed, a structural settlement test of on - site tensioning is carried out to check the working condition of the cutting edge member, and to obtain the relationship curve between the load size of the cutting edge member cutting the rock mass and the corresponding settlement displacement, which is used as the basis for active settlement during operation.

[0038] In summary, due to the adoption of the above - mentioned technical solutions,

[0039] The beneficial effects of a beam - slab - type tunnel bottom structure of the present invention are as follows:

[0040] 1. By using a beam - slab structure body to replace the traditional inverted arch structure, a reserved deformation space is formed below the beam - slab structure body, inducing the development of tunnel floor heave deformation towards the free face of the reserved deformation space, reducing the influence of floor heave deformation on the upper track. This structure is simple and convenient for construction, the stiffness of the tunnel bottom and the upper part is coordinated, reducing the influence of floor heave deformation on the upper track, and being beneficial to the overall force of the structure;

[0041] 2. Through the setting of the force - transmission support structure, most of the beam - slab structure body is suspended, changing the traditional contact - force mode between the tunnel bottom structure and the rock mass, optimizing from the traditional surface contact to local point contact, reducing the contact area between the tunnel bottom structure and the surrounding rock, thereby reducing the rock mass deformation pressure transmitted to the tunnel bottom structure. This structure has a clear force - transmission path and fully eliminates the influence of uneven deformation of the rock mass during surface contact.

[0042] 3. Through the beam-slab structure, the surrounding rock load of the tunnel arch, the self-weight loads of structures such as the tunnel lining and the ballastless track, and the train load are transmitted to the rock mass at the bottom of the tunnel through the force-transferring support structure, forming stress concentration at the bottom of the force-transferring support structure, applying a load to resist the floor heave deformation to the rock mass, effectively reducing the upward floor heave deformation amount at the position of the force-transferring support structure, achieving the active control of the tunnel floor heave deformation, being able to eliminate the influence of the tunnel floor heave disease on the track elevation, and ensuring the safety of railway operation.

[0043] The beneficial effects of a method for resisting floor heave deformation of a beam-slab type tunnel bottom structure of the present invention are as follows:

[0044] 1. By adopting the method of reserving a deformation space, it is possible to provide a release area for the floor heave deformation of the tunnel bottom through the reserved deformation space, reduce the contact area between the tunnel bottom structure and the surrounding rock, reduce the rock mass deformation pressure transmitted to the structure, effectively reduce the stress level of the structure, reduce the difficulty of controlling the floor heave deformation. At the same time, the reserved deformation space can be set according to the predicted deformation amount of the underlying floor heave, realizing the full utilization of the tunnel space and saving the project quantity;

[0045] 2. By adopting the method of inducing the development of deformation, it is possible to transmit the structural load through the beam-slab structure and the force-transferring support structure, form stress concentration at the bottom of the force-transferring support structure, and induce the floor heave deformation to develop towards the induced deformation groove by setting the cutting edge member with a tendency-induced deformation groove, reducing the floor heave deformation amount at the cutting edge position;

[0046] 3. By adopting the method of active settlement of the structure, it is possible to form stress concentration at the cutting edge member by artificially applying an adjustment load, cut the rock mass at the position of the cutting edge member, realize the active settlement of the structure, use the active settlement to counteract the floor heave deformation, balance the upward floor heave deformation, realize the active control of the deformation of the tunnel bottom structure, and lock the ballastless track at a fixed elevation;

[0047] 4. In summary, by adopting the three methods, a cyclic process of adapting to deformation - inducing deformation - actively settling and correcting - adapting to deformation is realized, realizing the dynamic adjustment and locking of the elevation of the ballastless track. Through this method, the tunnel floor heave disease can be effectively rectified, the smoothness of the track in the tunnel can be ensured, and the safe and stable operation of the train can be guaranteed;

[0048] The beneficial effects of a construction method for rectifying a beam-slab type tunnel bottom structure of the present invention are as follows: By reconstructing and setting the above beam-slab type tunnel bottom structure in the section where the tunnel floor heave disease is rectified, the rectification effect of the floor heave disease is good, the construction is safe, convenient, and has high feasibility, realizing the rapid, economical, and effective rectification of the tunnel floor heave disease. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic structural diagram of a beam-slab type tunnel bottom structure of the present invention;

[0050] Figure 2 is Figure 1Schematic diagram of A-A cross-section;

[0051] Figure 3 is Figure 1 Schematic diagram of B-B cross-section;

[0052] Figure 4 is the state of setting the beam-slab type tunnel floor structure in the renovation section of tunnel floor heave disease Figure 1 ;

[0053] Figure 5 is the state of setting the beam-slab type tunnel floor structure in the renovation section of tunnel floor heave disease Figure 2 ;

[0054] Figure 6 is the state of setting the beam-slab type tunnel floor structure in the renovation section of tunnel floor heave disease Figure 3 ;

[0055] Figure 7 is the state of setting the beam-slab type tunnel floor structure in the renovation section of tunnel floor heave disease Figure 4 ;

[0056] Figure 8 is the state of setting the beam-slab type tunnel floor structure in the renovation section of tunnel floor heave disease Figure 5 ;

[0057] Figure 9 is the state of setting the beam-slab type tunnel floor structure in the renovation section of tunnel floor heave disease Figure 6 ;

[0058] Figure 10 is the state of setting the beam-slab type tunnel floor structure in the renovation section of tunnel floor heave disease Figure 7 ;

[0059] Figure 11 is the state of setting the beam-slab type tunnel floor structure in the renovation section of tunnel floor heave disease Figure 8 .

[0060] Icon:

[0061] 1 - Rock mass groove, 11 - Induced deformation groove, 2 - Beam-slab structure body, 21 - Bottom slab, 22 - Cross beam, 23 - Longitudinal beam, 3 - Side wall, 4 - Force transfer support structure, 41 - Force transfer pier, 42 - Wall toe, 43 - Cutting edge member, 5 - Reserved deformation space, 6 - Filling layer, 7 - Deformation adjustment tie rod, 8 - Rock wall support structure, 81 - Support frame, 811 - First vertical support, 812 - Second vertical support, 813 - Cross support, 82 - Support bolt, 9 - Manhole, 10 - Track, 20 - Cable trough, 30 - Arch part, 40 - Inverted arch, 50 - Locking foot bolt. Specific implementation method

[0062] The present invention will be described in detail below with reference to the accompanying drawings.

[0063] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, 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.

[0064] Embodiment 1

[0065] As Figures 1-3 shown, a beam-slab type tunnel floor structure includes a rock mass groove 1 at the tunnel floor and a beam-slab structure body 2. The beam-slab structure body 2 is arranged in the rock mass groove 1. The top of the beam-slab structure body 2 is connected to the tunnel side wall 3, and a force transmission support structure 4 is arranged at the bottom. The force transmission support structure 4 is connected to the bottom surface of the rock mass groove 1. A reserved deformation space 5 is formed between the beam-slab structure body 2 and the rock mass groove 1. A filling layer 6 for supporting the track 10 is arranged above the beam-slab structure body 2.

[0066] Preferably, the rock mass groove 1 is an enlarged excavation space with a specific shape excavated longitudinally through the tunnel.

[0067] Preferably, in some embodiments, the beam-slab structure body 2 includes a bottom plate 21, a plurality of cross beams 22 and a plurality of longitudinal beams 23. The cross beams 22 are arranged transversely along the tunnel, and a plurality of cross beams 22 are arranged longitudinally along the tunnel. The longitudinal beams 23 are arranged longitudinally through the tunnel, and a plurality of longitudinal beams 23 are arranged transversely along the tunnel. The cross beams 22 and the longitudinal beams 23 intersect to form a grid body, and the bottom plate 21 is arranged in the grid of the grid body.

[0068] Specifically, the cross beams 22, the longitudinal beams 23 and the bottom plate 21 are all made of reinforced concrete. The cross beams 22 and the longitudinal beams 23 are both rectangular beams. The cross beams 22 and the longitudinal beams 23 are combined to form a grid structure to bear the structural loads of tunnel structures such as the ballastless track 10, the water channel, and the arch part 30 above.

[0069] Preferably, in some embodiments, the force transmission support structure 4 includes force transmission piers 41 and wall toes 42. The force transmission piers 41 are arranged within the tunnel floor projection plane of the track 10 and are arranged longitudinally through the tunnel, including reinforced concrete structural members. The wall toes 42 are arranged within the tunnel floor projection plane of the tunnel side wall 3 and are arranged longitudinally through the tunnel, including reinforced concrete structural members.

[0070] Specifically, the force transmission piers 41 and the wall toes 42 are in an inverted trapezoidal structure with a wider top and a narrower bottom in the tunnel cross-section. The wall toes 42 are arranged in contact with the side wall of the rock mass groove 1 for the transmission of loads between the beam-slab structure body 2 and the bottom of the rock mass groove 1. In this embodiment, it includes two force transmission piers 41 and two wall toes 42 that are symmetric left and right in the tunnel cross-section.

[0071] A beam-slab type tunnel floor structure in this embodiment is divided into segments every 3 m along the longitudinal direction of the tunnel. It includes five longitudinal beams 23, which are respectively located at the top of the wall toe 42, between the ballastless track 10 and the ditch and cable trough 20, and in the middle of the left-line ballastless track 10 and the right-line ballastless track 10. A transverse beam 22 is arranged every 1.5 m along the longitudinal direction of the tunnel, and there are three transverse beams 22 in each segment. The longitudinal beams 23 and the transverse beams 22 have the same height, preferably 50 cm. The main reinforcement is φ25 mm steel bars, arranged at intervals of 10 cm. The transverse beams 22 and the longitudinal beams 23 form eight grids, and a floor slab 21 is arranged in each grid. The thickness of the floor slab 21 is less than the height of the transverse beams 22 and the longitudinal beams 23, preferably 30 cm. The main reinforcement is φ25 mm steel bars, arranged in a criss-cross pattern horizontally and vertically at intervals of 10 cm to form a reinforced concrete structure. The force transfer piers 41 and the wall toes 42 are arranged continuously along the longitudinal direction of the tunnel. The top width of the wall toe 42 is 75 cm, the bottom width is 50 cm, the top width of the force transfer pier 41 is 150 cm, and the bottom width is 50 cm.

[0072] A beam-slab type tunnel floor structure in this embodiment replaces the traditional inverted arch structure by adopting a beam-slab structure body 2. A reserved deformation space 5 is jointly enclosed by the transverse beams 22, the longitudinal beams 23, the floor slab 21, the force transfer piers 41 and the wall toes 42 on the left and right sides, and the rock mass at the lower part. The height of the reserved deformation space 5 is set according to the predicted deformation amount of the floor heave of the underlying rock mass, while taking into account the needs of personnel maintenance. It is connected to the outside through a manhole 9 and serves as a maintenance passage for personnel during operation. During use, personnel enter the reserved deformation space 5 to regularly check the working state of the tunnel floor structure, the structural deformation of the floor slab 21, and the floor heave deformation of the rock mass. If the rock mass undergoes floor heave deformation, construction personnel can remove a certain thickness of the deformed rock mass to reduce the impact of the floor heave deformation on the elevation of the upper track 10 and the tunnel floor structure, and achieve rapid and effective treatment of the floor heave deformation.

[0073] Preferably, the predicted deformation amount of the floor heave can generally be predicted by regression of on-site tunnel bottom deformation monitoring data, or by conducting a rock mass creep test after taking core samples, or by numerical simulation calculation. Preferably, a rock mass creep test is used for prediction.

[0074] Preferably, the manhole 9 is arranged at both ends of the tunnel floor structure along the longitudinal direction of the tunnel to facilitate personnel to enter the reserved deformation space 5 to monitor the floor heave deformation of the rock mass.

[0075] A beam-slab type tunnel floor structure according to this embodiment, compared with the prior art which adopts the technical solutions of adjusting the curvature of the tunnel invert and increasing the thickness of the invert, the tunnel floor beam-slab structure body 2 of the present invention has a small thickness, a simple structure and convenient construction. The stiffness of the tunnel bottom is coordinated with the upper stiffness, which is beneficial to the overall stress of the structure. Compared with the prior art which adopts the technical solutions of using prestressed long anchor bolts or cable bolts to anchor the rock mass at the tunnel bottom, the present invention does not need to reinforce the rock mass to inhibit deformation, is not affected by geological factors, and there is no risk of loosening and failure of the prestressed structure. The method of controlling deformation is direct and convenient, and the deformation can be controlled at any time. Compared with the technical solutions of setting deformation absorption and isolation measures, the present invention does not need to analyze the reserved deformation amount at the tunnel bottom under a complex in-situ stress environment, and does not need to find the rock stratum that is stable and does not deform at the tunnel bottom through geological drilling. Theoretically, the adjustment ability of the floor heave deformation is infinite. Compared with the prior art of in-situ stress release, the present invention does not need to set structures such as pressure relief holes around the tunnel, does not affect the bearing structure in the rock mass around the tunnel, and will not cause the tunnel lining structure to be stressed due to in-situ stress adjustment.

[0076] A beam-slab type tunnel floor structure according to this embodiment uses the beam-slab structure body 2 to replace the traditional invert structure, suspends most of the tunnel floor structure, changes the contact form between the tunnel floor structure and the surrounding rock, reduces the contact between the tunnel floor structure and the surrounding rock, thereby reducing the transfer of rock mass deformation pressure to the structure. At the same time, the surrounding rock load of the tunnel arch 30, the self-weight loads of structures such as the tunnel lining and the ballastless track 10, and the train load are transmitted to the tunnel bottom rock mass through the force transfer and support structure 4, forming stress concentration at the bottom of the force transfer and support structure 4, applying a load to the rock mass to resist the floor heave deformation, reducing the upward floor heave deformation amount at the position of the force transfer and support structure 4, reducing the influence of the tunnel floor heave disease on the track elevation, realizing the effective guidance and control of the tunnel floor heave disease, and ensuring the safety of railway operation.

[0077] Embodiment 2

[0078] As Figures 1-11 shown, a beam-slab type tunnel floor structure according to this embodiment, on the basis of Embodiment 1, the tunnel floor structure further includes a rock wall support structure 8. The rock wall support structure 8 includes a support frame 81 and a plurality of support anchor bolts 82. The side surface of the support frame 81 is attached to the side wall of the rock mass groove 1, and the top surface is connected to the tunnel side wall 3. The support anchor bolts 82 are anchored to the side wall of the rock mass groove 1, and the support anchor bolts 82 are hung with a steel mesh to form an anchor mesh shotcrete support structure.

[0079] A beam-slab type tunnel floor structure according to this embodiment, the rock wall support structure 8 is used to improve the overall stability of the structure during the construction of the rock mass groove 1.

[0080] Preferably, the support frame 81 is formed by splicing I-beams, and the support anchor bolts 82 are made of deformed steel bars.

[0081] Preferably, the rock wall support structure 8 includes a first support structure and a second support structure connected vertically. The first support structure and the second support structure have the same composition structure, and each includes an I-beam support frame 81, a number of threaded steel support bolts 82, and a number of steel meshes. The support frame 81 includes a first vertical support 811, a second vertical support 812, and a cross brace 813. The first vertical support 811 includes a support I-beam erected on the side wall of the rock body groove 1 at the position of the side wall 3, and the second vertical support 812 includes a temporary support I-beam erected on the inner side of the tunnel at the position of the side wall 3. The tops of two rows of I-beams are welded and connected in parallel by 4 I-beams along the longitudinal direction of the tunnel to form the cross brace 813, which transfers the structural self-weight of the arch part 30 and the rock mass load to the structures below both sides of the demolished section, realizing the overhead of the structure at the side wall position.

[0082] Embodiment 3

[0083] As Figures 1-3 shown, for a beam-slab type tunnel bottom structure of this embodiment, on the basis of Embodiment 1, a number of induced deformation grooves 11 are further provided at the bottom of the rock body groove 2. The induced deformation grooves 11 are arranged longitudinally through the tunnel. The shape of the induced deformation grooves 11 in the tunnel cross-section is trapezoidal with a larger top and a smaller bottom. The included angle between the top edge and the hypotenuse of the induced deformation groove 11 is (45º + M / 2), where M is the internal friction angle of the rock mass.

[0084] For a beam-slab type tunnel bottom structure of this embodiment, the induced deformation groove 11 is a specific-shaped groove longitudinally penetrating the tunnel, specially excavated in the rock mass beside the tunnel bottom wall toe 42 and the force transfer pier 41. The function of the induced deformation groove 11 is to expand the deformation space of the rock mass below the tunnel bottom structure, provide the deformation space for the rock mass below, and induce the upward deformation of the rock mass to develop towards the free face of the groove body, realizing the two-way induction effect of the upward deformation of the rock mass below and the downward deformation of the structure above.

[0085] Specifically, the induced deformation groove 11 is formed by cutting and grinding the rock mass. In this embodiment, induced deformation grooves 11 are respectively arranged between the two force transfer piers 41 and between the force transfer pier 41 and the wall toe 42. The inverted trapezoidal structure of the induced deformation groove 11 is designed according to the slip line theory. Before manufacturing the induced deformation groove 11, the internal friction angle test of the rock mass should be carried out, and the specific parameters of the internal friction angle M of the rock mass should be determined according to the test. The surface cracking and deformation conditions of the induced deformation groove 11 should be regularly inspected during operation.

[0086] Specifically, the position of the induced deformation groove 11 between the two force transfer piers 41 is centered. The included angle between the top edge and the hypotenuse of the inverted trapezoid is (45º + M / 2), where M is the internal friction angle of the rock mass. The top width of this induced deformation groove 11 is 1 / 3 of the center distance between the two force transfer piers 41.

[0087] Specifically, the position of the induced deformation groove 11 between the force transfer pier 41 and the wall toe 42 is biased towards the wall toe 42. The included angle between the top side and the hypotenuse of the inverted trapezoid is (45º + M / 2) (where M is the internal friction angle of the rock mass), and the top width of the induced deformation groove 11 is 2 / 3 of the center distance between the force transfer pier 41 and the wall toe 42.

[0088] Embodiment 4

[0089] As Figures 1-3 shown, for a beam-slab type tunnel bottom structure of this embodiment, on the basis of Embodiments 1 - 3, the tunnel bottom structure further includes a deformation adjustment tie rod 7. The bottom of the deformation adjustment tie rod 7 is anchored in the tunnel bottom rock mass, and the top vertically passes through the beam-slab structure 2. The deformation adjustment tie rod 7 is connected to a reaction plate, the reaction plate is arranged on the top of the beam-slab structure 2, and the deformation adjustment tie rod 7 is connected to a tensioning mechanism.

[0090] For a beam-slab type tunnel bottom structure of this embodiment, the deformation adjustment tie rod 7 is arranged at the intersection position of the longitudinal beam 23 and the cross beam 22. Threaded sections are provided on the surfaces at both ends of the deformation adjustment tie rod 7. The lower end is anchored in the rock mass through a nut structure, and the upper end extends out of the beam-slab structure 2. The upper end of the deformation adjustment tie rod 7 is a free end and is connected to a hydraulic tensioning machine. During use, a tensile force is applied to the deformation adjustment tie rod 7 through the hydraulic tensioning machine, and through the reaction force, a downward adjustment load is applied to the beam-slab structure 2. The adjustment load forms stress concentration at the bottoms of the force transfer pier 41 and the wall toe 42 to resist deformation, actively adjusts the deformation of the tunnel bottom structure, or destroys the rock mass at the bottom of the tunnel, causing active settlement of the tunnel structure. The active settlement is used to counteract the floor heave deformation, realizing the active guidance and control of the deformation of the tunnel bottom structure, and locking the elevation of the ballastless track 10 at a normal level.

[0091] Preferably, as Figure 3 shown, the deformation adjustment tie rod 7 adopts a high-strength steel structural member with a diameter of φ42mm, the cross-section is circular, is arranged at the intersection position of the longitudinal beam 23 and the cross beam 22, and there are 9 in total, and the uplift resistance is not less than 300KN.

[0092] Preferably, the deformation adjustment tie rod 7 can also adopt a large-diameter cable according to the geological conditions.

[0093] Embodiment 5

[0094] As Figures 1-3 shown, for a beam-slab type tunnel bottom structure of this embodiment, on the basis of Embodiment 4, a cutting edge member 43 is further covered and arranged at the lower end of the force transfer support structure 4. The cutting edge member 43 is embedded in the bottom surface of the rock mass groove 1. The shape of the cutting edge member 43 in the tunnel cross-section is trapezoidal with a larger upper part and a smaller lower part, and the cutting edge member 43 includes a steel plate structural member.

[0095] A beam-slab type tunnel bottom structure of this embodiment. The cutting edge member 43 is a smooth-surfaced hollow stainless steel body arranged on the outer sides of the wall toe 42 and the load transfer pier 41. The shape of the cutting edge member 43 in the tunnel cross-section is adapted to the shapes of the wall toe 42 and the load transfer pier 41, wraps around the wall toe 42 and the load transfer pier 41, and together with the wall toe 42 and the load transfer pier 41, transfers the upper load to the underlying rock mass, and further strengthens the stress concentration effect of the upper load, cutting the rock mass to form a downward displacement.

[0096] Preferably, the cutting edge member 43 is arranged to wrap on both sides at the position of the load transfer pier 41, and wraps the bottom surface of the wall toe 42 and the surface close to the inner side of the tunnel at the position of the wall toe 42. The top width of the cutting edge member 43 is 50 cm, the bottom width is 10 cm, and the angle between the surface of the cutting edge member 43 and the horizontal plane is 75°.

[0097] Embodiment 6

[0098] A method for resisting floor heave deformation of a beam-slab type tunnel bottom structure, including reconstructing and setting a beam-slab type tunnel bottom structure as described above in the section for treating tunnel floor heave diseases, and the beam-slab type tunnel bottom structure provides a reserved deformation space 5 to induce floor heave deformation and / or provides a settlement adjustment load to resist floor heave deformation.

[0099] A method for resisting floor heave deformation of a beam-slab type tunnel bottom structure of this embodiment. By adopting the beam-slab type tunnel bottom structure of any one of Embodiments 1-5, a certain space is reserved at the bottom of the tunnel to induce the development of tunnel floor heave deformation towards the free face; at the same time, the contact form between the tunnel bottom structure and the rock mass is changed, artificially forming stress concentration, damaging the rock mass at the bottom of the tunnel, causing the active settlement of the tunnel structure, and using the active settlement to counteract the floor heave deformation, so as to realize the active guidance and control of the deformation of the tunnel bottom structure, and lock the elevation of the ballastless track 10 at the normal level.

[0100] Preferably, a reserved deformation space 5 is formed through the tunnel bottom structure, providing a release area for tunnel floor heave deformation, changing the contact form between the tunnel bottom structure and the surrounding rock, optimizing from the traditional surface contact to local point contact, greatly reducing the contact area between the tunnel bottom structure and the surrounding rock, thereby reducing the way of rock mass deformation pressure transmitted to the structure, and forming a method for resisting floor heave deformation by forming a reserved deformation space.

[0101] Preferably, the free face area of the rock mass is enlarged by inducing the deformation groove 11 to further provide conditions for the development of the floor heave deformation towards the free face. During use, the surrounding rock load of the tunnel arch, the self-weight loads of structures such as the tunnel lining and the ballastless track 10, and the train load are transmitted to the force transfer piers 41 and the wall toes 42 through the floor slab 21, the longitudinal beams 23, and the cross beams 22. The upper-wide and lower-narrow shape of the force transfer piers 41 and the wall toes 42 forms stress concentration at the four blade foot members 43 in contact with the rock mass, applying a load to resist the floor heave deformation to the rock mass, reducing the upward floor heave deformation amount at this position. At the same time, the floor heave deformation amount at the position of the blade foot member 43 is small, and the floor heave deformation amount at the position of the induced deformation groove 11 is large. By setting the blade foot member 43 inclined towards the induced deformation groove 11, the development of the induced floor heave deformation towards the induced deformation groove 11 is realized, forming the induced deformation development stage during the tunnel operation process, and forming a method for resisting floor heave deformation by induced deformation development.

[0102] Preferably, an adjustment load is applied through the deformation adjustment tie rod 7 to cut and break the rock mass at the position of the blade foot member 43 to form downward active settlement. When the active settlement amount is equal to the floor heave deformation amount, balance is achieved, realizing locking the ballastless track 10 at a fixed elevation, forming the active adjustment deformation stage during the tunnel operation process, and forming a method for resisting floor heave deformation by structural active settlement.

[0103] Preferably, the method for resisting floor heave deformation by reserving deformation space, the method for resisting floor heave deformation by induced deformation development, and the method for resisting floor heave deformation by structural active settlement can be used in combination or separately according to the actual situation. When used in combination, it can realize the cyclic process of adapting to deformation - inducing deformation - actively adjusting deformation correction - adapting to deformation, and realize the dynamic locking of the elevation of the ballastless track.

[0104] Specifically, the stress concentration coefficient = the transverse width of the beam and slab structure body / the sum of the transverse widths of the force transfer support structures 2. In this embodiment, the stress concentration coefficient = the width of the tunnel bottom structure / the sum of the bottom widths of the four blade foot members 43.

[0105] Specifically, during the induced deformation development stage, the degree of stress concentration on the blade foot member 43 should be less than the tensile strength of the rock mass, that is, the structural load * the stress concentration coefficient < the tensile strength of the rock mass, that is, (the surrounding rock load of the arch + the self-weight load of the structure + the train load) × the stress concentration coefficient < the tensile strength of the rock mass, to ensure that the rock mass will not be damaged and the tunnel structure will not settle under this load level, and only a small amount of upward floor heave deformation will occur.

[0106] Specifically, during the active adjustment deformation stage, (the adjustment load + the surrounding rock load of the arch + the self-weight load of the structure) × the stress concentration coefficient > the tensile strength of the rock mass, causing the blade foot member 43 to break and cut the rock mass for active settlement.

[0107] Preferably, during the induced deformation development stage, the structural load composed of the surrounding rock load of the tunnel arch above the beam-slab structure 2, the self-weight load of the tunnel structure, and the train load is used as the settlement adjustment load. During the active deformation adjustment stage, the active adjustment load applied to the beam-slab structure 2 by tensioning the deformation adjustment tie rod 7 through the tensioning mechanism is used as the settlement adjustment load.

[0108] Preferably, the active deformation adjustment stage is carried out in a timely manner according to the monitoring of the floor heave deformation. After the tunnel undergoes induced deformation and / or active deformation adjustment, it adapts to the deformation, and the track elevation is restored to the original elevation. According to the actual situation, the overall structure of the beam-slab type tunnel bottom structure can be adjusted to realize the cycle process of adapting to deformation - inducing deformation - actively adjusting deformation correction - adapting to deformation, and achieve the dynamic locking of the ballastless track elevation.

[0109] Example 7

[0110] A method for resisting floor heave deformation of a beam-slab type tunnel bottom structure, which is different from Example 6 in that: the above-mentioned beam-slab type tunnel bottom structure is continuously or intermittently set during the construction of the tunnel.

[0111] Example 8

[0112] As Figures 1-11 shown, a construction method for rectifying a beam-slab type tunnel bottom structure is illustrated by taking the transformation of a floor heave disease treatment section of a certain tunnel to set the above-mentioned beam-slab type tunnel bottom structure as an example, and specifically includes the following steps:

[0113] As Figure 4 shown, S1: Cut off the high-speed railway rails, remove the ballastless track 10, the water channel and the cable trough 20, and construct three rows of foot bolts 50 at the top of the tunnel side wall 3. A number of the foot bolts 50 are arranged in an array.

[0114] Specifically, the foot bolts 50 are made of φ42mm threaded steel. The main function is to ensure the stability of the arch structure 30 when the side wall 3 and the inverted arch 40 of the existing tunnel structure are demolished. The longitudinal and transverse spacing parameters of the foot bolts 50 can be adjusted according to the actual lining situation of the construction site.

[0115] As Figure 5 shown, S2: Demolish the secondary lining and the primary support above the bottom surface of the ballastless track 10 and below the top surface of the side wall 3 on one side of the tunnel, and use non-blasting construction to excavate the rock mass and set the first support structure; then demolish the inverted arch 40 and the filling layer 6 below the bottom surface of the ballastless track 10 and above the designed bottom surface of the rock mass groove 1, and use non-blasting construction to excavate the rock mass and set the second support structure. The first support structure and the second support structure are vertically connected to form a rock wall support structure 8.

[0116] Specifically, the single-time replacement length along the longitudinal direction of the tunnel does not exceed 4m.

[0117] Specifically, the first support structure includes I-beam supports 81, several threaded steel support bolts 82, and several steel meshes. The support bolts 82 are made of φ32 threaded steel and are used to reinforce the side wall of the rock mass to maintain the stability of the side wall of the rock mass. The longitudinal and transverse spacing parameters of the support bolts 82 can be adjusted according to the actual geological conditions of the construction site. A φ8mm steel mesh is hung between the support bolts 82, and the thickness of the shotcrete is 5 cm.

[0118] Preferably, the support 81 includes a first vertical support 811, a second vertical support 812, and a cross support 813. The first vertical support 811 includes a support I-beam erected on the side wall of the rock mass groove 1 at the position of the side wall 3. The second vertical support 812 includes a temporary support I-beam erected on the inner side of the tunnel at the position of the side wall 3. The longitudinal spacing of the first vertical support 811 is preferably 0.5 m, and it is positioned and fixed by using the support bolts 82. The longitudinal spacing of the second vertical support 812 is preferably 1 m, and it is positioned and fixed by using the first vertical support 811. Four I-beams are welded side by side along the longitudinal direction of the tunnel at the top of two rows of I-beams to form the cross support 813, which transfers the self-weight of the structure of the arch part 30 and the rock mass load to the structures below both sides of the demolition section, realizing the overhead of the structure at the position of the side wall 3.

[0119] Further, after the structure at the position of the side wall 3 is made overhead, the existing inverted arch 40 and filling layer 6 of the structure above the designed wall toe 42 and cutting edge 43 below the bottom surface of the ballastless track on the left side of the tunnel are demolished, and the rock mass below is excavated in a non-blasting manner. The longitudinal demolition length is the same as that above, and the lateral distance of the excavated position downward from the side wall is 3 m. A second support structure is set for the side wall of the rock mass, which is the same as the first support structure. The vertical support 81 is extended downward through the steel frame joint and reaches the bottom, realizing the excavation of the rock mass groove 1 and the rock wall support at the position of the left side wall 3 of the tunnel.

[0120] As Figure 6 shown, S3: Repeat S2 to carry out the excavation and support of the other side tunnel bottom side area; complete the excavation and support of the rock mass groove 1 at the position of the right side wall 3 of the tunnel.

[0121] As Figure 7 shown, S4: Demolish the central drainage ditch of the tunnel, the remaining inverted arch filling layer 6 and the inverted arch 40, and use non-blasting construction to excavate the rock mass to the designed bottom surface of the rock mass groove 1 to form the bottom surface structure of the rock mass groove 1.

[0122] As Figure 8 shown, S5: According to the designed position of the force transfer support structure 4, demolish the temporary support I-beams of the second vertical support 812 below the cross support 813 at the position of the wall toe 42, bind the steel bars, and form the force transfer support structure 4 by in-situ casting with formwork.

[0123] Specifically, both the wall toe 42 and the load transfer pier 41 are formed by integral cast-in-place molding with formwork. The center line of the load transfer pier 41 coincides with the center line of the line track 10. During construction, attention should be paid to protecting the connecting bars of the wall toe 42 and the load transfer pier 41 with the upper structure. During construction, the temporary support for the formwork of the wall toe 42 and the load transfer pier 41 should be strengthened. The formwork of the wall toe 42 and the load transfer pier 41 can only be removed after the formwork is propped against the cast-in-place upper beam and slab structure 2. At the same time, a manhole 9 is excavated at a suitable position in the center water channel of the rectification section as a later maintenance passage, and the center water channel of the existing structure is blocked.

[0124] As Figure 9 shown, S6: Bind the steel bars of the beam and slab structure 2, set up formwork and cast in place to form the beam and slab structure 2.

[0125] As Figure 10 shown, S7: Set connecting bars and isolation parts at the position of the tunnel side wall, and pour the concrete at the position of the side wall 3 to isolate the vertical displacement between the beam and slab structure 2 and the arch structure 30.

[0126] Specifically, before pouring the concrete at the position of the side wall 3, two rows of φ32mm connecting bars are installed at a certain distance, preferably 50 cm, on the longitudinal beam 22 at the position of the wall toe 42. The steel bar joints are covered with plastic covers. A rubber pad with openings is installed above the longitudinal beam 22 at the position of the wall toe 42. Preferably, the rubber pad is 20 mm thick. Then, the concrete at the position of the side wall 3 is poured to isolate the vertical displacement between the bottom structure of the tunnel and the upper arch structure 30.

[0127] As Figure 11 shown, S8: Pour at least 30 cm thick plain concrete on the beam and slab structure 2 as the filling layer 6 to serve as the reserved space for future cutting and lowering the track, improve the anti-deformation ability of the ballastless track 10 structure, and then form the ballastless track 10, the center water channel and the cable trough 20, restore the pipeline connection, weld the rails, and resume the operation of the high-speed railway.

[0128] Embodiment 9

[0129] As Figures 1-11 shown, for a construction method for rectifying a beam and slab type tunnel bottom structure in this embodiment, on the basis of Embodiment 8, the S4 further includes: drilling installation holes for the deformation adjustment tie rods 7 on the bottom surface of the rock mass groove 1 and installing the rock-injected part of the deformation adjustment tie rods 7; the bottom of the rock-injected part is anchored with an anchoring agent, and the top is reserved with a joint for connecting the free part of the subsequent deformation adjustment tie rods 7 above.

[0130] Preferably, the depth of the installation hole is generally set to 0.5 - 1 times the tunnel excavation span in combination with the integrity of the rock mass of the rock-injected part.

[0131] Preferably, as Figure 8As shown in the figure, the specific steps of S5 are as follows: According to the designed position of the force transmission support structure 4, remove the temporary support I-beam under the second vertical support 812 below the cross brace 813 at the position of the wall toe 42, install the cutting edge member 43, then bind the steel bars of the wall toe 42, formwork and cast the wall toe 42 in situ, then bind the steel bars of the force transmission pier 41, and formwork and cast the force transmission pier 41 in one piece in situ.

[0132] Specifically, before installing the cutting edge member 43, level the surrounding rock in the groove for installing the cutting edge member 43, and apply lubricating oil on the surface of the cutting edge member 43 to ensure smooth contact between the cutting edge member 43 and the surrounding rock.

[0133] Preferably, the longitudinal cutting edge members 43 under the tunnel lining structure are welded into a whole.

[0134] Preferably, as Figure 9 shown in the figure, the specific steps of S6 are as follows: Bind the steel bars of the cross beam 22, longitudinal beam 23 and bottom plate 21, embed steel pipes at the intersection positions of the cross beam 22 and the longitudinal beam 23, then formwork and cast in situ to form the beam and slab structure 2, form a through channel for the deformation adjustment tie rod 7, set at least 6 mm thick steel plate at the top of the through channel as the reaction plate, and then install the free part of the deformation adjustment tie rod 7, and connect the reserved joints of the free part and the rock-invading part.

[0135] Preferably, after the deformation adjustment tie rod 7 is installed, conduct a structural settlement test of on-site tensioning to check the working condition of the cutting edge member 43, obtain the relationship curve between the load of the cutting edge member 43 cutting the rock mass and the corresponding settlement displacement, and use it as the basis for active settlement during operation.

[0136] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A beam-slab tunnel bottom structure, characterized in that: The invention comprises a rock groove (1) and a beam-slab structure (2) at the bottom of a tunnel. The beam-slab structure (2) is arranged in the rock groove (1). The top of the beam-slab structure (2) is connected to the tunnel side wall (3). A force transmission support structure (4) is arranged at the bottom. The force transmission support structure (4) is connected to the bottom surface of the rock groove (1). A reserved deformation space (5) is formed between the beam-slab structure (2) and the rock groove (1). A filling layer (6) for supporting a track (10) is arranged above the beam-slab structure (2). A plurality of manholes (9) are arranged in the reserved deformation space (5). A plurality of induced deformation grooves (11) are arranged at the bottom of the rock groove (1). The induced deformation grooves (11) are grooves of a specific shape specially excavated in the rock mass beside the toe (42) of the tunnel bottom wall and the force transmission pier (41) and passing through the longitudinal direction of the tunnel. The induced deformation grooves (11) are arranged to pass through the longitudinal direction of the tunnel. The induced deformation grooves (11) are arranged to pass through the longitudinal direction of the tunnel. The cross-section is in the shape of a trapezoid with a larger top and a smaller bottom. The tunnel bottom structure also includes a deformation adjustment rod (7). The bottom of the deformation adjustment rod (7) is anchored in the tunnel bottom rock mass, and the top vertically passes through the beam-slab structure (2). The deformation adjustment rod (7) is connected to a reaction plate, and the reaction plate is arranged on the top of the beam-slab structure (2). The deformation adjustment rod (7) is connected to a tensioning mechanism. The lower end of the force transmission support structure (4) is covered with a blade foot member (43), and the blade foot member (43) is embedded in the bottom surface of the rock mass groove (1). The shape of the blade foot member (43) in the tunnel cross-section is in the shape of a trapezoid with a larger top and a smaller bottom. The blade foot member (43) includes a steel plate structural member. The force transmission support structure (4) includes a force transmission pier (41), and the force transmission pier (41) is arranged in the tunnel bottom projection surface of the track (10). The force transmission pier (41) is arranged to pass through the tunnel longitudinally. The force transmission pier (41) includes a reinforced concrete structural member. The force transmission support structure (4) comprises a wall toe (42), the wall toe (42) being arranged in a tunnel bottom projection surface of a tunnel side wall (3), the wall toe (42) being arranged to penetrate the tunnel longitudinally, and the wall toe (42) comprising a reinforced concrete structural member.

2. A beam-slab tunnel bottom structure according to claim 1, characterized in that: The beam-slab structure (2) comprises a bottom plate (21), a plurality of cross beams (22) and a plurality of longitudinal beams (23); the cross beams (22) are arranged in a transverse direction of the tunnel, and a plurality of the cross beams (22) are arranged in a longitudinal direction of the tunnel; the longitudinal beams (23) are arranged to penetrate the tunnel in a longitudinal direction, and a plurality of the longitudinal beams (23) are arranged in a transverse direction of the tunnel; the cross beams (22) and the longitudinal beams (23) are staggered to form a grid body, and the bottom plate (21) is arranged in grids of the grid body.

3. The beam-slab tunnel bottom structure according to claim 1, characterized in that: The tunnel bottom structure also includes a rock wall support structure (8), the rock wall support structure (8) including a support frame (81) and a plurality of support anchor rods (82), the top surface of the support frame (81) being connected to the tunnel side wall (3); The support frame (81) comprises a first vertical support (811), a second vertical support (812) and a horizontal support (813); A plurality of first vertical supports (811) are erected against the rock mass, the first vertical supports (811) are arranged at intervals along the longitudinal direction of the tunnel, and the first vertical supports (811) are positioned and fixed by support anchor rods (82); A plurality of second vertical supports (812) are erected adjacent to the inner side of the tunnel, the second vertical supports (812) are arranged at intervals along the longitudinal direction of the tunnel, and the second vertical supports (812) are positioned and fixed by the first vertical supports (811); The horizontal brace (813) is arranged to penetrate the top of the first vertical brace (811) and the second vertical brace (812) along the longitudinal direction of the tunnel.

4. A method for resisting bottom bulging deformation of a beam-slab tunnel bottom structure, characterized in that: include: A beam-slab tunnel bottom structure as described in any one of claims 1 to 3 is installed in the tunnel floor heave disease treatment section for renovation, or, when a tunnel is newly constructed, a beam-slab tunnel bottom structure as described in any one of claims 1 to 3 is continuously or discontinuously installed, wherein the beam-slab tunnel bottom structure provides reserved deformation space to induce floor heave deformation and / or provides settlement adjustment load to resist floor heave deformation.

5. A method for resisting bottom bulging deformation of a beam-slab tunnel bottom structure as claimed in claim 4, characterized in that: The settlement adjustment load includes a structural load composed of a surrounding rock load of a tunnel arch (30) above the beam-slab structure (2), a deadweight load of the tunnel structure and a train load, and / or an active adjustment load applied to the beam-slab structure (2) by tensioning a deformation adjustment rod (7) through a tensioning mechanism; The settlement adjustment load forms stress concentration at the bottom of the force transmission support structure (4), and the stress concentration coefficient = the sum of the width of the beam-slab structure (2) along the tunnel transverse direction / the width of the force transmission support structure (4) along the tunnel transverse direction; When the structural load*stress concentration factor is less than the rock mass tensile strength, the tunnel bottom structure is in the induced deformation development stage; When (structural load + active adjustment load)*stress concentration coefficient>rock mass tensile strength, the force transmission support structure (4) cuts the rock mass, and the tunnel bottom structure is in the active adjustment deformation stage, which is carried out in a timely manner according to the bottom drum deformation monitoring situation.

6. A construction method for improving the beam-slab tunnel bottom structure, characterized in that: A beam-slab tunnel bottom structure as claimed in any one of claims 1 to 3 is used for reconstruction and installation in a tunnel floor heave disease treatment section, and the reconstruction and installation comprises the following steps: S1: cutting off the high-speed railway rails, dismantling the ballastless track (10), the ditch and the cable trough (20), and applying a plurality of locking anchor rods (50) on the top of the tunnel side wall (3), wherein the plurality of locking anchor rods (50) are arranged in an array; S2: The secondary lining and the initial support above the bottom surface of the ballastless track (10) on one side of the tunnel and below the top surface of the tunnel side wall (3) are removed, the rock mass is expanded by non-explosive construction, and a first support structure is set; then the invert (40) and the filling layer (6) below the bottom surface of the ballastless track (10) on this side and above the designed bottom surface of the rock mass groove (1) are removed, the rock mass is expanded by non-explosive construction, and a second support structure is set; the first support structure and the second support structure are vertically connected to form a rock wall support structure (8); S3: Repeat S2 to expand and support the bottom side area of ​​the other side of the tunnel; S4: the tunnel center ditch, the remaining invert filling layer (6) and the invert (40) are removed, and the rock mass is excavated to the designed bottom surface of the rock mass trench (1) by non-explosive construction, so as to form the bottom surface structure of the rock mass trench (1); S5: according to the designed position of the force transmission support structure (4), tying steel bars and erecting a formwork to cast in situ the force transmission support structure (4); S6: tying the steel bars of the beam-slab structure (2), setting up the formwork for cast-in-place, and forming the beam-slab structure (2); S7: setting joint steel bars and isolation pieces at the tunnel side wall (3), pouring concrete at the tunnel side wall (3), and achieving vertical displacement isolation between the beam-slab structure (2) and the arch structure (30); S8: pour at least 30 cm thick plain concrete on the beam-slab structure (2) as a filling layer (6), reshape the ballastless track (10), the central ditch and the cable duct (20), restore the pipeline connection, weld the rails, and resume the high-speed railway operation.

7. A beam-slab tunnel bottom structure improvement construction method as claimed in claim 6, characterized in that: The step S4 further comprises: drilling a deformation adjustment rod (7) installation hole on the bottom surface of the rock groove (1), and installing the rock-entering portion of the deformation adjustment rod (7); the bottom of the rock-entering portion is anchored by an anchoring agent, and a joint is reserved at the top; The S5 further comprises: installing a blade foot member (43) on the bottom surface of the rock mass groove (1); The S6 specifically comprises: tying the steel bars of the cross beam (22), the longitudinal beam (23) and the bottom plate (21), pre-embedding a steel pipe at the intersection of the cross beam (22) and the longitudinal beam (23), then erecting a mold and casting in situ to form a beam-slab structure (2), forming a passage for the deformation adjustment rod (7), arranging a steel plate as a reaction plate at the top of the passage, and then installing the air-facing portion of the deformation adjustment rod (7), wherein the air-facing portion is connected to the rock-entering portion by a reserved joint; After the deformation adjustment rod (7) is installed, a structural settlement test is carried out on site to check the working condition of the blade foot member (43) and obtain a relationship curve between the load size of the blade foot member (43) cutting the rock mass and the corresponding settlement displacement, which is used as a basis for active settlement during operation.

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