Supporting device for targeted control of active fault fracture

Abstract

The invention relates to the technical field of tunnel faults, in particular to a supporting device for targeted control of active fault fracture. A fault fracture zone exists in the rock mass; the innermost side of the rock mass is provided with a tunnel internal space; the first-stage targeted support is connected to the fault fracture zone and comprises a plurality of guide pipes connected to the rock mass and strong grouting spaces formed among the guide pipes, the guide pipes are arranged and installed in a stepped structure, and fan-like arc-shaped guide surfaces are formed at the ends of the guide pipes through the strong grouting spaces; through a deformation channel formed by the arc-shaped guide surfaces formed on the two sides of the fault fracture zone, a target control fault potential fracture path is spread to a preset safety area along the arc lines of the sector-like arc-shaped guide surfaces to complete directional induction, a multi-stage target control support type is designed, multi-stage consumption and directional induction of fault fracture energy are achieved, and the fault fracture energy utilization rate is improved. And step-by-step energy consumption and targeted control of fault fracture path propagation from the stratum end to the tunnel end are realized.

Description

Technical Field

[0001] This invention relates to the field of tunnel fault technology, and in particular to a support device for targeted control of active fault rupture. Background Technology

[0002] With the deepening of my country's modern comprehensive transportation system development plan, an increasing number of tunnel projects inevitably traverse active fault zones. Fault fracture zones have poor geological conditions and insufficient uniformity of stratum stiffness, easily leading to concentrated release of fault dislocations and causing concentrated damage to the structure. In the Wenchuan and Menyuan earthquakes, multiple tunnels traversing active fault zones experienced severe damage such as lining collapse, misalignment, and cracking, posing a serious threat to tunnel structural safety and causing traffic congestion in the disaster areas, hindering subsequent rescue efforts. Therefore, the design and application of tunnel surrounding rock support structures, aiming to leverage the self-supporting function of the strata to better dissipate and disperse seismic energy, thereby ensuring tunnel safety and stable operation under seismic loads, is a key research area in engineering technology.

[0003] To address the challenge of structural damage caused by fault displacement in tunnels traversing active fault zones, current technologies primarily employ a single, passive support method near the excavation face. While this can improve rock stability and reduce tunnel damage to some extent, it cannot actively guide the propagation of fault fracture deformation paths. Existing research indicates that in long fault fracture zones, multiple uncertain fault cores exist, potentially leading to concentrated damage to critical tunnel components. To address this, an integrated active support device combining rock and tunnel structure is needed. This device should not only reduce the magnitude of fault displacement deformation but also centrally control fault fracture propagation within a predetermined safe zone, thereby releasing minor fault displacement within a small area of ​​the tunnel's resilient structure. Summary of the Invention

[0004] In view of the above-mentioned problems that the propagation of fault rupture deformation path cannot be actively guided and that lightweight fault displacement cannot be released in a small area of ​​the tunnel's ductile structure, this invention is proposed.

[0005] Therefore, the purpose of this invention is to provide a support device for targeted control of active fault rupture.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a support device for targeted control of active fault rupture, comprising, Rock mass; The fault fracture zone exists in the rock mass; The innermost part of the rock mass has a tunnel interior space; The primary targeted support connected to the fault fracture zone includes several guide pipes connected to the rock mass, a strong grouting space formed between the guide pipes, the guide pipes being arranged in a stepped structure, and a fan-shaped arc-shaped guide surface being formed at the end of the guide pipes through the strong grouting space. The deformation channel formed by the arc-shaped guide surfaces on both sides of the fault fracture zone enables the potential fracture path of the target-controlled fault to propagate along the arc of the fan-shaped arc-shaped guide surface to the preset safe zone to complete the directional induction.

[0007] As a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, there is an interface between the rock mass and the intermediate fault fracture zone, and one side of the guide pipe is installed on the interface.

[0008] As a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, the fault fracture zone contains several fault planes, and the fault planes are affected by primary targeted support, causing their paths to change.

[0009] In a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, the end of the arc-shaped guide surface extends to form a guide fracture surface, and the spacing between the guide fracture surfaces is smaller than the spacing between the junction surfaces.

[0010] As a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, the area space formed by the interface and the fault surface is used to guide the movement of the rupture path into the space between the fault surfaces, so that the rupture path is induced into a preset safe zone.

[0011] As a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, a secondary targeted support is installed within the range of the guiding fracture surface to initially block the extension of the rupture path.

[0012] As a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, the secondary targeted support includes a grouting reinforcement section, a support strengthening section, and a support intermediate section. High-intensity gradient grouting reinforcement is carried out within the range of the fault fracture zone, wherein the grouting reinforcement strength of the support strengthening section is greater than that of the support intermediate section and the grouting reinforcement section, thereby creating a stiffness difference with the support intermediate section, and forming a multi-level energy-dissipating target control structure in the overall longitudinal direction.

[0013] As a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, the support reinforcement section includes a first anchor bolt installed on the rock mass, grout is injected into the first anchor bolt to form a grouting cavity in the area, and a second anchor bolt is installed on the side opposite to the first anchor bolt on the grouting cavity.

[0014] As a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, the intermediate support section is connected between two reinforced support sections, and the intermediate support section includes a third anchor bolt installed on the rock mass, through which grout is added to form a grouting cavity.

[0015] As a preferred embodiment of the support device for targeted control of active fault rupture according to the present invention, a third-level targeted support is installed in the inner layer of the second-level targeted support, that is, in the tunnel interior space. The third-level targeted support includes an annular grooved induction zone opened in the middle section of the support. A multi-body collaborative support is installed on the annular grooved induction zone to further consume residual rupture deformation.

[0016] The advantages of this invention are as follows: This device is designed with a multi-level target-controlled support system, which realizes multi-level consumption and directional induction of fault fracture energy. First-level targeted support is set up in the deep strata within the fault fracture zone to form a fault fracture path barrier, targeting and controlling the propagation of the fracture path, reducing the diameter of the potential fracture zone, and transforming disordered risk into a deterministic process. Second-level targeted support involves grouting reinforcement and segmented arrangement of anchor bolts (cables) along the longitudinal excavation face, realizing multi-level consumption of fault fracture deformation energy, while simultaneously targeting and controlling it to the concentrated area in the middle section. Third-level targeted support utilizes the surrounding rock annular groove induction zone to construct a stiffness difference with the surrounding rock on both sides, further inducing the active fault fracture deformation to the grooved area, and then transferring it to the multi-body collaborative support structure to consume residual fracture deformation. This achieves step-by-step energy consumption and targeted control of fault fracture path propagation from the stratum end to the tunnel end, improving the safety performance of the tunnel under seismic action and fault displacement, ensuring the stable operation of transportation infrastructure, and protecting the safety of people's lives and property. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a support device for targeted control of active fault rupture.

[0019] Figure 2 This is a schematic diagram of a secondary and tertiary targeted support system for a targeted control of active fault rupture.

[0020] Figure 3 This is a schematic diagram of a support device for targeted control of active fault rupture.

[0021] Figure 4This is a schematic cross-sectional view of a primary targeted support for a support device that targets and controls active fault rupture.

[0022] Figure 5 This is a schematic cross-sectional view of a secondary targeted support system for a targeted control of active fault rupture.

[0023] Figure 6 This is a cross-sectional schematic diagram of a three-stage targeted support system for targeted control of active fault rupture.

[0024] Reference numerals: 1. Rock mass; 2. Fault fracture zone; 3. Tunnel interior space; 4. Primary targeted support; 41. Pipe guide; 42. Strong grouting space; 43. Arc-shaped guide surface; 5. Intersection surface; 6. Fault plane; 7. Guide fracture surface; 8. Secondary targeted support; 81. Grouting reinforcement section; 82. Support reinforcement section; 83. Support intermediate section; 821. First anchor bolt; 822. Grouting cavity; 823. Second anchor bolt; 831. Third anchor bolt; 832. Grouting cavity; 9. Tertiary targeted support; 91. Annular grooved guide zone; 92. Multi-body collaborative support. Detailed Implementation

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0028] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include the three-dimensional spatial dimensions of length, width, and depth.

[0029] Example Reference Figure 1 - Figure 6As an embodiment of the present invention, a support device for targeted control of active fault rupture is provided. This device includes a rock mass 1; a fault fracture zone 2 existing in the rock mass 1; a tunnel interior space 3 located on the innermost side of the rock mass 1; and a primary targeted support 4 connected to the fault fracture zone 2, which includes a plurality of guide pipes 41 connected to the rock mass 1, a strong grouting space 42 formed between the guide pipes 41, the guide pipes 41 being arranged in a stepped structure, and a fan-shaped arc-shaped guide surface 43 being formed at the end of the guide pipes 41 through the strong grouting space 42; through the deformation channel formed by the arc-shaped guide surfaces 43 on both sides of the fault fracture zone 2, the potential rupture path of the target-controlled fault is propagated along the arc of the fan-shaped arc-shaped guide surface 43 to a preset safe zone to complete directional induction.

[0030] First, borehole surveys were conducted to obtain the geological structural characteristics of the tunnel site area crossing the active fault, identify the fault rupture mode and the range of potential rupture propagation paths, and then determine the core area of ​​the tunnel surrounding rock support. The overall integrated support for the fault rupture path tunnel surrounding rock was established. The radial direction of the support from the deep part of the fault to the outline of the excavation face is as follows: first-level targeted support structure 4, second-level targeted support structure 8, and third-level targeted support structure 9. The primary targeted support 4 is implanted deep within the fault along the width of the fracture zone. The top-inserted guide pipe 41 and the strong grouting space 42 around the guide pipe 41 form a high-strength support body. The top-inserted guide pipe 41 serves as a load-bearing skeleton and is inserted in multiple sections at a 90-degree angle to the interface between the fault fracture zone 2 and the intact surrounding rock on both sides. One end is fixed in the rock mass 1. High-pressure grouting is injected inward to ensure that the grout fully fills the pores of the fracture zone and diffuses to form a strong grouting area. At the same time, it is bonded to the top-inserted guide pipe 41 to improve strength and form a stress barrier.

[0031] Among them, the potential fault rupture path includes the junction surface 5 and the fault plane 6. There is a junction surface 5 between the rock mass 1 and the intermediate fault fracture zone 2. One side of the guide tube 41 is installed on the junction surface 5.

[0032] Specifically, there are several fault planes 6 in the fault fracture zone 2. The path of the fault planes 6 is changed due to the influence of the primary targeted support 4.

[0033] Furthermore, the end of the arc-shaped guide surface 43 extends to form a guide fracture surface 7, and the spacing of the guide fracture surfaces 7 is smaller than the spacing of the junction surfaces 5.

[0034] Furthermore, the area formed by the junction surface 5 and the fault surface 6 is used to guide the movement of the rupture path into the space between the fault surfaces, so that the rupture path is induced into the preset safe zone.

[0035] Furthermore, a secondary targeted support 8 is installed within the range of the guiding fracture surface 7 to initially block the extension of the fracture path.

[0036] The secondary targeted support 8 includes a grouting reinforcement section 81, a support strengthening section 82, and a support intermediate section 83. High-intensity gradient grouting reinforcement is carried out within the fault fracture zone 2. The grouting reinforcement strength of the support strengthening section 82 is greater than that of the support intermediate section 83 and the grouting reinforcement section 81, creating a stiffness difference with the support intermediate section 83, and forming a multi-level energy-consuming target control structure in the overall longitudinal direction.

[0037] Furthermore, the support reinforcement section 82 includes a first anchor rod 821 installed on the rock mass 1. Grout is injected into the first anchor rod 821 to form a grouting cavity 822 in the area. A second anchor rod 823 is installed on the side opposite to the first anchor rod 821 on the grouting cavity 822.

[0038] Furthermore, the intermediate support section 83 is connected between the two reinforced support sections 82. The intermediate support section 83 includes a third anchor bolt 831 installed on the rock mass 1, and a grouting cavity 832 formed by adding grout through the third anchor bolt 831.

[0039] Among them, high-intensity gradient grouting reinforcement is carried out in the fault fracture zone 2 area. The grouting reinforcement strength of the support reinforcement section 82 is greater than that of the support middle section 83 and the grouting reinforcement section 81, creating a stiffness difference with the support middle section 83. The second anchor bolt 823 and the third anchor bolt 831 are evenly distributed in the support middle section 83 and the support reinforcement section 82 in a circumferential direction with an inclination angle of 60 degrees to the tunnel axis. In addition, the first anchor bolt 821 is evenly distributed in the support reinforcement section 82 to tighten and increase the friction coefficient at the junction of the fault fracture zone 2 and the rock mass 1, giving full play to the anchoring effect of the rock mass 1 on the middle fault fracture zone 2. In the secondary targeted support 8, the grouting reinforcement section 81, the support reinforcement section 82, and the support middle section 83 form a multi-level energy-consuming target control structure with "double high and double control" in the longitudinal direction. This weakens and controls the meter-level fault fracture deformation to the centimeter level and targets and controls the range of fault fracture deformation propagation in the concentrated area of ​​the support middle section 83.

[0040] Furthermore, a tertiary targeted support 9 is installed in the inner layer of the secondary targeted support 8, that is, in the tunnel interior space 3. The tertiary targeted support 9 includes an annular grooved induction zone 91 opened in the middle section 83 of the support. A multi-body collaborative support 92 is installed on the annular grooved induction zone 91. The multi-body collaborative support 92 structure includes shotcrete and steel arch support. Together with the multi-level energy-consuming target control structure in the secondary targeted support 8, it constitutes a collaborative energy-consuming unit for the tunnel surrounding rock. Circular grooves are made in the surrounding rock near the excavation face within the preset range of the middle section 83 of the support to form an induction zone. The difference in stiffness between the annular groove and the adjacent surrounding rock structure is used to construct the target control fault fracture deformation path to develop towards the position of the annular grooved induction zone 91 of the surrounding rock. The deformation development is directionally controlled within the multi-body collaborative support 92 structure corresponding to the annular groove area, further consuming the residual fracture deformation.

[0041] The radial grouting ring for grouting reinforcement has a radius of about 5m, and the grouting holes are arranged in a quincunx pattern with a circumferential spacing of 0.3m to 0.5m. The grouting pressure is controlled at 1MPa to 3MPa to ensure that the grout fully fills the pores of the fractured zone and diffuses, thereby improving the self-supporting capacity of rock mass 1. The grouting pressure is controlled at 4 to 6MPa within a certain range on both sides of the middle section along the longitudinal direction of the tunnel. Gradient grouting strengthens the surrounding rock on both sides and thus concentrates and controls the propagation of fault fracture deformation in the middle section. The anchor bolts are φ20~25mm high prestressed bonded anchor bolts with a length of 2m~4m. They intersect the fault dip angle of 45 degrees to 90 degrees and are anchored in the grouting reinforced body to form a suspended combination structure that bears the large deformation of the surrounding rock. The anchor bolts are arranged radially along the tunnel in the reinforced sections on both sides of the middle section of the grouting reinforced area. One end is anchored in the intact rock mass 1. The length of the anchoring section is 1.2 to 1.5 times the tunnel radius. The angle between the anchor cable and the interface is 45 degrees to 90 degrees. The high prestress tension increases the friction coefficient between the two sides of the fractured zone and the intact rock mass 1, giving full play to the anchoring effect of the intact rock mass 1 on the fractured zone and the preset safety zone.

[0042] During the operation, firstly, the geological structural characteristics of the tunnel site area crossing the active fault are obtained through borehole survey; based on the geological structural characteristics of the tunnel site area crossing the active fault, the fracture mode and potential fracture propagation path range of fault fracture zone 2 are identified, and the core area of ​​the tunnel surrounding rock support is determined; in the core support area, a targeted control support device for the tunnel surrounding rock along the fault fracture path is established at the engineering site crossing the active fault; the targeted control integrated support device is deployed sequentially from the deep fault to near the excavation outline, with primary targeted support 4, secondary targeted support 8, and tertiary targeted support 9. Primary targeted support 4 includes a guide pipe 41 and an arc-shaped guide surface 43 to guide the path; secondary targeted support 8 is of type... The system includes grouting reinforcement of the fracture zone and anchor bolts to target and control the propagation range of fault rupture deformation within the concentrated area of ​​the middle section 83 of the support; the three-level targeted support 9 includes annular grooved induction zone 91 and multi-body collaborative support 92 structure to further consume residual rupture deformation; based on the potential rupture path of the fault and the physical parameters of the tunnel site, the key parameters for target control of each level of targeted support are configured to form a target-controlled rupture and deformation channel reaching the multi-body collaborative support 92 structure; through targeted control integrated support device, the fault rupture energy is actively consumed step by step and targeted to the preset area, ultimately consuming the residual fault rupture energy and causing minimal damage to the inner operating section of the tunnel.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A support device for targeted control of active fault rupture, characterized in that: include, Rock mass (1); The rock mass (1) contains a fault fracture zone (2); The innermost side of the rock mass (1) has a tunnel interior space (3); The primary targeted support (4) connected to the fault fracture zone (2) includes several guide pipes (41) connected to the rock mass (1), and a strong grouting space (42) formed between the several guide pipes (41). The guide pipes (41) are arranged in a stepped structure, and a fan-shaped arc-shaped guide surface (43) is formed at the end of the guide pipes (41) through the strong grouting space (42). Through the deformation channel formed by the arc-shaped guide surface (43) formed on both sides of the fault fracture zone (2), the potential fracture path of the target-controlled fault is propagated along the arc of the fan-shaped arc-shaped guide surface (43) to the preset safe zone to complete the directional induction.

2. The support device for targeted control of active fault rupture according to claim 1, characterized in that: There is an interface (5) between the rock mass (1) and the intermediate fault fracture zone (2), and one side of the guide pipe (41) is installed on the interface (5).

3. The support device for targeted control of active fault rupture according to claim 2, characterized in that: There are several fault planes (6) in the fault fracture zone (2), and the path of the fault planes (6) is changed due to the influence of the primary targeted support (4).

4. The support device for targeted control of active fault rupture according to claim 3, characterized in that: The end of the arc-shaped guide surface (43) extends to form a guide fracture surface (7), and the spacing of the guide fracture surfaces (7) is smaller than the spacing of the junction surfaces (5).

5. The support device for targeted control of active fault rupture according to claim 4, characterized in that: The area formed by the interface (5) and the fault surface (6) is used to guide the movement of the rupture path into the space between the fault surfaces, so that the rupture path is induced into the preset safe zone.

6. The support device for targeted control of active fault rupture according to claim 5, characterized in that: A secondary targeted support (8) is installed within the range of the guiding fracture surface (7) to initially block the extension of the fracture path.

7. The support device for targeted control of active fault rupture according to claim 6, characterized in that: The secondary targeted support (8) includes a grouting reinforcement section (81), a support strengthening section (82), and a support intermediate section (83). High-intensity gradient grouting reinforcement is carried out within the fault fracture zone (2). The grouting reinforcement strength of the support strengthening section (82) is greater than that of the support intermediate section (83) and the grouting reinforcement section (81), creating a stiffness difference with the support intermediate section (83), and forming a multi-level energy-consuming target control structure in the overall longitudinal direction.

8. The support device for targeted control of active fault rupture according to claim 7, characterized in that: The support reinforcement section (82) includes a first anchor rod (821) installed on the rock mass (1), grout is injected into the first anchor rod (821) to form a grouting cavity (822) in the area, and a second anchor rod (823) is installed on the side opposite to the first anchor rod (821) on the grouting cavity (822).

9. The support device for targeted control of active fault rupture according to claim 8, characterized in that: The intermediate support section (83) is connected between two reinforced support sections (82). The intermediate support section (83) includes a third anchor rod (831) installed on the rock mass (1) and a grouting cavity (832) formed by adding grout through the third anchor rod (831).

10. The support device for targeted control of active fault rupture according to claim 9, characterized in that: A third-level targeted support (9) is installed in the inner layer of the secondary targeted support (8), that is, in the tunnel interior space (3). The third-level targeted support (9) includes an annular grooved guide zone (91) opened in the middle section (83) of the support. A multi-body collaborative support (92) is installed on the annular grooved guide zone (91) to further consume residual fracture deformation.

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