New type tunnel shock absorption and energy dissipation system implemented by using prestress special shock absorption anchor rod

Abstract

A novel tunnel vibration reduction and energy dissipation system utilizing prestressed special vibration-damping anchors comprises several prestressed special vibration-damping anchors, shotcrete walls, and arch frames. Each prestressed special vibration-damping anchor is arranged in a ring within the shotcrete wall, loose surrounding rock, and deep stable surrounding rock. The prestressed special vibration-damping anchor includes a vibration-damping energy-dissipating free section and an anchoring section. The vibration-damping energy-dissipating free section includes the anchor rod body and the vibration-damping energy-dissipating device. This invention is applied to tunnel support and safety assurance after excavation. During tensioning and operation, the anchor vibration-damping energy-dissipating device only serves to anchor and transmit tensile force. During earthquakes, the vibration-damping energy-dissipating device prevents the anchor rod from bending or being crushed out of the soil due to overall compression, while simultaneously dissipating some seismic energy. The anchor rod structure itself has the characteristic of spontaneously changing stiffness with external force and velocity. No monitoring, calculation, or control system is required; it is compact, simple in construction, and easy to install.

Description

Technical Field

[0001] This application relates to the field of retaining structures and is an application of a new type of prestressed special vibration damping anchor rod that can realize vibration reduction and energy dissipation during prestressed tensioning. It is suitable for tunnel vibration reduction and energy dissipation scenarios and plays a significant role in protecting the surrounding rock and lining. Background Technology

[0002] After tunnel excavation, shotcrete and rock bolt support is one of the most commonly used support methods, applicable to both soil and rock tunnels. The supporting effect of this structure during tunnel use is undeniable. However, when faced with tunnel disasters that cause support failure, tunnel instability or even collapse can easily occur. my country experiences frequent earthquakes. During an earthquake, the reciprocating force of the earthquake causes the anchorage section of the anchor bolt to reciprocate with the soil, easily altering the prestress (tension) state of the original anchor bolt, turning it into a compressive state. This makes the anchor bolt highly susceptible to compressive fracture or even anchor failure, leading to the anchor bolt being forced out of the soil.

[0003] Current tunnel support systems often neglect the protection of anchor bolt support structures under seismic loads. Considering the prestressing characteristics of anchor bolts, current technologies typically employ simple spring or damping structures applied to the free section of the anchor bolt, without considering the application of prestress and the weakening of its performance. Chinese patent application 201911373495.1 simply places the damping structure within the anchor bolt body, dividing the free section into several segments. This fails to apply and transmit prestress, cannot provide timely support force during reciprocating motion, and cannot provide the anchor bolt's effective function under normal use. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this application provides a novel anchor structure for vibration reduction and energy dissipation.

[0005] The objective of this application can be achieved through the following technical solutions:

[0006] A novel tunnel vibration reduction and energy dissipation system utilizing prestressed special vibration damping anchors includes several prestressed special vibration damping anchors, a shotcrete wall 11, and several anchors 10, etc. Each prestressed special vibration damping anchor is arranged in a ring within the shotcrete wall 11, loose surrounding rock, and deep stable surrounding rock.

[0007] Each prestressed special vibration damping anchor is a new type of prestressed anchor structure with vibration damping and energy dissipation, including a vibration damping and energy dissipation free section 1 and an anchoring section 2; one end of the prestressed special vibration damping anchor is fixed to the sprayed concrete wall 11 by the anchor 10, and the other end is fixed in the deep stable surrounding rock by the anchor anchoring section 2.

[0008] Furthermore, the new tunnel vibration reduction and energy dissipation system also includes an arch frame 12, which is set at the top of the tunnel for supporting the tunnel; one end of the prestressed special vibration reduction anchor rod is fixed to the vibration reduction and energy dissipation free section 1 on the sprayed concrete wall 11 and the arch frame 12 through the anchor 10.

[0009] Specifically, the shock-absorbing and energy-dissipating free section 1 includes an anchor rod body 3 and a shock-absorbing and energy-dissipating device 4. There are one or more shock-absorbing and energy-dissipating devices 4, and the shock-absorbing and energy-dissipating device 4 is disposed on the anchor rod body 3.

[0010] The shock absorption and energy dissipation device 4 includes a protective shell 5, a shock absorption and energy dissipation spring 6, thin rods 7, and limiting rings 8. There are two thin rods 7, which are fixedly connected to the two ends of the shock absorption and energy dissipation spring 6, respectively. There are two limiting rings 8, which are fixedly connected to the two thin rods, respectively. Thus, the two limiting rings 8 are connected to the two ends of the shock absorption and energy dissipation spring 6 through the two thin rods and are limited to the inside of the protective shell 5. The protective shell 5 is a closed shell and has reserved holes 9 on the front and rear sides. The diameter of the reserved holes 9 is the same as that of the anchor rod body 3, and the protective shell 5 can be opened.

[0011] The anchor rod 3 passes through the reserved hole on the protective shell 5 of the shock absorption and energy dissipation device 4 and is fixedly connected to the limiting ring inside the protective shell.

[0012] Specifically, the prestressed special vibration damping anchor section 2 is anchored in deep stable soil by grouting, while the end of the free section 1 is anchored to the shotcrete wall 11 by the anchor 10.

[0013] The above technical solution, after the installation of dedicated vibration-damping anchors, has the following vibration-damping and energy-dissipating mechanism:

[0014] In the static stage, prestress is obtained by tensioning the free section of the rod 3; at the same time, the anchor rods, arch frame and shotcrete wall work together to provide internal pressure and support.

[0015] During an earthquake, the vibration of the soil around anchorage section 2 causes the anchor rod to move. At this time, the anchor rod is subjected to alternating tension and compression, and the shock-absorbing energy-dissipating spring undergoes alternating compression and tension. This not only protects the anchor rod from being crushed or pushed out of the soil, but also plays a role in shock absorption and energy dissipation. At the same time, the alternating compression and tension of the shock-absorbing energy-dissipating spring can also provide timely support to the surrounding rock (loose surrounding rock) during an earthquake.

[0016] Compared with the prior art, this application has the following advantages and beneficial effects:

[0017] 1. Structural vibration control and self-protection: The novel anchor structure for vibration reduction and energy dissipation of this application can separate the tension and compression states of the anchor. During tension and operation, the vibration reduction and energy dissipation device only serves to anchor and transmit tension. When an earthquake occurs, due to the reciprocating action of the earthquake, the entire anchor moves with the soil, which can easily lead to compression failure of the anchor and anchor failure, causing the anchor to be pushed out of the soil. In operation, when the anchor structure of this application is under compression, the vibration reduction and energy dissipation device plays a role, and the spring is compressed to prevent the entire anchor from being compressed and causing problems such as anchor protrusion failure. Moreover, the opening of the protective shell is small inside and large outside, and the anchor rod of the vibration reduction and energy dissipation free section can be bent when subjected to soil shear during an earthquake, thereby protecting the anchor from damage during the shear process and achieving the purpose of vibration reduction and energy dissipation.

[0018] 2. Energy dissipation effect: Seismic waves, carrying enormous energy, are transmitted to loosened bodies on the exposed surface of rock and soil, causing the loosened bodies to periodically move back and forth. The spring of the vibration damping and energy dissipation device of this application can dissipate part of the seismic energy.

[0019] 3. Spontaneous and proactive: The structure does not require external human intervention or complex algorithm control. It has the characteristic of spontaneously changing stiffness with external force and velocity, and actively works in response to earthquake action.

[0020] 4. Deformation adaptability: Under both static and dynamic conditions, it can coordinate with the deformation of loose soil and rock, optimize the force transmission of the anchor bolt under seismic action, and enhance the stability of the support.

[0021] 5. Small footprint: Compared with traditional active or semi-active structural vibration control technologies, this application does not require monitoring, calculation and control systems, and is compact in size.

[0022] 6. Integrated Static and Dynamic Vibration Reduction and Energy Dissipation: Compared with traditional energy dissipation and vibration reduction anchors, this application retains the prestressed tension properties of anchors, enabling the structure to perform its function under both static and dynamic loads. It has a simple structure, easy-to-understand principle, low technical threshold, and convenient construction. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the novel tunnel vibration reduction and energy dissipation system proposed in this application.

[0024] Figure 2 This is a schematic diagram of the vibration-damping and energy-dissipating anchor rod in the novel tunnel vibration-damping and energy-dissipating system of this application;

[0025] Figure 3 This is a schematic diagram of the anchor bolt vibration damping and energy dissipation device in the novel tunnel vibration damping and energy dissipation system of this application;

[0026] Figure 4 This is a schematic diagram of the anchor bolt under tension in this application;

[0027] Figure 5 This is a schematic diagram of the anchor bolt under compression in this application;

[0028] Figure 6 This is a schematic diagram of the anchor bolt subjected to shear displacement as described in this application.

[0029] Figure label:

[0030] Vibration damping and energy dissipation free section 1, anchoring section 2,

[0031] Anchor rod body 3, vibration damping and energy dissipation device 4

[0032] 5. Protective shell; 6. Shock-absorbing and energy-dissipating spring; 7. Thin rod; 8. Limiting ring; 9. Pre-drilled hole.

[0033] Anchor 10, shotcrete wall 11, arch frame 12. Detailed Implementation

[0034] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0035] Figure 1 The application scenarios of the tunnel support face shown are, from the inside out: the excavated tunnel, loose surrounding rock, and deep stable surrounding rock. The novel tunnel vibration reduction and energy dissipation system technology of this invention is applied to the support and safety of the tunnel after the tunnel excavation is completed.

[0036] A novel tunnel vibration reduction and energy dissipation system utilizing prestressed special vibration damping anchors includes several prestressed special vibration damping anchors, a shotcrete wall 11, an arch frame 12, and several anchors 10. Each prestressed special vibration damping anchor is arranged in a ring within the shotcrete wall 11, loose surrounding rock, and deep stable surrounding rock. The arch frame is a basic concept in tunnel construction, used to support the surrounding rock at the top of the tunnel, especially for surrounding rock with poor geological conditions. The main function of the arch frame is to share the surface load and ensure the stability and safety of the tunnel structure.

[0037] like Figure 2 As shown, each prestressed special vibration damping anchor is a new type of prestressed anchor structure with vibration damping and energy dissipation, including a vibration damping and energy dissipation free section 1 and an anchoring section 2; one end of the prestressed special vibration damping anchor is fixed to the sprayed concrete wall 11 and the arch frame 12 by the anchor 10, and the other end is fixed to the deep stable surrounding rock by the anchor anchoring section 2.

[0038] The vibration-damping and energy-dissipating free section 1 includes an anchor rod body 3 and a vibration-damping and energy-dissipating device 4. There are one or more vibration-damping and energy-dissipating devices 4, and each device is mounted on the anchor rod body 3. Wherein:

[0039] For example Figure 3As shown, the shock absorption and energy dissipation device 4 includes a protective shell 5, a shock absorption and energy dissipation spring 6, thin rods 7, and limiting rings 8. There are two thin rods 7, each fixedly connected to one end of the shock absorption and energy dissipation spring 6. There are two limiting rings 8, each fixedly connected to one of the two thin rods 7. Thus, the two limiting rings 8 are connected to both ends of the shock absorption and energy dissipation spring 6 via the two thin rods 7 and are confined within the protective shell 5. The protective shell 5 is a closed shell with pre-drilled holes 9 on both the front and rear sides. The diameter of the pre-drilled holes 9 is the same as that of the anchor rod body 3, and the protective shell 5 can be opened. The closed design of the protective shell prevents soil from entering the shell.

[0040] The anchor rod 3 passes through the reserved hole on the protective shell 5 of the shock absorption and energy dissipation device 4 and is fixedly connected to the limiting ring inside the protective shell.

[0041] Furthermore, the stiffness of the shock-absorbing and energy-dissipating spring 6 of the shock-absorbing and energy-dissipating device 4 is less than the stiffness of the anchor rod body 3.

[0042] During implementation, the anchor rod body 3 is fixedly connected to the limiting ring 8 inside the protective shell by welding or casting. After the shock-absorbing spring, thin rod, and limiting ring are fixedly connected, they are placed inside the protective shell, and the protective shell is locked. The anchor rod body then protrudes through the pre-drilled hole in the protective shell. In actual engineering, depending on the working conditions, one or more shock-absorbing and energy-dissipating devices can be installed on the free section of the anchor rod, and multiple repeated connections can form a shock-absorbing and energy-dissipating free section.

[0043] Furthermore, the prestressed special vibration damping anchor rod has its vibration damping and energy dissipation free section 1 end anchored to the surface of the sprayed concrete wall 11 through the anchor 10. The vibration damping and energy dissipation free section 1 is located in shallow rock and soil (loose surrounding rock), and the anchoring section 2 is anchored in deep stable rock and soil (deep stable surrounding rock) through grouting.

[0044] The working principle of the novel anchor structure for vibration reduction and energy dissipation in this application is as follows:

[0045] During normal operation, the anchor rod is pre-stressed due to pre-tensioning. The tension on the anchor rod 3 is transmitted to the adjacent section of the anchor rod 3 through the protective shell 5. At this time, the vibration damping and energy dissipation device does not participate in the operation. When the tension is applied, the limiting ring is located inside the protective shell, ensuring that the spring is not tensioned, thus guaranteeing the smooth application of the prestress in the anchor rod. Figure 4 As shown;

[0046] Under seismic activity or other factors, the anchorage section 2 of the anchor bolt reciprocates with the soil, or the anchor bolt is compressed due to internal pressure in the tunnel. At this time, the vibration damping and energy dissipation device 4 comes into play. Because the stiffness of the damping spring 6 in the vibration damping and energy dissipation device 4 is less than that of the anchor bolt body 3, the damping spring 6 in the vibration damping and energy dissipation device 4 is compressed first when compressed, preventing the anchor bolt from being damaged by pressure and the anchorage from failing. Figure 5 As shown.

[0047] Specifically, when under pressure, the anchor rod 3 transmits the force to the thin rod 7 through the limiting ring 8. The two thin rods 7 at both ends of the damping spring 6 squeeze the damping spring 6, thereby preventing the anchor rod from being damaged during the pressure process and achieving the purpose of damping and energy dissipation.

[0048] Furthermore, the opening of the protective shell 5 is smaller inside and larger outside, allowing the anchor rod body 3 of the shock-absorbing and energy-dissipating free section 1 to bend under soil shear during an earthquake, thus preventing the anchor rod from being damaged during shearing and achieving the purpose of shock absorption and energy dissipation. Figure 6 As shown.

[0049] The novel tunnel vibration reduction and energy dissipation system utilizing prestressed special vibration-damping anchors has the following vibration reduction and energy dissipation mechanism:

[0050] In the static stage, prestress is obtained by tensioning the free section of the rod 3; at the same time, the anchor rods, arch frame and shotcrete wall work together to provide internal pressure and support.

[0051] During an earthquake, the vibration of the soil around anchorage section 2 causes the anchor rod to move. At this time, the anchor rod is subjected to alternating tension and compression, and the shock-absorbing energy-dissipating spring undergoes alternating compression and tension. This not only protects the anchor rod from being crushed or pushed out of the soil, but also plays a role in shock absorption and energy dissipation. At the same time, the alternating compression and tension of the shock-absorbing energy-dissipating spring can also provide timely support to the surrounding rock (loose surrounding rock) during an earthquake.

[0052] Example:

[0053] Step (1): Prefabricate and assemble anchor rods: According to the engineering design requirements, determine the length of the anchoring section 3, the anchor rod body 3 of the shock-absorbing and energy-dissipating free section 2, and the shock-absorbing and energy-dissipating device 4. Determine the dimensions of the protective shell 5, shock-absorbing spring 6, thin rod 7 and limiting ring 8 of the shock-absorbing and energy-dissipating device 4, and assemble the anchor rods according to the above prestressed anchor rod structure.

[0054] Step (2): Laying out and positioning: Laying out lines on the tunnel according to the design requirements, positioning the anchor bolts and drilling holes;

[0055] Step (3): Install the prefabricated anchor rod from step (1) into the borehole;

[0056] Step (4): Grouting: Insert the grouting pipe into the borehole and begin grouting the anchoring section;

[0057] Step (5): Apply prestress and anchor: After the grouting of the anchoring section has completely solidified, apply prestress to the end of the free section and anchor it through anchor 10;

[0058] Step (6): Construct the anchor bolts 1 for the next working face according to steps (2), (3), (4), and (5) until all support construction is completed. (Alternatively, the tensioned anchor bolts can be welded to the arch frame.)

[0059] This application separates the tension and compression states of the anchor rod. During tension and working states, the vibration damping and energy dissipation device only serves to anchor and transmit tension. When an earthquake occurs, the anchor rod structure is in operation and under compression. The vibration damping and energy dissipation device then comes into play, and the spring is compressed to prevent the anchor rod from being compressed as a whole and causing problems such as anchor rod protrusion failure.

[0060] During an earthquake, the anchor structure in this application:

[0061] ① It can ensure the support function when the anchor bolts are working normally, and play a role in suspension, internal pressure and arching in tunnel support to prevent tunnel collapse and subsidence;

[0062] ② It can also ensure the reciprocating action of the earthquake. As the anchor section moves with the soil, the anchor rod will not be crushed or crushed out of the soil due to anchor failure.

[0063] ③At the same time, as the soil moves back and forth, the anchor bolt can switch between tension and compression states in a timely manner, providing timely support for the tunnel;

[0064] ④ The reciprocating motion of the spring in the vibration damping and energy dissipation device within the same cross-section also plays a role in vibration damping and energy dissipation.

[0065] The above description is merely a description of preferred embodiments of this application and is not intended to limit the scope of this application in any way. Any changes or modifications made by those skilled in the art based on the above-disclosed technical content should be considered as equivalent and valid embodiments and fall within the scope of protection of the technical solution of this application.

Claims

1. A new type of tunnel shock absorption and energy dissipation system implemented by using prestressed special shock absorption anchor rods, characterized in that, It includes several prestressed special damping anchor rods, shotcrete wall (11), and several anchors (10). Each prestressed special damping anchor rod is arranged in a ring within the shotcrete wall, loose surrounding rock, and deep stable surrounding rock. Each prestressed special vibration damping anchor is a novel prestressed anchor structure for vibration damping and energy dissipation, including a vibration damping and energy dissipation free section (1) and an anchoring section (2); one end of the prestressed special vibration damping anchor is fixed to the sprayed concrete wall (11) by an anchor (10), and the other end is fixed to the deep stable surrounding rock by the anchoring section (2); wherein the vibration damping and energy dissipation free section (1) includes an anchor rod body (3) and a vibration damping and energy dissipation device (4), and there are one or more vibration damping and energy dissipation devices (4), which are installed on the anchor rod body (3); wherein: The shock absorption and energy dissipation device (4) includes a protective shell (5), a shock absorption and energy dissipation spring (6), thin rods (7), and limiting rings (8); there are two thin rods (7), which are fixedly connected to the two ends of the shock absorption and energy dissipation spring (6); there are two limiting rings (8), which are fixedly connected to the two thin rods (7); thus, the two limiting rings (8) are connected to the two ends of the shock absorption and energy dissipation spring (6) through the two thin rods (7) and are limited to the inside of the protective shell (5); the protective shell (5) is a closed shell and has reserved holes (9) on the front and rear sides. The diameter of the reserved holes (9) is the same as that of the anchor rod body (3), and the protective shell (5) can be opened; The anchor rod (3) passes through the reserved hole on the protective shell (5) of the shock absorption and energy dissipation device (4) and is fixedly connected to the limiting ring inside the protective shell; Each prestressed special damping anchor is a new type of prestressed anchor structure with damping and energy dissipation working principle as follows: During normal operation, the anchor rod is prestressed due to the pre-tensioning of the anchor rod body. The tension on the anchor rod body (3) is transmitted to the adjacent section of the anchor rod body (3) through the protective shell (5). At this time, the shock absorption and energy dissipation device does not participate in the work. When the tension is applied, the spring is not tensioned because the limiting ring is located inside the protective shell, thus ensuring the smooth application of the prestress of the anchor rod body. Under the influence of ground motion or other factors, the anchor section (2) of the anchor rod moves back and forth with the soil, or the anchor rod is compressed due to the internal pressure of the tunnel. At this time, the shock absorption and energy dissipation device (4) participates in the work. Since the stiffness of the shock absorption and energy dissipation spring (6) of the shock absorption and energy dissipation device (4) is less than that of the anchor rod (3), the shock absorption and energy dissipation spring (6) in the shock absorption and energy dissipation device (4) is compressed first when compressed, so as to avoid the anchor rod being damaged by pressure and the anchor failure. The vibration damping energy dissipation mechanism is as follows: In the static stage, prestress is obtained by tensioning the free section of the rod (3); at the same time, the anchor rods and the arch frame and the shotcrete wall work together to provide internal pressure and support. During an earthquake, the vibration of the soil around the anchor section (2) causes the anchor rod to move. At this time, the anchor rod is subjected to alternating tension and compression, and the shock-absorbing energy-dissipating spring undergoes alternating compression and tension. This not only protects the anchor rod from being crushed or pushed out of the soil, but also plays a role in shock absorption and energy dissipation. At the same time, the alternating compression and tension of the shock-absorbing energy-dissipating spring can also provide timely support to the loose surrounding rock during an earthquake.

2. The novel tunnel vibration reduction and energy dissipation system according to claim 1, characterized in that, The new tunnel vibration reduction and energy dissipation system also includes an arch frame (12), which is set at the top of the tunnel for tunnel support; One end of the prestressed special shock-absorbing anchor rod is fixed to the shock-absorbing and energy-dissipating free section (1) on the sprayed concrete wall (11) and the arch frame (12) by the anchor (10).

3. The novel tunneling shock dissipating energy system of claim 2, wherein, The stiffness of the shock-absorbing energy-dissipating spring (6) of the shock-absorbing energy-dissipating device (4) is less than the stiffness of the anchor rod (3).

4. The novel tunnel vibration reduction and energy dissipation system according to claim 1, characterized in that, The end of the shock-absorbing and energy-dissipating free section (1) is anchored to the surface of the sprayed concrete wall (11) by the anchor (10). The shock-absorbing and energy-dissipating free section (1) is located in the shallow rock and soil body, and the anchoring section (2) is anchored to the deep stable rock and soil body by the grouting body.

5. The novel tunnel vibration reduction and energy dissipation system according to claim 1, characterized in that, When under pressure, the anchor rod (3) transmits the force to the thin rod (7) through the limiting ring (8). The two thin rods (7) at both ends of the shock-absorbing and energy-dissipating spring (6) squeeze the shock-absorbing and energy-dissipating spring (6), thereby preventing the anchor rod from being damaged during the pressure process and achieving the purpose of shock absorption and energy dissipation.

6. The novel tunnel vibration reduction and energy dissipation system according to claim 1, characterized in that, The opening of the protective shell (5) is small inside and large outside. The shock-absorbing and energy-dissipating free section (1) and the anchor rod body (3) can be bent when subjected to soil displacement and shearing during an earthquake, thereby avoiding the anchor rod being damaged during shearing and achieving the purpose of shock absorption and energy dissipation.

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