Municipal road foundation pit safety protection device

Abstract

The application discloses a municipal road foundation pit safety protection device, and relates to the technical field of foundation pit safety protection equipment, which comprises a foundation pit surface, a protection frame and a base body arranged at the bottom of the protection frame. The base body comprises fastening assemblies. The fastening assemblies are arranged in multiple groups. The fastening assemblies comprise a self-tightening cavity extending axially and an ejection channel extending obliquely which are arranged in the base body. The one-way locking cooperation formed by the inner and outer ratchet groups in the fastening assemblies converts the continuous traffic microseismic energy around the foundation pit into the progressive expansion anchoring force of the conventional anchoring pin on the soil body, realizes the self-adaptive step-by-step enhancement of the anchoring force, effectively prevents the loosening of the device due to the foundation vibration in the long-term use process, and improves the long-term stability of the protection device.

Description

Technical Field

[0001] This invention relates to the field of foundation pit safety protection equipment technology, specifically a municipal road foundation pit safety protection device. Background Technology

[0002] Excavation of foundation pits is a common construction operation in municipal road construction and various building projects. To ensure the safety of construction workers and prevent pedestrians and materials from accidentally falling into the pit, safety protection devices are usually installed at the edge of the pit. Currently, common foundation pit safety protection devices mainly consist of a protective frame and a base. The base is fixed to the soil surface at the edge of the pit by fasteners such as anchor pins, and the protective frame stands on top of the base to form a protective barrier.

[0003] In existing technologies, anchoring methods are mostly passive, where anchor pins are driven into the soil and rely on static friction and simple barbed structures to maintain anchoring force. However, during foundation pit construction, construction vehicles and pedestrians continuously pass through the surrounding roads, and the resulting micro-vibrations from traffic repeatedly act on the anchoring structure, causing the anchor pins to gradually loosen from the surrounding soil. The anchoring force weakens over time, affecting the overall stability of the protective device. Although some existing technologies incorporate simple anti-settlement structures in the base, they lack a self-locking mechanism to convert external vibration energy into anchoring reinforcement, failing to achieve adaptive maintenance of the anchoring force. Furthermore, the existing protective devices provide purely passive protection, relying solely on the physical barrier of the protective frame to prevent personnel and materials from falling into the foundation pit. When a collapse occurs at the edge of the foundation pit, the base slides towards the pit along with the collapsed soil, causing the protective frame to tilt or shift, resulting in the instantaneous failure of the original protective barrier and making it impossible to establish a new protective barrier after the accident. Summary of the Invention

[0004] The purpose of this invention is to provide a safety protection device for municipal road foundation pits to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a safety protection device for a municipal road foundation pit, comprising a foundation pit surface, a protective frame, and a base body disposed at the bottom of the protective frame. The base body includes fastening components, which are configured in multiple sets. Each fastening component includes a self-tightening cavity extending axially and an ejection channel extending obliquely along the interior of the base body. The self-tightening cavity is equipped with a conventional anchoring pin that penetrates vertically into the soil and an inertial wedge block that is connected to the conventional anchoring pin. The inner wall of the self-tightening cavity and the outer periphery of the inertial wedge block are respectively provided with interlocking inner ratchet groups and outer ratchet groups. The inner and outer ratchet groups are used to limit the inertial wedge block to move unidirectionally into the depth and prevent it from sliding back in the opposite direction. They are used to convert external traffic micro-vibrations into conventional expansion force of the conventional anchoring pin on the soil.

[0006] Preferably, the ejection channel is equipped with an arc-shaped anchoring pin that is oriented towards the side away from the pit, and a burst energy accumulator for driving the arc-shaped anchoring pin to be ejected. The base body is connected to a displacement difference trigger cable at the bottom rear. The far end of the displacement difference trigger cable is fixed in deep stable soil away from the edge of the foundation pit, and the near end extends into the base body and is connected to the release linkage installed on the side of the burst accumulator.

[0007] Preferably, the top of the protective frame houses a hanging net roll, one end of which is connected to an arc-shaped anchor pin via a steel wire rope. When the collapse of the foundation pit causes displacement of the base body, the displacement difference trigger cable is tightened and the release linkage is pulled to drive the burst accumulator to fire, ejecting the arc-shaped anchoring pin into the deep stable soil, which is used to achieve self-anchoring of the unstable suspension of the protective frame and the suspension net roll.

[0008] Compared with the prior art, the beneficial effects of the present invention are: In this invention, the unidirectional locking mechanism formed by the inner and outer ratchet groups in the fastening assembly converts the continuous traffic micro-vibration energy around the foundation pit into a progressive tightening anchoring force on the soil using conventional anchoring pins. This achieves adaptive, step-by-step enhancement of the anchoring force, effectively preventing the device from loosening due to ground vibration during long-term use and improving the long-term stability of the protective device. Simultaneously, through the precise linkage between the displacement-triggered cable and the release link, when the foundation pit collapses and causes displacement of the base body, the accumulator is automatically triggered to fire, propelling the arc-shaped anchoring pin into the deep, stable soil at high speed. Simultaneously, the suspension net roll is unfurled via the steel wire rope, forming a suspended protective system with the deep, stable soil as the anchor point. This effectively intercepts falling personnel and objects, preventing them from falling into the foundation pit. The entire device requires no external energy supply and exhibits good adaptability and high reliability in field construction environments due to the installed triggering structure. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the main structure in this invention; Figure 2 This is a schematic diagram of the main body of the present invention from another angle; Figure 3This is a schematic diagram of the steel wire rope structure in this invention; Figure 4 This is a schematic diagram of the structure of the base body in this invention; Figure 5 This is a schematic diagram showing the structural separation of the fastening assembly in this invention; Figure 6 This is a schematic diagram of the installation position structure of the transfer ring in this invention; Figure 7 In this invention Figure 4 A magnified structural diagram at point A; Figure 8 This is a schematic diagram showing the state comparison of the fastening components in this invention; Figure 9 This is a schematic diagram comparing the suspended net roll in its normal state and unfolded state in this invention.

[0010] In the diagram: 100, pit surface; 200, protective frame; 210, suspended net roll; 220, steel wire rope; 300, base body; 310, side seat; 320, fastening assembly; 321, self-tightening cavity; 322, position groove; 323, inner ratchet group; 324, outer ratchet group; 325, inertial wedge block; 326, elastic element; 327, conventional anchor pin; 328, rotating pin head; 329, swivel ring; 330, ejection channel; 331, elastic plate groove; 332, arc-shaped anchor pin; 340, displacement difference trigger cable; 350, flange joint; 360, frame; 370, release linkage; 380, explosive accumulator. Detailed Implementation

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] Reference Figures 1-3 As shown: A safety protection device for a municipal road foundation pit includes a foundation pit surface 100, a protective frame 200, and a base body 300 disposed at the bottom of the protective frame 200.

[0013] In this embodiment, the protective frame 200 is a rectangular or square frame structure, composed of multiple horizontal and vertical bars welded or bolted together, and stands vertically or slightly inclined on the soil surface at the edge of the foundation pit. The bottom of the protective frame 200 is fixedly connected to the base body 300, which lies flat on the soil surface at the edge of the foundation pit to transfer the weight of the protective frame 200 and the impact load to the foundation soil. The foundation pit surface 100 is the original soil surface at the edge of the foundation pit to be protected. Multiple sets of protective frames 200 are continuously arranged along the edge of the foundation pit, and adjacent protective frames 200 are connected to each other by connecting fasteners or steel wire ropes to form a continuous protective barrier extending along the edge of the foundation pit, preventing personnel and materials from accidentally falling into the foundation pit.

[0014] according to Figure 4 , Figure 5 and Figure 8 As shown, the base body 300 includes a fastening assembly 320, which is configured in multiple groups. The fastening assembly 320 includes a self-tightening cavity 321 extending axially along the inside of the base body 300 and an ejection channel 330 extending obliquely. The self-tightening cavity 321 has a conventional anchoring pin 327 that penetrates vertically into the soil and an inertial wedge block 325 that is connected to the conventional anchoring pin 327. The inner wall of the self-tightening cavity 321 and the outer periphery of the inertial wedge block 325 are respectively provided with an inner ratchet group 323 and an outer ratchet group 324 that interlock with each other. The inner ratchet group 323 and the outer ratchet group 324 are used to limit the inertial wedge block 325 to move unidirectionally into the depth and prevent it from sliding backward. They are used to convert the external traffic micro-vibration into the conventional expansion force of the conventional anchoring pin 327 on the soil.

[0015] In this embodiment, multiple sets of fastening components 320 are evenly arranged along the length of the base body 300. Each set of fastening components 320 works independently, together anchoring the base body 300 to the soil at the edge of the foundation pit. The self-tightening cavity 321 is a vertical cylindrical cavity opened inside the base body 300, with its axis perpendicular to the bottom surface of the base body 300. The self-tightening cavity 321 penetrates the base body 300 and extends into the soil below.

[0016] like Figure 5As shown, the conventional anchoring pin 327 is a slender cylindrical pin with an elastic element 326 fitted on its exterior. Multiple elastic expansion rings or expansion claws can be installed at the bottom of the elastic element 326 as needed. When the conventional anchoring pin 327 is subjected to axial thrust, the expansion claws at its bottom open radially outward and embed into the surrounding soil, forming a reliable anchoring force. The inertial wedge block 325 is movably embedded inside the self-tightening cavity 321, its top abutting against the upper end of the conventional anchoring pin 327 via a wedge-shaped inclined surface. When external vehicles pass over the road surface around the pit, the micro-vibrations generated on the ground are transmitted to the base body 300, and then to the inertial wedge block 325, causing a slight downward displacement of the inertial wedge block 325 within the self-tightening cavity 321. This downward displacement is converted into a radial tightening force on the conventional anchoring pin 327 through the wedge-shaped inclined surface, causing the expansion claws of the conventional anchoring pin 327 to further expand into the soil, achieving automatic enhancement of the anchoring force.

[0017] Furthermore, such as Figure 5 As shown, the inner ratchet group 323 consists of multiple unidirectional ratchets distributed circumferentially along the inner wall of the self-tightening cavity 321, with each ratchet inclined towards the depth of the self-tightening cavity 321. The outer ratchet group 324 consists of multiple unidirectional ratchets correspondingly arranged along the outer periphery of the inertial wedge block 325, with each ratchet inclined in the opposite direction to the inner ratchet group 323. When the inertial wedge block 325 moves downward, the inclined surface of the ratchet in the outer ratchet group 324 slides along the inclined surface of the ratchet in the inner ratchet group 323, allowing the inertial wedge block 325 to move downward smoothly. However, when the inertial wedge block 325 is subjected to an upward counter-thrust, the ratchets of the outer ratchet group 324 and the ratchets of the inner ratchet group 323 jam against each other, preventing the inertial wedge block 325 from sliding backward, ensuring that the conventional anchoring pin 327 always maintains a tightened anchoring state to the soil, effectively utilizing the continuous traffic micro-vibration energy around the foundation pit to enhance the anchoring stability of the device.

[0018] It should be noted that, as Figure 8 As shown, L1 represents the normal installation state, while L2 represents the state where the inertial wedge block 325 moves downward, causing the conventional anchor pin 327 to move deeper into the foundation pit.

[0019] according to Figure 4 and Figure 7 As shown, the ejection channel 330 is equipped with an arc-shaped anchoring pin 332 that is directionally launched towards the side away from the foundation pit, and an explosive accumulator 380 for driving the arc-shaped anchoring pin 332 to be launched; a displacement difference trigger cable 340 is connected to the rear bottom of the base body 300. The distal end of the displacement difference trigger cable 340 is fixed in the deep stable soil away from the edge of the foundation pit, and the proximal end extends into the base body 300 and is connected to the release link 370 installed on the side of the explosive accumulator 380.

[0020] In this embodiment, as Figure 3As shown, the ejection channel 330 is an oblique through-hole opened inside the base body 300, which can extend upward or downward. In this design, it extends downward. One end of the ejection channel 330 opens on the outer wall of the base body 300 facing away from the pit, and the other end extends into the interior of the base body 300 and connects to the installation chamber of the explosive accumulator 380. The arc-shaped anchoring pin 332 has an overall arc-shaped curved rod structure, with a sharp front end and barbs or hooks, and a lug or ring for attaching a wire rope at the tail end.

[0021] The arc-shaped anchor pin 332 is pre-filled inside the ejection channel 330, with its front end facing the launch port of the ejection channel 330. The burst accumulator 380 is fixedly installed inside the base body 300, located at the rear end of the ejection channel 330. Its energy release end directly abuts against the tail of the arc-shaped anchor pin 332, used to eject the arc-shaped anchor pin 332 out of the ejection channel 330 at high speed at the moment of triggering. The displacement difference trigger cable 340 is a high-strength flexible cable made of steel wire rope or high-strength fiber rope.

[0022] Furthermore, the distal end of the displacement differential trigger cable 340 is firmly fixed to the interior of deep, stable soil 3 to 10 meters away from the edge of the pit by pre-embedded anchors. This deep, stable soil will not shift during a pit collapse. The proximal end of the displacement differential trigger cable 340 extends into the base body 300 and is fixedly connected to the release link 370 installed on the side of the explosive accumulator 380. The release link 370 is a lever-type component that can rotate around a fulcrum. One end of it is connected to the displacement differential trigger cable 340, and the other end abuts against the trigger mechanism of the explosive accumulator 380.

[0023] When the base body 300 collapses and displaces along with the soil at the edge of the pit, the displacement difference triggers the near end of the cable 340 to move synchronously with the base body 300, while the far end remains stationary in the stable soil. The displacement difference between the two triggers the cable 340 to tighten, which in turn pulls the release link 370 to rotate, triggering the burst accumulator 380 to release energy instantaneously.

[0024] according to Figure 2 , Figure 3 , Figure 9 As shown, the top of the protective frame 200 houses a suspended net roll 210. One end of the suspended net roll 210 is connected to the arc-shaped anchor pin 332 via a steel wire rope 220. When the foundation pit collapses and causes the base body 300 to shift, the displacement difference triggers the tension cable 340 to be tightened and drives the burst accumulator 380 to be fired by pulling the release link 370, which ejects the arc-shaped anchor pin 332 into the deep stable soil, thereby achieving self-anchoring of the protective frame 200 and the suspended net roll 210 in case of instability.

[0025] In this embodiment, the suspended net roll 210 is a flexible protective net roll that is pre-folded or rolled up and stored in the inner space of the top of the protective frame 200. The suspended net roll 210 is woven from high-strength synthetic fibers and has sufficient tensile strength and impact toughness. One end of the suspended net roll 210 is fixedly connected to the inner horizontal bar at the top of the protective frame 200, and the other end extends and is fixedly connected to one or more steel wire ropes 220. The free end of the steel wire rope 220 passes through the side guide hole of the protective frame 200 and extends downward, and finally is fixedly connected to the lug or ring at the end of the arc-shaped anchor pin 332.

[0026] Under normal use, the wire rope 220 is in a slack state, and the hanging net roll 210 is kept folded and retracted, without occupying the working space at the edge of the pit.

[0027] When a collapse occurs at the edge of the foundation pit, the base body 300 slides and displaces towards the foundation pit along with the collapsed soil. The displacement difference triggers the cable 340 to be tightened instantly, pulling the release link 370 to trigger the burst accumulator 380 to fire, and the arc-shaped anchor pin 332 is launched at high speed along the ejection channel 330 into the deep stable soil away from the foundation pit.

[0028] After the arc-shaped anchor pin 332 is driven into the stable soil, the barbs or hooks at its front end quickly open and anchor deep into the stable soil. As the base body 300 continues to slide towards the pit, the originally slack steel wire rope 220 is gradually straightened. When the steel wire rope 220 is fully taut, the arc-shaped anchor pin 332 applies tension to the free end of the suspended net roll 210 through the steel wire rope 220, pulling the suspended net roll 210 out from the inside of the top of the protective frame 200 and unfolding it.

[0029] Ultimately, the protective frame 200 and the unfolded suspended net roll 210 together form a suspended protection system with the arc-shaped anchoring pin 332 as the deep anchor point and the protective frame 200 as the edge support, effectively intercepting falling personnel and objects and preventing them from falling into the foundation pit. Figure 9 As shown, W1 represents the state where the suspended net roll 210 is folded and retracted inside the top of the protective frame 200 under normal use, W2 represents the state where the suspended net roll 210 is pulled out and covers the edge of the pit after a collapse accident, and H is a schematic diagram of the structure of the suspended net roll 210 after it is unfolded.

[0030] It should be noted that the orientation of the suspended net roll 210 and the base body 300 of the overall device can be adjusted according to the installation requirements of the foundation pit.

[0031] according to Figure 5 and Figure 6As shown, the fastening assembly 320 further includes: a sliding block rotatably connected to the bottom end of the inertial wedge block 325, and a rotating ring 329 rotatably connected to the gap connection end between the inertial wedge block 325 and the sliding block; an elastic element 326, which is sleeved on the outside of the conventional anchor pin 327, the top end of the elastic element 326 is connected to the bottom of the sliding block, and the bottom end of the elastic element 326 is connected to the bottom end of the frame 360 ​​of the base body 300; a position groove 322 is provided on the inner wall surface of the self-tightening cavity 321, the position groove 322 is slidably connected to the sliding block, and a rotating pin head 328 is installed on the top of the conventional anchor pin 327. The rotating pin head 328 is used to drive the conventional anchor pin 327 to rotate, so that the inner ratchet group 323 and the outer ratchet group 324 disengage.

[0032] In this embodiment, as Figure 6 As shown, the sliding block has a disc-shaped or annular block structure, and its outer periphery is slidably engaged with the position groove 322 opened on the inner wall of the self-tightening cavity 321. The sliding block is located below the inertia wedge block 325, and the two are rotatably connected by a rotating ring 329. The rotating ring 329 is an annular rotating connector, with its inner ring fixedly connected to the lower end of the inertia wedge block 325 and its outer ring rotatably connected to the upper end of the sliding block, so that the inertia wedge block 325 can rotate freely relative to the sliding block about the vertical axis.

[0033] The elastic element 326 is a helical compression spring, such as Figure 5 As shown, the top end of the elastic element 326 abuts against the lower end face of the sliding block, and the bottom end of the elastic element 326 abuts against the bottom end face inside the frame 360 ​​of the base body 300, which is sleeved on the outside of the conventional anchor pin 327.

[0034] When the inertial wedge block 325 moves downward under the action of traffic micro-vibrations, the sliding block moves downward synchronously and compresses the elastic element 326. After the external load is removed, the elastic force of the elastic element 326 pushes the sliding block and the inertial wedge block 325 upward to reset. The position groove 322 is a vertical guide groove opened longitudinally along the inner wall of the self-tightening cavity 321. The outer peripheral protrusion of the sliding block is embedded in the position groove 322, so that the sliding block can only slide in the vertical direction and cannot rotate.

[0035] A rotating pin head 328 is located on top of the conventional anchor pin 327. The upper surface of the rotating pin head 328 has a specially designed polygonal or multi-faceted wrench socket, allowing the operator to rotate the rotating pin head 328 using a dedicated wrench, causing the conventional anchor pin 327 to rotate around its own axis by a certain angle. When the conventional anchor pin 327 rotates, the wedge-shaped inclined surface engagement between its top and the inertial wedge block 325 changes, causing the meshing relationship between the inner ratchet group 323 and the outer ratchet group 324 to disengage, releasing the one-way locking state. This design allows operators to easily release the anchor lock by rotating the rotating pin head 328 with a simple tool after the foundation pit construction is completed or when the protective device needs to be removed. This enables the conventional anchor pin 327 to be pulled out of the soil, facilitating the rapid recovery and reuse of the device. It should be noted that when the conventional anchor pin 327 rotates, the spline or transmission key on the outer circumference of the upper end of the conventional anchor pin 327, along with the corresponding keyway on the inner circumference of the inertial wedge block 325, causes the inertial wedge block 325 to rotate synchronously at a certain angle. This causes the ratchet teeth of the outer ratchet group 324 and the ratchet teeth of the inner ratchet group 323 to misalign and disengage in the circumferential direction, thus releasing the one-way locking state.

[0036] according to Figure 4 As shown, the base body 300 also includes a side seat 310, which is symmetrically installed on both sides of the frame 360 ​​along the central axis of the frame 360. A flange joint 350 is installed on the side end of the side seat 310. An elastic plate groove 331 is opened on the surface of the ejection channel 330. The bottom end of the steel wire rope 220 and the end of the arc-shaped anchor pin 332 are connected. After the steel wire rope 220 is pulled by the arc-shaped anchor pin 332, it is used to slide the elastic plate groove 331.

[0037] In this embodiment, the frame 360 ​​is the central load-bearing structure of the base body 300, and is welded from high-strength steel profiles. Two side seats 310 are symmetrically fixed on the left and right sides of the frame 360, respectively. The bottom surface of the side seats 310 is flush with the bottom surface of the frame 360, together forming the bottom support surface of the base body 300. This increases the contact area between the base body 300 and the ground, reduces the foundation contact pressure, and prevents excessive settlement of the base body 300 under vertical loads.

[0038] The flange joint 350 is a connection interface located on the side of the side seat 310. It is used to connect adjacent base bodies 300 in series with each other by bolts or pins, so that multiple protective devices arranged along the edge of the pit can form an overall force-bearing group, or be installed separately inside the pit.

[0039] The surface of the ejection channel 330, that is, the periphery of the launch port where the ejection channel 330 connects to the outside of the base body 300, is provided with an elastic plate groove 331. The elastic plate groove 331 is an arc-shaped groove distributed around the circumference of the launch port of the ejection channel 330. An elastic metal plate or an elastic sealing plate is embedded in the elastic plate groove 331 to close the launch port of the ejection channel 330 when the arc-shaped anchor pin 332 is in the ready-to-launch state, so as to prevent soil particles or debris from falling into the ejection channel 330 and causing blockage.

[0040] When the arc-shaped anchor pin 332 is ejected, the elastic plate in the elastic plate groove 331 is pushed open by the tail of the arc-shaped anchor pin 332, allowing the wire rope 220 to slide smoothly along the elastic plate groove 331, ensuring that the wire rope 220 is not blocked during the tightening process.

[0041] The bottom end of the wire rope 220 is fixedly connected to the lug or buckle at the tail of the arc-shaped anchor pin 332 via a tie ring. The middle section of the wire rope 220 passes through the elastic plate groove 331 and extends upward to the suspended net roll 210 at the top of the protective frame 200. After the arc-shaped anchor pin 332 is ejected, it drives the wire rope 220 to slide and pull in the elastic plate groove 331, thereby unfolding the suspended net roll 210. When the wire rope 220 is fully taut, the arc-shaped anchor pin 332 applies a traction force towards the pit to the free end of the suspended net roll 210 through the wire rope 220, pulling the suspended net roll 210 out from the inside of the top of the protective frame 200 towards the pit and unfolding it, so that the suspended net roll 210 covers the edge of the pit.

[0042] according to Figure 5 As shown, the inertial wedge block 325 and the conventional anchor pin 327 are connected by a wedge-shaped inclined surface. When the inertial wedge block 325 moves deeper along the self-tightening cavity 321 under the action of traffic micro-vibration, it drives the conventional anchor pin 327 to expand radially through the wedge-shaped inclined surface.

[0043] In this embodiment, the lower end face of the inertial wedge block 325 is set as a first wedge-shaped inclined surface. The first wedge-shaped inclined surface gradually slopes downward from the center of the inertial wedge block 325 to the outer periphery. The upper end face of the conventional anchoring pin 327 is set as a second wedge-shaped inclined surface with the inclination direction opposite to that of the first wedge-shaped inclined surface. The first wedge-shaped inclined surface and the second wedge-shaped inclined surface fit and abut against each other.

[0044] When the inertial wedge block 325 is excited by external traffic micro-vibration, the inertial wedge block 325 will generate a small downward displacement relative to the base body 300 due to its own inertia. The first wedge-shaped inclined surface slides along the second wedge-shaped inclined surface, converting the vertical downward movement of the inertial wedge block 325 into a radial outward pushing force on the conventional anchor pin 327.

[0045] Under the radial thrust generated by the conventional anchoring pin 327, the multiple expanding claws or elastic expansion rings at the bottom of the elastic element 326 overcome the soil resistance and open radially in all directions, embedding into the surrounding soil to form an anchoring force.

[0046] When traffic micro-vibrations disappear or the downward displacement of the inertial wedge block 325 stops, due to the unidirectional locking effect of the inner ratchet group 323 and the outer ratchet group 324, the inertial wedge block 325 cannot return to its upward position. Therefore, the radial expansion of the conventional anchoring pin 327 is maintained, and the anchoring force continues to exist. As the traffic micro-vibrations continue to accumulate, the inertial wedge block 325 gradually moves downward, the radial expansion of the conventional anchoring pin 327 gradually increases, and the anchoring force gradually strengthens, achieving an adaptive, progressive anchoring effect.

[0047] according to Figure 7 As shown, the burst accumulator 380 is a compression spring accumulator or a compressed gas accumulator. The release end of the burst accumulator 380 abuts against the tail of the arc-shaped anchor pin 332. The release connecting rod 370 passes through the trigger hole of the burst accumulator 380 and is fixedly connected to the proximal end of the displacement difference trigger cable 340.

[0048] In this embodiment, when the burst accumulator 380 adopts a compression spring accumulator, it contains one or more sets of powerful compression springs. One end of the powerful compression spring is fixed to the rear end of the accumulator housing, and the other end is connected to the firing push rod of the accumulator. The front end of the firing push rod is the release end, which tightly abuts against the tail of the arc-shaped anchor pin 332. In the ready-to-fire state, the compression spring is compressed to its shortest state by the locking mechanism inside the accumulator, storing a large amount of elastic potential energy. The release link 370 is L-shaped or straight. One end of it passes through the trigger hole of the burst accumulator 380 and abuts against the release claw of the locking mechanism. The other end extends to the outside of the base body 300 and is fixedly connected to the proximal end of the displacement difference trigger cable 340. When the displacement difference trigger cable 340 is tightened, the cable pulls the release link 370 to rotate around its hinge point. The inner end of the release link 370 pushes the release claw, releasing the lock on the compression spring. The compressed spring instantly releases its elastic potential energy, propelling the firing push rod forward at high speed. The release end of the firing push rod violently strikes the tail of the arc-shaped anchor pin 332, ejecting the arc-shaped anchor pin 332 out of the ejection channel 330 at high speed.

[0049] When the burst accumulator 380 uses a compressed gas accumulator, it is filled with high-pressure inert gas and sealed by a diaphragm or piston. When the release rod 370 is triggered, it punctures the diaphragm or opens the valve, releasing the high-pressure gas instantly and driving the piston to push the arc-shaped anchor pin 332 out.

[0050] Therefore, installation can be carried out based on the actual construction situation and construction cost.

[0051] according to Figures 1-3As shown, the bottom of the base body 300 is provided with an anti-settlement base plate. The anti-settlement base plate has a guide hole for the conventional anchor pin 327 to pass through. A sealing sleeve is provided in the guide hole to prevent soil particles from entering the self-tightening cavity 321.

[0052] In this embodiment, the anti-settlement base plate is a large-area steel plate or engineering plastic plate fixedly installed at the bottom of the base body 300. Its planar dimensions are larger than the bottom outline dimensions of the base body 300. It is used to disperse the vertical pressure transmitted from the base body 300 to the foundation soil and reduce the amount of foundation settlement.

[0053] Multiple guide holes are formed on the anti-settlement base plate corresponding to the self-tightening cavity 321. The guide holes are coaxially arranged with the self-tightening cavity 321, and the diameter of the guide holes is slightly larger than the outer diameter of the conventional anchor pin 327, allowing the conventional anchor pin 327 to pass through the guide holes and be vertically inserted into the soil below. A sealing sleeve is fixedly installed on the inner wall of the guide hole. The sealing sleeve is made of wear-resistant rubber or polyurethane material, and its inner diameter forms an interference fit with the outer diameter of the conventional anchor pin 327. The upper end of the sealing sleeve is sealed to the lower opening of the self-tightening cavity 321, and the lower end is flush with the lower surface of the anti-settlement base plate.

[0054] When the conventional anchor pin 327 slides up and down in the guide hole, the sealing sleeve tightly fits the outer surface of the conventional anchor pin 327, effectively preventing soil particles, sand and water on the ground from entering the self-tightening cavity 321 through the gap between the conventional anchor pin 327 and the guide hole. This prevents the precision mechanisms such as the inner ratchet group 323, the outer ratchet group 324 and the inertial wedge block 325 inside the self-tightening cavity 321 from being stuck or corroded by mud and sand, ensuring the reliability and stability of the device throughout the entire construction cycle of the foundation pit.

[0055] according to Figure 3 and Figure 4 As shown, the axis of the ejection channel 330 forms an angle of 30°-60° with the horizontal plane, and the launch port of the ejection channel 330 faces the side away from the pit at an angle upward. The tail of the arc-shaped anchor pin 332 is provided with a lug or ring for attaching the steel wire rope 220. The protective frame 200 is connected to the base body 300 by at least one set or more conventional anchor pins 327.

[0056] In this embodiment, the angle between the axis of the ejection channel 330 and the horizontal plane is preferably 45°. This angle can be selected to be downward or upward to ensure that the arc-shaped anchor pin 332 obtains sufficient horizontal range and vertical lifting height after being ejected, or to enable the arc-shaped anchor pin 332 to penetrate into the soil layer obliquely when it is injected into the soil, thereby obtaining the best anchoring effect.

[0057] The launch port of the ejection channel 330 is located on the rear side wall of the base body 300 facing away from the foundation pit, and the launch port faces the oblique upward direction away from the foundation pit. This ensures that after the arc-shaped anchor pin 332 is launched, it flies away from the edge of the foundation pit and towards the deep stable soil area, thus avoiding the arc-shaped anchor pin 332 from accidentally entering the foundation pit and causing a safety accident.

[0058] Furthermore, the tail of the arc-shaped anchor pin 332 is fixedly provided with a lug or ring, which is made of high-strength steel and welded or riveted to the rear end face of the arc-shaped anchor pin 332 for secure connection with the bottom end tie ring of the steel wire rope 220. The bottom of the protective frame 200 is fixedly connected to the base body 300 through one or more sets of conventional anchor pins 327. When multiple sets of conventional anchor pins 327 are provided, each conventional anchor pin 327 is evenly distributed along the length of the base body 300, and together they transfer the vertical load and horizontal impact load of the protective frame 200 to the base body 300 and the foundation soil, ensuring the structural stability and impact resistance of the protective frame 200 under normal use.

[0059] That is, as a whole, as follows: In the first-level protection state, the inner ratchet group 323 and the outer ratchet group 324 remain engaged, and the inertial wedge block 325 moves deeper step by step under the drive of traffic micro-vibration. The conventional anchor pin 327 is radially expanded by the wedge-shaped inclined surface, so that the conventional anchor pin 327 remains tightly anchored to the soil.

[0060] In the second-level protection state, when the collapse of the foundation pit causes the base body 300 to shift, the displacement difference triggers the tension cable 340 to be tightened and drives the release link 370 to fire the accumulator 380, which ejects the arc-shaped anchor pin 332 into the deep stable soil. At the same time, the arc-shaped anchor pin 332 is pulled by the steel wire rope 220 to unfold the suspension net roll 210 towards the foundation pit, forming a suspended protection covering the edge of the foundation pit.

[0061] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A safety protection device for a municipal road foundation pit, comprising a foundation pit surface (100), a protective frame (200), and a base body (300) disposed at the bottom of the protective frame (200), characterized in that: The base body (300) includes a fastening assembly (320), which is configured in multiple sets. The fastening assembly (320) includes an axially extending self-tightening cavity (321) and an obliquely extending ejection channel (330) formed inside the base body (300). The self-tightening cavity (321) is provided with a conventional anchor pin (327) that penetrates vertically into the soil and an inertial wedge block (325) that is connected to the conventional anchor pin (327). The inner wall of the self-tightening cavity (321) and the outer periphery of the inertial wedge block (325) are respectively provided with an inner ratchet group (323) and an outer ratchet group (324) that mesh with each other. The inner ratchet group (323) and the outer ratchet group (324) are used to limit the inertial wedge block (325) to move unidirectionally into the depth and prevent it from sliding backward. They are used to convert the external traffic micro-vibration into the conventional expansion force of the conventional anchor pin (327) on the soil. The ejection channel (330) is equipped with an arc-shaped anchor pin (332) that is oriented to be launched toward the side away from the pit, and an explosive accumulator (380) for driving the arc-shaped anchor pin (332) to be launched. The bottom rear of the base body (300) is connected to a displacement difference trigger cable (340). The far end of the displacement difference trigger cable (340) is fixed in the deep stable soil away from the edge of the foundation pit, and the near end extends into the base body (300) and is connected to the release link (370) installed on the side of the burst accumulator (380). The top of the protective frame (200) houses a hanging net roll (210), one end of which is connected to an arc-shaped anchor pin (332) via a steel wire rope (220). When the collapse of the foundation pit causes displacement of the base body (300), the displacement difference trigger cable (340) is tightened and the release link (370) is pulled to drive the burst accumulator (380) to fire, ejecting the arc-shaped anchor pin (332) into the deep stable soil body, which is used to realize the self-anchoring of the unstable suspension of the protective frame (200) and the suspension net roll (210).

2. The municipal road foundation pit safety protection device according to claim 1, characterized in that: The fastening assembly (320) also includes: A sliding block is rotatably connected to the bottom end of the inertial wedge block (325), and a rotating ring (329) is rotatably connected to the sliding gap connection end of the inertial wedge block (325). An elastic element (326) is sleeved on the outside of a conventional anchor pin (327). The top end of the elastic element (326) is connected to the bottom of the sliding block, and the bottom end of the elastic element (326) is connected to the bottom end of the frame (360) of the base body (300). The inner wall surface of the self-tightening cavity (321) is provided with a position groove (322), which is slidably connected to the sliding block. The top of the conventional anchoring pin (327) is provided with a rotating pin head (328), which is used to drive the conventional anchoring pin (327) to rotate, so that the inner ratchet group (323) and the outer ratchet group (324) are disengaged.

3. The municipal road foundation pit safety protection device according to claim 1, characterized in that: The base body (300) also includes a side seat (310), which is symmetrically installed on both sides of the frame (360) along the central axis of the frame (360). A flange joint (350) is installed on the side end of the side seat (310). An elastic plate groove (331) is opened on the surface of the ejection channel (330). The bottom end of the steel wire rope (220) is connected to the end of the arc-shaped anchor pin (332). The steel wire rope (220) is used for sliding in the elastic plate groove (331) after being pulled by the arc-shaped anchor pin (332).

4. The municipal road foundation pit safety protection device according to claim 1, characterized in that: The inertial wedge block (325) and the conventional anchor pin (327) are connected by a wedge-shaped inclined surface. When the inertial wedge block (325) moves deeper along the self-tightening cavity (321) under the action of traffic micro-vibration, the conventional anchor pin (327) is driven to expand radially through the wedge-shaped inclined surface.

5. The municipal road foundation pit safety protection device according to claim 1, characterized in that: The burst accumulator (380) is a compression spring accumulator or a compression gas accumulator. The release end of the burst accumulator (380) abuts against the tail of the arc-shaped anchor pin (332). The release link (370) passes through the trigger hole of the burst accumulator (380) and is fixedly connected to the proximal end of the displacement difference trigger cable (340).

6. The municipal road foundation pit safety protection device according to claim 1, characterized in that: The bottom of the base body (300) is provided with an anti-settlement base plate. The anti-settlement base plate has a guide hole for the conventional anchor pin (327) to pass through. A sealing sleeve is provided in the guide hole to prevent soil particles from entering the self-tightening cavity (321).

7. The municipal road foundation pit safety protection device according to claim 1, characterized in that: The axis of the ejection channel (330) forms an angle of 30°-60° with the horizontal plane, and the launch port of the ejection channel (330) faces the side away from the pit at an angle upward. The tail of the arc-shaped anchor pin (332) is provided with a lug or ring for attaching the steel wire rope (220).

8. The municipal road foundation pit safety protection device according to claim 1, characterized in that: The protective frame (200) is connected to the base body (300) by at least one set or more conventional anchor pins (327).

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