CN113265963B - Variable-rigidity anti-impact self-cleaning shed tunnel protection device - Google Patents

Abstract

The invention discloses a variable-rigidity impact-resistant and self-cleaning shed tunnel protection device, which comprises: an intercepting net; the pressure spring support seats are supported below the intercepting net; each pressure spring support comprises a variable-stiffness impact-resistant assembly formed by nesting a series of springs; the primary spring has the minimum elastic coefficient, the maximum height and the strongest deformation capacity; at least one secondary spring, wherein the elastic coefficient of each secondary spring is gradually increased, the height size is gradually reduced, and the cross section size is gradually reduced or gradually increased; and the tension spring end seats are arranged around the periphery of the interception net and are connected with the interception net and a shed tunnel top plate or a gable wall. The shed tunnel protection device can automatically adjust the rigidity of the system to achieve the optimal impact resistance effect in the whole process of one specific impact in the face of the mass and the diversity of the falling height of the stones, thereby better coping with various possible working conditions which randomly occur and realizing the impact resistance targets of self-cleaning of small stones and no damage of broken large stones.

Description

Variable-rigidity anti-impact self-cleaning shed tunnel protection device

Technical Field

The invention relates to the field of constructional engineering, in particular to a variable-rigidity impact-resistant and self-cleaning shed tunnel protection device.

Background

When highway and railway traffic passes through dangerous areas such as cut walls, canyons and the like, serious threats of rock rolling and falling are faced, and the shed tunnel plays an extremely important role in engineering as a protective structure. However, the existing general protection cushion layer shed tunnel (gravel cushion layer is laid on the shed tunnel plate) and the novel energy-consuming and shock-absorbing shed tunnel (cylindrical shell energy-consuming part is arranged at the support) and various flexible shed tunnels appeared in recent years are adopted, although the damage of falling rock impact is relieved to a certain extent by the schemes, the threats of rolling and falling rock are not completely relieved, and the defects exist.

As for the protective cushion layer shed tunnel, although the sand gravel cushion layer can play a role of energy absorption and buffering to a certain extent, the essence that the falling stone kinetic energy is violently released in a 'small range' can not be changed, and the key index that the impact resistance efficiency depends on the cushion layer thickness is caused. And the method for preventing accidental action with relatively small occurrence probability by increasing the overlarge permanent load is not economical and unreasonable, the cushion layer is too thick (often more than 1.5 m-2.5 m), the construction cost is obviously increased, and the popularization and the application of the cushion layer are restricted.

For the energy-consuming and shock-absorbing shed tunnel, an attempt is made to replace a sandstone cushion layer to absorb kinetic energy of falling rocks by additionally arranging an energy-consuming shock absorber at a shed tunnel support, so that the effect of reducing impact is achieved. However, the drop point is not a shock absorber setting point, the method does not change the essence of hard-to-hard collision at the drop point, the falling rock kinetic energy is violently released at the drop point to form impact damage, the shock absorber at the supporting position is intuitively shown to have no time to deform and consume energy, and the concrete at the collision point is broken by smashing, so the impact damage is still very common in application.

For various flexible shed tunnels rising in recent years, intercepting nets and spring parts are added, but the randomness and diversity of sizes and masses of falling rocks and rolling rocks are difficult to effectively deal with by a single intercepting net; an impact-resistant system consisting of the impact-resistant unit only comprising one spring is difficult to effectively cope with the impact of falling rocks with different masses m and different falling heights H. Acceleration of recoil due to impact resistance of the elastic system: (

g is weight acceleration) range of variation and minimum height requirement for impact resistance

The height H and the mass m of the stone are random variables, the range is too wide, and in the case of various possible conditions, the deceleration effect and the impact resistance height can be controlled within an acceptable range, and a solid stone is selectedA constant impact stiffness K is obviously not possible. When the system rigidity K is too small relative to the rock falling mass m, the deceleration effect is not obvious due to too small recoil acceleration, the deformation length required for completing impact resistance is too long to be met, the rock falling speed is still very large when the actual deformation length of the spring is completely compressed or the spring is damaged, and at the moment, the parts at the two ends of the spring still have hard collision; when the rigidity K of the system is too large relative to the mass m of the falling rocks, the deformation length required for finishing impact resistance tends to zero, namely the falling rocks are hardly compressed, the force transfer of the spring is equal to the force transfer of a rigid body, and the falling rocks and the spring still have hard collision with each other.

In view of the fact that the existing shed tunnel design method cannot well solve the problem of shock resistance of the shed tunnel, the variable-rigidity shock-resistant shed tunnel design scheme is obviously of great practical significance, the rigidity of the variable-rigidity shock-resistant shed tunnel system is automatically adjusted along with the falling rock mass and height in the shock process, and therefore the effects of reasonable recoil deceleration and energy conversion are achieved, effective deceleration is achieved within a shock-resistant height h which is not changed greatly, and stable energy conversion is achieved.

Disclosure of Invention

In view of the problem that the existing shed tunnel design method cannot well solve the impact damage resistance of the shed tunnel, the invention provides a variable-rigidity impact-resistant and self-cleaning shed tunnel protection device.

The technical scheme adopted by the invention is as follows:

a variable stiffness impact resistant and self-cleaning shed tunnel protection device comprising:

an interception net;

the pressure spring support seats are supported below the intercepting net;

each pressure spring support comprises a variable-stiffness impact-resistant assembly formed by nesting a series of springs; the primary spring has the minimum elastic coefficient, the maximum height and the strongest deformation capacity; at least one secondary spring, wherein the elastic coefficient of each secondary spring is gradually increased, the height size is gradually reduced, and the cross section size is gradually reduced or gradually increased;

and the tension spring end seats are arranged around the periphery of the interception net and are connected with the interception net and a shed tunnel top plate or a gable wall.

As a preferred embodiment of the device of the present invention, the tension spring end seat includes an anchor member and a tension spring, the anchor member is embedded in the ceiling or the gable wall of the shed tunnel, and the tail end of the anchor member is exposed, the first end of the tension spring pulls the tail end of the anchor member, and the second end of the tension spring is connected to the cable end of the intercepting net; when the anchor piece is anchored on the shed tunnel top plate, the tension spring end seat further comprises a supporting piece, the lower end of the supporting piece is embedded in the shed tunnel top plate, and the upper end of the supporting piece is provided with a cross slideway.

As a preferred embodiment of the device of the invention, the interception net is formed by overlapping a loose net arranged at the lower side and a dense net arranged at the upper side, and the cross section area of a net cable, the bearing capacity and the mesh opening of the loose net are all more than 3 times of those of the dense net; the sparse net is a plane net formed by intersecting a plurality of net cables at certain intervals and at certain angles; the end part of the net rope of the sparse net is connected with the second end of the tensile spring.

As a preferred embodiment of the device, the primary spring and each secondary spring of the variable-stiffness anti-impact assembly are horn-shaped spiral springs with small top and large bottom.

As a preferred embodiment of the device of the present invention, each of the compressed spring supports further comprises a directional tube assembly located at the center of the primary spring and each of the secondary springs, an impact loading head located at the upper end of the directional tube assembly, and a mesh cable sliding end support located at the top of the impact loading head, wherein the mesh cable sliding support directly supports the crossed mesh cables at the intersection of the sparse network boundaries.

As a preferred embodiment of the device of the invention, the impact loading head is composed of a primary loading top plate and a plurality of secondary loading rings, the number of the secondary loading rings is equal to the number of the secondary springs, the diameter of each secondary loading ring is the same as that of the top end of the corresponding secondary spring, the nesting sequence of the secondary loading rings is consistent with that of the secondary springs, and the primary loading top plate is provided with a first connecting structure.

As a preferred embodiment of the device of the present invention, the upper side of the net cable sliding support is provided with an upward-opening vertically-staggered cross slideway at the same interval as the crossing angle of the sparse net cable, the cross slideway can allow a plurality of net cables at the crossing point of the inner net cables of the sparse net to freely slide at the same time, and the lower side of the net cable sliding support is provided with a second connecting structure matched with the first connecting structure.

As a preferred embodiment of the device of the present invention, the directional pipe assembly comprises a lower pipe and an upper pipe which are freely telescopically connected, wherein the lower end of the lower pipe is embedded in the ceiling of the shed tunnel, the upper end of the upper pipe is connected to the impact loading head, and the lower end of the upper pipe is inserted into the upper end of the lower pipe for a certain length.

As a preferred embodiment of the apparatus of the present invention, the top of the primary spring is in close contact with the primary loading top plate, the top of each secondary spring is spaced from each corresponding secondary loading ring by a certain distance, and the distance between each secondary spring and the corresponding secondary loading ring increases gradually.

As a preferred embodiment of the device of the present invention, the bottom of each of the impact-resistant spring sets is provided with an impact force diffuser, the impact force diffusers are disposed on or in the shed tunnel roof, and the centers of the impact force diffusers are provided with holes through which the lower tubes of the directional tube assemblies can pass, and are not connected to the lower tubes.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

the variable-rigidity impact-resistant and self-cleaning shed tunnel device provided by the invention comprises three parts, namely a density-variable combined intercepting net, a variable-rigidity pressure spring support under the net and a support type tension spring end seat on the net side. The dense net can intercept rolling stones and falling stones with relatively small sizes, distribute inertial impact force to the nearest net-thinning net cables, and prevent small stone blocks broken by impact from being accumulated at the top of the shed tunnel; the sparse net can buffer the inertial impact force transmitted by the dense net and disperse the kinetic energy of the dense net, can directly intercept the rolling stones and falling stones with larger sizes and kinetic energies, and effectively transmit and disperse the strong inertial impact force and kinetic energy at the falling point to a distance by means of the strong tensile bearing capacity of the sparse rope; the pressure spring support under the net can directly and effectively relieve vertical inertia impact of falling rocks and rolling rocks and absorb kinetic energy of the falling rocks, the horn shape with small upper part and large lower part of the pressure spring support not only ensures that lateral instability does not occur under strong impact force, but also can disperse and transmit inertia impact force to a large range of a shed tunnel top plate, a primary spring with relatively small rigidity can buffer and drive away the rolling rocks and the falling rocks with relatively small height and relatively small mass, and secondary springs with gradually increased rigidity and the primary springs can resist the falling rocks with relatively large height and relatively large mass together, so that the mass and the height range of the impact-resistant intercepted rocks are enlarged; the plurality of tension spring end seats on the periphery of the net side can effectively transmit and share the inertia impact force and kinetic energy of falling stones and rolling stones by means of the steel cable net; a large number of pressure spring support seats with variable rigidity face diversified and variable stone masses and kinetic energies to automatically adjust respective rigidity so as to realize effective speed reduction and stable energy conversion.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some specific embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of a first usage state of the variable stiffness, impact resistance and self-cleaning shed tunnel protection device of the present invention.

FIG. 2 is a schematic diagram of a second usage state of the variable stiffness impact resistance and self-cleaning shed tunnel protection device of the present invention.

FIG. 3 is a general plan view of the shed tunnel guard of the present invention.

FIG. 4 is a three-dimensional distribution diagram of a multi-stage trumpet-shaped compressed spring support in the shed tunnel protection device of the invention.

FIG. 5 is a partial sectional view showing the three-dimensional structure of the multi-stage trumpet-shaped compressed spring support in the shed tunnel protection device according to the present invention.

FIG. 6 is a perspective view of the tension spring of the shed tunnel protection device of the present invention.

FIG. 7 is an overall external view of a wire rope sliding support in the shed tunnel protection device of the present invention.

Fig. 8 to 10 are schematic cross-sectional views illustrating the middle, middle and upper runners of the cable shoe and the cable penetrating condition, wherein fig. 8 shows the lower runner, fig. 9 shows the middle runner, and fig. 10 shows the upper runner.

The reference numbers are related as follows:

a shed tunnel top plate-1; gable-11; an interception net-2; a sparse net-21; a dense net-22; a pressure spring support-3; impact loading head-31; secondary load ring-311; a primary load ceiling-312; a first connection formation-313; an orienting tube assembly-32; an upper pipe-321; a down tube-322; a primary spring-33; a secondary spring-34; an impact force spreading member-35; a tension spring end seat-4; a support-41; an anchor-42; a tension spring-43; a net cable sliding support-5; second connection configuration-51; a slide-52.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below.

The invention provides a variable-rigidity anti-impact and self-cleaning shed tunnel protection method, aiming at solving the problem that the existing shed tunnel design method cannot well solve the anti-impact damage of the shed tunnel. The method adopts an elastic cable net supported by a large number of spring supports (including a pressure spring support and a tension spring end seat) to intercept the rock rolling and the rock falling in a soft contact mode, prolongs the action time, effectively relieves the inertia impact strength, and transmits the inertia impact force and the rock falling kinetic energy to the periphery; the large-scale pressure spring support and the peripheral tension spring end seats are respectively compressed and stretched under the effective transmission of the steel cable net, so that the effect of relieving the inertia impact force is achieved, and meanwhile, the falling rock kinetic energy is absorbed and converted into the potential energy of a large number of springs which is stored in a dispersed manner; then the pressure spring and the tension spring rebound to react with the falling stone and the rolling stone and release the stored elastic potential energy. For rolling stones and small falling stones, the mass and the kinetic energy are relatively small, only the primary spring in the pressure spring support participates in the work, and the primary spring and the tensile spring of the tension spring end seat can directly bounce and drive the primary spring and the tensile spring away from the cable net structure. For falling rocks with high falling height or large mass, the elastic coefficient of the primary spring of the pressure spring support is small, the energy absorption and deceleration effects are not obvious, when the independent impact-resistant height of the primary spring is rapidly compressed, the falling rocks speed is still large, and the energy is still high; then, the secondary loading ring touches the secondary spring, the secondary spring participates in the work, the elastic coefficient of the secondary spring is several times higher than that of the primary spring, the energy absorption and deceleration effects are increased several times, and the stone falling speed and the kinetic energy are reduced and accelerated; if the height of the secondary primary spring working together with the primary spring is completely compressed again, the falling rock speed can not be forced to be reduced to zero; the secondary loading ring touches the secondary spring, the secondary spring participates in work, the energy absorption and deceleration effects are increased … … in a plurality of times again, and because the coefficients of all levels of springs are increased in a multiplying rate step by step, the impact resistant negative acceleration and the energy absorption capacity are increased in a multiplying rate step by step, the falling speed is increased more and more rapidly, the kinetic energy conversion efficiency is higher and more, and the falling can be stopped until the falling is stopped, so that the occurrence of hard collision is avoided.

Referring to fig. 1 to 4, an embodiment of the present invention provides a variable-stiffness impact-resistant and self-cleaning shed tunnel protection device, which mainly includes: the device comprises an interception net 2, a two-stage variable-rigidity pressure spring support 3 and a tension spring end seat 4.

The interception net 2 is a density combination net and is formed by overlapping a density net 21 arranged on the lower side and a density net 22 arranged on the upper side, and the cross section area, the bearing capacity and the mesh opening of the net 21 are all more than 3 times of those of the density net 22; the sparse net 21 is a plane net formed by intersecting a plurality of net cables at certain intervals and certain angles, and the end parts of the net cables of the sparse net 21 are connected with the second end of the tension spring end seat 4; the net cable bearing capacity of the open net 21 is higher than that of the dense net 22. As a preferred embodiment of the device of the present invention, the sparse net 21 is installed on site by using steel strands or other flexible high-strength materials with large bearing capacity, and the grid shape is regular rectangles, diamonds, and three-stage shapes, as shown in fig. 3 and 4, the net cable spacing is 1m to 2m, and the arrangement form of the net cables preferentially considers that two lines cross at 90 degrees and three lines cross at 60 degrees, as shown in fig. 3 and 4; the dense net 22 can be woven on site by steel wires and thin steel cables, or can be laid, assembled and bound on the steel cable net by steel wire mesh sheets prefabricated in factories, the latter is taken as a preferred embodiment, the shape of the meshes of the dense net 22 is not limited, and the meshes can be rectangular, rhombic, triangular, honeycomb-shaped, circular and the like, as shown in fig. 3 and 4, but the size of the meshes of the dense net 22 is strictly limited and can be selected from 10cm to 30 cm.

The shed tunnel top plate 1 has a certain inclination angle, the sparse net 21 and the dense net 22 are arranged above the shed tunnel top plate 1 in parallel at a certain height, and the peripheral end parts of the sparse net 21 are fixed with the peripheral edges of the shed tunnel top plate 1 by adopting tension spring end seats 4, as shown in figure 1; when the side of the shed roof 1 is close to the gable 11, the end of the wire netting 21 on the side of the gable 11 is directly tied to the side of the gable 11 by the tension spring 43, as shown in fig. 2.

And a plurality of tension spring end seats 4 are distributed around the periphery of the interception net 2 and are connected with the interception net 2 and the shed tunnel top plate 1 or the gable 11 in a pulling and knotting manner. With reference to fig. 1 and 2, the tension spring end seat includes an anchor member and a tension spring, the anchor member is embedded in the ceiling 1 (as shown in fig. 1) or the gable 11 (as shown in fig. 2), and the tail end is exposed, the first end of the tension spring pulls the tail end of the anchor member (as shown in fig. 6), and the second end is connected to the cable end of the intercepting net (as shown in fig. 6); when the anchor piece is anchored on the shed tunnel top plate 1, the tension spring end seat also comprises a support piece, the lower end of the support piece is embedded in the shed tunnel top plate, and the upper end of the support piece is provided with a cross slideway (as shown in figure 6). With reference to fig. 6, a specific implementation structure of the tension spring end seat 4 connected to the shed tunnel roof 1 is shown, the tension spring end seat 4 is composed of an anchor member 42, two tension springs 43 and a plurality of supporting members 41, the anchor member 42 can be a pull ring with hooks, the lower end of the anchor member 42 hooks the bottom steel bars of the shed tunnel roof and is embedded in the shed tunnel roof, and the tail end of the anchor member is exposed out of the shed tunnel roof; the lower end of the supporting piece 41 is anchored in the ceiling of the shed tunnel, and the top surface of the upper end is provided with a cross slideway which can allow each net rope at the boundary intersection point of the dredging net 21 to freely slide at the same time. The tension spring 43 has a first end pulling the trailing end of the anchor member 42 and a second end connected to the openwork 21 of the interceptor net. As an embodiment of the device of the invention with better effect, when the net cables of the sparse net 21 are formed by crossing two lines at 90 degrees, the tension spring end seats are only arranged along the periphery; when the net cables of the sparse net 21 are formed by crossing three lines of 60 degrees, the two ends of the sparse net 21 are required to be provided with the tension spring end seats 4 in the width direction of the shed tunnel, and two rows of tension spring end seats 4 which are oppositely arranged are required to be arranged at the positions of every 3-5 times of the width dimension in the length direction of the shed tunnel; the support piece 41 of the tension spring end seat 4 is a space structure formed by a central straight rod and two oblique rods, and the bottom ends of the straight rod and the oblique rods are embedded in the concrete of the ceiling of the shed tunnel; the top end of the central straight rod is provided with a cross slideway structure, and the height of the cross slideway structure is consistent with that of the compressed spring support when the central straight rod is not pressed.

And a plurality of variable-rigidity pressure spring supports 3 are supported below the interception net 2. With reference to fig. 5, each compressed spring support includes a variable-stiffness anti-impact assembly formed by nesting a series of springs with different elastic coefficients and heights, and the multi-stage springs may be secondary springs nested inside the outermost primary springs step by step, such as second-stage, second-stage and fourth-stage springs, or the multi-stage springs may also be secondary springs nested outside the innermost primary springs step by step, such as second-stage, second-stage and fourth-stage springs. As long as the lowest elastic coefficient, the highest height and the highest deformation capacity of the primary springs 33 at the innermost side or the outermost side are ensured, at least one secondary spring 34 is arranged, the elastic coefficient of each secondary spring 34 is gradually increased according to the progressive increase, the height size is gradually decreased according to the progressive increase, and the transverse section size can be gradually decreased or gradually increased so as to meet the requirement of the progressive nesting of the multi-stage springs. In the embodiment of the device, the primary spring 33 is positioned at the outermost side, the secondary springs 34 are nested in the primary spring 33 step by step in a gradually and progressively increasing manner, and the elastic coefficient, the height dimension and the spiral line diameter of the primary spring 33 are determined by calculation according to the design height and the design amount of the common rockfall; the number of the secondary springs 34 is 1-3, the increasing multiplying power of the elastic coefficient of the primary, secondary and secondary springs is set to be 3-5 times, the number of stages is less, a large value is selected, the number of stages is more, a small value is selected, the more reasonable method is comprehensively determined according to the energy multiplying power of rare falling rocks and common falling rocks and the calculation effect of the shock resistance effect, and the transverse section size adopts a decreasing mode; the elastic coefficient and the height of each secondary spring are conveniently determined by directly determining according to the energy multiplying power, the number of the secondary springs and the linear difference of the heights of the primary springs, and a more reasonable method needs to be comprehensively determined by combining the impact coefficient calculated by impact resistance and the energy absorption effect of the springs; and the spiral line diameter of each secondary spring is determined by calculation according to the elastic coefficient, the spring height and the property function of each secondary spring.

Preferably, the primary spring 33 and each secondary spring 34 of the variable-stiffness anti-impact assembly are both a coil spring with a small top and a large bottom and a trumpet shape, and the primary spring 33 and each secondary spring 34 are nested step by step in a manner that the transverse cross-sectional dimension is gradually increased from small to large to form the variable-stiffness anti-impact assembly. As a better implementation mode of the device, the diameter of the lower end of the primary horn-shaped spring is designed to be 3-5 times of that of the upper end, so that the effective diffusion of the inertial impact force and the lateral stability of the spring under the action of strong impact are guaranteed.

Each pressure spring support further comprises a directional tube assembly 32 positioned at the center of the primary spring and each secondary spring, an impact loading head 31 positioned at the upper end of the directional tube assembly 32, and a net rope sliding support 5 positioned at the top of the impact loading head 31, wherein the net rope sliding support 5 directly supports the boundary net rope intersection point of the sparse net 21.

Wherein the impact loading head 31 is composed of a primary loading top plate 311 and a plurality of secondary loading rings 312, the primary loading top plate 311 is preferably a primary loading dome plate, the number of the secondary loading rings 312 is equal to the number of the secondary springs 34, the diameter of the secondary loading ring 312 is the same as the diameter of the top end of the corresponding secondary spring 34, the nesting order of the secondary loading rings 312 is identical to the nesting order of the respective secondary springs 34, and the primary loading top plate 311 is provided with a first connection structure 313. As a preferred embodiment of the apparatus of the present invention, the first connecting structure 313 on the upper side of the primary loading top plate 311 may be designed as a threaded hole or a smooth square hole.

With reference to fig. 7 to 10, a plurality of vertically staggered and crossing slideways 52 which are open upwards are arranged on the upper side of the net cable sliding support 5 at the same interval angle as the sparse net 21, the crossing slideways 52 can allow a plurality of net cables at the intersection points of the net cables on the inner sides of the sparse net 21 to freely slide at the same time, and a second connecting structure 51 matched with the first connecting structure 313 is arranged on the lower side of the net cable sliding support 5. As a better implementation mode of the device, the slide ways are designed into a combination form of a straight slide way and a vertical curved slide way, and the outlets of the slide ways are on the same plane, so that the net ropes penetrating through the slide ways are basically on the same plane after exiting from the slide ways, and the laying of the upper side dense net and the transmission of stress are facilitated; the second connecting structure 52 on the lower side of the cable sliding support 5 can be designed as a threaded rod or a smooth square hole, and is matched and connected with the first connecting structure 313 on the upper side of the primary loading top plate 311.

In conjunction with fig. 5, the directional pipe assembly 32 includes a lower pipe 322 and an upper pipe 321 which are freely telescopically connected, a lower end of the lower pipe 322 is pre-buried in the ceiling of the shed tunnel, an upper end of the upper pipe 321 is connected to the impact loading head 31, and a lower end of the upper pipe 321 is inserted into an upper end of the lower pipe 322 by not less than one pipe diameter length. As an embodiment of the apparatus of the present invention, the directional tube assembly 32 is made of a material which is not easily corroded and corroded, and in a preferred embodiment, the upper tube 321 is made of an aluminum tube or a galvanized steel tube, and the lower tube 322 is made of a polished stone tube, a steel wire concrete tube, an aluminum tube or a galvanized steel tube.

The top of the primary spring 33 is in close contact with the primary loading top plate 312, the top of each secondary spring 34 is spaced from each corresponding secondary loading ring by a certain distance, and the distance between each secondary spring 34 and the corresponding secondary loading ring is gradually increased, wherein the increment of the distance is the deformation range of the joint work of the total stiffness of the springs of several stages before the stage of spring.

The bottom of each anti-impact spring set is provided with an impact force diffuser 35, the impact force diffuser 35 is arranged on or in the ceiling of the shed tunnel, the center of the impact force diffuser 35 is provided with a hole for the lower pipe 322 of the orientation pipe assembly 32 to pass through, and is not connected with the lower pipe 322, and the shape of the center hole matches with the shape of the lower pipe of the orientation pipe assembly, and is preferably circular. As an embodiment of the device of the present invention, the impact diffuser 35 may be designed as a circular plate with a hole in the middle, and is disposed on the upper surface of the ceiling of the shed tunnel, or may be designed as a reinforcing mesh with anti-punching function, and is disposed in the concrete of the ceiling of the shed tunnel; the preferred embodiment is that 2-3 interlamellar spacing is not more than 10cm reinforcing bar net piece for the design, and from top to bottom the radius increases step by step.

Preferably, the top of each multistage trumpet-shaped pressure spring support 3 is connected with a net cable sliding support 5, the net cable sliding supports 5 are provided with slideways 52 for net cables in multiple directions in the sparse net 21 to pass through, and the slideways 52 are overlapped and staggered, so that the steel cables can be communicated in multiple directions, mutual influence of the net cables in all directions at the overlapped part is avoided, and the purpose of free passing and free sliding of the net cables is achieved. In this embodiment, three upward open slideways 52 with an included angle of 60 degrees are provided on the net cable sliding support 5, the lower slideway is a straight slideway, the middle and upper slideways are both protruded upward and go around the vertical curved slideway under the middle and upper slideways, as shown in fig. 7, the three cable slideways are staggered and not affected with each other along the vertical direction, so that three steel cables penetrating through the three cable slideways can freely slide along respective directions, and the penetrated steel cables are substantially on the same plane, thereby facilitating the laying of the dense net 22 and the uniform distribution of impact force. The top of the impact loading head 31 is provided with a threaded hole, the bottom of the net cable sliding support 5 is provided with a threaded connector which is screwed with the threaded hole, and the net cable sliding support 5 is in threaded connection with the impact loading head 31, so that the angle of the net cable sliding support 5 can be properly adjusted, and the net cable sliding support is better adapted to the arrangement condition of net cable cross nodes in the steel cable sparse net 21.

The variable-rigidity anti-impact and self-cleaning shed tunnel protection device can achieve the anti-impact aims of self-cleaning of small stones and no damage of broken large stones. The interception net composed of the open net 21 and the close net 22 is used for intercepting rock fall and falling rocks, the close net 22 transmits acting force to the open net 21, the open net 21 applies the acting force to the impact loading head 31 through the net cable sliding support 5, and the primary loading round 312 plate of the impact loading head 31 drives the primary spring 33 to move downwards.

(1) When the mass of the rolling stones and falling stones is small, the speed is high, the compression amount of the primary spring 33 (with small rigidity) is small, and the rolling stones and falling stones directly bounce up and are driven away from the shed tunnel when being compressed and contracted, so that the aim of impact resistance of self-cleaning of small stones is achieved;

(2) when the mass of the rock rolling and falling rocks is large, the elastic coefficient of the primary spring 33 is relatively small, the primary spring is compressed at a high speed and generates large deformation, so that only the primary spring 33 cannot play an effective impact resistance role, the lower end of the secondary loading ring 311 of the impact loading head 31 contacts with the secondary spring 34 (with high rigidity), the secondary spring 34 with high rigidity starts to work, the primary spring 33 and the secondary spring 34 jointly form an impact resistance defense line with high rigidity, the falling rocks with large mass are forced to decelerate rapidly to zero, the falling rocks with large mass cannot be rebounded and driven away from the top of the shed tunnel when the spring contracts, but the top plate of the shed tunnel can still be prevented from being damaged by impact, and the impact resistance target that the falling rocks cannot be broken is achieved.

The design method of the variable-rigidity impact-resistant and self-cleaning shed tunnel comprises three parts, namely a density-variable combined intercepting net, a variable-rigidity pressure spring support under the net and a supporting type tension spring end seat on the net side. The steel wire dense net can intercept rolling stones and falling stones with relatively small sizes and transmit inertia impact force to the nearest steel wire rope; the steel cable sparse net can evacuate the inertial impact force and kinetic energy transmitted by the steel cable dense net, can directly intercept large-size rolling stones and falling stones, and effectively transmit and evacuate the strong inertial impact force and kinetic energy at the falling point to a remote place by means of the strong tensile strength of the steel cable; the pressure spring support under the net can effectively balance and buffer the vertical inertia force of the falling rocks and the rolling rocks and absorb the kinetic energy of the falling rocks, the horn shape with small upper part and large lower part of the pressure spring support not only ensures that the falling rocks are not laterally unstable under strong impact force, but also can play a role of diffusing the impact force applied to the ceiling plate of the shed tunnel, the primary spring with relatively small rigidity can buffer and drive away the rolling rocks and the falling rocks with relatively small mass, and the secondary spring with relatively large rigidity and the primary spring can jointly resist the impact of the larger falling rocks; the tension spring end seats around the net side can share the inertia impact force and kinetic energy transferred by the falling rocks and the rolling rocks by means of the tensile deformation of the steel cable net.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Although the present application has been described with reference to the present specific embodiments, it will be recognized by those skilled in the art that the foregoing embodiments are merely illustrative of the present application and that various changes and substitutions of equivalents may be made without departing from the spirit of the application, and therefore, it is intended that all changes and modifications to the above-described embodiments that come within the spirit of the application fall within the scope of the claims of the application.

The techniques, shapes, and configurations not described in detail in the present invention are all known techniques.

Claims (8)

1. The utility model provides a become rigidity and resist shock and self-cleaning shed tunnel protector which characterized in that includes:

an intercepting net;

the pressure spring support seats are supported below the intercepting net;

each pressure spring support comprises a variable-stiffness impact-resistant assembly formed by nesting a series of springs; the primary spring has the advantages of minimum elastic coefficient, maximum height and strongest deformation capacity; at least one secondary spring, wherein the elastic coefficient of each secondary spring is gradually increased, the height size is gradually reduced, and the cross section size is gradually reduced or gradually increased;

the tension spring end seat is arranged around the interception net and is connected with the interception net and a shed tunnel top plate or a gable wall, the tension spring end seat comprises an anchoring piece and a tensile spring, and the first end of the tensile spring pulls the tail end of the anchoring piece;

the interception net is formed by overlapping a sparse net arranged on the lower side and a dense net arranged on the upper side, and the cross section area, the bearing capacity and the meshes of net cables of the sparse net are more than 3 times of those of the dense net; the sparse net is a plane net formed by intersecting a plurality of net cables at certain intervals and at certain angles; the net cable end part of the sparse net is connected with the second end of the tensile spring;

each pressure spring support also comprises a directional tube assembly positioned in the centers of the primary spring and each secondary spring, an impact loading head positioned at the upper end of the directional tube assembly, and a mesh cable sliding support positioned at the top of the impact loading head, wherein the mesh cable sliding support directly supports the crossed mesh cables at the intersection of the sparse mesh cables.

2. The variable stiffness, impact resistant and self-cleaning shed tunnel protection device of claim 1, wherein: the anchoring piece is embedded in a ceiling or a gable wall of the shed tunnel, and the tail end of the anchoring piece is exposed; when the anchor piece is anchored on the shed tunnel top plate, the tension spring end seat further comprises a supporting piece, the lower end of the supporting piece is embedded in the shed tunnel top plate, and the upper end of the supporting piece is provided with a cross slideway.

3. The variable stiffness, impact resistant and self-cleaning shed tunnel protection device of claim 1, wherein: the primary spring and each secondary spring of the variable-stiffness anti-impact assembly are respectively a horn-shaped spiral spring with a small top and a large bottom.

4. The variable stiffness, impact resistant and self-cleaning shed tunnel protection device of claim 1, wherein: the impact loading head is composed of a primary loading top plate and a plurality of secondary loading rings, the number of the secondary loading rings is equal to that of the secondary springs, the diameters of the secondary loading rings are the same as those of the top ends of the corresponding secondary springs, the nesting sequence of the secondary loading rings is consistent with that of the secondary springs, and the primary loading top plate is provided with a first connecting structure.

5. The variable stiffness, impact resistant and self-cleaning shed tunnel protection device of claim 4, wherein: the upper side of the net cable sliding support is provided with upwards-opened and vertically-staggered crossed slideways at the same angle with the crossing angle of the sparse net cables at intervals, the crossed slideways can allow a plurality of net cables at the crossing points of the inner net cables of the sparse net to freely slide at the same time, and the lower side of the net cable sliding end seat is provided with a second connecting structure matched with the first connecting structure.

6. The variable stiffness, impact resistant and self-cleaning shed tunnel protection device of claim 1, wherein: the directional pipe assembly comprises a lower pipe and an upper pipe which are in free telescopic connection, the lower end of the lower pipe is embedded in the shed tunnel top plate, the upper end of the upper pipe is connected with the impact loading head, and the lower end of the upper pipe is inserted into the upper end of the lower pipe by a certain length.

7. The variable stiffness, impact resistance and self-cleaning shed tunnel protection device of claim 4, wherein: the top of the primary spring is in close contact with the primary loading top plate, the top of each secondary spring is spaced from each corresponding secondary loading ring by a certain distance, and the distance between each secondary spring and each corresponding secondary loading ring is gradually increased.

8. The variable stiffness, impact resistance and self-cleaning shed tunnel protection device of claim 6, wherein: the bottom of the anti-impact spring group is provided with an impact force diffusion piece, the impact force diffusion piece is arranged on or in the shed tunnel top plate, and the center of the impact force diffusion piece is provided with a hole for the lower pipe of the directional pipe assembly to pass through and is not connected with the lower pipe.

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