CN214836409U - Tunnel drainage type corrugated steel preliminary bracing structure - Google Patents

Abstract

The utility model discloses a tunnel drainage type corrugated steel preliminary bracing structure, including setting gradually the instant supporting construction of I-steel on the tunnel internal face, stock extension supporting construction, corrugated steel reinforcement supporting construction, through this integrated configuration and waterproof board, impervious secondary lining, tunnel drainage pipe system constitutes one and blocks water earlier, the drainage again, waterproof combination formula drainage structure system is prevented to back, can improve tunnel supporting construction's drainage performance by a wide margin, effectively improve the tunnel percolating water problem of operation phase, and through the instant supporting construction of I-steel, stock extension supporting construction, corrugated steel reinforcement supporting construction three combines, can effectively improve preliminary bracing's bulk strength and stability, improve tunnel construction's operation environment, improve preliminary bracing's structural quality by a wide margin.

Description

Tunnel drainage type corrugated steel preliminary bracing structure

Technical Field

The utility model relates to a tunnel drainage type corrugated steel preliminary bracing structure belongs to tunnel construction technical field.

Background

The existing mountain tunnels are mostly built by adopting composite linings, and mainly comprise primary supports, secondary linings and waterproof and drainage systems arranged between two support structures. The existing tunnel drainage system comprises a circumferential drainage pipe, a longitudinal drainage pipe, a transverse drainage pipe and a central drainage ditch (or a drainage side ditch), underground water permeating through the primary support is collected through the circumferential drainage pipe arranged on the inner side of the primary support, and the water is sequentially guided to the longitudinal drainage pipe, the transverse drainage pipe and the central drainage ditch (or the drainage side ditch). However, the discontinuous circumferential drainage pipes (the longitudinal distance is generally about 10 m) have poor overall drainage effect, so that the water seepage between the primary support and the secondary lining cannot be quickly drained away in the first time, and the phenomenon of local or large-area water accumulation between the support structures is caused. Meanwhile, the tunnel waterproof board is easy to damage due to rough and uneven surface of the primary support or the influence of the pointed protrusion. The seeped water permeates into the tunnel through the damaged position of the waterproof plate, which is an important reason for the problem of water leakage of the tunnel.

Meanwhile, the primary support is used as an important support structure for preventing surrounding rocks from continuously deforming or collapsing after tunnel excavation, and has strict requirements on the aspects of the timeliness, the structural stability and the construction operability of the support. At present, the most conventional primary support structure in mountain tunnel construction is a support system formed by combining anchor rods, steel frames and sprayed concrete, and the support system can deal with most tunnel surrounding rock conditions by matching with an advanced support measure, so that the support structure is relatively mature in technology and relatively reasonable in system. However, with the continuous improvement of the requirements of tunnel construction on the aspects of construction environment, construction quality, construction progress and the like, the corresponding defects of the primary support are continuously shown, and the method mainly comprises the following steps: the existing primary support requires two shotcrete procedures of primary shotcrete on the surrounding rock surface and secondary shotcrete between steel frames, the thickness of a shotcrete layer is large, the construction time of shotcrete is long, the construction environment is poor, and the quality of the shotcrete is difficult to ensure; the construction angle of the foot-locking anchor rod is not easy to control, and the connection rigidity of the foot-locking anchor rod and the I-shaped steel cannot be effectively guaranteed; the coupling between the I-steel and the sprayed concrete is poor, and the risk of cracking and deformation of the primary support is high under the condition of poor surrounding rock; limited by the construction method, the I-steel joints are limited on the same horizontal plane, and the primary support has obvious weak point of stress; the overall strength of the primary support is closely related to the distance between the I-beams, and the construction progress is severely limited due to the fact that the I-beam distance cannot be pulled open in a section with poor surrounding rock; the surface of the primary support is rough and uneven, even has a pointed projection, and a waterproof plate constructed in the later period is easy to damage. In addition, some researchers propose a supporting structure adopting corrugated steel primary support, but the supporting structure is seriously lagged in the aspect of supporting timeliness, cannot provide timely and effective support in a short time after tunnel excavation, is high in construction risk, and is difficult to popularize and apply in tunnels with poor surrounding rock self-stability capability. Meanwhile, the corrugated steel primary support has defects in the aspects of advanced support positioning construction, corrugated steel assembly, mold concrete pouring, construction joint treatment and the like, and has poor construction operability and large field construction difficulty.

It can be seen that the existing water-proof and drainage system and the conventional primary support structure have obvious defects, and the corrugated steel primary support has certain defects in the aspects of support system design and construction operation details. In view of the above, research on a tunnel drainage type corrugated steel primary supporting structure has become an urgent problem to be solved in the engineering field.

Disclosure of Invention

In view of this, the utility model aims at providing a tunnel drainage type corrugated steel preliminary bracing structure can overcome the not enough of prior art.

The utility model aims at realizing through the following technical scheme:

a tunnel drainage type corrugated steel primary support structure comprises an I-shaped steel instant support structure, an anchor rod expansion support structure and a corrugated steel reinforcing support structure which are sequentially arranged on the inner wall surface of a tunnel, wherein the I-shaped steel instant support structure is fixedly connected to the inner wall of the tunnel and used for inhibiting loose deformation of surrounding rock at the initial excavation stage; the anchor rod expansion supporting structure penetrates through the I-shaped steel instant supporting structure and penetrates into the tunnel surrounding rock to form a surrounding rock reinforcing structure; the corrugated steel reinforcement supporting structure comprises a spliced corrugated plate structure corresponding to the shape of the inner wall of the tunnel, the spliced corrugated plate structure is rigidly connected with the I-steel instant supporting structure to form an outer steel mould structure, and mold concrete is filled between the I-steel instant supporting structure and the outer steel mould structure to form a reinforcement structure; and the spliced corrugated plate structure is connected with a tunnel drainage pipeline system and is used for water blocking and drainage in the tunnel.

The waterproof plate and the impervious secondary lining are sequentially arranged on the outer side of the corrugated steel reinforced supporting structure and used for preventing water in the tunnel.

And a staggered joint mold sealing steel base plate and a top sealing steel cover plate which are convenient for demolding are arranged at the position of the joist steel arch foot of the instant joist steel supporting structure, so that a splicing interface of the spliced corrugated plate structure, a molded concrete construction joint and a joist steel joint interface form a staggered joint structure.

The I-steel instant supporting structure comprises sprayed concrete used for sealing a surrounding rock surface after tunnel excavation and a plurality of I-steels closely attached and erected with the sprayed concrete; the I-steel includes the I-steel roof beam, is provided with the bolt trompil on the I-steel roof beam inboard pterygoid lamina, and both ends are equipped with connecting plate about the I-steel roof beam, and the left and right sides just is close to the hunch foot position and is equipped with L type location steel sheet, offers a pair of positioning hole that the position is relative on two sides of L type location steel sheet.

The anchor rod extended supporting structure comprises a surrounding rock grouting reinforcement measure formed by a system anchor rod and a foot locking anchor rod.

The spliced corrugated plate structure comprises a first corrugated steel member arranged at the top of the tunnel, second corrugated steel members arranged at the lower parts of side walls on two sides of the tunnel and a third corrugated steel member arranged on an inverted arch of the tunnel, wherein the first corrugated steel member, the second corrugated steel member and the third corrugated steel member are all bent into an arc shape which is attached to the shape of the tunnel and are sequentially connected into a closed structure corresponding to the shape of the inner wall of the tunnel through driven expansion bolts; and an arc-shaped diversion trench is arranged at the middle lower part of the second corrugated steel component and communicated with the tunnel drainage pipeline system.

The first corrugated steel member is provided with a plurality of first splicing units arranged in the range of 180 degrees of the vault, and each first splicing unit is of a combined structure of a composite corrugated steel plate and a common short corrugated steel plate; the second corrugated steel component is a second splicing unit arranged in the range of side walls on two sides of the tunnel, the second splicing unit is a combined structure of a composite corrugated steel plate, an arc-shaped diversion trench and a common long-wave-line steel plate, one end of the arc-shaped diversion trench is welded with the common long-wave-line steel plate, and the other end of the arc-shaped diversion trench is connected with a tunnel drainage pipeline system; and the third corrugated steel member is that many third concatenation units set up in the tunnel invert scope, and the third concatenation unit is ordinary corrugated steel plate.

The composite corrugated steel plate comprises corrosion-resistant corrugated steel, wherein the outer surface of the corrosion-resistant corrugated steel is attached with a high-molecular waterproof coating, the inner surface of the corrosion-resistant corrugated steel is provided with a composite waveform drainage pad, and the outer end surface of the composite waveform drainage pad is provided with an antifouling covering layer; the composite corrugated drainage pad comprises a corrugated inner layer attached to the inner surface of the corrosion-resistant corrugated steel and a plane layer opposite to the inner surface, wherein a polypropylene drainage material is filled between the corrugated inner layer and the plane layer, the corrugated inner layer and the plane layer are made of geotextile, the corrugated inner layer is fixedly attached to the inner side of the corrosion-resistant corrugated steel through a strong adhesive, and the plane layer is provided with a hot-melt cushion block.

Compared with the prior art, the beneficial effects of the utility model are that:

(1) the utility model prevents the groundwater from penetrating through the primary support as much as possible by the waterproof material which is sprayed on the outer side of the added corrugated steel in a full-circle manner, and can effectively improve the integral impermeability of the primary support compared with the existing primary support structure;

(2) the composite corrugated drainage cushion is adhered to the inner side of the corrugated steel, the arc-shaped diversion trench at the lower part of the composite corrugated drainage cushion can quickly guide and drain the underground water penetrating through the corrugated steel plate into a tunnel drainage system, and compared with the existing primary support structure, the construction process of installing the annular drainage pipe is omitted, the full coverage of a drainage channel at the inner side of the primary support is realized, the drainage efficiency of the underground water can be greatly improved, and the problem of accumulated water clogging between the primary support and the secondary lining is effectively solved;

(3) the combined type corrugated steel material of the utility model establishes a combined type waterproof and drainage structure system of 'water blocking first, water drainage then and water proofing later' by matching with a waterproof board, an impervious secondary lining and the like, can greatly improve the waterproof and drainage performance of a tunnel supporting structure compared with the existing tunnel waterproof and drainage system, and effectively improves the problem of serious tunnel water leakage in the operation period;

(4) tunnel drainage type corrugated steel preliminary bracing structure, it divides preliminary bracing structure into the instant supporting construction of injection concrete processing word steel combination formula, the system stock of middle period construction, the corrugated steel of expanding supporting construction such as lock foot stock and later stage construction behind the corrugated steel adds the modular reinforcement supporting construction of corrugated steel back of the body concrete. The early-construction instant supporting structure can effectively inhibit loose deformation of surrounding rock at the initial excavation stage, and ensures the stability of the surrounding rock; the expanded supporting structure constructed in the middle stage can effectively reinforce the surrounding rock and fully exert the self bearing capacity of the surrounding rock; compared with the existing primary supporting structure and corrugated steel primary supporting, a tunnel drainage type corrugated steel primary supporting structure system of 'I-steel instant supporting, anchor rod expanding supporting and corrugated steel reinforcing supporting' is established, the supporting concept is more scientific, the structural stress is more reasonable, and the construction process division is more definite;

(5) the I-steel in the instant support structure of the tunnel drainage type corrugated steel primary support structure can be used as a positioning steel frame for advanced support, and the tunnel drainage type corrugated steel primary support structure has stronger harmony with the advanced support compared with the corrugated steel primary support;

(6) the tunnel drainage type corrugated steel primary supporting structure has the construction thickness of sprayed concrete of only 5-10cm, and only needs to be operated once, compared with the existing primary supporting structure, the construction strength of the sprayed concrete is greatly reduced, and the construction operation environment is obviously improved;

(7) the utility model discloses a tunnel drainage type corrugated steel preliminary bracing structure, it is through the L type location steel sheet of welding on the I-steel web, can the accurate application angle of control lock foot stock to for the lock foot stock provides the structural configuration who establishes rigid connection with the I-steel, compare in current preliminary bracing structure, the construction quality of lock foot stock is ensured, and can effectively lock solid the I-steel, improve the structural stability of preliminary bracing;

(8) the utility model discloses a tunnel drainage type corrugated steel preliminary bracing structure, its corrugated steel bolt anchor have left and right sides erect on the completion I-steel, and the corrugated steel after the installation forms confined mould concrete space with the concrete spraying face in the outside, the I-steel of both sides and the staggered joint die sealing steel backing plate in bottom, for corrugated steel preliminary bracing, the installation construction and the mould concrete pouring construction of corrugated steel are convenient and fast more, construction maneuverability improves by a wide margin;

(9) the utility model discloses a tunnel drainage type corrugated steel preliminary bracing structure, it realizes corrugated steel assembly interface, corrugated steel back mould concrete construction seam and the upper, middle, lower staggered joint effect of I-steel joint interface through the staggered joint die sealing steel backing plate that sets up in I-steel hunch foot position, compare in current preliminary bracing structure and corrugated steel preliminary bracing, it has effectively improved because of the structural defect that the flush joint structure of I-steel joint or mould concrete construction seam leads to the existence of obvious weak position of atress in the preliminary bracing structure, tunnel drainage type corrugated steel preliminary bracing structure's whole atress is more even;

(10) tunnel drainage type corrugated steel preliminary bracing structure, its bolted connection through corrugated steel and I-steel, survey in preliminary bracing and pull the district and form the steel drum structure that seals the cyclization, can improve preliminary bracing's surface crack resistance and longitudinal connectivity by a wide margin. Meanwhile, the molded concrete replaces part of sprayed concrete, so that the quality of the primary support concrete is guaranteed technically, and compared with the existing primary support structure, the quality of the support structure is greatly improved;

(11) tunnel drainage type corrugated steel preliminary bracing structure, the I-steel only is as instant supporting construction's component, its importance in the preliminary bracing structure system reduces by a wide margin. In the actual construction process, on the premise of ensuring construction safety, the advance support can be reasonably strengthened through reasonable reinforcement, the tunneling speed of the tunnel face position is improved through a measure of properly enlarging the distance between the I-shaped steel, and then the overall structural strength of the preliminary support is reinforced through corrugated steel and corrugated steel back molding concrete.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and/or combinations particularly pointed out in the appended claims.

Drawings

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail with reference to the accompanying drawings, in which:

fig. 1 is a schematic view of the structure of the arch foot of the combined drainage system of the present invention.

Fig. 2 is the structure schematic diagram of the vertical tangent plane of the combined primary support arch of the utility model.

Fig. 3 is a schematic diagram of a splicing structure of the corrugated steel reinforced supporting structure 3 in fig. 1.

Fig. 4 is an enlarged schematic view of a portion a in fig. 3.

Fig. 5 is a schematic structural view of the first corrugated steel member 31.1 of fig. 4.

Fig. 6 is a schematic structural view of the second corrugated steel member 31.2 of fig. 4.

Fig. 7 is a schematic structural view of the third corrugated steel member 31.3 in fig. 4.

Fig. 8 shows a schematic view of a driven expansion bolt 31.4.

Fig. 9 is a schematic structural view of the spiral expansion bolt 8.

Fig. 10 is a schematic structural view of a transverse section of the combined primary support side wall of the present invention.

Fig. 11 is a schematic structural view of a radial section of the combined type preliminary bracing side wall of the present invention.

Fig. 12 is a connection structure diagram of the arch springing position i-steel 1.2 and the locking anchor rod 2.2.

Fig. 13 is a schematic view of a connection structure of an i-steel 1.2, a construction joint connecting steel bar 11 and a staggered joint sealing steel backing plate 9.

Fig. 14 is a schematic view of the connection structure of the corrugated steel, the i-steel 1.2 and the staggered seam sealing die steel backing plate 9.

Fig. 15 is a side view of fig. 14.

Fig. 16 is a schematic structural view of the corrugated steel back molding concrete 32 construction.

Fig. 17 is a schematic structural diagram of the demolded I-steel 1.2 arch foot position stagger joint die-sealing steel backing plate 9 and the top-sealing steel cover plate 10.

FIG. 18 is a schematic view of the butt joint installation of H-shaped steel of upper and lower steps of a tunnel.

Fig. 19 is a schematic side structure view of the tunnel upper and lower step corrugated steel plate butt joint installation.

Fig. 20 is a schematic view of the staggered joint effect of the present invention.

Fig. 21 is a schematic structural view of the stagger-joint sealing die steel backing plate 9.

Fig. 22 is a schematic structural view of the capped steel cover plate 10.

Fig. 23 is a first construction process diagram of the present invention.

Fig. 24 is a second construction process diagram of the present invention.

Fig. 25 is a third construction process diagram of the present invention.

Fig. 26 is a fourth construction process diagram of the present invention.

Fig. 27 is a fifth construction process diagram of the present invention.

Fig. 28 is a sixth construction process diagram of the present invention.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the preferred embodiments are for purposes of illustration only and are not intended to limit the scope of the present invention.

As shown in fig. 1-6, the temporary supporting structure comprises an i-steel immediate supporting structure 1, an anchor rod expansion supporting structure 2 and a corrugated steel reinforcement supporting structure 3 which are sequentially arranged on the inner wall surface of the tunnel, wherein the i-steel immediate supporting structure 1 is fixedly connected to the inner wall of the tunnel and is used for inhibiting the loose deformation of the surrounding rock at the initial excavation stage; the anchor rod expansion supporting structure 2 penetrates through the I-steel instant supporting structure 1 and penetrates into the tunnel surrounding rock to form a surrounding rock reinforcing structure; the corrugated steel reinforcing and supporting structure 3 comprises a spliced corrugated plate structure 31 corresponding to the shape of the inner wall of the tunnel, the spliced corrugated plate structure 31 is rigidly connected with the I-shaped steel instant supporting structure 1 to form an outer steel mould structure, and mold concrete 32 is filled between the I-shaped steel instant supporting structure and the outer steel mould structure to form a reinforcing structure; and the spliced corrugated plate structure 31 is connected with a tunnel drainage pipeline system 6 and used for water blocking and drainage in the tunnel.

The I-steel instant supporting structure 1 comprises sprayed concrete 1.1 used for sealing the surrounding rock surface after tunnel excavation and a plurality of I-steel 1.2 closely erected with the sprayed concrete 1.1, so that loose deformation after the surrounding rock excavation can be effectively inhibited, and the surrounding rock stability of the tunnel excavation to corrugated steel mold concrete forming strength construction intermittent sections is ensured.

At the poor paragraph of country rock, instant supporting construction of I-steel 1 still includes reinforcing bar net piece 1.3, and reinforcing bar net piece 1.3 only sets up under the poor ability of country rock self-stability, and the shotcrete 1.1 fracture phenomenon is serious, can not set up under the better condition of country rock self-stability.

The anchor rod extension supporting structure 2 comprises a surrounding rock grouting reinforcement measure formed by a system anchor rod 2.1 and a foot locking anchor rod 2.2, surrounding rock can be effectively reinforced, and the bearing capacity of the surrounding rock is fully exerted.

The thickness of the sprayed concrete 1.1 is determined according to the surrounding rock conditions, and is generally about 5-10 cm.

The I-steel 1.2 comprises an I-steel beam 1.2.1, bolt holes are formed in an inner side wing plate of the I-steel beam 1.2.1, and connecting steel plates 1.2.2 are arranged at the upper end and the lower end of the I-steel beam 1.2.1; the left and right sides has increased L type location steel sheet 1.2.3, set up a pair of opposite position's positioning hole on two sides of L type location steel sheet 1.2.3, L type location steel sheet 1.2.3 is in advance the symmetric welding in the side about I-steel girder 1.2.1 when I-steel 1.2 hole outer processing, and its positioning hole is used for the drilling location of lock foot stock 2.2 construction stage to reach lock foot stock 2.2 and I-steel 1.2 rigid connection's joint construction.

The size of the L-shaped positioning steel plate 1.2.3 is determined according to the type of the foot-locking anchor rod 2.2 and the angle required to be constructed.

Preferably, the L-shaped positioning steel plate 1.2.3 is additionally arranged only at the position where the foot-locking anchor rod 2.2 needs to be arranged, and the I-shaped steel 1.2 section where the foot-locking anchor rod 2.2 is not arranged does not need to be additionally arranged. Specifically, the L-shaped positioning steel plate 1.2.3 is only arranged on the I-shaped steel 1.2 close to the arch springing position.

The arrangement distance of the I-beams 1.2 is flexibly selected according to the surrounding rock conditions, the importance of the I-beams in a primary support structure system is greatly reduced in view of the fact that the I-beams 1.2 are only used as the components of an instant support structure, the I-beam distance can be properly increased compared with the arrangement distance of a conventional primary support so as to improve the tunneling speed of the tunnel face position, and then the overall structural strength of the primary support is reinforced through corrugated steel and corrugated steel rear mold building concrete.

The spliced corrugated plate structure 31 comprises a first corrugated steel member 31.1 arranged at the top of the tunnel, second corrugated steel members 31.2 arranged at the lower parts of side walls on two sides of the tunnel and a third corrugated steel member 31.3 arranged on an inverted arch of the tunnel, wherein the first corrugated steel member 31.1, the second corrugated steel member 31.2 and the third corrugated steel member 31.3 are all bent into arcs matched with the shape of the tunnel and are sequentially connected into a closed structure corresponding to the shape of the inner wall of the tunnel through driven expansion bolts 31.4; an arc-shaped diversion trench 31.5 is formed in the middle lower portion of the second corrugated steel member 31.2, the arc-shaped diversion trench 31.5 is communicated with the tunnel drainage pipeline system 6, and accumulated water collected on the upper portions of the first corrugated steel member 31.1 and the second corrugated steel member 31.2 can be drained into the tunnel drainage pipeline system 6; the tunnel drainage pipeline system 6 is an existing tunnel drainage structure and comprises a longitudinal drainage pipe, a transverse drainage pipe and a central drainage pipe (or a roadside ditch) which are communicated with each other.

And a waterproof plate 5 and an impervious secondary lining 4 are sequentially arranged on the outer side of the corrugated steel reinforcing and supporting structure 3. The waterproof board 5 and the secondary lining 4 are used for preventing water in the tunnel. The I-steel instant supporting structure 1, the anchor rod expanding supporting structure 2, the corrugated steel reinforcing supporting structure 3, the waterproof plate 5 and the impervious secondary lining 4 which are sequentially arranged can establish a combined waterproof and drainage structure system with the functions of firstly blocking water, then draining water and then preventing water.

The first corrugated steel member 31.1 is formed by arranging a plurality of first splicing units in a 180-degree arch crown range, and each first splicing unit is of a combined structure of a composite corrugated steel plate and a common short corrugated steel plate; the second corrugated steel component 31.2 is a second splicing unit arranged in the lower range of the side walls at two sides of the tunnel, the second splicing unit is a combined corrugated steel plate, an arc-shaped diversion trench 31.5 and a common long-wave-line steel plate combined structure, one end of the arc-shaped diversion trench 31.5 is welded with the common long-wave-line steel plate, and the other end is connected with a tunnel drainage pipeline system 6; and the third corrugated steel member 31.3 is that a plurality of third splicing units are arranged in the range of the tunnel inverted arch, and the third splicing units are common corrugated steel plates.

The composite corrugated steel plate comprises corrosion-resistant corrugated steel, a high-molecular waterproof coating is attached to the outer surface of the corrosion-resistant corrugated steel, a composite waveform drainage mat is arranged on the inner surface of the corrosion-resistant corrugated steel, and an antifouling covering layer is arranged on the end face of the composite waveform drainage mat. The corrosion-resistant corrugated steel is made of corrosion-resistant steel, and the waveform parameters of the corrosion-resistant corrugated steel are in a model with a small wave depth, preferably 178 x 45mm and 200 x 55mm, so as to reduce the primary support space occupied by the corrugated steel as much as possible; spraying high-molecular waterproof paint on the outer surface of the corrosion-resistant corrugated steel to serve as an important water-blocking barrier for preventing underground water from permeating into the primary support; the composite wave-shaped drainage pad comprises a wave-shaped inner layer attached to the inner surface of the rust-resistant corrugated steel and a plane layer opposite to the wave-shaped inner layer, and composite materials such as polypropylene drainage materials and the like are filled between the wave-shaped inner layer and the plane layer; the corrugated inner layer and the plane layer are made of geotextile, and the corrugated inner layer is fixedly adhered to the inner side of the anticorrosive corrugated steel through a strong adhesive.

The antifouling covering layer is a layer of plastic mucous membrane and covers the outer side surface of the composite wave-shaped drainage pad so as to prevent the composite wave-shaped drainage pad from being polluted during construction.

The plane layer is provided with a hot melting cushion block; and when the waterproof plate 5 is constructed in the later stage, the waterproof plate 5 is subjected to hot melt bonding with the hot melt cushion block on the composite wave-shaped drainage mat.

The I-shaped steel 1.2 and the corrugated steel reinforcing and supporting structure 3 are rigidly connected through a spiral expansion bolt 8. The upper step I-steel arch foot position of the I-steel instant supporting structure 1 is provided with a staggered joint mold sealing steel backing plate 9 and a top sealing steel cover plate 10 which are convenient for demolding, so that the splicing interface of the splicing corrugated plate structure, the mold concrete 32 construction joint and the I-steel joint interface form a staggered joint structure.

Specifically, the 1.2 hunch foot position of the upper step I-steel of the instant supporting construction of I-steel is equipped with stagger joint die sealing steel backing plate 9, seals top steel apron 10 and construction joint connecting reinforcement 11, stagger joint die sealing steel backing plate 9 include that steel backing plate 9.1, steel backing plate 9.1 both sides are equipped with stagger joint overlap 9.4, the intermediate position is equipped with steelframe recess 9.2, steelframe recess 9.2 bilateral symmetry is equipped with construction joint connecting reinforcement jack 9.3. During installation, the connecting steel plate 1.2.2 of the I-steel is inserted into the steel frame groove 9.2 on the steel backing plate, the steel frame groove 9.2 notch is sealed by the capping steel cover plate 10, the construction joint connecting steel bar 11 is installed in the construction joint connecting steel bar insertion hole 9.3, and so on, a plurality of I-steels 1.2 are connected with the corresponding staggered joint sealing mold steel backing plate 9, meanwhile, the staggered joint connection of two adjacent steel backing plates is realized through the staggered joint scrap 9.4, the spliced corrugated plate structure 31 is installed on the I-steel 1.2 through the spiral expansion bolt 8, so that the sprayed concrete 1.1, the I-steel 1.2, the spliced corrugated plate structure 31 and the steel backing plate 9.1 form a cavity, the mold building concrete 32 is filled in the cavity, and the reinforcing support taking the spliced corrugated plate structure 31 as an outer mold steel plate and the staggered joint mold building concrete 32 structure is formed.

The thickness of the steel backing plate 9.1 is more than 20cm so as to ensure the staggered joint effect of the I-steel 1.2 joint and the mold concrete 32, and the steel backing plate 9.1 is of a hollow grid structure, so that the whole weight is reduced, meanwhile, the sufficient strength is ensured, and deformation and damage in the repeated use process are prevented;

the size of the steel frame groove 9.2 is slightly larger than that of the I-shaped steel connecting steel plate 1.2.2, so that the installation is convenient;

the capping steel cover plate 10 is of a two-half butt joint structure, is 1-2cm thick, is matched with I-shaped steel in shape, is used for covering a notch of a steel frame groove 9.2 and blocking concrete from being poured into the steel frame groove 9.2 so as to ensure that the lower part of the I-shaped steel 1.2 has a certain exposed section, so that the subsequent butt joint installation of upper and lower I-shaped steels is facilitated, and the I-shaped steel joint interface or a molded concrete construction joint generates a staggered joint effect.

The construction joint connecting steel bar 11 adopts ribbed screw steel as a connecting reinforcing bar at the position of the cast concrete construction joint.

The construction method based on the tunnel drainage type corrugated steel primary support structure comprises the following steps:

(1) carrying out face excavation construction, positioning by using an I-shaped steel frame erected near the face of the tunnel, constructing an advance support to the front of the face, excavating the face under the protection of the advance support, cleaning dangerous stones, and carrying out slag tapping construction;

(2) the I-steel instant supporting structure 1 is constructed, after slag discharging is finished, sprayed concrete 1.1 is immediately constructed to seal a rock surrounding surface, after the sprayed concrete 1.1 is finished, a staggered joint mould sealing steel backing plate 9 is arranged at the position of an upper step arch foot, then upper step I-steel 1.2 is installed, and a top sealing steel cover plate 10 is arranged;

(3) constructing an anchor rod expansion supporting structure 2, and constructing reinforcement measures of an upper step foot locking anchor rod 2.2 and a system anchor rod 2.1 under the protection of sprayed concrete 1.1 and I-steel 1.2;

(4) constructing a corrugated steel reinforcing and supporting structure 3, namely inserting construction joint connecting steel bars 11 into construction joint connecting steel bar insertion holes 9.3, then installing a spliced corrugated plate structure 31 on I-shaped steel 1.1, and then performing mould construction on a corrugated steel back rear closed cavity through grouting holes reserved in the corrugated steel;

(5) the stage of lowering the platform and the position of the inverted arch are used for carrying out construction of an instant supporting structure and an extended supporting structure,

after the lower step is excavated, sprayed concrete is constructed to seal the surrounding rock surface, then the staggered joint die sealing steel backing plate 9 and the top sealing steel cover plate 10 are subjected to demoulding treatment, then the lower step I-steel and the inverted arch I-steel are sequentially butted and anchored with the upper step I-steel, and then a lower step system anchor rod is constructed;

(6) constructing a lower step and an inverted arch reinforcing and supporting structure, installing corrugated steel at the positions of the lower step and the inverted arch, and further constructing corrugated steel backs and then molding concrete;

(7) and (5) constructing a tunnel drainage pipeline system 6 and a secondary lining 4.

In the step (2), the thickness of the sprayed concrete 1.1 is adjusted according to the surrounding rock conditions, and is generally controlled to be 5-10 cm.

The staggered joint die sealing steel backing plates 9 are longitudinally and sequentially arranged, longitudinal lap joints of adjacent blocks are carried out through staggered joint overlap edges 9.4, then step I-shaped steel 1.2 is installed, I-shaped steel connecting steel plates 1.2.2 are placed in steel frame grooves 9.2 of the staggered joint die sealing steel backing plates, and capping steel cover plates 10 are used for covering the notches.

A release agent is coated on the staggered joint die-sealing steel backing plate 9 and the top-sealing steel cover plate 10, so that the subsequent disassembly and reuse are facilitated; meanwhile, the I-steel 1.2 and the sprayed concrete 1.1 are closely attached, and if gaps exist, the sprayed concrete is applied to carry out secondary spraying and compacting.

In the step (3), the foot-locking anchor rod 2.2 is rigidly connected with the I-steel 1.2, the exposed ends of the foot-locking anchor rod 2.2 and the system anchor rod 2.1 are not too long, and the part occupying the subsequent corrugated steel installation space is cut off in advance.

The foot-locking anchor rod 2.2 is positioned and connected by means of an L-shaped positioning steel plate 1.2.3 welded on the I-shaped steel 1.2, and the specific process is as follows:

in the drilling construction stage of the foot-locking anchor rod 2.2, a drill rod penetrates through a pair of positioning through holes of the L-shaped positioning steel plate 1.2.3, drilling is conducted according to the straight line determined by the positioning through holes, after the drilling is completed, the drill rod is pulled out, the foot-locking anchor rod 2.2 sequentially penetrates through the positioning through holes and the drilling, and the foot-locking anchor rod 2.2 is in close contact with a rock body in the modes of grouting and the like; the end of the foot-locking anchor rod 2.2 slightly exceeds the end of the L-shaped positioning steel plate 1.2.3, but does not exceed the inner side wing plate of the I-shaped steel 1.2, so as to avoid invading the subsequent corrugated steel installation space.

The foot-locking anchor rod 2.2 and the L-shaped positioning steel plate 1.2.3 are clamped through two positioning holes with different angles, welding can be omitted between the foot-locking anchor rod 2.2 and the L-shaped positioning steel plate 1.2.3, and the process of welding construction in a hole can be omitted.

And (3) performing circular construction according to the working procedures (1) to (3) at the position of the tunnel face, and orderly performing construction of the corrugated steel reinforced supporting structure 3 in a section 5-8 meters away from the tunnel face.

In the step (4), the specific method of the corrugated steel reinforced supporting structure 3 is as follows: the construction joint connecting steel bars 11 are placed in construction joint connecting steel bar inserting holes 9.3 of the staggered joint mould sealing steel backing plate 9, then left and right I-shaped steel beams 1.2 are used as positioning steel frames, the spliced corrugated plate structure 31 is installed on the I-shaped steel beams 1.2.1 through spiral expansion bolts 8, and mould building concrete 32 construction is conducted on a closed cavity formed by the corrugated steel, concrete 1.1 on the surrounding rock surface, the I-shaped steel 1.2 on the two sides and the staggered joint mould sealing steel backing plate 9 at the bottom through grouting holes reserved in the corrugated steel plates.

When the composite corrugated steel plate is installed, the front side and the back side are distinguished, the side coated with the high-molecular waterproof coating faces the surrounding rock side, and the side adhered with the composite corrugated drainage mat faces the inside of the tunnel.

And (5) according to corresponding specifications and in combination with the surrounding rock conditions, after the upper step and the tunnel face are separated by a certain distance, excavating the lower step, spraying concrete to the surrounding rock face for 1.1 sealing, and installing the lower step and the inverted arch I-steel.

Separating a staggered joint die sealing steel backing plate 9 and a top sealing steel cover plate 10 arranged in the installation process of the I-steel 1.2 of the upper step section, and recycling the steel backing plate and the top sealing steel cover plate in subsequent cycle construction; and butting the upper connecting steel plate of the I-steel at the stage of the lower platform with the lower connecting steel plate of the I-steel at the step of the upper platform, and rigidly connecting the upper connecting steel plate and the lower connecting steel plate through a common high-strength bolt 7.

In the step (6), the staggered joint sealing steel backing plate 9 is not arranged at the arch springing position of the lower step, only a common channel steel backing plate needs to be arranged, and the channel steel backing plate is taken as a permanent structure and does not need to be dismantled.

And after the length of the inverted arch reaches the proper length, the installation construction of the corrugated steel at the lower step and the inverted arch and the construction of the corrugated steel back rear mold concrete 32 are finished by referring to the installation construction of the corrugated steel at the upper step and the construction of the corrugated steel back rear mold concrete 32.

In the step (7), after the construction of the whole ring structure is completed according to the steps, the inverted arch filling and the construction of the tunnel drainage pipeline system 6 are carried out according to the construction requirements.

Because the composite corrugated steel plate is adhered with the composite wave-shaped drainage cushion, the installation of the annular drainage pipe is not needed, and the arc-shaped diversion trench 31.5 is directly connected with the longitudinal drainage pipe in the tunnel drainage pipe system 6. And then, tearing off the antifouling covering layer on the outer side of the composite corrugated steel plate, and further carrying out hot melt bonding on the waterproof plate 5 and the hot melt cushion block on the composite corrugated drainage mat to finish the laying construction of the waterproof plate 5.

And after the waterproof plate 5 is laid, binding a second lining steel bar, and pouring a secondary lining 4 to complete the construction of the tunnel supporting structure of one section.

The above-mentioned excavation method only exemplifies with two-step excavation method, is only the preferred embodiment of the utility model, and is not right the utility model discloses do the secret restriction of any form, any does not break away from the technical scheme content of the utility model, according to the utility model discloses a technical entity is to any simple modification, the equivalent change and the decoration of making of above embodiment, all still belong to the technical scheme scope of the utility model.

Claims (8)

1. The utility model provides a tunnel drainage type corrugated steel preliminary bracing structure which characterized in that: the device comprises an I-shaped steel instant supporting structure (1), an anchor rod expanding supporting structure (2) and a corrugated steel reinforcing supporting structure (3) which are sequentially arranged on the inner wall surface of a tunnel, wherein the I-shaped steel instant supporting structure (1) is fixedly connected to the inner wall of the tunnel and is used for inhibiting the loose deformation of surrounding rock at the initial excavation stage; the anchor rod expansion supporting structure (2) penetrates through the I-steel instant supporting structure (1) and penetrates into the tunnel surrounding rock to form a surrounding rock reinforcing structure; the corrugated steel reinforcing and supporting structure (3) comprises a spliced corrugated plate structure (31) corresponding to the shape of the inner wall of the tunnel, the spliced corrugated plate structure (31) is rigidly connected with the I-shaped steel instant supporting structure (1) to form an outer side steel mould structure, and mold concrete (32) is filled between the I-shaped steel instant supporting structure (1) and the outer side steel mould structure to form a reinforcing structure; and the spliced corrugated plate structure (31) is connected with a tunnel drainage pipeline system (6) and is used for water blocking and drainage in the tunnel.

2. The tunnel drainage type corrugated steel preliminary bracing structure according to claim 1, characterized in that: the corrugated steel reinforcing and supporting structure (3) is characterized in that a waterproof plate (5) and an impervious secondary lining (4) are sequentially arranged on the outer side of the corrugated steel reinforcing and supporting structure, and the waterproof plate (5) and the impervious secondary lining (4) are used for preventing water in a tunnel.

3. The tunnel drainage type corrugated steel preliminary bracing structure according to claim 1 or 2, characterized in that: the I-steel arch foot position of the instant I-steel supporting structure (1) is provided with a staggered joint mold sealing steel base plate (9) and a top sealing steel cover plate (10) which are convenient for demolding, so that the assembled interface of the spliced corrugated plate structure, the construction joint of the mold concrete (32) and the I-steel joint interface form a staggered joint structure.

4. The tunnel drainage type corrugated steel preliminary bracing structure according to claim 3, characterized in that: the instant I-steel supporting structure (1) comprises sprayed concrete (1.1) used for surrounding rock face sealing after tunnel excavation and a plurality of I-steels (1.2) closely attached and erected with the sprayed concrete (1.1), the I-steels (1.2) comprise I-steel beams (1.2.1), bolt holes are formed in side wing plates in the I-steel beams (1.2.1), connecting steel plates (1.2.2) are arranged at the upper end and the lower end of each I-steel beam (1.2.1), L-shaped positioning steel plates (1.2.3) are arranged on the left side and the right side and close to arch foot positions, and a pair of positioning through holes opposite in position are formed in two side edges of each L-shaped positioning steel plate (1.2.3).

5. The tunnel drainage type corrugated steel preliminary bracing structure according to claim 3, characterized in that: the anchor rod extended supporting structure (2) comprises a surrounding rock grouting reinforcement measure formed by a system anchor rod (2.1) and a foot locking anchor rod (2.2).

6. The tunnel drainage type corrugated steel preliminary bracing structure according to claim 3, characterized in that: the spliced corrugated plate structure (31) comprises a first corrugated steel member (31.1) arranged at the top of the tunnel, second corrugated steel members (31.2) arranged at the lower parts of side walls on two sides of the tunnel and a third corrugated steel member (31.3) arranged on an inverted arch of the tunnel, wherein the first corrugated steel member, the second corrugated steel member and the third corrugated steel member are all bent into an arc shape which is attached to the shape of the tunnel and are sequentially connected into a closed structure corresponding to the shape of the inner wall of the tunnel through drive-in expansion bolts (31.4); an arc-shaped diversion trench (31.5) is arranged at the middle lower part of the second corrugated steel component (31.2), and the arc-shaped diversion trench (31.5) is communicated with a tunnel drainage pipeline system (6).

7. The tunnel drainage type corrugated steel preliminary bracing structure according to claim 6, characterized in that: the first corrugated steel member (31.1) is formed by arranging a plurality of first splicing units in a 180-degree arch crown range, and each first splicing unit is of a combined structure of a composite corrugated steel plate and a common short corrugated steel plate; the second corrugated steel component (31.2) is a second splicing unit arranged in the lower range of the side walls at two sides of the tunnel, the second splicing unit is a combined structure of a composite corrugated steel plate, an arc-shaped diversion trench (31.5) and a common long corrugated steel plate, one end of the arc-shaped diversion trench (31.5) is welded with the common long corrugated steel plate, and the other end of the arc-shaped diversion trench is connected with a tunnel drainage pipeline system (6); and the third corrugated steel member (31.3) is formed by arranging a plurality of third splicing units in the range of the inverted arch of the tunnel, and the third splicing units are common corrugated steel plates.

8. The tunnel drainage type corrugated steel preliminary bracing structure according to claim 7, characterized in that: the composite corrugated steel plate comprises corrosion-resistant corrugated steel, the outer surface of the corrosion-resistant corrugated steel is attached with a high-molecular waterproof coating, the inner surface of the corrosion-resistant corrugated steel is provided with a composite waveform drainage pad, and the outer end surface of the composite waveform drainage pad is provided with an antifouling covering layer; the composite corrugated drainage pad comprises a corrugated inner layer attached to the inner surface of the corrosion-resistant corrugated steel and a plane layer opposite to the inner surface, wherein a polypropylene drainage material is filled between the corrugated inner layer and the plane layer, the corrugated inner layer and the plane layer are made of geotextile, the corrugated inner layer is fixedly attached to the inner side of the corrosion-resistant corrugated steel through a strong adhesive, and the plane layer is provided with a hot-melt cushion block.

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