CN214062993U - Shallow excavation tunnel excavation supporting system that buries - Google Patents

Abstract

The utility model provides a shallow-buried underground excavation tunnel excavation supporting system, which relates to the technical field of tunnel engineering, and is characterized in that a long pipe shed and a small pipe are adopted for pre-grouting and reinforcing a forepoling, and the long pipe shed and the small pipe grouting supporting are arranged, so that the reinforcing effect is good, and the grouting quality is easy to control; by arranging the inclination-adjustable pipe shed orifice guide device and the guide pipe inclination adjusting device which are fixedly arranged on the steel arch frame, the inclination and the installation position of the pipe shed and the guide pipe can be accurately controlled, the construction speed is high, and the effect is obvious; through adopting water injection bag cluster thick liquid to carry out interim shutoff and installation tunnel vault bulky trickle cavity support system, can effectively prevent the lax deformation of country rock, improve the wholeness of vault country rock, play fine stifled row effect to pore water.

Description

Shallow excavation tunnel excavation supporting system that buries

Technical Field

The utility model relates to a tunnel engineering technical field, concretely relates to shallow excavation tunnel excavation supporting system that buries.

Background

Along with the rapid development of urban construction in China, urban traffic pressure is relieved due to urban expansion. In recent years, the construction of urban tunnels is increasing, and due to the limitation of land utilization and the fact that most of the urban tunnels are located in busy sections and close to dense buildings or residential areas, tunnels with various complex geology are increasing, and the safety of tunnel construction is receiving more and more attention from society. The construction of the tunnel penetrating through the broken zone, the loose zone and the weak stratum has the defects of high construction difficulty, higher construction risk and poor safety. The construction method can safely and quickly pass through the unfavorable geological section, effectively control the ground subsidence caused in the construction process and the influence on peripheral structures, and has high requirements on the technical scheme, the construction organization and constructors. In the construction of a weak surrounding rock tunnel, vault collapse caused by the conditions of geological sudden change of water spraying, unstable argillaceous interlayers of the surrounding rock softening when encountering water or weak broken surrounding rock and the like can leave behind engineering quality hidden dangers if being not properly treated in construction, and brings potential safety hazards to the tunnel in the application stage, so that the method is particularly important for treating a large-volume water spraying cavity of the vault in tunnel construction under the principles of safety, rapidness, quality guarantee and conservation.

The entrance and exit construction of mountain tunnels is faced with complex entrance environment, large investment amount and high requirement on cooperation of personnel operation and machinery, so that the tunneling speed is accelerated in the construction of mountain road tunnels, labor and mechanical resources are reasonably distributed, the construction cost is reduced, and the rapid construction, safe entrance and exit are particularly important on the premise of ensuring the quality and safety.

In view of this, a new excavation and support construction method for shallow-buried underground tunnel is urgently needed to overcome the defects of low excavation and support construction speed, poor support effect, low installation speed and accuracy of pipe shed and small guide pipe, poor plugging effect, poor integrity of surrounding rock of cavity body and the like of the conventional shallow-buried underground tunnel, improve construction efficiency, improve construction quality and ensure safe and reliable construction quality.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a shallow undercut tunnel excavation of burying is strutted system aims at solving the shallow undercut tunnel excavation of burying of present stage and struts construction speed slow, strut the effect poor, pipe shed and little pipe installation speed slow and accuracy poor, the shutoff effect poor and the poor technical problem of cavity body country rock wholeness.

In order to achieve the above purpose, the utility model discloses a following technical scheme realizes:

the shallow-buried underground excavation tunnel excavation supporting system comprises a pre-grouting reinforcement advanced support, a steel arch frame inclination-adjustable pipe shed orifice guiding device, a penetrating profile steel section conduit inclination adjusting device, a water-injection bag string slurry temporary plugging device and a tunnel vault large-volume water spraying cavity supporting system;

the pre-grouting reinforcement advanced support comprises a steel arch frame, a long pipe shed and a small pipe; the steel arch frame is matched with the profile of the concrete tunnel; the long pipe shed and the small pipe penetrate through the steel arch frame from outside to inside in a positioning mode and are used for achieving inward penetration of the arch crown and then grouting;

the inclination-adjustable pipe shed orifice guiding device with the steel arch comprises a first fixed base, a lantern ring, a guide pipe and a lifting rod; the first fixed base is arranged on the steel arch frame; one end of the guide pipe is positioned on the first fixing base through a fixing support, and the other end of the guide pipe is connected with the lifting rod through the fixing support to realize lifting;

the inclination adjusting device for the guide pipe with the section penetrating steel comprises a second fixed base, a fixed disc, a square frame and a telescopic device; the fixed disc is arranged on a second fixed base through a fixed rod; the two telescopic devices are positioned on the fixed disc; the telescopic rods of the telescopic device are respectively connected with two ends of the square frame in a positioning manner and are used for realizing the inclination adjustment of the square frame;

the temporary plugging device for the serial slurry of the water injection bag comprises a water injection bag, a water outlet, an opening and closing valve, a water inlet and a pumping pipe; the water outlet is arranged at one end of the water injection bag; the opening and closing valve is arranged at the water outlet; the water inlet is arranged at the position opposite to the water outlet, and the pumping pipe is arranged at the water inlet;

the tunnel vault large-volume water spraying cavity supporting system comprises a temporary steel sleeve arch, connecting steel bars, a steel bar net rack, a drain pipe, an expansion plate, a shed frame and a temporary support; the temporary steel arch is arranged at the lower part of the steel arch frame and is connected into a whole through a connecting steel bar; the reinforcing steel bar net rack is arranged at the lower part of the cavity body, and a drain pipe is arranged on the reinforcing steel bar net rack; the top of the shed frame is provided with an expansion plate for supporting the cavity body, and the bottom of the shed frame is supported on the temporary steel sleeve arch; support one end temporarily and support the rack, one end is connected on the reinforcing bar rack.

As a further improvement of the utility model, the front end of the small conduit is a steel pipe structure with a closed conical head; grouting holes are uniformly distributed in the circumferential direction of the small guide pipe; and the rear end of the small guide pipe is also provided with an iron hoop which is reserved with a grout stopping section and connected with grouting equipment.

As a further improvement of the utility model, the lifting rod further comprises a lifting control handle and a lifting sleeve; the lifting sleeve is connected with the bottom plate and is fixed on the fixed base through screws; the lifting rod can be controlled in the lifting sleeve through a lifting control handle.

As a further improvement of the utility model, the telescopic device comprises an automatic telescopic rod and a telescopic control button; one end of the automatic telescopic rod is fixed on the fixed disc, and the telescopic control button is arranged in the automatic telescopic rod; two ends of the square frame are fixed on the automatic telescopic rod.

As a further improvement of the utility model, the water injection bag is a three-dimensional bag made of rubber materials.

As a further improvement of the utility model, the large-volume water spraying cavity supporting system of the tunnel vault also comprises a pumping pipe and a small conduit; the small guide pipe is arranged on the outer side of the cavity body, and the pumping pipe extends into the cavity body from the bottom of the cavity body.

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

according to the method, the long pipe shed and the small pipe grouting support are arranged, the advance support is reinforced by adopting the long pipe shed and the small pipe grouting support, the reinforcing effect is good, and the grouting quality is easy to control; by arranging the inclination-adjustable pipe shed orifice guide device and the guide pipe inclination adjusting device which are fixedly arranged on the steel arch frame, the inclination and the installation position of the pipe shed and the guide pipe can be accurately controlled, the construction speed is high, and the effect is obvious; through adopting water injection bag cluster thick liquid to carry out interim shutoff and installation tunnel vault bulky trickle cavity support system, can effectively prevent the lax deformation of country rock, improve the wholeness of vault country rock, play fine stifled row effect to pore water.

Drawings

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

FIG. 1 is a schematic view of a pre-grouting reinforced forepoling structure;

FIG. 2 is a schematic structural view of a small catheter;

FIG. 3 is a schematic view of the duct shed orifice guide construction;

FIG. 4 is a top view of the structure of the catheter inclination adjusting device;

FIG. 5 is a schematic structural view of a temporary plugging device for water injection bag slurry stringing;

FIG. 6 is a schematic structural view of a large-volume water spraying cavity supporting system of a tunnel vault;

FIG. 7 is a schematic diagram of a primary cavity support construction structure of a large-volume water spraying cavity support system of a tunnel vault;

FIG. 8 is a schematic diagram of a construction structure of cavity backfill concrete of a large-volume water spraying cavity supporting system of a tunnel vault;

FIG. 9 is a block diagram of a construction process of a large-volume water spraying cavity supporting system of a tunnel vault;

the reference numbers in the figures illustrate:

1. pre-grouting to reinforce the forepoling; 11. a steel arch frame; 12. a long pipe shed; 13. a small catheter; 2. the steel arch frame can adjust the inclination of the orifice guide device of the pipe shed; 21. a first fixed base; 22. a collar; 23. a guide tube; 24. a lifting rod; 241. A lift control handle; 242. a lifting sleeve; 25. fixing a bracket; 3. a gradient adjusting device for the guide pipe penetrating through the section steel; 31. a second fixed base; 32. fixing the disc; 33. a square frame; 34. a telescoping device; 341. automatically telescoping the rod; 342. a telescoping control button; 35. fixing the rod; 4. a temporary plugging device for the water-injection bag string slurry; 41. a water injection bag; 42. a water outlet; 43. opening and closing a valve; 44. a water inlet; 45. pumping the pipe; 5. a large-volume water spraying cavity supporting system of a tunnel vault; 51. temporary steel sleeve arches; 52. connecting reinforcing steel bars; 53. a steel bar net rack; 54. a drain pipe; 55. an expansion plate; 56. a shed frame; 57. temporary support; 6. a concrete tunnel.

Detailed Description

To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the embodiments of the present invention are combined to clearly and completely describe the technical solution in the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Combine attached figure 1 to fig. 9, the utility model provides a shallow undercut tunnel excavation supporting system that buries aims at solving the shallow undercut tunnel excavation supporting construction speed that buries in the present stage slow, strut that the effect is poor, pipe shed and little pipe installation speed slow and the accuracy is poor, the shutoff effect is poor and the poor technical problem of cavity body country rock wholeness.

Specifically, the shallow-buried underground excavation tunnel excavation supporting system comprises a pre-grouting reinforcement advanced support 1, a steel arch frame inclination-adjustable pipe shed orifice guiding device 2, a penetrating profile steel section conduit inclination adjusting device 3, a water-injection bag serial slurry temporary plugging device 4 and a tunnel vault large-volume water spraying cavity supporting system 5;

the pre-grouting reinforcement advance support 1 comprises a steel arch 11, a long pipe shed 12 and a small pipe 13; the steel arch 11 is matched with the profile of the concrete tunnel 6; the long pipe shed 12 and the small pipe 13 are positioned from outside to inside to penetrate through the steel arch 11 and are used for realizing the inward penetration of the arch crown and then grouting;

the steel arch inclination-adjustable pipe shed orifice guiding device 2 comprises a first fixed base 21, a lantern ring 22, a guide pipe 23 and a lifting rod 24; the first fixed base 21 is arranged on the steel arch frame 11; one end of the guide pipe 23 is positioned on the first fixed base 21 through a fixed support 25, and the other end of the guide pipe is connected with a lifting rod 24 through the fixed support 25 to realize lifting;

the inclination adjusting device 3 for the guide pipe with the section penetrating steel comprises a second fixed base 31, a fixed disc 32, a square frame 33 and a telescopic device 34; the fixed disc 32 is arranged on the second fixed base 31 through a fixed rod 35; two telescopic devices 34 are positioned on the fixed disk 32; the telescopic rods of the telescopic device 34 are respectively connected with two ends of the square frame 33 in a positioning manner, so that the inclination adjustment of the square frame 33 can be realized;

the temporary plugging device 4 for the water injection bag serial slurry comprises a water injection bag 41, a water outlet 42, a switch valve 43, a water inlet 44 and a pumping pipe 45; the water outlet 42 is arranged at one end of the water injection bag 41; the opening and closing valve 43 is arranged at the position of the water outlet 42; the water inlet 44 is arranged at the position opposite to the water outlet 42, and the pumping pipe 45 is arranged at the water inlet 44;

the tunnel vault large-volume water spraying cavity supporting system 5 comprises a temporary steel sleeve arch 51, connecting steel bars 52, a steel bar net rack 53, a drain pipe 54, an expansion plate 55, a shed frame 56 and a temporary support 57; the temporary steel sleeve arches 51 are arranged at the lower parts of the steel arch frames 11 and are connected into a whole through connecting steel bars 52; the reinforcing steel bar net rack 53 is arranged at the lower part of the cavity body, and a drain pipe 54 is arranged on the reinforcing steel bar net rack; the top of the shed frame 56 is provided with an expansion plate 55 to support the cavity body, and the bottom of the shed frame is supported on the temporary steel sleeve arch 51; the temporary support 57 has one end supporting the canopy frame 56 and the other end connected to the reinforcing bar net rack 53.

Further, the front end of the small conduit 13 is of a steel pipe structure with a closed conical head 131; grouting holes 132 are uniformly distributed in the circumferential direction of the small guide pipe 13; the rear end of the small conduit 13 is also provided with a reserved grout stopping section 133 and an iron hoop 134 connected with grouting equipment.

Further, the collar 22 is fixed to one end of the first fixing base 21 through a fixing bracket 25.

Further, the lifting rod 24 further comprises a lifting control handle 241 and a lifting sleeve 242; the lifting sleeve is connected with the bottom plate and is fixed at the other end of the first fixed base 21 through a screw; the lift lever 24 is controlled to be lifted and lowered in the lift sleeve by a lift control handle 241.

Further, the telescopic device 34 includes an automatic telescopic rod 341 and a telescopic control button 342; one end of the automatic telescopic rod 341 is fixed on the fixed disc 32, and the telescopic control button 342 is installed in the automatic telescopic rod 341; both ends of the square frame 33 are fixed to the automatic telescopic rod 341.

Further, the water injection bag 41 is a three-dimensional bag of a rubber material.

Further, the tunnel vault large-volume water spraying cavity supporting system 5 further comprises a pumping pipe 45 and a small conduit 13; the small guide pipe 13 is arranged outside the cavity body, and the pumping pipe 45 extends into the cavity body from the bottom of the cavity body.

Shallow excavation tunnel excavation supporting system that buries includes the following step:

s1, construction preparation: completely familiarizing drawings, making on-site traffic control, familiarizing the position of an on-site pipeline, protecting the periphery of a site, and preparing construction machinery and materials to enter the site;

s2, mounting the steel arch center 11: the arch center is processed on site, stacked in a centralized way and installed by manual matching with a machine;

s3, installing a pipe shed orifice guide device: the steel arch 11 is erected according to the outline of the concrete tunnel 6, the first fixed base 21 is installed on the steel arch 11, the lantern ring 22 is fixed on the first fixed base 21 through a fixed support 25, the lifting sleeve is connected with the bottom plate and fixed to the other end of the first fixed base 21 through a screw, the lifting rod 24 can be controlled to lift through a lifting control handle 241 in the lifting sleeve, one end of the guide pipe 23 is fixed through the lantern ring 22, the other end of the guide pipe is connected with the lifting rod 24 through the fixed support 25, and direction adjustment can be conducted through lifting;

s4, installing a guide pipe inclination adjusting device: the fixed disc 32 is mounted on the second fixed base 31 through a fixed rod 35, one end of the automatic telescopic rod 341 is fixed on the fixed disc 32, and the telescopic control button 342 is mounted in the automatic telescopic rod 341; both ends of the square frame 33 are fixed on the automatic telescopic rod 341;

s5, construction of the long pipe shed 12 and the small guide pipe 13: the long pipe shed 12 and the small guide pipes 13 are arranged according to the specified positions by a pipe shed orifice guide device and a guide pipe inclination adjusting device;

s6, grouting construction: after the pipeline and mechanical condition is checked, performing grouting construction by using a double-liquid grouting machine;

s7, temporary plugging construction: the water injection bag 41 is a three-dimensional bag made of rubber materials, the water outlet 42 is arranged at one end of the water injection bag 41, the open-close valve 43 is arranged at the position of the water outlet 42, the water inlet 44 is arranged at the position opposite to the water outlet 42, and the pumping pipe 45 is arranged at the water inlet 44; the temporary plugging device 4 for the water-injection bag string slurry is used for directly plugging a slurry leakage place after slurry injection;

s8, constructing a tunnel vault large-volume water spraying cavity supporting system 5: the small guide pipe 13 is arranged outside the cavity body, the temporary steel arch 51 is arranged at the lower part of the steel arch frame 11 and is connected into a whole through a connecting steel bar 52, the steel bar net frame 53 is arranged at the lower part of the cavity body and is provided with a drain pipe 54, the top of the shed frame 56 is provided with an expansion plate 55 to support the cavity body, the bottom of the shed frame is supported on the temporary steel arch 51, one end of the temporary support 57 supports the shed frame 56, the other end of the temporary support is connected to the steel bar net frame 53, and the pumping pipe 45 extends into the cavity body from the bottom of the cavity body;

s9, dismantling the steel arch 11 and monitoring and measuring.

According to the method, the long pipe shed and the small pipe grouting support are arranged, the advance support is reinforced by adopting the long pipe shed and the small pipe grouting support, the reinforcing effect is good, and the grouting quality is easy to control; by arranging the inclination-adjustable pipe shed orifice guide device and the guide pipe inclination adjusting device which are fixedly arranged on the steel arch frame, the inclination and the installation position of the pipe shed and the guide pipe can be accurately controlled, the construction speed is high, and the effect is obvious; through adopting water injection bag cluster thick liquid to carry out interim shutoff and installation tunnel vault bulky trickle cavity support system, can effectively prevent the lax deformation of country rock, improve the wholeness of vault country rock, play fine stifled row effect to pore water.

The method has the advantages that the process operation is simple, the construction efficiency and the construction precision are improved, the overhead working time is reduced, and special equipment is not required to be input; the investment of equipment and personnel is less, the labor intensity is low, and the occupied area is small; the engineering cost is reduced; the construction method achieves good effects in construction in engineering example projects, has wide popularization and application values under similar equivalent conditions, and has very obvious economic and social benefits.

Setting a temporary steel arch sleeve locking primary support for the primary support which is close to the finished cavity body, and applying radial small guide pipe grouting reinforcement to form a cavity section construction safety operation area; on the basis, arch frames and auxiliary shed frame supports are arranged one by one on the water spraying section of the cavity to form a containment and discharge the fracture water of the surrounding rock; and finally, backfilling concrete into the cavity, and grouting to compact the concrete to form an integral stressed shell, so that the safe implementation of subsequent excavation and supporting construction is ensured.

The construction method of the tunnel vault large-volume water spraying cavity supporting system comprises the following steps:

construction preparation: measuring and lofting, namely firstly measuring a tunnel center line, determining an elevation, and then measuring the longitudinal position of a steel frame; the plane of the steel frame is vertical to the central line of the tunnel;

increase interim I-steel bow member cover and encircle: the unit steel frames transported to the site are piled in units, section size inspection is carried out before installation to ensure that the steel frames are correctly installed, loose slag under a base plate is removed before installation of arch legs or wall legs, the steel frames are placed on original hard rock, and a method of backing steel plates or channel steel is adopted in soft and weak areas. The trusses are arranged below the original steel arch frame in a one-to-one correspondence mode and are wedged and adhered by steel wedges or wood wedges to ensure the stability of the steel arch frame;

the cavity is enclosed to little pipe reinforcement cavity of safety helmet advance slip casting: and (4) measuring and lofting, marking on a designed hole position, drilling by using a rock drill, wherein the hole diameter is larger than the pipe diameter of the designed conduit by more than 10mm, and the hole depth and the external insertion angle must meet the design requirements. Inserting an angle outside: the value should be taken by considering the length of the small guide pipe 13, the distance between steel frames and the section height of the steel frames, and the general external insertion angle is 10-15 degrees (the collapse range is adjusted to 30-50 degrees, the collapse section is not subjected to air escape control), and can be adjusted according to the actual situation; the small guide pipes 13 are subjected to hole arrangement and lofting according to the central elevation and the hole pitch of the arch crown outer contour, and the red circles are used as marks to control the pitch of the small guide pipes 13; before the small guide pipe 13 is drilled and installed, the small guide pipe 13 is inserted into a hole according to the design requirement, or the small guide pipe 13 is directly punched into the hole from the upper part or the abdomen of the section steel frame by a rock drill; the small guide pipe 13 is installed by adopting a hole leading jacking method, the drilling direction is smooth and straight, and the diameter of the drilled hole is matched with the diameter of the grouting pipe and is not more than 50 mm; after the small guide pipe 13 is manufactured and installed, a grouting valve and a pipeline are installed, and grouting adopts cement and water glass double-liquid slurry;

the sprayed concrete seals the cavity, and the drain pipe is embedded: for the steel pipe which is forcibly driven, the accumulated materials in the pipe are firstly washed away, and then grouting is carried out; the grouting sequence is from bottom to top, and the cement slurry is stirred by a mixer; the double-liquid slurry adopts slurry injection pump pressure water injection muddy water glass double-liquid slurry.

Support temporarily and set up the safety canopy arch crown cavity department: after the construction of the safety helmet is finished, the construction of a containment vessel is started, and in a safety range right below the temporary steel arch sleeve, danger is eliminated by adopting manual work and mechanical cooperation, so that loose stones in the cavity body of the arch crown are removed;

after danger elimination is finished, C20 sprayed concrete is adopted for the cross section of the cavity body to seal the cross section, and meanwhile, a circumferential permeable pipe is embedded to conduct water to a drainage ditch according to a dredging and blocking combination principle; after the rock surface of the cavity is sprayed with slurry and sealed, observing a water outlet part, leading and discharging seepage water to a drainage ditch by adopting a pre-buried annular permeable pipe at a part with smaller convection water quantity, and installing the part on the back of an arch frame or on a reinforcing mesh sheet so as to be conveniently fixed in principle to form a full-section permeable pipe;

when the water flow is large, the auxiliary support steel pipe is used for draining the drainage pipe to the primary support, and the waterproof plate is used for wrapping and fixing the annular drainage pipe on the primary support to drain the drainage pipe to the longitudinal drainage pipe of the tunnel;

after the section of the cavity is closed, an excavation trolley and a steel arch frame constructed in the previous cycle are used for arranging a shed frame, the rock face of the cavity is supported and reinforced in an auxiliary mode, the shed frame is made of profile steel, steel pipes and other materials according to the safety and convenience construction principle, blanking is carried out according to the length requirement of on-site construction, the cavity rock is supported quickly, one end of the shed frame is welded on the steel arch frame during construction, the other end of the shed frame is attached to the rock face, and when the contact surface area of the rock face end is too small, a steel plate can be welded on the shed frame or the end of the steel pipe, so that the contact area is increased;

support temporarily and set up the safety canopy arch crown cavity department: installing primary steel arch trusses one by one from the cross section of the cavity, wherein the steel arch trusses are I20b I-shaped steel and are spaced by 50 cm; when the steel arch is installed, the arch springing position of the arch is fixed and supported, the connection position is slightly inclined towards the safe operation area, so that an operator is in the safe operation area when connecting the steel arch, and after the connection is finished, the arch is adjusted to the design position; when one I-steel beam is installed, the collapsed top surface is subjected to shed frame auxiliary supporting and reinforcing by using the steel arch frame, the shed frame auxiliary supporting is obliquely auxiliary, and the vertical direction of the I-steel beam also needs to be vertically supported after the I-steel beam is installed vertically;

strengthening, supporting and protecting one by one under the safety shed to construct a containment: the I-beams are longitudinally connected by phi 22 connecting bars, the circumferential distance is 1.0m, the I-beams are arranged in a quincunx manner, phi 8 reinforcing steel bar meshes are arranged on the I-beams, and the mesh pitch is 10cm x 10 cm; 1-2 trusses are installed, C20 sprayed concrete with the thickness not less than 25cm is immediately used for connecting a safety shell among the I-beams, the reinforcing mesh sheets, the longitudinal connecting ribs and the steel pipe supports, so that a safety operation area for constructing the next truss is formed; simultaneously embedding two phi 125 pumping concrete pipes and a phi 42 grouting pipe, wherein the outlet of the grouting pipe is 20cm away from the vault, and grouting and filling the cavity by using the grouting pipe after the concrete is backfilled; after the I-steel and shell-making circular operation is finished, monitoring measuring points are immediately arranged, 2 sections are arranged, each section has 3 points, observation is enhanced, records are made, and measuring data are processed in time to guide construction and ensure construction safety;

and (3) constructing a radial grouting anchor rod or a small guide pipe after the containment body is formed: after the safety shell is integrally formed and is tightly attached to the tunnel face, grouting small guide pipes 13 are arranged at the arch waist and arch foot positions of each steel arch frame of the cavity for reinforcing, the length of each small guide pipe 13 at the arch waist is 5m, the circumferential and longitudinal spacing is 0.4m by 0.5m, the length of each small guide pipe 13 at the arch foot position is 4m, and the circumferential and longitudinal spacing is 0.4m by 0.5 m; after the construction and grouting of the arch waist and arch foot grouting small pipes 13 are completed, radial system anchor rods are applied to the collapsed cavity section one by one, and the anchor rods are phi 22 explosive roll anchor rods, and are circumferentially spaced by 0.75m and longitudinally spaced by 1.0 m. In the radial system anchor rod construction process, monitoring measurement is enhanced, and arch centering and surrounding rock deformation observation are enhanced;

and (3) performing pumping concrete grouting filling on the cavity: when a shell is constructed in the cavity section, a C20 sprayed concrete test block is reserved in a laboratory, and after the sprayed concrete shell reaches over 70% of the design strength through test detection, the cavity is filled with pumped concrete; filling concrete in a layer at intervals, namely performing secondary construction, filling a layer of concrete after solidification, reinforcing monitoring measurement in the filling process, reinforcing the deformation observation of an arch frame and surrounding rocks, immediately stopping construction when abnormality is found, and performing construction after treatment measures are taken; and (5) confirming that the rock face is closed, the tunnel face and the backfilled concrete are tightly bonded, and no obvious slurry leakage and slurry leakage phenomenon exists. The filling is preferably waterproof C25 concrete, the slump is controlled between 12 cm and 18cm, the grouting treatment is carried out after the concrete filling is finished and the concrete is solidified with the auxiliary support steel pipe shed frame into a whole, and the treatment of the cavity section is finished by closing the gap and the concrete shrinkage void part;

after the inverted arch construction is completed, dismantling the temporary arch frame: in the backfilling process, a measurer uses a total station to monitor the sinking of the vault of the tunnel in an enhanced manner, so that the phenomenon that a steel frame is deformed and invades into a secondary lining limit due to overlarge once backfilled concrete is prevented; the deformation monitoring and measurement of the primary support are enhanced, after the arch crown cavity is processed and the slurry consolidation strength reaches the design strength, the primary support needs to form a closed ring as early as possible, the inverted arch and the secondary lining are constructed as early as possible, and the temporary steel arch sleeve is removed after the inverted arch construction is completed.

In the step of adding temporary H-shaped steel arch frames for arch sleeving, the steel arch frames are connected by phi 22 connecting ribs, the length of each connecting rib is 1m, the circumferential distance is 1m, the connecting ribs are arranged in a quincunx manner, and phi 22 shear diagonal braces are arranged every 1 m; and (3) immediately laying monitoring measuring points with 5 points per section after the construction of the temporary steel arch is finished, carrying out enhanced observation according to the frequency of 2 times in 1 day, making a record, and timely processing measured data to guide the construction and ensure the construction safety.

In the construction step of the advanced grouting small conduit (safety helmet), the specification of the small conduit 13 is as follows: the diameter of the hot-rolled seamless steel pipe is phi 42mm, quincunx holes are drilled on the pipe wall every 10-20 cm, the diameter of each hole is phi 6-8 mm, no hole is drilled when the tail length is 100cm, and the length L is 4-7.0 m; the small guide pipes 13 are arranged on the arch centering at the circumferential direction of 40cm in a staggered mode, the front ends of the small guide pipes are machined into conical shapes, and the tail portions of the small guide pipes are welded to the steel arch centering to increase the common supporting effect; the external insertion angles of the small pipes are respectively 10-15 degrees and 30-50 degrees of the cavity area, and construction is controlled without being empty.

The cement and water glass double-liquid slurry grouting parameters are as follows: the water-cement ratio of the cement paste is 0.8:1 to 1: 1; the volume ratio of the cement paste to the water glass is 1: 0.5-1: 0.8; the modulus of the water glass is 2.4 to 3.4, the baume degree is 22 to 40 degrees, the grouting pressure is 0.5 to 1.5Mpa, the diffusion radius is 0.3 to 0.5m, the holes are separated and grouted at intervals, the water cement ratio is gradually reduced, and the grouting pressure is gradually increased.

In the grouting step, after the small guide pipe 13 is installed, a pressurized water test is carried out by adopting a double-liquid grouting machine with a calibrated pressure gauge, and grouting parameters are determined according to the design and test results. Grouting pressure: the pressure is generally 0.5-1.5 MPa, and the slurry must fill the steel pipe and the gaps around the steel pipe; cement grout is prepared by adopting a mixing station, a tank truck is transported to the site, impurities are prevented from being mixed when the cement grout or diluted water glass grout is prepared, the prepared grout must be used after being filtered, and the grout is completely injected within a specified time; the slurry sequence is from bottom to top, the slurry is diluted and then concentrated, the grouting amount is increased and then decreased, and the grouting pressure is increased from low to high. And (5) finishing grouting standard: when the pressure reaches the final pressure of the designed grouting and is stabilized for 10-15min, and the grouting amount reaches more than 80% of the designed grouting amount, finishing the hole grouting; if the grouting process is interrupted due to reasons, grouting should be resumed as soon as possible. In order to prevent excessive deformation of surrounding rock during grouting, grouting is performed by adopting a method of interval grouting sections and interval grouting holes of each section in a grouting sequence, a special person is arranged to take charge during grouting, grouting records are made, grouting amount, grouting pressure and peripheral deformation conditions are monitored at any time, monitoring and measuring are enhanced, and construction is stopped immediately when large deformation is found.

The construction method introduces the construction process of the large-volume water spraying cavity of the arch crown of the tunnel, personnel and mechanical organization systematically, wherein the construction method has the advantages of rapidness, convenience, safety and reliability in advancing small guide pipes, building the shell and filling concrete, accelerates the construction progress of the project, saves the construction cost, and saves about 18 ten thousand yuan by taking a land ridge tunnel as the construction for building the shell and filling the concrete in the cavity. Meanwhile, the construction method provides reliable reference basis and technical indexes for cavity backfill construction with tight construction period, broken surrounding rocks, large cavity volume and water spraying and water seepage phenomena, the novel construction method technology can promote the construction technology progress of the highway tunnel engineering, and the social benefit and the environmental benefit are obvious.

The construction of the safety helmet, the containment and the backfill has the advantages of convenient construction, easily controlled quality, better pre-supporting effect, safety, effectiveness, fast construction progress, less interference factors, less damage to the environment, contribution to civilized construction, better utilization of various limited resources and capability of ensuring the intact and undamaged surrounding existing facilities and the life and property safety of residents. Quickening the construction efficiency and producing better economic benefit. Meanwhile, the construction method conforms to and meets the national requirements on energy-saving construction of buildings.

It should be noted that the detailed description of the present invention is not included in the prior art, or can be obtained directly from the market, and those skilled in the art can obtain the detailed description without creative efforts, and the detailed connection method has a very wide application in the field or daily life, and is not described in detail herein.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship indicated based on the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (6)

1. Shallow excavation tunnel excavation supporting system that buries, its characterized in that: the device comprises a pre-grouting reinforcement advanced support, a steel arch frame inclination-adjustable pipe shed orifice guiding device, a penetrating profile steel section conduit inclination adjusting device, a water-injection bag serial slurry temporary plugging device and a tunnel vault large-volume water spraying cavity support system;

the pre-grouting reinforcement advanced support comprises a steel arch frame, a long pipe shed and a small pipe; the steel arch frame is matched with the profile of the concrete tunnel; the long pipe shed and the small pipe penetrate through the steel arch frame from outside to inside in a positioning mode and are used for achieving inward penetration of the arch crown and then grouting;

the inclination-adjustable pipe shed orifice guiding device with the steel arch comprises a first fixed base, a lantern ring, a guide pipe and a lifting rod; the first fixed base is arranged on the steel arch frame; one end of the guide pipe is positioned on the first fixing base through a fixing support, and the other end of the guide pipe is connected with the lifting rod through the fixing support to realize lifting;

the inclination adjusting device for the guide pipe with the section penetrating steel comprises a second fixed base, a fixed disc, a square frame and a telescopic device; the fixed disc is arranged on a second fixed base through a fixed rod; the two telescopic devices are positioned on the fixed disc; the telescopic rods of the telescopic device are respectively connected with two ends of the square frame in a positioning manner and are used for realizing the inclination adjustment of the square frame;

the temporary plugging device for the serial slurry of the water injection bag comprises a water injection bag, a water outlet, an opening and closing valve, a water inlet and a pumping pipe; the water outlet is arranged at one end of the water injection bag; the opening and closing valve is arranged at the water outlet; the water inlet is arranged at the position opposite to the water outlet, and the pumping pipe is arranged at the water inlet;

the tunnel vault large-volume water spraying cavity supporting system comprises a temporary steel sleeve arch, connecting steel bars, a steel bar net rack, a drain pipe, an expansion plate, a shed frame and a temporary support; the temporary steel arch is arranged at the lower part of the steel arch frame and is connected into a whole through a connecting steel bar; the reinforcing steel bar net rack is arranged at the lower part of the cavity body, and a drain pipe is arranged on the reinforcing steel bar net rack; the top of the shed frame is provided with an expansion plate for supporting the cavity body, and the bottom of the shed frame is supported on the temporary steel sleeve arch; support one end temporarily and support the rack, one end is connected on the reinforcing bar rack.

2. The shallow-buried underground excavation tunnel excavation supporting system of claim 1, characterized in that: the front end of the small conduit is of a steel pipe structure with a closed conical head; grouting holes are uniformly distributed in the circumferential direction of the small guide pipe; and the rear end of the small guide pipe is also provided with an iron hoop which is reserved with a grout stopping section and connected with grouting equipment.

3. The shallow-buried underground excavation tunnel excavation supporting system of claim 1, characterized in that: the lifting rod further comprises a lifting control handle and a lifting sleeve; the lifting sleeve is connected with the bottom plate and is fixed on the fixed base through screws; the lifting rod can be controlled in the lifting sleeve through a lifting control handle.

4. The shallow-buried underground excavation tunnel excavation supporting system of claim 1, characterized in that: the telescopic device comprises an automatic telescopic rod and a telescopic control button; one end of the automatic telescopic rod is fixed on the fixed disc, and the telescopic control button is arranged in the automatic telescopic rod; two ends of the square frame are fixed on the automatic telescopic rod.

5. The shallow-buried underground excavation tunnel excavation supporting system of claim 1, characterized in that: the water injection bag is a three-dimensional bag made of rubber materials.

6. The shallow-buried underground excavation tunnel excavation supporting system of claim 1, characterized in that: the tunnel vault large-volume water spraying cavity supporting system also comprises a pumping pipe and a small guide pipe; the small guide pipe is arranged on the outer side of the cavity body, and the pumping pipe extends into the cavity body from the bottom of the cavity body.

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