CN212563261U - Half cut single-pressure type open cut tunnel advances hole protective structure fast - Google Patents

Abstract

The utility model discloses a protection structure for rapid entering of a half cut single-pressure open cut tunnel, which comprises a plurality of steel arches which are arranged outside a tunnel portal in sequence from inside to outside, wherein the steel arches are connected into a whole through a plurality of transversely arranged connecting rods to form a cover arch, and a plurality of sleeves are sequentially arranged on the cover arch in parallel; one end of the sleeve arch is connected with the bias wall through the bolt assembly, the other end of the sleeve arch is vertically connected with a plurality of mounting pieces, a foot locking anchor rod is movably arranged on the mounting pieces and penetrates through the mounting pieces to be connected with the mountain rock stratum, and a semi-arc-shaped protection structure is formed. The utility model discloses follow "zero excavation" and "advance the hole earlier, go out the construction principle of hole later", do not dig big brush greatly, the self-stability of the current mountain topography of make full use of realizes avoiding the too much protection of opposite side slope, reduces the risk that the high side slope brought, has avoided the destruction of entrance to a cave vegetation, has not only practiced thrift the time limit for a project, has still reduced construction cost and safe risk, has also produced fine social.

Description

Half cut single-pressure type open cut tunnel advances hole protective structure fast

Technical Field

The utility model relates to a tunnel advances hole construction method fast, specifically relates to a half cutting single die mould open cut tunnel advances hole protective structure and construction method fast, is applicable to the construction of advancing hole fast of half cutting single die mould open cut tunnel highway, railway tunnel under the special topography of mountain, also can be used to highway, the similar tunnel construction of water conservancy project, belongs to tunnel construction technical field.

Background

Along with the continuous expansion of the construction range of highways in China, the high-speed flying development of plateau areas of Yunpichuan is driven, plateau mountain tunnels are increasingly increased, the complexity, the particularity and the limitation of the terrains of the plateau mountains greatly improve the construction difficulty of the mountain tunnels, the rapid and safe tunnel entrance of the tunnels often becomes the key point and the difficulty of early construction, the tunnel entrance requirement meets the principles of 'early entrance and late exit', the tunnel entrance is pursued to be 'zero excavation', the self-stability of original rock masses of tunnel mouths is fully utilized, the disturbance to rock masses is reduced, and the adoption of large blasting is strictly forbidden.

The existing traditional open cut tunnel construction method adopted for entering the tunnel often enables the position of the tunnel opening to be completely exposed due to complex terrain, and in order to increase a large amount of excavation of the working surface of the tunnel opening, high slopes are easy to form, damage to the ecological environment is also caused, construction cost is increased, excavation protection engineering quantity is increased in the early stage, and construction backfill engineering quantity is also increased in the later stage.

Meanwhile, aiming at the special situation of the tunnel entrance 'half cutting' terrain, in the traditional construction method, large excavation is often adopted, then the side slope is protected strongly, the construction method seriously damages the original landform and the self-stability of the mountain, the construction cost is also increased, and the side slope is easy to crack and lose stability in the excavation process, so that accidents such as landslide and collapse of the mountain are caused, and serious potential safety hazards exist.

Therefore, the situation of the tunnel portal is comprehensively researched and determined in combination with the actual situation, the excavation of the side and up slopes is reduced as much as possible, and only the side and up slopes and the mountain on the left side of the open cut tunnel arch protection are required to be repaired, so that the key point for solving the technical problems is to develop the half-cut single-pressure open cut tunnel rapid entry protection structure and the construction method with high construction safety and construction efficiency.

SUMMERY OF THE UTILITY MODEL

Aiming at the problems of slow tunnel entering speed, long construction period, high construction cost, great environmental pollution and the like of the traditional construction method, the large-opening and large-digging method is adopted, then the side slope is protected strongly, the construction method seriously damages the original landform and the self-stability of the mountain and also increases the construction cost, and slope fracture unstability easily appears in the excavation process, causes mountain landslide, collapse the equal accident, has a great deal of defects and not enough such as serious potential safety hazard, the utility model discloses improve and the innovation to this, aim at provides one kind and can follow "zero excavation" and "advance the hole early, go out the construction principle of hole late", does not dig big brush, and the self-stability of make full use of current mountain topography realizes avoiding the too much protection of side slope, reduces such half cutting single-die type open cut tunnel of the risk that the high side slope brought and advances hole protective structure and construction method fast.

The utility model discloses another utility model aims at combining "hidden hole open cut" theory, according to local conditions, in the mountain body outside with doing the open cut tunnel and protect the arch, make the single blank pressing excavation protection in later stage, build one set of whole reliable protection system to single blank pressing with lock foot stock, bias voltage wall together.

The utility model discloses a still another utility model aims at adopting I20 a's I-steel bow member and C25 reinforced concrete to protect encircleing, and the hidden tunnel just props up effective overlap joint, need not install moreover and protects and encircle both sides template, safe and reliable, construction convenience can develop the next process construction fast.

The utility model discloses a still another utility model aims at can adopting the cover to encircle and open cut tunnel protects the mode of encircleing and has realized advancing the hole construction fast according to the actual topography condition of job site, compares with traditional technology, and this method advances the hole and has avoided the destruction of entrance to a cave vegetation, has not only practiced thrift the time limit for a project, has still reduced construction cost and safe risk, has also produced fine social.

The utility model discloses a still another utility model aims at according to tunnel "zero excavation" and "advance the hole earlier, the construction principle of the hole of going out later", make full use of massif self-stability, do not dig big brush greatly, adopt the hole protection mode of advancing of "open cut tunnel arch + lock foot stock + bias voltage wall", the protection encircles one side and relies on the massif to support, opposite side foot bias voltage wall that falls, the cover encircles and open cut tunnel arch I-steel length can be according to the appropriate adjustment of massif position, guaranteeing ecological environment, under the safe prerequisite of construction, effectual half cutting single-die tunnel of having solved advances the difficult problem in hole.

The utility model discloses a still another utility model aims at construction method convenient operation, with low costs, construction safety can reduce entrance to a cave earth and stone side excavation engineering volume, reduces unnecessary side and heading slope and struts, and the effectual construction risk of having guaranteed the workman reduces entrance to a cave construction environment spoilage, has practiced thrift construction cost, has shortened the time limit for a project, has apparent economic benefits and social.

In order to solve the above problems and achieve the above object, the utility model relates to a protection structure and construction method for entering a cut single-die open cut tunnel fast is realized through adopting following project organization and adopting following technical scheme:

as the improvement of the utility model, the protection structure comprises a plurality of steel arches (1) which are arranged in parallel outside the tunnel portal in sequence from inside to outside, the steel arches (1) are connected into a whole by a plurality of connecting rods (2) which are transversely arranged to form a cover arch, a plurality of sleeves (3) are arranged in parallel on the cover arch in sequence, and the sleeves (3) and the connecting rods (2) are arranged in parallel; the one end that the cover was encircleed is passed through bolt assembly and is connected with bias voltage wall (4), the other end that the cover was encircleed is connected with many installed parts (5) perpendicularly, and the activity is equipped with lock foot stock (6) on installed part (5), and lock foot stock (6) pass installed part (5) and are connected with massif rock stratum (7), form half arc protective structure.

As the utility model discloses foretell improvement, steel bow member (1) is half arc shape I-steel bow member, and the model size of this half arc shape I-steel bow member processes the preparation according to actual construction needs.

In the above further improvement of the present invention, the connecting rod (2) is a hollow or solid tubular body or a rod-shaped member.

In a further improvement of the present invention, the connecting rod (2) is a rod-shaped member which is solid inside and is a reinforcing bar.

As the utility model discloses foretell further improvement again, connecting rod (2) set up to many, are the equidistance between many connecting rod (2) or not the equidistance lays.

As a still further improvement of the above aspect of the present invention, the sleeve (3) is a tubular member having a hollow interior.

As the above mentioned further improvement of the present invention, the sleeves (3) are arranged into a plurality of sleeves, and the plurality of sleeves (3) are arranged in equal distance or in unequal distance.

As the utility model discloses foretell still further improvement, bias voltage wall (4) bottom is poured through concreting foundation (8) and massif excavation step (9) and is linked as an organic whole.

As a still further improvement of the above structure of the present invention, the mounting member (5) is a vertically disposed i-steel or channel steel, and two through holes for the foot-locking anchor rods (6) to pass through are formed in the i-steel or channel steel; the foot locking anchor rod (6) is a grouting foot locking anchor rod with a hollow inner part.

As the utility model discloses foretell still further improvement more, all from interior to exterior according to the preface spraying have the layer of moulding plastics and antirust coat and waterproof layer on the surface of steel bow member (1), connecting rod (2), sleeve pipe (3) and installed part (5) and lock foot stock (6).

Compared with the prior art, the utility model produced beneficial effect is:

1. the utility model follows the construction principle of 'zero excavation' and 'early entering and late exiting', does not dig a big brush, fully utilizes the self-stability of the existing mountain terrain, avoids the protection of too much side slope and reduces the risk brought by high slope;

2. the utility model combines the concept of 'open cut in blind hole', additionally makes an open cut arch protection outside the mountain according to local conditions, makes later-stage single-blank-pressing excavation protection, and builds a protection system which is reliable to single blank pressing integrally with a foot-locking anchor rod and a bias wall;

3. the utility model adopts the I-shaped steel arch centering of I18 and the C25 reinforced concrete arch protection, and the I-shaped steel arch centering and the C25 reinforced concrete arch protection are effectively lapped with the primary support of the hidden tunnel, and the templates at the two sides of the arch protection are not needed to be installed, thereby being safe and reliable, convenient for construction, and capable of quickly carrying out the next procedure construction;

4. the utility model discloses according to the construction principle of tunnel "zero excavation" and "advance the hole in the morning, go out the hole later", make full use of mountain self-stability, do not dig big brush greatly, adopt the hole protection mode of "open cut tunnel protects and encircles + lock foot stock + bias voltage wall", protect and encircle one side and rely on the mountain body to support, opposite side foot bias voltage wall, cover encircles and open cut tunnel protects and encircles the I-steel length and can suitably adjust according to the mountain position, under the prerequisite of guaranteeing ecological environment, construction safety, the difficult problem of half cutting list die mould tunnel entering hole has effectively been solved;

5. the construction method of the utility model has the advantages of convenient operation, low cost and safe construction, can reduce the excavation work amount of the earth and stone at the opening, reduce unnecessary slope support, effectively ensure the construction risk of workers, reduce the damage rate of the construction environment at the opening, save the construction cost, shorten the construction period and have obvious economic and social benefits;

6. the utility model discloses according to the actual topography condition of job site, the mode that adopts half set to encircle and open cut tunnel fender arch has realized advancing the hole construction fast, compares with traditional handicraft, and this method advances the hole and has avoided the destruction of entrance to a cave vegetation, has not only practiced thrift the time limit for a project, has still reduced construction cost and safe risk, has also produced fine social.

7. The utility model reduces the side and upward slope excavation, only the side and upward slope and the mountain body at the left side of the open cut tunnel arch protection are required to be repaired, and then the anchor spraying support is carried out; one side of the open cut tunnel arch protection is supported by a mountain body, the foot falling at the right side biases the wall, and the lengths of the sleeve arch and the open cut tunnel arch protection joist steel can be properly adjusted according to the relative positions of the mountain body and the biasing wall; after the arch protection construction is finished, the underground tunnel excavation construction is effectively protected, and the underground tunnel construction can be smoothly carried out and smoothly enters the tunnel;

8. the arch center of the utility model is installed and the sprayed concrete is conveniently applied outside the hole, thereby realizing safe, high-efficiency and quick hole entering, greatly reducing the side and back slope brushing or groove-drawing earthwork amount, reducing masonry protection and leading the hole section to form construction capacity as soon as possible; disturbance to loose sandy loess slope soil is reduced, the construction process is safe and reliable, and the stress of the tunnel structure is more reasonable; meanwhile, the construction range is small, the stability of the tunnel portal section is facilitated, the construction efficiency is high, the construction process is simple, the construction speed is high, the damage to earth surface vegetation around the tunnel is small, the ecology is not damaged, the environmental pollution is small, and the environment-friendly and civilized construction degree is high.

Drawings

The following detailed description of embodiments of the invention is provided with reference to the accompanying drawings, in which:

fig. 1 is one of the overall structural schematic diagrams of the present invention;

fig. 2 is a second schematic view of the overall structure of the present invention;

fig. 3 is a third schematic view of the overall structure of the present invention;

FIG. 4 is a fourth schematic view of the overall structure of the present invention;

FIG. 5 is a fifth schematic view of the overall structure of the present invention;

FIG. 6 is a sixth schematic view of the overall structure of the present invention;

fig. 7 is one of the overall use states of the present invention;

fig. 8 is a second schematic view of the overall usage state of the present invention;

fig. 9 is a third schematic view of the overall usage state of the present invention;

FIG. 10 is a fourth schematic view of the overall usage status of the present invention;

FIG. 11 is a fifth schematic view of the overall usage status of the present invention

FIG. 12 is a sixth schematic view of the overall usage status of the present invention;

FIG. 13 is a block diagram of the overall construction process of the present invention;

FIG. 14 is a block diagram of the process of arch sheathing construction of the present invention;

FIG. 15 shows the construction process of the advanced pipe shed construction process of the present invention

Table 1 shows the materials and equipments of the present invention;

table 2 is a material table of the present invention;

table 3 is the mechanical equipment table of the utility model;

wherein, the reference numbers in the figures: 1-steel arch centering, 2-connecting rod, 3-sleeve, 4-bias wall, 5-mounting piece, 6-locking anchor rod, 7-mountain rock stratum, 8-pouring concrete foundation, 9-mountain excavation step, 10-slope top intercepting ditch;

s1, construction preparation;

s2, intercepting the ditch at the top of the slope;

s3, excavating and supporting a side and upward slope;

s4 construction of a bias wall foundation and a lower wall body;

s5 construction of a set of arches and a pipe shed;

s6, open cut tunnel arch protection construction and wall body construction on the upper part of the bias wall;

s7, constructing the upper wall body of the bias wall;

s8, excavating a dark tunnel and performing primary support;

a1 — measurement lofting;

a2-manufacturing and trial splicing of the steel arch frame;

a3 installation of steel arch;

a4-installation of guide tubes;

a5, erecting a mould and pouring concrete;

b1-construction preparation;

b2-drill in place;

b3-drilling;

b4, installing a steel pipe;

b5-grouting the pipe shed;

b6-detection and acceptance.

Detailed Description

In order to make the technical means, the inventive features, the objectives and the functions of the present invention easy to understand, the technical solution of the present invention will be further described in detail with reference to the accompanying drawings and the following detailed description, and it should be noted that the embodiments and the features of the embodiments in the present application can be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The protection structure comprises a plurality of steel arch frames 1 which are sequentially arranged on the outer side of a tunnel opening in parallel from inside to outside, the plurality of steel arch frames 1 are connected into a whole through a plurality of transversely arranged connecting rods 2 to form a cover arch, a plurality of sleeves 3 are sequentially arranged on the cover arch in parallel, and the sleeves 3 and the connecting rods 2 are arranged in parallel; the one end that the cover was encircleed is passed through bolt assembly and is connected with bias voltage wall 4, and the other end that the cover was encircleed is connected with many installed parts 5 perpendicularly, and the activity is equipped with lock foot stock 6 on the installed part 5, and lock foot stock 6 passes installed part 5 and is connected with massif stratum 7, forms half arc protective structure.

Further, the steel arch 1 is a semi-arc I-shaped steel arch, and the model size of the semi-arc I-shaped steel arch is processed and manufactured according to actual construction requirements.

Further, the connecting rod 2 is a tubular body or a rod-shaped body member which is hollow or solid inside.

Specifically, the tie bar 2 is a rod-shaped member that is solid inside and is a reinforcing bar.

Specifically, the connecting rods 2 are arranged to be multiple, and the connecting rods 2 are arranged at equal intervals or at unequal intervals.

Further, the sleeve 3 is a tubular body member having a hollow inside.

More specifically, the sleeves 3 are provided in a plurality, and the plurality of sleeves 3 are arranged at equal intervals or at unequal intervals.

Further, the bottom end of the bias pressure wall 4 is connected with a mountain excavation step 9 through a pouring concrete foundation 8 in a pouring mode.

Further, the mounting piece 5 is a vertically arranged I-steel or channel steel, and two through holes for the foot-locking anchor rods 6 to pass through are formed in the I-steel or channel steel; the foot-locking anchor rod 6 is a grouting foot-locking anchor rod with a hollow interior.

Further, an injection molding layer, an anti-rust layer and a waterproof layer are sequentially sprayed on the outer surfaces of the steel arch frame 1, the connecting rod 2, the sleeve 3, the mounting piece 5 and the foot locking anchor rod 6 from inside to outside.

Specifically, a high-molecular wear-resistant material is injected on the injection molding layer; the anti-rust layer comprises epoxy zinc-rich primer, chlorinated rubber finish paint and epoxy mica iron intermediate paint positioned between the epoxy zinc-rich primer and the chlorinated rubber finish paint; the waterproof layer is polyurethane waterproof paint.

Further, a protection structure for fast entering of a half cut single-pressure open cut tunnel and a construction method thereof are provided, wherein the method comprises the following steps:

s1, construction preparation: firstly, determining a tunnel entrance construction scheme, then performing measurement lofting, and finally determining tunnel entrance construction;

s2, slope top intercepting drain: before side-up slope construction, firstly, digging a slope top intercepting ditch 10 outside 5 meters of the edge line of the side-up slope at a cave entrance, building the intercepting ditch by using M7.5 grouted rubble, and cleaning earth surface trees and vegetation according to the line shape of construction lofting;

s3, excavating and supporting the side and upward slopes: the side and upward slope excavation uses mechanical excavation, the slope is strictly designed and controlled during excavation, a stable structural layer of the slope surface is kept as much as possible during the side and upward slope excavation, and a design scheme with less brushing or no brushing is adopted; the side and upward slope support adopts anchor-shotcrete support;

s4, construction of the bias wall foundation and the lower wall body: excavating an outer side wall foundation pit of the bias wall by adopting a step-placing excavation method;

s5, arch sheathing and pipe shed construction: firstly, installing an arch frame and a conduit of a cover arch, wherein the cover arch is used as a guide wall of a pipe shed and is constructed outside a bright and dark cut-off line of a tunnel; then, erecting a mold and pouring concrete; finally, advancing the construction of the large pipe shed;

s6, open cut tunnel arch protection construction: the open cut tunnel arch protection construction method is similar to the set arch construction method, and construction parameters and processes are completely consistent except that no guide pipe is added;

the matters to be noted in the open cut tunnel construction process are as follows:

the outside template adopts steel mould or wooden mold to assemble and consolidate, and the concrete adopts pump concrete pouring, and the concrete is from bottom to top layering, left and right alternation, and the difference in height of the concrete pouring surface of both sides should be controlled within fifty centimetres, pours into to the vault symmetrically from both sides.

The construction should pour in succession, and the vibration is closely knit, avoids the outage to cause the cold joint, and the speed needs slowly at the uniform velocity when concreting, and after the concrete strength reached the form removal requirement, carries out the template and demolishs and in time carries out concrete maintenance, and the arch ring concrete outer lane reaches the intensity of designing requirement, carries out waterproof layer hoop blind ditch and the vertical blind ditch construction of hunch foot, guarantees that the drainage is unblocked, and the waterproof board should not be less than 0.5 meter to the extension in the tunnel. And is well connected with the hidden hole waterproof board. The arch ring concrete reaches the design strength, open cut tunnel backfilling can be carried out after the waterproof facilities of the arch wall back are finished, and the backfilling mode adopts grouted rubble and earthwork backfilling. The grouted rubble is built by adopting seat grouting, pulp squeezing and symmetrical layered staggered joint building. And symmetrically tamping the open cut tunnel backfill earth in layers. The backfilling to the vault is carried out in a layered full-paved mode, clay is preferably adopted as a top-layer backfilling material to be beneficial to water insulation, the clay water-proof layer of the open cut tunnel is well and tightly connected with the upward slope in a lap joint mode, when mechanical backfilling is used, manual filling is firstly carried out to be tamped to be 1.0 meter above the vault, mechanical backfilling is used, small machines are used for compacting according to specifications, surface vegetation recovery of the side slope and the upward slope of the opening of the tunnel is timely carried out, after open cut tunnel construction is completed, smooth water outlets must be formed for water drainage in the tunnel, and a water drainage system in the tunnel is perfect and smooth.

S7, construction of the wall body on the upper part of the bias wall: after the open cut tunnel arch protection construction is finished, the construction of the wall body on the upper part of the bias wall can be carried out according to the design size;

s8, excavation of a dark hole and primary support: and after the construction of the arch protection is finished, constructing according to the advanced geological forecast and the monitoring measurement result and according to the construction by adopting a reserved core soil three-step subsection excavation method, excavating a soil body of the hidden tunnel, and after the construction of the primary support of the inverted arch is finished, sealing the inverted arch and the arch protection into a ring, thereby finishing the tunnel entering construction.

Furthermore, in S1, before construction, the surveyor checks the ground line according to the design drawing, and lays out the construction of the elevations and the plane positions of the arch cover, the bias wall foundation and the like, if the deviation exists, the design is reported in time for adjustment, construction can be carried out after the deviation is confirmed, and the length of the arch center is determined according to the bias wall and the mountain body position in the later period.

In S2, the slope top intercepting drain 10 is adjusted and laid according to the actual field topography and must be finished before the construction of the side and top slopes, and water in the slope top intercepting drain 10 is drained to natural drains on two sides of the tunnel.

Further, in S3, the side and upward slopes comprise a hole side slope and an upward slope, the side and upward slope is excavated by an open excavation method, footmarks are excavated from top to bottom, a hole entering step is reserved, and after the side and upward slope is excavated and formed, an anchor-spraying hanging net is adopted for protection in time; in order to reduce disturbance to rock mass and ensure stability of excavated mountain, anchor spraying protection and small guide pipe grouting reinforcement are carried out on side slopes within a certain range during construction, and the reinforcement process flow is anchor rod construction → reinforcing mesh paving → concrete spraying;

the anchor-spraying support comprises a mortar anchor rod hanger, a reinforcing mesh and C20 sprayed concrete; wherein, the stock adopts L to be 3.0m, 100cm x 100cm quincunx to arrange, and reinforcing bar net size is 25cm x 25cm, and C20 shotcrete thickness is 10 cm.

In S4, after excavation of an outer side wall foundation pit of the bias wall is finished, basic steel bar binding and C25 basic concrete pouring are carried out, and then steel bar binding and concrete pouring of a lower wall body are carried out; the side wall concrete is poured by a segmented pouring method, each segment is 5 meters, concrete roughening is carried out at the position of each layer of construction joint, connecting ribs are added if necessary, the reserved quantity of steel bars is ensured, full pouring is forbidden when foundation concrete is poured, a retaining wall foundation and surrounding rocks are required to be closed and separated, disturbance to the side wall concrete is reduced when underground excavation is carried out, and the stability of the structure is ensured.

Further, in S5, after the opening is excavated in an overhead downward manner, core soil is reserved, a measurer determines the height of a central line and an arch-sleeving position line and the like on the slope surface, then soil at the arch-sleeving position of the mountain side is excavated, the side slope is excavated while supporting, the side slope supporting mode is the same as the side slope supporting mode of the opening, and the stable rock stratum is excavated; erecting four I20a steel arch sleeves at a distance of 50cm, excavating an integral channel steel fixed on a rock body by a left foot of the arch frame on the premise of ensuring the height of the arch crown and the position line of the arch sleeve, installing a fixed channel steel on a bias wall foundation, and effectively connecting an I-steel connecting flange with the channel steel through bolts; the I-shaped steel is welded by using longitudinal connecting ribs, so that the integrity is enhanced; phi 140 guide pipes are welded on the I-shaped steel, the circumferential distance is 40cm, the number of the guide pipes is 2 m/piece, the guide pipes must be accurately positioned, and the accurate positions of the two ends of each steel pipe are measured by a total station;

in S5, before concrete pouring, the template and the guide pipe need to be checked again and corrected as necessary, the center line, elevation and geometric dimension of the template need to meet the design requirements, the position and angle of the guide pipe need to be correct, the template installation and the support erection need to be stable and firm, the cover arch adopts C20 concrete for pouring, in the construction process, the quality control of the raw materials and the quality control of all construction links such as concrete pouring and maintenance need to be enhanced, and the pouring sequence is from symmetrical pouring of two sides of the arch springing to the arch crown.

Furthermore, in S5, after the arch sleeving construction is finished, a pipe shed drilling platform is built, a drilling machine is installed, different drilling tool combinations are adopted according to different stratums, the drilling is performed inwards from the guide pipe, odd holes are drilled firstly, even holes are drilled after grouting, grouting is not performed on even holes, and continuous numbered drilling construction is not required to avoid hole collapse and drill jamming, and grouting is performed from two sides to the direction of the arch crown during grouting.

Furthermore, in S7, arch protection construction parameters and processes are similar to those of arch sheathing construction, after the construction of the arch sheathing and the advanced large pipe shed is finished, if the design size of the arch protection is longer, each section is required to be poured by no more than 5m, the interior of the arch protection is reinforced by I18I-steel with the distance of 50cm, on a mountain rock stratum excavated by a left foot of an arch frame, a right foot of the arch frame is biased to a wall, a well-fixed channel steel is installed on a bias wall foundation, and an I-steel connecting flange is effectively connected with the channel steel through bolts; the I-shaped steel is welded by using longitudinal connecting ribs, so that the integrity is enhanced; the contact position of the left side of the arch center and the rock surface is additionally provided with a 4.5m hollow grouting foot locking anchor rod, the angle of the foot locking anchor rod is 15 degrees to the vertical line of the tangent plane of the steel arch center, the foot locking anchor rod is connected with the steel arch center, concrete is poured by C20 concrete, and the pouring sequence is that the foot locking anchor rod is symmetrically poured from the two sides of the arch center until reaching the arch top.

Further, in S8, the soil body of the hidden tunnel is excavated by a three-step reserved core soil method, after the excavation is finished at the side close to the rock body, the steel arch frames are connected with arch protection steel arch frames, two adjacent steel arch frames are longitudinally connected into a whole by phi 20 steel bars, the circumferential distance is 1.0m, the steel arch frames are longitudinally arranged in a crossed manner along the inner side and the outer side of the steel arch frames, hollow grouting anchor rods with the length of 300cm and phi 25 are adopted for reinforcing the rock body, the distance is 60cm multiplied by 100cm quincunx arrangement, after the phi 8 steel bar net piece with the thickness of 15cm multiplied by 15cm is laid, C25 concrete with the thickness of 25cm is sprayed, so that the tunnel can be smoothly entered after the initial supporting construction is finished and the arch protection is closed into a ring after the initial supporting construction.

The utility model discloses in, cover and encircle construction process flow does: measurement lofting → manufacture and trial assembly of steel arch → installation of steel arch → determination of direction of guide tube and welding → erection of mould and concrete pouring. Wherein the content of the first and second substances,

survey lofting

And after construction and lofting are carried out on the position of the hole, reserving core soil on the upper step for arch sheathing construction, wherein the length of the arch sheathing is not less than 2m, and embedding a pipe shed guide pipe.

Manufacture and trial assembly of steel arch frame

The steel arch frame is manufactured in a centralized way and is assembled in a trial way after being processed, whether the I-shaped steel is distorted and deformed or not and whether the I-shaped steel is on the same plane or not are checked after the assembly,

mounting of steel arch frame

The steel arch is installed by excavating the side and upward slope to the position of the bottom foot of the designed advanced pipe shed, and the arch is installed after the protection of the upward slope surface is implemented, the steel arch can be installed after the plane is ensured to be correct for the elevation, the bottom foot of the steel arch should fall on a solid foundation during the installation, if the foundation is loose, measures should be taken to increase the bearing capacity of the foundation, the top beam close to the rock surface is installed firstly, the top beams are installed from inside to outside one by one, the arch is connected into a whole by adopting longitudinal connecting steel bars, and the arch is fixed.

Guide tube installation

And (3) fixing the guide pipe on the steel arch frame according to the angle and the position of a design drawing, wherein the external insertion angle is 1-3 degrees, and after the guide pipe is welded, performing arch sheathing vertical formwork, namely concrete pouring construction.

Vertical mould and concrete pouring

The cover arch is erected outside the excavation contour line of the opening, the inner mold is supported by a steel arch frame, the steel mold is assembled, the outer mold can be assembled by a wood mold, stirrups are fixed and reinforced, a movable template is reserved for vibration, a crack between the mold and the mold is tightly sewed to ensure no slurry leakage, after the template is assembled, concrete is poured, the left side and the right side of the formwork are symmetrically poured according to the concrete strength required by design during pouring, vibration is carried out in time, regular maintenance is required after pouring is finished,

the utility model discloses in, the construction process flow of leading pipe shed is: construction preparation → drill machine in place → drilling → steel pipe installation → grouting of pipe shed → detection and acceptance.

Wherein the content of the first and second substances,

preparation for construction

Before the support construction of the forepoling, 2 holes are selected at the arch foot part as test holes for carrying out grouting test, the grouting radius, the grouting pressure and the single pipe grouting amount are determined or adjusted, proper guide pipes are selected for grouting, the guide pipes are processed as required in a processing factory, mechanical equipment mainly comprises a pipe shed drilling machine, a high-pressure grouting machine, high-pressure air equipment, a cement mixer and the like, the length of a steel pipe is determined according to the thickness of weak broken surrounding rock and is generally 20 m-30 m.

Drill in place

The drilling construction is preferably carried out by adopting a crawler-type down-the-hole drill or a spiral drill and drilling by utilizing a sleeve following method, the hole depth meets the design requirement, the diameter of the steel pipe of the aperture wall pipe shed is 20-30 mm, and the drilling is carried out from a high hole position to a low hole position in sequence.

Drilling holes

After the drilling machine is in place, drilling can be carried out according to preset point positions, a large arm of the drilling machine needs to be tightly propped against a tunnel face or abut against a sleeve arch to prevent excessive vibration, the angle of the drilling machine is checked at any time in the drilling process to correct deviation in time, the drilling speed is low when the drilling machine drills a hole, the drilling depth is 20cm, the normal drilling speed is shifted, the collection and analysis of rock powder are paid attention in the drilling process, the rock powder is sampled according to the drilling depth, a record is made, and after the drilling is finished, residual slag in the hole is cleaned by high-pressure air to prevent pipe clamping in pipe jacking.

Mounting steel pipe

When the holes are drilled to the designed depth and checked to be qualified, the steel pipes are jacked, hot rolled seamless steel pipes with the diameter of 108mm, the wall thickness of 6mm, the section length of 4m and 6m are selected for the steel pipes, no holes are formed in the pipe orifice section with the length of 2.5m, the longitudinal distance of the steel pipes is 15-20 cm, the circumferential distance of 9-12 cm, grouting holes with the diameter of 10mm are arranged in a quincunx shape, the steel pipes are connected through screw threads, the length of the screw threads is not smaller than 150mm, the steel pipes are pre-arranged, the length is matched, the number of joints on the same cross section is not larger than 50%, the steel pipes are jacked manually or mechanically in an auxiliary mode, jacking is slow and uniform, a reinforcement cage is arranged in the steel pipes of the pipe shed according to the design requirements, so that the rigidity of the steel pipes of the pipe shed is increased, and.

Pipe roof grouting

After the steel pipe is pushed into the ground, the pipe is cleaned by high-pressure air to ensure that a grouting pipeline is smooth, the pipe opening of the steel pipe is blocked by a steel plate, a grouting guide pipe is welded, single-liquid grouting or double-liquid grouting is selected for pipe shed grouting, construction is started from two ends during grouting construction, the pipe is pushed towards the arch crown of a tunnel, or interval grouting is used, namely, a single-hole grouting is firstly carried out, then a double-hole grouting is carried out, the concentration of the grout is lower when the grouting is started, the grout is gradually thickened to the designed concentration, the grout is prepared according to the mixing ratio, the mixed chemical is uniform, the fluidity and the viscosity are good, the initial pressure is 0.5-1.0 MPa, the grout is pressed into the holes by a grouting pump and then is pressed for more than 10min with the pressure to close the grout, the final pressure grouting is carried out when the grout is discharged from an exhaust port, the final pressure is 2.0MPa, the grouting is stopped when the grouting amount meets the design requirement, and the grout in the exhaust pipe is removed, and cement mortar is tightly filled to enhance the rigidity and strength of the pipe shed, a detector detects the grouting effect after grouting is finished, and the next procedure can be carried out when the strength of the slurry reaches 70% after the slurry is qualified.

Wherein, the concrete used in the invention is high-strength light polyphenyl granule concrete; the high-strength light polyphenyl particle concrete is internally provided with a cement-based heat-insulation and noise-elimination layer, a metal plate layer, a rock wool plate layer, a damping layer, a waterproof layer and a stress dispersion layer, wherein the cement-based heat-insulation and noise-elimination layer, the metal plate layer, the rock wool plate layer, the waterproof layer and the stress dispersion layer are sequentially stacked or mixed together.

Quality control:

1. quality assurance system

(1) Tissue assurance

The project department establishes a quality management leader group taking a project manager as a group leader, and a project assistant manager, a chief worker and each department are responsible for quality management of human members and are responsible for project quality decision, and a quality inspection department is responsible for quality management daily affairs.

(2) System guarantee

And establishing and strictly executing quality management regulations such as quality responsibility system, inspection system, reward and punishment system and the like. In particular, a large quality inspection of items in the middle and at the end of the month and an irregular inspection at a quality inspection place have been seriously conducted. Establishing a project quality plan, a quality system file and a job file, and strictly managing a project quality process according to a quality system program; the quality tracking system is established, the responsibility is carried out to specific operators, and the traceability is realized.

(3) Idea guarantee

Quality consciousness education is strengthened, and quality consciousness of first quality and lifelong responsibility of employees is established.

2. Process control

(1) Accurately paying off according to a design drawing strictly, ensuring the line shape to be accurate, rechecking the lead at regular intervals, and checking and calibrating the measuring instrument;

(2) paying attention to the construction technology bottom-crossing work and the quality bottom-crossing before work, determining respective responsibilities, ensuring that each operator of construction operation knows the design intention, constructing according to the requirements of a design drawing strictly, and carrying out technology bottom-crossing on newly-entered civil workers in time aiming at the high mobility of the civil workers of the project;

(3) before each process is constructed, the operation can be started after the construction instruction of the supervision engineer is obtained;

(4) the construction technical specification and the special specification of the items in the contract file are strictly executed in the construction process, and the construction of each part is ensured to meet the technical specification and the design requirement;

(5) the inspection method strictly checks the incoming quality of the materials, carries out a method of specially-assigned inspection and random sampling inspection according to regulations, and ensures that various raw materials for the structure meet the design and specification requirements by acquiring the qualified materials and not adopting unqualified materials according to the specification requirements, and meanwhile, the incoming materials are properly stored to prevent pollution and corrosion;

(6) carrying out a mix proportion test and selection in concrete construction, and carrying out construction strictly according to the selected mix proportion;

(7) the machine tools and equipment such as incoming molds, machinery and the like are checked and accepted, so that the technical indexes of the machine tools and equipment reach the standard, the machine tools and equipment run normally, and the construction requirements are met;

(8) the excavation of the bias wall foundation needs to be in place and is processed strictly according to the design requirement, and the next procedure can be carried out after the bearing capacity of the foundation reaches the design requirement;

(9) drilling and grouting a pipe shed to certain jump hole construction, and constructing from two sides to the middle;

(10) during excavation, mechanical cooperation and manual excavation are adopted as much as possible, so that disturbance to surrounding rocks and damage to surrounding vegetation are reduced;

(11) during the bow member course of working, strictly process the bow member radian according to the design, guarantee the bow member circle in the same direction as, the linkage segment welding must be full, and satisfy design and standard requirement:

(12) in the process of concrete spraying construction, the thickness and the density of the sprayed concrete are strictly controlled, and filling by using fillers is strictly forbidden;

(13) and summarizing and improving, namely calling up the technology and construction summary in time according to the construction condition of the previous stage, and guiding the construction of the next stage.

Safety measures are as follows:

1. security system

(1) And (4) organization assurance. Establishing a safety leader group which takes a project manager as a group leader and is responsible for project safety work decision; the manager part is provided with a safety part and is responsible for daily affairs of project safety work; the safety department is provided with a full-time safety worker for following up the shift work and is responsible for the field safety management work;

(2) and (5) ensuring a system. And establishing a sound and complete safety responsibility system, a safety inspection system, a safety reward and punishment system and other regulation systems and performing hard execution. Especially, carefully developing a safety large inspection system in the middle and at the end of a month and irregular patrol in security places, carefully developing a before-shift safety training system, compiling various safety operation rules of a project and organizing construction according to the operation rules strictly;

(3) and (5) ensuring the idea. The staff safety awareness education and safety skill training are enhanced, and staff are organized to carry out safety technology background crossing so that the staff have safety skills suitable for corresponding occupations, and the staff are prevented from injuring others and being injured by others in the construction process;

(4) and (5) technical assurance. The construction organization design is optimized, and construction is strictly carried out according to the construction organization design, so that the construction safety of the project is ensured;

(5) and (4) economic guarantee. The communication with each party of design, supervision, owner and the like is enhanced, the capital investment of safety facilities is increased, and the reward and punishment can be realized in time according to the reward and punishment system.

2. On-site security management

(1) Construction electricity consumption is strictly in a three-phase five-wire system, and all electric equipment is protected by one machine and one brake, so that the accidents of electric leakage and injury to people are prevented;

(2) working aloft, and wearing safety protection articles correctly;

(3) the special operating personnel is insisted on keeping on duty and needs a special person to command and operate the equipment, and command signals are clear and accurate;

(4) the construction machinery equipment and the like are provided with the edge protection and warning marks according to requirements, so that the construction safety is ensured;

(5) in the construction process, the surrounding rock monitoring and measurement and advanced geological forecast are enhanced, and the construction scheme and the support parameters are adjusted in time according to the surrounding rock monitoring and measurement and various geological data, so that the construction safety is ensured.

And (3) environmental protection measures:

(1) executing the requirements of an environmental management manual and a program file, establishing an environmental management system, and strictly complying with laws, regulations and regulations related to environmental protection issued by national and local governments;

(2) strengthening employee civilized construction and environment protection consciousness education by an environment protection method, relevant regulations and typical cases;

(3) in the construction and operation field, the signs are reasonably arranged, the signs are complete and clear, various marks are striking, and the construction field is neat and civilized;

(4) construction wastewater and domestic sewage cannot pollute the surrounding environment, and the wastewater must be precipitated or filtered and purified to meet the environmental protection requirement. The solid waste is recovered, stacked and disposed in a centralized way;

(5) the principle of less land occupation and pollution reduction is adopted to reasonably select, arrange the living camp and construct the sidewalk;

(6) the vegetation recovery is carried out on the slope damaged by clearing, constructing an access road and the like by taking measures of tree planting and the like, and the ecological damage is reduced to the minimum.

And (3) benefit analysis:

1. economic benefits

The utility model still adopts conventional equipment and materials, optimizes construction procedures by improving construction technology, simplifies and standardizes production process, and has less equipment material consumption;

the utility model discloses a supporting effect that incomplete cover was encircleed and the open cut tunnel is protected and is encircleed makes the tunnel get into the undercut construction in advance, reduces excavation, the protection of entrance to a cave high side adverse slope, reduces entrance to a cave potential safety hazard and environmental destruction, save time and manpower. Due to the function of the arch protection, the excavation of earth and stone is reduced, the construction safety is ensured, the construction of the front tunnel is promoted, and the construction time is saved to a great extent;

because the construction speed is high, the working procedures are closely connected, the construction period is advanced, and the machine-to-machine work cost and the labor cost of certain mechanical equipment are saved;

the utility model discloses the construction is compared in brushing the method on side slope and upward slope according to traditional handicraft greatly, can practice thrift time limit for a project 2 months, and corresponding manual work, equipment cost saving conditions statistics as follows promptly:

personnel cost: 38 field constructors and 8 project department early managers can save labor cost (38+8) 6000 yuan/month 276000 yuan;

cost of large-scale machinery equipment:

excavator cost: one excavator is thrown into the Hitachi 220 excavator, and the load machine is saved by 25000 yuan per month;

loader cost: putting 2 50-type loaders into construction such as auxiliary support erection, wherein the 50-type loaders are counted according to 15000 yuan/month, namely the loaders save 15000 x 2 to 30000 yuan;

cost of the generator: putting one 350kw generator, and calculating according to 13000 yuan/month, namely saving 13000 yuan by the generator;

cost of the dump truck: 3 dump trucks of 20m3 are thrown into the dump truck, and the calculation is carried out according to 20000 yuan/month, namely the dump truck saves 20000 x 3 to 60000 yuan;

mixing station and tanker cost: putting 3 tank cars and 1 mixing station of 120, and calculating according to 100000 yuan/month, namely saving 100000 yuan for the mixing station and the tank cars;

to sum up, through the utility model discloses can practice thrift

276000+25000+30000+13000+60000+100000 ═ 504000 membered

2. Social benefits

10.2.1 the utility model discloses adopt this worker method construction basically, reduced the destruction to original entrance to a cave landform, protect ecological environment, and this construction utility model safe and reliable has avoided high side slope, high uphill slope, has guaranteed the operation safety during the construction and the safety during the operation, has embodied good social.

10.2.2 the utility model discloses a open cut tunnel protects and encircles supplementary construction, gets into the dark hole construction in advance, has increased the security of construction, has avoided the high slope protection construction.

10.2.3 the utility model has advanced working procedure time, short construction period and good social and economic benefits.

Table 1 is the utility model discloses a material and equipment table:

serial number	Work kind/job	Number of people	Responsibility
					1	Work shift long	1
2	Driller	4	Including blasters
				3	Anchoring-bolt and steel frame	6
4	Operating grouting pump	4
				5	Concrete spraying tool	4	By spraying the slurry vehicle
6	Ballast driver	2
				7	Driver of automobile	4
8	Carpenter's work	2
				9	Steel reinforcement worker	4
10	Template worker	4

Table 3 is the mechanical equipment table of the utility model;

table 2 is the material table of the utility model:

engineering example:

yuan green highway civil engineering five-part small mussel 2 tunnel, single hole length 1277m, wherein the left hole entrance of the small mussel 2 tunnel belongs to half cutting single pressure formula open cut tunnel and advances the hole construction, and successful application has adopted in the construction the utility model discloses a construction method digs into the hole in 2017, 12 months 1 day smoothly in dark.

Yuan green high-speed civil engineering part bears the construction of numb village tunnel, the long 2727m in single hole in tunnel, and wherein numb village tunnel export right side hole entrance belongs to half cutting list pressure formula open cut tunnel and advances the hole construction, and successful application has adopted in the construction the utility model discloses a construction method secretly digs smoothly into the hole in 2018 4 months 21 days.

Tunnel under the blue and green highway fan card that blue and green high-speed civil engineering thirteen parts were born, single hole length 1203m, wherein fan card under tunnel import right side entrance to a cave belong to half cutting single pressure formula open cut tunnel and advance the hole construction, successful application has adopted in the construction the utility model discloses a construction method, in 2019 the 16 days of 5 months smooth hidden excavations in the hole.

The utility model discloses in the construction of entering the hole at the little mussel Ga 2 tunnel of Yuanyang to green spring highway project (disconnect-type, the long 1272.96 meters in right side, the long 1276.96m in left side), the first left side of unit sun, in view of tunnel entrance to a cave precipitous complicated topography, I unit has adopted the utility model discloses the novel construction method of "a half cutting list die type open cut tunnel advances hole protective structure and construction method fast", this construction method convenient operation, with low costs, construction safety can reduce entrance to a cave earthwork excavation engineering volume, reduces unnecessary side slope and struts, the effectual construction risk of guaranteeing the workman, reduces entrance to a cave construction environment destruction rate, has practiced thrift construction cost, has shortened the time limit for a project, has apparent economic benefits and social.

And simultaneously, the utility model discloses according to the actual topography condition of job site, the mode that adopts half set of arch and open cut tunnel to protect the arch has realized advancing the hole construction fast, compares with traditional handicraft, and this method advances the hole and has avoided the destruction of entrance to a cave vegetation, has not only practiced thrift the time limit for a project, has still reduced construction cost and safe risk, has also produced fine social. In view of the above advantages, the system is favored by construction units and supervision units. Practice proves that the construction utility model is safe and reliable, simple to operate, good in quality of the constructed product, operable, wide in application prospect and outstanding in social, economic and environmental protection benefits;

finally, it should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and those skilled in the art may change or modify the technical content disclosed above into equivalent embodiments with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical substance of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims (10)

1. The utility model provides a half cutting list die mould open cut tunnel advances hole protective structure fast which characterized in that: the protective structure comprises a plurality of steel arch frames (1) which are sequentially arranged on the outer side of a tunnel portal in parallel from inside to outside, wherein the plurality of steel arch frames (1) are connected into a whole through a plurality of connecting rods (2) which are transversely arranged to form a sleeve arch, a plurality of sleeves (3) are sequentially arranged on the sleeve arch in parallel, and the sleeves (3) and the connecting rods (2) are arranged in parallel; the one end that the cover was encircleed is passed through bolt assembly and is connected with bias voltage wall (4), the other end that the cover was encircleed is connected with many installed parts (5) perpendicularly, and the activity is equipped with lock foot stock (6) on installed part (5), and lock foot stock (6) pass installed part (5) and are connected with massif rock stratum (7), form half arc protective structure.

2. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 1, characterized in that: the steel arch (1) is a semi-arc I-shaped steel arch, and the model size of the semi-arc I-shaped steel arch is processed and manufactured according to actual construction requirements.

3. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 1, characterized in that: the connecting rod (2) is a tubular body or a rod-shaped body member which is hollow or solid inside.

4. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 3, characterized in that: the connecting rod (2) is a rod-shaped body member with solid inside, and the rod-shaped body member is a steel bar.

5. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 4, characterized in that: the connecting rods (2) are arranged to be multiple, and the multiple connecting rods (2) are arranged at equal intervals or at unequal intervals.

6. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 1, characterized in that: the sleeve (3) is a tubular body member with a hollow interior.

7. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 6, characterized in that: the sleeve pipes (3) are arranged to be multiple, and the multiple sleeve pipes (3) are arranged at equal intervals or at unequal intervals.

8. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 1, characterized in that: the bottom end of the bias pressure wall (4) is connected with a mountain excavation step (9) into a whole through pouring concrete foundations (8).

9. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 1, characterized in that: the mounting piece (5) is vertically arranged I-steel or channel steel, and two through holes for the foot-locking anchor rods (6) to pass through are formed in the I-steel or the channel steel; the foot locking anchor rod (6) is a grouting foot locking anchor rod with a hollow inner part.

10. The rapid tunnel entering protection structure of the half cut single-pressure open cut tunnel according to claim 1, characterized in that: an injection molding layer, an anti-rust layer and a waterproof layer are sequentially sprayed on the outer surfaces of the steel arch centering (1), the connecting rod (2), the sleeve (3), the mounting piece (5) and the foot locking anchor rod (6) from inside to outside.

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