CN111425217A

CN111425217A - Reusable assembled type arch sheathing structure and construction method thereof

Info

Publication number: CN111425217A
Application number: CN202010355512.5A
Authority: CN
Inventors: 张生; 雷良; 占盼; 黄钒
Original assignee: Sichuan Communication Surveying and Design Institute Co Ltd
Current assignee: Sichuan Communication Surveying and Design Institute Co Ltd
Priority date: 2020-04-29
Filing date: 2020-04-29
Publication date: 2020-07-17

Abstract

The invention discloses a reusable assembled arch sleeving structure, which consists of an arch sleeving base, a steel arch frame, connecting steel bars for connecting the steel arch frame and an orifice pipe; at least 3 steel arches are connected through connecting steel bars, and each steel arch is connected with the arch sheathing base; the orifice pipe is arranged at the top of the steel arch frame; when the cover arch structure is used, the orifice pipes are fixed in the large pipe shed in a one-to-one correspondence mode, the 3 steel arch frames at the bottom play a role in fixing and supporting the large pipe shed through the orifice pipes, and pipe shed construction can be rapidly carried out after the assembled cover arch structure is positioned. Assembled pipe shed cover encircles and does not have high expectations to the foundation bearing capacity, uses the assembled cover arch structure that this scheme provided when meetting the bias pressure tunnel entrance to a cave of mountain area topography precipitous fluctuation big, topography skew, can realize carrying out "zero" excavation to the adverse slope to avoid appearing the slope of tunnel entrance to a cave and the too high potential safety hazard of adverse slope height, also can realize the environment coordination simultaneously, embody green highway theory.

Description

Reusable assembled type arch sheathing structure and construction method thereof

Technical Field

The invention relates to the field of highway tunnels, in particular to a reusable assembled type cover arch structure and a construction method thereof.

Background

In recent years, more and more mountain highways have been planned and constructed. The highway brings great convenience to the mountain traffic. However, since the highway belongs to a high-grade highway, the requirement on linear indexes is high, the terrain in mountainous areas is steep and has large fluctuation, more and more tunnels are formed, and the design and construction difficulty is higher and higher. Generally speaking, tunnel excavation advances the hole and often adopts big pipe shed to carry out supplementary construction, ensures progress safety, and pipe shed construction needs the cover to encircle and fixes a position, and conventional pipe shed cover encircles and has higher requirement to the foundation bearing capacity, and the cover arch foundation subsides to lead to the cover to encircle to invade the limit carelessly can take place slightly, and its occupation space is great moreover, and the pipe shed construction finishes the back and no longer demolishs, especially some narrow places of topography, and it invades and occupies limited space, and is not too pleasing to the eye again.

The invention provides a reusable fabricated arch sleeving structure, which can be used for quickly constructing a pipe shed after being positioned and carrying out zero excavation on an opposite side and an upward slope, has short installation time, can be installed in one day, saves a large amount of time in one week compared with the conventional arch sleeving construction, and can be dismantled and moved to another tunnel for construction after the pipe shed is constructed, so that a large amount of social resources are saved, the attractiveness of a tunnel door is not influenced, the requirement on the bearing capacity of a foundation is low, and the applicability is wide.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: conventional pipe shed cover encircles construction cycle length, and is higher to the foundation bearing capacity requirement, and the set arch foundation subsides to lead to the cover to encircle to invade the limit slightly carelessly can take place, and its occupation space is great moreover, and the pipe shed construction finishes the back and no longer demolishs, especially some narrow places of topography, and it invades and occupies limited space, and is not too pleasing to the eye again.

In order to solve the technical problems, the invention provides a reusable assembled type cover arch structure and a construction method thereof.

The invention is realized by the following technical scheme:

this scheme provides a but reuse's assembled cover encircles structure, includes: the arch sleeving base, the steel arch frame, connecting steel bars for connecting the steel arch frame and the orifice pipe;

at least 3 steel arches are longitudinally arranged and connected, and each steel arch is bent, extended and connected to the right side of the arch base from the left side of the arch base; the connecting steel bars are connected between the steel arch frames and are vertical to the steel arch frames, and the orifice pipes are arranged at the tops of the steel arch frames along the longitudinal arrangement direction of the steel arch frames.

The working principle of the scheme is as follows: the invention provides a reusable assembled type arch sleeving structure which comprises an arch sleeving base, a steel arch frame, connecting steel bars for connecting the steel arch frame and an orifice pipe, wherein the arch sleeving base is provided with a plurality of arch sleeving holes; at least 3 steel arch frames are longitudinally connected through connecting steel bars, then the steel arch frames are connected with the arch sleeving bases, and the orifice pipes are arranged at the tops of the steel arch frames, so that the assembled arch sleeving of the scheme is formed; generally speaking, tunnel excavation is advanced the hole and is often adopted the big pipe roof to carry out supplementary construction, in order to ensure to advance the hole safety, need cover to encircle during big pipe roof construction and fix a position and support, conventional pipe roof cover is encircleed and is installed the tool rest strutting arrangement earlier, then install the reinforcing bar net piece, the welding steel pipe, it is firm to consolidate to cover the arch installation template, the measurement concreting after checking, this type of conventional pipe roof cover encircles and has higher requirement to the foundation bearing capacity, it can also take place to overlap the arch foundation subsides to lead to the cover to encircle to sink slightly carelessly, and its occupation space is great, inconvenient demolishment again after the pipe roof construction finishes, especially in some narrow places of topography, the pipe roof invades the space that occupies limitedly, and the pipe roof influences again. When the reusable fabricated arch sleeving structure is used, the orifice pipes are fixed in the large pipe shed in a one-to-one correspondence mode, the 3 steel arch frames at the bottom can fix and support the large pipe shed through the orifice pipes, and pipe shed construction can be rapidly carried out after the fabricated arch sleeving structure is positioned.

Because the assembled cover arch structure is composed of the steel arch frame and the reinforcing steel bars, the assembled pipe shed cover arch has low requirements on the bearing capacity of a foundation, and when meeting a bias tunnel portal of a highway, which has high requirements on linear indexes, steep and big fluctuation of mountainous terrain and oblique terrain, the assembled cover arch structure provided by the scheme can be used for realizing zero excavation on an inverted slope, so that the situation that the safety of tunnel construction and operation periods is influenced due to too high heights of the side slope and the inverted slope of the tunnel portal is avoided, environment coordination can be realized at the same time, and the concept of a green road is embodied. The assembled cover arch structure does not need to be poured with concrete, the installation time is short, the installation can be completed one day, a week of time is saved in comparison with the conventional cover arch construction, after the pipe shed construction is finished, the assembled cover arch structure can be dismantled and moved to another tunnel for construction, a large amount of social resources are saved, the attractiveness of a tunnel door is not influenced, and the practicability is very wide.

Further preferably, the steel arch frames are arranged at equal intervals along the longitudinal direction at intervals of 70 cm.

Further preferred scheme is that the circumferential spacing of the connecting steel bars along the steel arch is 0.5m, and the two ends of the connecting steel bars are welded with the steel arches which are respectively connected.

The working principle of the technical scheme is as follows: each steel arch is connected with the arch sheathing base through an anchor rod, the steel arches are fixed in the vertical direction, a connecting steel bar is arranged between the two steel arches in the circumferential direction at the interval of 0.5m and is longitudinally connected, the inner side and the outer side of the connecting steel bar are arranged in a staggered mode, and the steel arches are fixed transversely, so that the whole arch sheathing is more stable.

More preferably, each steel arch is composed of 2 prefabricated parts A and at least 1 prefabricated part B, and the prefabricated parts B are connected among the 2 prefabricated parts A through bolts.

Each steel arch is divided into three units, each unit is composed of 2 prefabricated parts A and at least 1 prefabricated part B, the units are connected through bolts, the steel arch is convenient to disassemble into three units when the set arch is removed before tunnel excavation, and occupied space is reduced.

The steel arch unit division is planned according to the division excavation, and can be adjusted according to the actual conditions during construction.

The further preferred scheme is that the prefabricated part B is formed by welding two steel plates A at two ends of an I-steel respectively, one end of the I-steel of the prefabricated part A is welded with the steel plate A, and the other end of the I-steel of the prefabricated part A is welded with the steel plate B.

Further preferably, the prefabricated part A is connected with the arch sheathing base through a connecting steel plate B.

Further preferably, the connecting steel plate a is: the length of 220mm, the width of 260mm and the thickness of X16mm are as follows: 220mm long X400mm wide X16mm thick.

The connecting steel plate B is connected with the steel arch base and the steel arch, and the connecting steel plate B with larger area can better bear the steel arch.

Further preferred scheme is that orifice pipes are uniformly arranged in the range of 120 degrees at the top of the steel arch along the longitudinal arrangement direction of the steel arch, the circumferential distance of the orifice pipes along the steel arch is 40cm, and the orifice pipes are directly welded with the steel arch or welded through steel backing blocks. Further preferred scheme is that the longitudinal external insertion angle of the orifice pipe and the steel arch is 2 degrees.

On the one hand the orifice pipe installation supports and fixes big pipe shed in advancing big pipe shed, on the other hand the orifice pipe also is the stand pipe of big pipe shed, play the effect of a direction, because the country rock is the three-phase inhomogeneous, especially boulder in the soil property can make drilling deviation, the orifice pipe can make the orifice pipe grout the consolidation form the consolidation body of round in the hole top certain limit with steel bow member vertical external insertion angle be 2 in addition, rather than this consolidation body has partly inside the tunnel excavation contour line, the external insertion angle is adjusted according to actual rock stratum production situation.

The invention also provides a construction method of the reusable assembled pipe shed cover arch structure, which comprises the following specific steps:

s1, pouring a sleeve arch foundation next to secondary linings outside the secondary linings on two sides of an arch camber line;

s2, reserving a deformation amount after reserving a corresponding lining thickness range on the inner contour of the tunnel, and prefabricating and installing a steel arch center of the assembled arch sleeving structure according to the determined tunnel contour line;

s3, after the slope of the tunnel is protected by adopting anchor net spraying, fixing the steel arch on the base by adopting anchor bolts;

and S4, grouting is carried out on the pipe shed, and the pipe shed is not perforated at the gap section between the cover arch and the slope surface, so that slurry leakage is prevented.

And S5, after the grouting slurry is initially set, cutting off exposed sections of the pipe shed before final setting, removing the cover arch, and excavating the tunnel.

The reusable assembled cover arch has wide applicability, can be suitable for various terrain conditions, no matter whether the terrain is orthogonal or oblique, no matter whether the slope is bedrock or soil layer. The construction cost is low, and processing is simple, and the construction is swift, practices thrift more time and cost than conventional pipe canopy, and the project that a specially adapted project has more tunnel.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the invention provides a reusable fabricated arch sleeving structure and a construction method thereof, wherein at least 3 steel arch frames are longitudinally connected through connecting steel bars, then the steel arch frames are connected with an arch sleeving base, and a hole pipe is arranged at the top of the steel arch frames to form a fabricated arch sleeving, so that the requirement on the bearing capacity of the base is not high, and zero excavation can be performed on an opposite side slope, thereby avoiding the potential safety hazard that the side slope of a tunnel portal and the opposite slope are too high, realizing environmental coordination and embodying the concept of a green road;

2. according to the reusable assembled type arch sleeving structure and the construction method thereof, concrete does not need to be poured in the later period, the installation time is short, the installation can be completed in one day, a lot of time is saved in one week compared with the conventional arch sleeving construction, after the pipe shed construction is completed, the assembled type arch sleeving structure can be dismantled and moved to another tunnel for construction, a lot of social resources are saved, the attractiveness of a tunnel door is not influenced, and the practicability is very wide.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a view of the assembled arch of the present invention.

Fig. 2 is a combined installation diagram of the steel arch.

Fig. 3 is a schematic view of the prefabricated part a.

Fig. 4 is a schematic view of the prefabricated part B.

FIG. 5 is a schematic view of an orifice tube installation.

Fig. 6 is a schematic sectional view of the construction of the prefabricated arch cover.

FIG. 7 is a cross-sectional view of a large pipe shed

Reference numbers and corresponding part names in the drawings:

1-set arch base, 2-steel arch, 3-connecting steel bars for connecting the steel arch, 4-orifice pipe, 5-prefabricated part A, 6-prefabricated part B, 7-connecting steel plate A, 8-connecting steel plate B, 9-I-shaped steel, 10-steel cushion block, 11-tunnel center line ground line, 12-grouting diffusion radius, 13-large pipe shed, 14-primary support, 15-secondary lining, 16-reserved deformation, 17-construction branch hole center line, 18-design elevation point, 19-bolt, 20-large pipe shed conduit with external diameter of 108mm, 21-grouting hole, 22-fixed steel pipe with diameter of 42mm, 23-main bar and 24-welding.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example 1

As shown in fig. 1, a reusable fabricated arch wrap structure includes: the arch sleeving device comprises an arch sleeving base 1, a steel arch frame 2, connecting steel bars 3 for connecting the steel arch frame and an orifice pipe 4;

at least 3 steel arches 2 are longitudinally arranged and connected, and each steel arch 2 is bent, extended and connected to the right side of the arch sheathing base 1 from the left side of the arch sheathing base 1; the connecting steel bars 3 are connected between the steel arch frames 2 and are vertical to the steel arch frames 2, and the orifice pipes 4 are arranged at the tops of the steel arch frames 2 along the longitudinal arrangement direction of the steel arch frames 2.

As shown in fig. 2, the steel arch frames 2 are arranged at equal intervals along the longitudinal distance of 70cm, and the steel arch frames 2 are longitudinally connected by the connecting steel bars 3. The circumferential distance of the connecting steel bars 3 along the steel arch frames 2 is 0.5m, and the two ends of the connecting steel bars 3 are welded with the steel arch frames 2 which are respectively connected.

Each steel arch 2 is composed of 2 prefabricated parts A5 and 1 prefabricated part B6, and the prefabricated parts B6 are connected among the 2 prefabricated parts A5 through bolts.

The prefabricated part 6 is formed by welding two steel plates A at two ends of an I-shaped steel respectively, one end of the I-shaped steel of the prefabricated part 5 is welded with the steel plate A7, and the other end of the I-shaped steel is welded with the steel plate B8.

The connecting steel plate A7 is: the length of 220mm, the width of X260 mm and the thickness of X16mm are as follows, and the connecting steel plate B8 is as follows: 220mm long X400mm wide X16mm thick.

Fig. 3 is a schematic view of the prefabricated part a, and fig. 4 is a schematic view of the prefabricated part B.

The orifice pipes are uniformly arranged at the top of the steel arch frame within 120 degrees in the longitudinal direction, the circumferential distance between the orifice pipes within 120 degrees at the top of the steel arch frame is 40cm, and the orifice pipes are directly welded with the steel arch frame or welded through the steel cushion blocks 10. As shown in fig. 5, which is a schematic view of the orifice tube installation.

The longitudinal outward inserting angle of the orifice pipe and the steel arch is 2 degrees.

Example 2

A construction method for a reusable fabricated pipe shed cover arch structure comprises the following specific steps:

As shown in fig. 5, the secondary lining is placed outside the secondary lining on both sides of the arch springing line next to the secondary lining pouring arch C30 concrete foundation according to the construction method of the recyclable prefabricated pipe shed arch structure.

The radius of the inner contour of the tunnel is enlarged by 1m, the range above the arch raising line is the arch covering range, and the enlargement of the radius of the inner contour of the tunnel by 1m considers the thickness of a secondary lining, the thickness of a primary support and the reserved deformation 16. According to the determined contour line, I18 steel arches are prefabricated, each steel arch is divided into three units (two prefabricated parts A5 and 1 prefabricated part B6), and the units are connected by bolts 19.

The steel arch frames 2 are arranged at 3 equal intervals along the longitudinal direction at intervals of 70cm, the longitudinal connecting steel bars 3 between the steel arch frames 2 are steel bars with the diameter of 22mm, one steel bar is arranged at each 0.5m along the circumferential direction of the steel arch frame, and two ends of the steel bars are welded with the steel arch frames to form a whole. Each set of arches has 3 pairs.

And orifice pipes 4 with the diameter of 140mm are uniformly arranged within the range of 120 degrees at the top of each steel arch, the circumferential distance is 40cm, and the longitudinal external insertion angle is 2 degrees. The steel members are all produced in a steel member processing factory, and the precision of the size is ensured. The orifice pipe 4 is a hot-rolled steel pipe with a diameter of 140mm, a wall thickness of 5mm and a length of 2 m.

Adopt the anchor net to spout to tunnel slope and protect, its measure is:

the small grouting guide pipes are 4.5m long and are arranged in a quincunx arrangement at intervals of 1.2 m.

The spacing between the reinforcing meshes is 25 × 25cm, the average sprayed concrete thickness is 10 cm., and the pipe shed is also consideredAnd (5) grouting a sealing layer.

The 3-joint processed steel arch centering 2 is arranged on the arch centering base 1, namely the steel arch centering 2 is fixed on the arch centering base 1 by adopting an anchor bolt 10. The large pipe shed 13 is drilled by a horizontal drilling machine C6 or a drill jumbo. Grouting the large pipe shed 13, and preventing the large pipe shed 13 from being perforated at the gap section between the assembled cover arch and the slope surface to prevent slurry leakage.

As shown in fig. 7, the large shed design parameters:

(1) the specification of the large pipe shed conduit 22 is as follows: the hot-rolled seamless steel perforated pipe has the outer diameter of 108mm, the wall thickness of 6mm and the length of each section of 4-6 m, and is assembled in sections to reach the length of a forepoling.

(2) Grouting holes 21 are drilled in the guide pipe, the hole diameter is 8mm, the hole distance is 20cm, the guide pipe is arranged in a quincunx shape, and a grout stopping section without drilling holes is reserved at the tail part 2 m.

(3) Tube distance: the circumferential spacing is 40 cm.

(4) Inclination angle: the external insertion angle is 2 °

(5) Grouting materials: pure cement slurry, wherein the grouting pressure is 1-2 Mpa, and the water-cement ratio is 1: 0.5-1: 1.

(6) the stiffening reinforcement cage is inserted in the guide pipe, 4 main reinforcements 23 are required, the diameter is 22mm, the fixed steel pipe 22 is made of hot-rolled seamless steel pipes with the diameter of 42mm, each section is 4cm long, the distance is 150cm, and the stiffening reinforcement cage is welded 24 with the main reinforcements.

After the grouting slurry is initially set, the exposed section of the large pipe shed 13 is cut off before final setting, the assembled cover arch is moved away, the orifice pipe 4 is cleaned (convenient for next use), and tunnel excavation is carried out.

And (3) large pipe shed construction:

(1) assembling the tunnel portal pipe shed cover arches; three steel arches (with the distance of 70cm) are erected on the working platform.

(2) Drilling a pipe shed conduit: the pipe shed is constructed according to the designed position, and the direction of a drilling vertical shaft must be accurately controlled to ensure that the hole direction of the orifice is correct. When the hole wall of the drill hole of the guide pipe is not collapsed, a steel pipe is jacked after each hole is drilled; when the hole wall of the pipe drill hole is easy to collapse, a method (namely, a follow-up drilling) that the pipe and the drill bit drill simultaneously is adopted. During drilling, a lateral inclinometer is often adopted to measure the deflection degree of steel pipe drilling, and the deflection is found to exceed the design requirement and is corrected in time.

(3) And (3) grouting of stratum: and after drilling is finished, removing the drill rod, leaving the guide pipe, connecting with a grouting joint, and performing stratum grouting by using pure cement slurry as a grouting material.

(4) Filling and reinforcing the conduit: cleaning holes by a drilling tool, flushing, inserting a grouting pipe, and filling M20 cement mortar.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A reusable fabricated arch wrap structure comprising: the steel arch centering device comprises a cover arch base (1), a steel arch frame (2), connecting steel bars (3) for connecting the steel arch frame, and an orifice pipe (4);

at least 3 steel arches (2) are longitudinally arranged and connected, and each steel arch (2) is bent, extended and connected to the right side of the arch sheathing base (1) from the left side of the arch sheathing base (1); the connecting steel bars (3) are connected between the steel arch frames (2) and are vertical to the steel arch frames (2), and the orifice pipes (4) are arranged at the tops of the steel arch frames (2) along the longitudinal arrangement direction of the steel arch frames (2).

2. A reusable fabricated shell arch structure according to claim 1, characterised in that the steel arches (2) are equally spaced along the longitudinal direction by 70 cm.

3. A reusable fabricated arch sheathing structure according to claim 2, wherein the connecting reinforcing bars (3) are circumferentially spaced apart by 0.5m along the steel arch (2), and both ends of the connecting reinforcing bars (3) are welded to the respective connected steel arches (2).

4. A reusable fabricated arch construction according to claim 2, wherein each arch (2) is composed of 2 prefabricated parts a (5) and at least 1 prefabricated part B (6), and the prefabricated parts B (6) are connected between the 2 prefabricated parts a (5) by bolts.

5. The reusable fabricated arch sheathing structure according to claim 4, wherein the prefabricated member B (6) is formed by welding a steel plate A to each of both ends of an I-steel; the prefabricated part A (5) is formed by welding one end of an I-shaped steel with a steel plate A (7) and welding the other end of the I-shaped steel with a steel plate B (8).

6. A reusable fabricated arch-sheathing structure according to claim 5, wherein the prefabricated member A (5) is connected to the arch-sheathing base (1) through a connecting steel plate B (8).

7. A reusable fabricated arch-type structure according to claim 5, wherein the connecting steel plate A (7) is: a length of 220mm, a width of 260mm and a thickness of 16mm, wherein the connecting steel plate B (8) is as follows: 220mm long X400mm wide X16mm thick.

8. A reusable fabricated arch sheathing structure according to claim 1, wherein the orifice pipes (4) are uniformly arranged in the longitudinal arrangement direction of the steel arch (2) within 120 ° of the top of the steel arch (2), the interval between the orifice pipes (4) in the circumferential direction of the steel arch (2) is 40cm, and the orifice pipes (4) are welded to the steel arch (2) directly or via steel spacers.

9. A reusable fabricated shell arch structure according to claim 8, characterised in that the orifice pipe (4) is at a 2 ° angle to the longitudinal direction of the steel arch (2).

10. A construction method for a reusable fabricated pipe shed cover arch structure comprises the following specific steps:

s4, grouting is conducted on the pipe shed, and the pipe shed is not perforated at a gap section between the cover arch and the slope surface, so that slurry leakage is prevented;