CN110439571B - Transverse channel construction method for leading flat pilot tunnel to main tunnel and transverse channel - Google Patents

Transverse channel construction method for leading flat pilot tunnel to main tunnel and transverse channel Download PDF

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Publication number
CN110439571B
CN110439571B CN201910773570.7A CN201910773570A CN110439571B CN 110439571 B CN110439571 B CN 110439571B CN 201910773570 A CN201910773570 A CN 201910773570A CN 110439571 B CN110439571 B CN 110439571B
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China
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tunnel
main
transverse channel
hole
excavated
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CN110439571A (en
Inventor
王亚锋
曹耀祖
马亮
朱建民
刘强
吴文娟
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China Railway Tunnel Group Co Ltd CRTG
China Railway Tunnel Stock Co Ltd
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China Railway Tunnel Group Co Ltd CRTG
China Railway Tunnel Stock Co Ltd
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Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/04Lining with building materials
    • E21D11/10Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/14Lining predominantly with metal
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/14Lining predominantly with metal
    • E21D11/15Plate linings; Laggings, i.e. linings designed for holding back formation material or for transmitting the load to main supporting members
    • E21D11/152Laggings made of grids or nettings
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/14Lining predominantly with metal
    • E21D11/18Arch members ; Network made of arch members ; Ring elements; Polygon elements; Polygon elements inside arches
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D20/00Setting anchoring-bolts
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D9/00Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
    • E21D9/008Driving transverse tunnels starting from existing tunnels
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D9/00Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
    • E21D9/01Methods or apparatus for enlarging or restoring the cross-section of tunnels, e.g. by restoring the floor to its original level
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D9/00Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
    • E21D9/14Layout of tunnels or galleries; Constructional features of tunnels or galleries, not otherwise provided for, e.g. portals, day-light attenuation at tunnel openings
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21FSAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
    • E21F16/00Drainage
    • E21F16/02Drainage of tunnels

Abstract

The invention discloses a construction method of a transverse passage leading a flat pilot tunnel to a main tunnel and the transverse passage, the construction method of the transverse passage leading the flat pilot tunnel to the main tunnel comprises the steps of firstly, selecting a proper position in the flat pilot tunnel to open an initial hole opening at the intersection of the transverse passage and the flat pilot tunnel, then excavating a tunnel body of the transverse passage from the initial hole opening to the main tunnel direction, in the excavating process, in the direction leading the transverse passage from the flat pilot tunnel to the main tunnel, excavating the tunnel top of the transverse passage upwards along a certain gradient, and then constructing a locking opening. The construction method of the transverse channel leading from the flat pilot tunnel to the main tunnel reduces the height difference of the transverse channel entering the main tunnel to jack by lifting the top of the transverse channel, reduces the difficulty of jack construction and prevents jack collapse; in the top-raising construction process, the temporary portal frame is excavated along with the support, so that the instability and collapse caused by overlong exposure time of surrounding rocks are prevented. In addition, a transverse channel is arranged from the excavated tunnel section of the horizontal pilot tunnel to the unearthed tunnel section of the main tunnel, so that the construction progress of the main tunnel can be accelerated.

Description

Transverse channel construction method for leading flat pilot tunnel to main tunnel and transverse channel
Technical Field
The invention relates to the technical field of tunnel construction, in particular to a construction method of a transverse passage leading from a horizontal pilot tunnel to a main tunnel and the transverse passage.
Background
The tunnel horizontal pilot tunnel is commonly used in some long tunnel projects, the horizontal pilot tunnel is an auxiliary construction tunnel parallel to a tunnel main tunnel, a transverse channel is usually arranged between the horizontal pilot tunnel and the main tunnel, in case of collapse in the tunnel main tunnel construction process, the horizontal pilot tunnel can be used for supporting and following, and the horizontal pilot tunnel can also be used for water drainage, slag discharge, feeding and ventilation of the main tunnel.
In engineering, because the transverse channel is constructed in a hole, the construction difficulty of the opening of the horizontal pilot tunnel entering the transverse channel and the construction difficulty of the opening of the horizontal channel entering the main tunnel are high, the sections of the horizontal pilot tunnel and the transverse channel are usually much smaller than the section of the main tunnel, different construction methods are needed for the opening of the horizontal pilot tunnel entering the transverse channel and the opening of the horizontal channel entering the main tunnel, the construction difficulty is further improved, the opening of the horizontal channel entering the main tunnel faces the top with a high height, and the construction difficulty is high when the top lifting height is high.
Chinese patent publication No. CN106089215A describes a construction method for a highway tunnel to enter a transverse channel opening through a parallel pilot tunnel, which is to shift the central line of a primary supporting structure at the front and back of the intersection of the parallel pilot tunnel and the central line of the transverse channel to the transverse channel direction, increase the radius of an upper step steel arch according to the design contour, and continue the original construction use radius of a lower step steel arch; on the basis of the steel arch centering with the normal profile of the transverse channel, angle changing treatment is respectively carried out on each arch centering unit, and grouting anchor pipes for locking feet are respectively arranged at the joints and the arch tops of the connecting plates of each unit. Chinese patent publication No. CN104632228A describes a transverse passage entering main line construction method and a transverse passage, relating to the field of subway tunnel construction, and consisting of the following sequential steps: firstly, measuring and paying off, and putting the position of a positive line hole door on the side wall of a transverse channel; secondly, installing a grid steel frame at the position of the main line hole door, and arranging a small advanced guide pipe at the inner arch part of the grid steel frame; arranging anchor pipes and double-layer reinforcing meshes on the side wall outside the main entrance; grouting the advanced small guide pipe and the anchor pipe, and welding the advanced small guide pipe and the anchor pipe with the double-layer reinforcing mesh into a whole; fifthly, spraying concrete to form the support wall.
The construction methods described in the above patent documents are all local constructions of the lateral passage, and cannot effectively reduce the construction risk of high-lift top at the entrance of the lateral passage into the main tunnel.
Disclosure of Invention
The invention aims to solve the technical problems that a construction method of a transverse channel leading from a horizontal pilot tunnel to a main tunnel and the transverse channel are provided, and the technical problems that the jacking height of the transverse channel entering the main tunnel is high, the construction difficulty is high and the risk is high in the prior art are solved.
To solve the above technical problem, a first aspect of the present invention is:
a construction method for designing a transverse channel leading from a horizontal pilot tunnel to a pilot tunnel is provided, wherein the top of the section of the pilot tunnel is higher than that of the section of the horizontal pilot tunnel, and the construction method comprises the following steps:
(1) opening of the transverse channel: selecting a proper position in the horizontal pilot tunnel and forming an initial hole at the intersection of the horizontal channel and the horizontal pilot tunnel;
(2) construction of a transverse channel: excavating a tunnel body of the transverse channel from the initial tunnel portal to the main tunnel direction, wherein in the excavating process, in the direction that the transverse channel leads to the main tunnel from the flat pilot tunnel, the tunnel top of the transverse channel is excavated upwards along a certain slope;
(3) and (3) locking construction: and when the hole body of the transverse channel is excavated to reach the intersection with the main hole, constructing a locking notch at the intersection of the transverse channel and the main hole, wherein the locking notch is used for reinforcing the hole at the intersection of the transverse channel and the main hole.
Preferably, the crossroads are led to the main-tunnel unearthed tunnel section from the flat pilot tunnel excavated tunnel section, after the step (3), the construction method further comprises a step (4) of main-tunnel topping construction at the lock hole, and the step (4) comprises:
and in the expanding excavation process, the top of the locking port is lifted upwards to the top direction of the main hole at a certain gradient to perform upward top expanding excavation.
Preferably, the step (2) specifically comprises:
(2.1) excavating the hole body of the transverse channel by adopting a step method, in the excavating process, supporting a transverse channel steel frame with the corresponding size in the transverse channel, laying anchor rods on the hole wall of the supporting steel frame, and spraying concrete to form primary support;
(2.2) when the transverse channel is excavated forwards, paving a reinforcing mesh and a supporting template on the tunnel wall of the primary support formed at the rear, and then injecting concrete into the supported template to form a secondary lining;
and (2.3) in the process of excavating the tunnel body of the transverse channel, backfilling the ballast on the bottom surface excavated in the transverse channel to form a traveling road surface, wherein the traveling road surface gradually rises in the direction from the flat pilot tunnel to the main tunnel at a certain gradient in the transverse channel.
Preferably, the step (3) includes:
(3.1) densely erecting a plurality of locking port supports in parallel at the intersection of the transverse channel and the designed side wall of the main tunnel, wherein each locking port support comprises an internal transverse channel locking port steel frame and an external reinforced door-shaped steel frame, each transverse channel locking port steel frame is provided with an arched top, and a plurality of vertical upright posts are arranged between a cross beam at the top of each reinforced door-shaped frame and the arched top of each transverse channel locking port steel frame;
(3.2) a plurality of the fore shaft supports are welded and connected into a whole through steel materials, and the bottom of each fore shaft support is provided with a foot-falling beam for supporting.
Preferably, the step (4) specifically includes:
(4.1) expanding and digging the upper part of the section of the main hole from the lock opening: in the expanding excavation process, expanding a certain distance along the outline of the tunnel top designed by the main tunnel to be used as a space for offsetting the deformation of the expanded excavated tunnel top and a space for performing temporary support, erecting a temporary portal steel frame with a corresponding size in time after expanding excavation for a certain distance, and performing anchor rod on the excavated tunnel top and spraying concrete for performing temporary support until expanding excavation is performed from the lock hole to the other side of the width direction of the main tunnel;
(4.2) erecting a tunnel arch center of the main tunnel under the temporary support excavated at the upper part of the main tunnel: the part of the main tunnel arch frame, which is close to one side of the locking notch, is an oblique beam extending from the top of the locking notch to the direction of the tunnel top excavated by the main tunnel, the rest part of the main tunnel arch frame is an arch part attached to the tunnel top excavated by the main tunnel, and the lower end of the oblique beam is welded on a cross beam at the top of the locking notch support;
(4.3) performing spray anchor support on the top of the upper partial excavation space of the main tunnel: and (2) driving locking anchor pipes into the top wall surfaces of the tunnel from two sides of the main tunnel arch, hanging a reinforcing mesh piece on the main tunnel arch, and spraying concrete to the main tunnel arch and the reinforcing mesh piece.
Preferably, the driving road surface extends from the bottom surface of the initial hole to a central line of the bottom surface of the excavation space at the upper part of the main tunnel.
Preferably, after the step (4.3), a step (5) of continuing to excavate the front hole in front of the locking notch is further included, and the step (5) includes:
(5.1) when the strength of the concrete sprayed on the arch frame of the tunnel with the main tunnel and the reinforcing mesh sheet meets the requirement, dismantling the support legs of the temporary portal steel frames;
(5.2) excavating the front and back extension directions in the main tunnel by adopting a three-step method on the basis of the space excavated at the upper part of the intersection of the main tunnel and the transverse passage, so that the tunnel section at the intersection of the main tunnel and the transverse passage forms a full-section tunnel section, and gradually removing the tunnel ballast backfilled by the driving pavement formed in the transverse passage in the excavation process;
(5.3) right the positive hole is located the hole section in fore of the fore shaft carries out inverted arch space excavation, after the inverted arch space is excavated, erect the inverted arch frame in the inverted arch space and lay the reinforcing bar net piece, then pour concrete and form the primary support sheath of the inverted arch.
Preferably, the step (1) specifically comprises:
(1.1) measuring and marking an excavation contour line of an opening of a transverse channel on the side surface of the flat pilot tunnel, wherein the inner space of the excavation contour line is an initial hole of the transverse channel, expanding a certain distance along the excavation contour line to form a small advanced guide pipe, arranging the small advanced guide pipe upwards at a certain gradient, and welding and connecting the small advanced guide pipe and a crossed flat pilot tunnel steel frame by using a steel bar;
(1.2) after the advanced small guide pipes are completely constructed, chiseling off the concrete support layer positioned in the excavation contour line on the side wall of the flat pilot tunnel, cutting off the steel frame part of the flat pilot tunnel in the excavation contour line, and then adopting the section steel to weld the steel frame cuts along the excavation contour line.
The second aspect of the present invention is:
designing a transverse passage leading a horizontal pilot tunnel to a main tunnel, wherein the top of the section of the main tunnel is higher than the top of the section of the horizontal pilot tunnel, the transverse passage comprises an initial tunnel portal and a transverse passage tunnel body which are positioned at the intersection of the transverse passage and the horizontal pilot tunnel, and a locking opening which is positioned at the intersection of the transverse passage and the main tunnel, an initial tunnel portal supporting steel frame is arranged around the initial tunnel portal, a locking opening supporting steel frame is arranged at the locking opening, and the top of the transverse passage gradually rises from the top of the initial tunnel portal to the top of the intersection of the initial tunnel along a certain gradient.
Preferably, the transverse channel further comprises a top ram which is transited from the top of the locking opening to the top of the main opening, the top ram comprises a top ram supporting steel frame, the top ram supporting steel frame comprises a plurality of oblique beams which extend from the top of the locking opening to the top of the main opening, the top of the door-shaped supporting steel frame is a cross beam, one end of each oblique beam is fixed to the top of the cross beam, the other end of each oblique beam is connected with an arch frame corresponding to the top of the main opening, the tail end of each arch frame extends to the main opening and is located at the opposite side of the locking opening, and locking anchor pipes are arranged at the end parts of the oblique beams and the arch frames into the wall surface of the main opening.
The invention has the beneficial technical effects that:
1. the construction method of the transverse channel leading the flat pilot tunnel to the main tunnel reduces the height difference of the transverse channel entering the main tunnel to jack by lifting the tunnel top of the transverse channel, reduces the difficulty of jack construction and prevents the jack from collapsing.
2. In the top-raising construction process, the temporary portal frame is excavated along with the support, so that the instability and collapse caused by overlong exposure time of surrounding rocks are prevented.
3. The invention provides the transverse channel from the excavated tunnel section of the horizontal pilot tunnel to the unearthed tunnel section of the main tunnel, thereby accelerating the construction progress of the main tunnel.
4. The initial opening and the locking opening of the transverse passage are reinforced and supported, so that the stability of the opening which is easy to lose stability is enhanced.
Drawings
FIG. 1 is a schematic plan view of a newly added lateral channel between a main tunnel and a horizontal pilot tunnel according to an embodiment of the present invention;
FIG. 2 is a flow chart of a construction method of a horizontal passage leading from a horizontal pilot tunnel to a main tunnel according to an embodiment of the present invention;
FIG. 3 is a schematic structural diagram of an arch at an initial opening of a transverse passage according to an embodiment of the present invention;
FIG. 4 is a schematic view of the arch center layout of the transverse passage between the main tunnel and the horizontal pilot tunnel according to an embodiment of the present invention;
FIG. 5 is a schematic cross-sectional view of a newly added lateral channel between a pilot hole and a horizontal pilot hole according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a fore shaft bracket provided at the fore shaft according to an embodiment of the present invention.
In the drawings, each reference numeral means: the structure comprises a main hole 11, a cantilever top 111, a step surface 112, a temporary portal frame 113, a step surface 114, an oblique beam 115, an arch part 116, an inverted arch excavation surface 117, a main hole side drainage ditch 118, a main hole middle drainage ditch 119, a flat guide hole 12, a flat guide hole support steel frame 121, a flat guide hole drainage ditch 122, a transverse channel 13, an initial hole opening 131, an initial hole opening arch frame 1311, a hole body 132, three parallel arch frames 1321, a middle arch frame 1322, an initial hole top marking high line 1324, a locking opening support 1325, a transverse channel locking opening steel frame 1325-1, a reinforcing portal frame 1325-2, a transverse beam 1325-3, a transverse channel bottom surface 133, a traffic road surface 134, a locking opening 135 and a transverse channel drainage ditch 136.
Detailed Description
The following examples are intended to illustrate the present invention in detail and should not be construed as limiting the scope of the present invention in any way.
Example 1:
a construction method of a horizontal channel leading from a horizontal pilot tunnel to a main tunnel, please refer to fig. 1 to 6.
As shown in fig. 1, in the construction method of a transverse passage leading from a horizontal pilot tunnel to a pilot tunnel according to an embodiment of the present invention, a section of the pilot tunnel 11 is larger than a section of a horizontal pilot tunnel 12, the horizontal pilot tunnel 12 is parallel to the pilot tunnel 11, the pilot tunnel 11 is a tunnel for constructing a road or a railway, and the horizontal pilot tunnel 12 is a tunnel for assisting the construction of the pilot tunnel 11.
In the embodiment, the sections where the main tunnel 11 and the pilot tunnel 12 are located in a certain southwest area of China, the rock mass of the sections where the main tunnel 11 and the pilot tunnel 12 are located is V-level surrounding rock, the stability of the rock mass is poor, the crack water of the surrounding rock grows relatively, and the construction working condition is extremely complex. Based on the fact that the geological sections of the main tunnel 11 and the pilot tunnel 12 are severe, the main tunnel 11 and the pilot tunnel 12 are dug by mainly adopting a TBM + drilling and blasting method.
Because the section of the flat pilot tunnel 12 is small, the excavation speed is relatively high, the excavation progress of the flat pilot tunnel 12 is ahead of that of the main tunnel 11, in order to accelerate the construction progress of the main tunnel 11, a transverse channel 13 leading to the un-excavated tunnel section of the main tunnel 11 is additionally arranged on the excavated tunnel section in front of the flat pilot tunnel 12, and the un-excavated tunnel section on the design route in front of the main tunnel 11 can be accessed through the transverse channel 13 for construction, so that the construction speed of the main tunnel 11 is accelerated.
In fig. 1, the section of the newly added transverse channel 13 is 5.48m × 6.14m (width × height), and the excavated section is a square meter 39; the size of the cross section of the main hole 11 is 16.42m multiplied by 11.94m (width multiplied by height), the excavated cross section is 180 square meters, the top-picking height at the intersection of the transverse passage 13 and the main hole 11 is larger, and the construction difficulty is extremely high.
As shown in fig. 2, the construction method of the transverse passage leading from the horizontal pilot tunnel to the main tunnel provided by the embodiment of the invention comprises the following steps:
step S10, horizontal passage opening: and (4) opening an initial hole at the intersection of the transverse channel and the flat pilot tunnel at a proper position in the flat pilot tunnel.
Firstly, an excavation contour line of a transverse channel opening is measured and marked on the side surface of the horizontal pilot tunnel 12 close to the main tunnel 11, the inner space of the excavation contour line is an initial hole 131 of the transverse channel 13 in the figure 1, a small advance guide pipe is arranged along the excavation contour line by expanding 30cm, the small advance guide pipe is arranged in an upward mode at a gradient of 20%, and the small advance guide pipe is welded and connected with a steel frame on the hole wall of the crossed horizontal pilot tunnel 12 through L-shaped steel bars, so that the small advance guide pipe is prevented from loosening.
And grouting is performed to the surrounding rock around the excavation contour line through the advanced small guide pipe so as to enhance the stability of the surrounding rock. Here, the purpose of the advanced small duct being drilled up at a 20% slope is to prepare the roof of the cross passage 13 to reach the main tunnel along a certain slope.
As shown in fig. 3, after the advanced small guide pipe is completely constructed, the concrete support layer in the excavation contour line on the side wall of the flat guide tunnel 12 is chiseled, the part of the flat guide tunnel support steel frame 121 in the excavation contour line is cut off, then the steel frame cuts are welded and connected along the excavation contour line by adopting I14 steel to form an initial opening arch 1311, and the initial opening arch 1311 and the excavated rock surface are sprayed with concrete for covering.
The section steel I14 is a 14-size I-steel, and the horizontal pilot tunnel supporting steel frame 121 is an arch frame matched with the top of the horizontal pilot tunnel 12. The small guide pipe and the initial opening arch 1311 together support the surrounding rock around the initial opening 131.
Step S20, construction of a transverse channel: and excavating the tunnel body of the transverse channel from the initial tunnel portal to the main tunnel direction, wherein in the excavating process, the tunnel top of the transverse channel is excavated upwards along a certain slope in the direction that the transverse channel leads to the main tunnel from the flat pilot tunnel.
In the step, firstly, the tunnel body 132 of the transverse channel 13 in fig. 1 is excavated by a step method, wherein the step method is a commonly used construction method for excavating tunnels in V-level surrounding rocks, a designed section of the transverse channel 13 is divided into an upper half section and a lower half section, the upper half section is excavated firstly after being staggered for a certain distance, the lower half section is excavated after being excavated to a certain length, and the upper half section and the lower half section are excavated at different working faces simultaneously. The working face is increased in the step construction method, the construction progress is accelerated, the one-step excavation area is small, and the stability of the tunnel face is facilitated.
Along with the excavation of the transverse tunnel, the tunnel wall of the transverse tunnel needs to be supported, the supporting parameters of the transverse tunnel 13 are shown in table 1, and the supporting of the transverse tunnel 13 is divided into primary supporting and later-stage molded lining supporting.
In the excavation process, the transverse channel steel frames with the corresponding sizes are supported in the transverse channel 13, the system anchor rods and the foot locking anchor rods are arranged on the wall of the supporting steel frame, then concrete is sprayed to form primary support, and the construction parameters of the transverse channel steel frames, the system anchor rods, the foot locking anchor rods and the sprayed concrete are shown in table 1.
Here, the steel frame of the transverse passage is an arch frame made of I14 steel and corresponding to the cross section of the transverse passage, and as shown in fig. 4, the arch frame includes three parallel arch frames 1321 arranged at the initial opening 131, a fore shaft support 1325 arranged at the end of the opening 132, and the rest of middle arch frames 1322, and the adjacent middle arch frames 1322 are spaced by 1 meter.
The system anchor rods are used for ensuring the stability of surrounding rocks of the wall of the transverse channel, the foot-locking anchor rods are used for preventing the arch frame from sinking, two foot-locking anchor rods are respectively driven into the wall of the transverse channel at the lower parts of the support legs at the two sides of each arch frame, and the foot-locking anchor rods are welded with the support legs of the arch frame, so that four foot-locking anchor rods are correspondingly arranged on each arch frame.
TABLE 1 supporting parameter table for increasing transverse channel
And (3) paving a reinforcing mesh and a supporting template on the wall of the primary support formed at the rear part while the transverse channel 13 is excavated forwards, and then injecting concrete into the supported template to form a secondary lining, wherein the parameters of the secondary lining are shown in the column of the molded lining in the table 1.
As shown in fig. 4, for the convenience of driving, one side of the initial opening 131 is extended outward by a certain distance relative to the tunnel center line of the cross passage 13, and then excavated toward the tunnel center line at an included angle of 75 degrees until it is narrowed to a position having the same size as the designed section of the main hole section of the cross passage 13.
As shown in fig. 5, in this embodiment, the hole top 132 of the cross passage 13 is excavated upward along a slope of 20% until the cross passage 13 intersects with the main hole 11, so that the intersection position of the cross passage 13 and the main hole 11 is raised by several meters (about 3.28 meters in this embodiment) than the initial hole top elevation line 1324, and the initial hole top elevation line 1324 indicates the hole top elevation at the initial hole 131 of the cross passage 13.
By carrying out upward excavation on the 132 tunnel top edge of the transverse channel 13 along the slope of 20%, the height difference between the tunnel top of the transverse channel 13 and the tunnel top of the main tunnel 11 is reduced, favorable conditions are created for later-stage top-lifting construction, and the top-lifting construction difficulty is reduced.
In addition, as shown in fig. 5, in the process of excavating the tunnel body of the lateral passage 13, the tunnel top of the lateral passage 13 is excavated at a gradient of 20%, the bottom surface 133 of the lateral passage is excavated at a designed elevation, the ballast is filled back into the bottom surface 133 of the lateral passage excavated in the lateral passage 13 to form a traffic surface 134, and the traffic surface 134 gradually rises at a gradient of 18% in the direction from the pilot tunnel 12 to the main tunnel 11 in the lateral passage 13. Laying the inclined driving pavement 134 prepares for excavating the tunnel 11 in the later stage, and facilitates excavating the upper part of the crossed tunnel section of the tunnel 11 and the transverse channel 12 in the later stage.
Step S30, locking construction: when the hole body of the transverse passage is excavated to reach the intersection with the main hole, a locking notch is constructed at the intersection of the transverse passage and the main hole, and the locking notch is the hole at the intersection of the transverse passage and the main hole.
As shown in fig. 1 and 5, since the locking notch 135 is located at the intersection of the cross passage 13 and the main opening 11, and the cross section of the main opening 11 is large, a larger space needs to be excavated in the front and rear of the locking notch 135, and the locking notch 135 needs to be reinforced and braced.
Therefore, as shown in fig. 4 and 5, three fore-and-aft supports 1325 are erected at the intersection of the lateral passage 13 and the side wall of the designed main opening 11, the fore-and-aft supports 1325 are made of I14 type steel, and the three fore-and-aft supports 1325 are welded by I14 type steel to integrate the fore-and-aft supports 1325.
As shown in FIG. 6, the fore shaft support 1325 includes an inner transverse steel frame 1325-1 and an outer reinforced door frame 1325-2, the transverse steel frame 1325-1 has an arched top, and a plurality of vertical columns 1325-4 are arranged between a cross beam 1325-3 at the top of the reinforced door frame 1325-2 and the arched top of the transverse steel frame 1325-1, so that the fore shaft support 1325 has a strong bearing capacity.
The collar bracket 1325 needs to bear the oblique beam 115 arranged at the top, so that after the collar bracket 1325 is installed at the collar, a foot-falling beam is arranged at the bottom of the collar bracket 1325 to serve as a support, and the foot-falling beam and the collar anchor rod jointly prevent the collar bracket 1325 from sinking.
After step S30, the construction method of the present invention further includes step S40 of performing main-hole topping construction at the fore shaft.
And step S40, expanding and digging forwards from the locking notch along the width direction of the main tunnel, and in the expanding and digging process, carrying out upward top-lifting expanding and digging towards the top direction of the main tunnel at a certain gradient at the top of the locking notch.
Firstly, the upper part of the cross section of the hole 11 is enlarged and excavated from the position of the locking notch 135, specifically, as shown in fig. 5, the part above the step surface 112 in the hole 11 is enlarged and excavated, wherein the enlarged and excavated cross section of the hole 11 refers to the cross section of a hole body which is formed by excavating the hole 11 and is not supported, the step surface 112 has a certain height from the top surface 114 of the inner rail of the hole 11, and the part above the step surface 112 in the hole 11 is enlarged and excavated, which is equivalent to excavating the part of the hole 11 in front of the locking notch 135 by adopting a step method, so that the transition from the locking notch 135 to the top 111 of the hole 11 is supported, and the support of the hole top excavated from the hole 11 is supported.
In the expanding excavation process, a certain distance is expanded along the outline of the tunnel top designed in the main tunnel 11 and is used as a space for offsetting the deformation of the expanded excavated tunnel top and a space for temporary support, wherein the deformation refers to the sinking amount of surrounding rocks, and the section size of the formed clear space of the tunnel is equivalent to the section size of the originally designed clear space of the main tunnel by reserving a certain space after the surrounding rocks sink and are supported.
As shown in fig. 5, each time the temporary portal steel frames 113 with corresponding sizes are erected in time after being dug for a certain distance, the temporary portal steel frames 113 are made of I20B h-beams, the lower ends of the legs at the two sides of the temporary portal steel frames 113 are supported on the step surface 112, and the top of the temporary portal steel frames supports the top of the dug hole of the main hole 11 along the axial direction. And applying anchor rods on the top of the excavated hole and spraying concrete for temporary support, and thus, excavating from the locking notch 135 to the other side of the width direction of the main hole.
After the excavation of the earth above the step surface 112 is finished, erecting a main tunnel arch on the top of a part of the tunnel excavated at the upper part of the main tunnel 11, wherein the part of the main tunnel arch, which is close to one side of the locking notch 135, is an oblique beam 115 extending from the top of the locking notch 135 to the top of the main tunnel, the rest part of the main tunnel arch is an arch part 116 attached to the top of the main tunnel, the lower end of the oblique beam 115 is welded on the upper surface of a cross beam 1325-3 at the top of the locking notch support 1325, and the bottom of the oblique beam 115 and the cross beam 1325 are firmly welded by full-weld. The arch part 116 in the tunnel arch center of the main tunnel is tied by adopting steel bars, the oblique beam 115 can adopt I-shaped steel, and the top end of the oblique beam 115 is fixed at the corresponding end of the arch part 116. The tunnel arch centering of the main tunnel has a plurality of arch centering until the top of the tunnel to be excavated is fully paved.
And then performing spray anchor support on the top of the upper part of the expanded excavation space of the tunnel 11: two locking anchor pipes are driven into the top wall surface of the tunnel at two ends of the tunnel arch frame in the main tunnel, namely, two locking anchor rods with the diameter of 22mm and the length of 4 meters are driven into the tunnel wall at the lower end of the oblique beam 115, then the lower end of the oblique beam 115 is welded on the locking anchor rods, two locking anchor rods with the diameter of 22mm and the length of 4 meters are driven into the tunnel wall at the tail end of the arch part 116, and then the tail end of the arch part 116 is welded on the locking anchor rods, so that the tunnel arch frame in the main tunnel is prevented from sinking.
And (3) hanging a reinforcing mesh on the arch frame of the tunnel in the main tunnel, and then spraying concrete to the arch frame of the tunnel in the main tunnel and the reinforcing mesh to form secondary temporary support.
In the process of excavating the earth above the step surface 112, the driving road surface 134 extends from the bottom surface of the initial opening 131 to the center line of the step surface 112 of the excavation space at the upper part of the main tunnel 11, so that the excavating machinery is convenient to operate, and the excavated sludge is convenient to transport.
After step S40, the construction method of the present invention further includes step S50.
And step S50, continuing to dig the alignment hole in front of the locking notch.
Here, the continued reaming of the alignment hole in front of the fore shaft is to ream a portion below the stepped surface 112.
When the strength of the concrete sprayed on the arch frame and the reinforcing mesh sheets of the tunnel with the main tunnel meets the requirement, the support legs of the temporary portal steel frame 113 are removed, and the support legs can be removed in a cutting mode to reduce the disturbance to the support of the tunnel top.
Excavating the inner part of the front tunnel 11 along the axial front-back extending direction by adopting a three-step method on the basis of the space excavated at the upper part of the step surface 112 at the intersection of the front tunnel 11 and the transverse passage 13, so that the tunnel section at the intersection of the front tunnel 11 and the transverse passage 13 forms a full-section tunnel section, and gradually removing the tunnel slag backfilled by the driving pavement 134 formed in the transverse passage 13 in the excavating process to expose the bottom surface 133 of the transverse passage.
Then, the tunnel section of the front tunnel 11 located in front of the locking opening 135 is excavated in an inverted arch space, namely, earth above an inverted arch excavation surface 117 is expanded and excavated, after the inverted arch space is excavated, an inverted arch frame is erected and a reinforcing mesh is laid in the inverted arch space, and then concrete is poured to form an inverted arch primary supporting layer 1171. And in the later stage, two inverted arches are needed to be constructed in the hole and the wall of the hole is molded and lined.
In the above construction process, the positive-hole side drain 118, the positive-hole middle drain 119, and the lateral passage drain 136 are constructed simultaneously, the positive-hole side drains 118 on both sides are connected to the middle positive-hole middle drain 119, and both ends of the lateral passage drain 136 are connected to the positive-hole middle drain 119 and the pilot hole drain 122, respectively.
Example 2:
a horizontal channel for a horizontal pilot tunnel to a pilot tunnel is shown in FIGS. 5 and 6.
The construction method of the embodiment 1 is adopted for the transverse passage leading from the horizontal pilot tunnel to the main tunnel, the transverse passage 13 comprises an initial hole 131, a hole body 132 and a locking hole 135, the initial hole 131 is located at the intersection of the transverse passage 13 and the horizontal pilot tunnel 12, the locking hole 135 is located at the intersection of the transverse passage 13 and the main tunnel 11, an initial hole supporting steel frame is arranged around the initial hole 131, a locking hole supporting steel frame is arranged at the locking hole 135, and the top of the transverse passage 13 gradually rises from the top of the initial hole 131 to the top of the intersection of the initial hole 11 along the gradient of 20%.
Further, the transverse channel 13 further comprises a top 111 which is transited from the top of the locking opening 135 to the top of the main hole 11, the top 111 comprises a top support steel frame which comprises a plurality of oblique beams 115 extending from the top of the locking opening 135 to the top of the main hole 11, the locking opening support steel frame is formed by 3 door-shaped support steel frames shown in fig. 6 in parallel, and section steel is welded between the door-shaped support steel frames, so that the locking opening support steel frames are integrated. The top of the door-shaped supporting steel frame is a cross beam 1325-3, the lower end of the oblique beam 115 is fixed to the top of the cross beam 1325-3, the other end of the oblique beam is connected with an arch part 116 corresponding to the top of the main tunnel, the arch part is a part of a single finished main tunnel arch frame, the tail end of the arch part 116 extends to the opposite side of the main tunnel 11 positioned at the lock opening 135, and lock leg anchor pipes are drilled into the wall surfaces of the main tunnel 11 at the tail ends of the oblique beam 115 and the arch part 116 to support the oblique beam 115 and the arch part 116 and prevent the oblique beam 115 and the arch part 116 from sinking.
While the present invention has been described in detail with reference to the drawings and the embodiments, those skilled in the art will understand that various specific parameters in the above embodiments can be changed without departing from the spirit of the present invention, and a plurality of specific embodiments are formed, which are common variation ranges of the present invention, and will not be described in detail herein.

Claims (3)

1. A construction method of a transverse channel leading from a horizontal pilot tunnel to a pilot tunnel, wherein the top of the section of the pilot tunnel is higher than that of the horizontal pilot tunnel, and is characterized by comprising the following steps:
(1) opening of the transverse channel: selecting a proper position in the horizontal pilot tunnel and forming an initial hole at the intersection of the horizontal channel and the horizontal pilot tunnel;
the step (1) specifically comprises:
(1.1) measuring and marking an excavation contour line of an opening of a transverse channel on the side surface of the flat pilot tunnel, wherein the inner space of the excavation contour line is an initial hole of the transverse channel, expanding a certain distance along the excavation contour line to form a small advanced guide pipe, arranging the small advanced guide pipe upwards at a certain gradient, and welding and connecting the small advanced guide pipe and a crossed flat pilot tunnel steel frame by using a steel bar;
(1.2) after the application of the advanced small guide pipes is finished, chiseling off a concrete support layer positioned in the excavation contour line on the side wall of the flat pilot tunnel, cutting off a steel frame part of the flat pilot tunnel in the excavation contour line, and then welding and connecting the steel frame cuts along the excavation contour line by adopting section steel;
(2) construction of a transverse channel: excavating a tunnel body of the transverse channel from the initial tunnel portal to the main tunnel direction, wherein in the excavating process, in the direction that the transverse channel leads to the main tunnel from the flat pilot tunnel, the tunnel top of the transverse channel is excavated upwards along a certain slope;
the step (2) specifically comprises:
(2.1) excavating the hole body of the transverse channel by adopting a step method, in the excavating process, supporting a transverse channel steel frame with the corresponding size in the transverse channel, laying anchor rods on the hole wall of the supporting steel frame, and spraying concrete to form primary support;
(2.2) when the transverse channel is excavated forwards, paving a reinforcing mesh and a supporting template on the tunnel wall of the primary support formed at the rear, and then injecting concrete into the supported template to form a secondary lining;
(2.3) in the process of excavating the tunnel body of the transverse channel, in order to reduce the difficulty of raising the top height difference, backfilling tunnel ballast on the bottom surface excavated in the transverse channel to form a traveling road surface, wherein the traveling road surface gradually rises in the direction from the flat pilot tunnel to the main tunnel in the transverse channel at a certain gradient; (3) and (3) locking construction: when the hole body of the transverse channel is excavated to reach the intersection with the main hole, constructing a locking notch at the intersection of the transverse channel and the main hole, wherein the locking notch is used for reinforcing the hole at the intersection of the transverse channel and the main hole;
the step (3) comprises the following steps:
(3.1) densely erecting a plurality of locking port supports in parallel at the intersection of the transverse channel and the designed side wall of the main tunnel, wherein each locking port support comprises an internal transverse channel locking port steel frame and an external reinforced door-shaped steel frame, each transverse channel locking port steel frame is provided with an arched top, and a plurality of vertical upright posts are arranged between a cross beam at the top of each reinforced door-shaped steel frame and the arched top of each transverse channel locking port steel frame;
(3.2) welding a plurality of the fore shaft brackets into a whole through steel materials, and arranging a foot-falling beam at the bottom of each fore shaft bracket as a support;
leading the transverse channel from the excavated tunnel section of the horizontal pilot tunnel to the unearthed tunnel section of the main tunnel, wherein after the step (3), the construction method further comprises a step (4) of main tunnel top lifting construction at the lock hole, and the step (4) comprises the following steps: expanding and digging forwards from the locking notch along the width direction of the transverse channel, and in the expanding and digging process, carrying out upward top-lifting expanding and digging towards the top direction of the main tunnel at a certain gradient at the top of the locking notch;
the step (4) specifically comprises:
(4.1) expanding and digging the upper part of the section of the main hole from the lock opening: in the expanding excavation process, expanding a certain distance along the outline of the tunnel top designed by the main tunnel to be used as a space for offsetting the deformation of the expanded excavated tunnel top and a space for performing temporary support, erecting a temporary portal steel frame with a corresponding size in time after expanding excavation for a certain distance, and performing anchor rod on the excavated tunnel top and spraying concrete for performing temporary support until expanding excavation is performed from the lock hole to the other side of the width direction of the main tunnel;
(4.2) erecting a tunnel arch center of the main tunnel under the temporary support excavated at the upper part of the main tunnel: the part of the main tunnel arch frame, which is close to one side of the locking notch, is an oblique beam extending from the top of the locking notch to the direction of the tunnel top excavated by the main tunnel, the rest part of the main tunnel arch frame is an arch part attached to the tunnel top excavated by the main tunnel, and the lower end of the oblique beam is welded on a cross beam at the top of the locking notch support;
(4.3) performing spray anchor support on the top of the upper partial excavation space of the main tunnel: and (2) driving locking anchor pipes into the top wall surfaces of the tunnel from two sides of the main tunnel arch, hanging a reinforcing mesh piece on the main tunnel arch, and spraying concrete to the main tunnel arch and the reinforcing mesh piece.
2. The method of constructing a lateral passage of a horizontal pilot tunnel to a main tunnel according to claim 1, wherein the traffic surface extends from the bottom surface of the initial opening to a center line of the bottom surface of the excavated space in the upper portion of the main tunnel.
3. The construction method of the transverse channel of the flat pilot tunnel to the main tunnel according to claim 1, characterized by further comprising a step (5) of continuing enlarging and digging the main tunnel in front of the locking notch after the step (4.3), wherein the step (5) comprises:
(5.1) when the strength of the concrete sprayed on the arch frame of the tunnel with the main tunnel and the reinforcing mesh sheet meets the requirement, dismantling the support legs of the temporary portal steel frames;
(5.2) excavating the front and back extension directions in the main tunnel by adopting a three-step method on the basis of the space excavated at the upper part of the intersection of the main tunnel and the transverse passage, so that the tunnel section at the intersection of the main tunnel and the transverse passage forms a full-section tunnel section, and gradually removing the tunnel ballast backfilled by the driving pavement formed in the transverse passage in the excavation process;
(5.3) right the positive hole is located the hole section in fore of the fore shaft carries out inverted arch space excavation, after the inverted arch space is excavated, an inverted arch frame is erected in the inverted arch space and a reinforcing steel bar net piece is laid, and then concrete is poured to form a support and seal a ring.
CN201910773570.7A 2019-08-21 2019-08-21 Transverse channel construction method for leading flat pilot tunnel to main tunnel and transverse channel Active CN110439571B (en)

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CN111577383B (en) * 2020-05-11 2021-04-09 中铁一局集团有限公司 Method for treating tunnel leakage water in alpine region
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