CN109611100A - A kind of tunnel middle drift bilateral Enlargement excavation method - Google Patents

A kind of tunnel middle drift bilateral Enlargement excavation method Download PDF

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Publication number
CN109611100A
CN109611100A CN201811382767.XA CN201811382767A CN109611100A CN 109611100 A CN109611100 A CN 109611100A CN 201811382767 A CN201811382767 A CN 201811382767A CN 109611100 A CN109611100 A CN 109611100A
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tunnel
middle drift
preliminary bracing
construction
hole
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CN109611100B (en
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剧仲林
董化瑞
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China Railway 12th Bureau Group Co Ltd
Fourth Engineering Co Ltd of China Railway 12th Bureau Group Co Ltd
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China Railway 12th Bureau Group Co Ltd
Fourth Engineering Co Ltd of China Railway 12th Bureau Group Co Ltd
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    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK 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
    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK 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 OR ROCK 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
    • E21D9/12Devices for removing or hauling away excavated material or spoil; Working or loading platforms

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  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Lining And Supports For Tunnels (AREA)
  • Excavating Of Shafts Or Tunnels (AREA)

Abstract

A kind of tunnel middle drift bilateral Enlargement excavation method, the section or excavation width of middle drift are generally no greater than common two-wire or two-lane tunnel, and benching tunnelling method is taken to construct, and are no different with common two-wire or two-lane tunnel construction method, it is construction method known to construction personnel, no difficulty of construction.Middle drift preliminary bracing profiled can dig after being closed at least 3 meters, if side face is stable, overcomes manually installed steelframe and the operation height problem of anchor bolt construction, can once excavate and supporting, construction will be facilitated more;Otherwise side hole is excavated according to two or three benching tunnelling methods.Middle drift preliminary bracing can be closed in time;The deformation of various errors and country rock and supporting influence can be stayed in the processing of inverted arch position with drop-over completely by the connection of the preliminary bracing of side hole and middle drift preliminary bracing;Construction speed is no different substantially with common two-wire or two-lane tunnel.

Description

A kind of tunnel middle drift bilateral Enlargement excavation method
Technical field
The present invention relates to the construction methods to tunnels and underground engineering, and in particular to a kind of tunnel middle drift bilateral, which digs, to be applied Work method.
Background technique
For the soft rock tunnel construction method of extra-large cross-section, currently popular method generally takes two side-wall pilot tunnel, this It is the engineering method that a last century the eighties are formed, it is horizontal mutually suitable with construction quality, progress, technology and construction technology at that time It answers, had been a safety, quickly good method at that time.However, era development is to today, with quality, progress, technology etc. at that time It is required that comparing, all have a qualitative leap, this engineering method is difficult to adapt to present demand, and it is hidden to expose many quality, safety Suffer from, mainly there is the following aspects:
1) preliminary bracing of double -side approach is not closed, as shown in Figure 1.Due to being difficult to apply in narrow side wall drift Secondary lining inverted arch also can not just apply inverted arch filling, therefore can not set up inverted arch trestle, so the inverted arch of side wall drift can not Closure.The preliminary bracing of side wall drift be closed in time be this engineering method core, make the engineering method complete because that can not be closed now Original meaning is lost entirely.
2) the preliminary bracing drop-over that the preliminary bracing of two sidewalls can not be hit exactly with vault.As shown in Fig. 2, since steelframe is processed The position of the reasons such as error, installation measurement error, the Support Deformation of production, the preliminary bracing of two sides can not be located at design position It sets, especially because being completely unpredictable and control, this results in two sides preliminary bracing and positive hogging the reason of surrouding rock deformation Top preliminary bracing connector is staggered and is unable to drop-over, this defect is absolutely not can be manageable (let alone existing by reinforcing welding Field welding can only weld exposed face, and the inside can not weld) because the most serious consequence of this defect is increased preliminary bracing knot The eccentricity of structure, so that structure becomes large eccentricity by intrinsic small eccentricity, so that moment herein increases severely.
3) sidewall bottom is in vacant state when inverted arch excavates, as shown in figure 3, since side heading method supporting above-mentioned does not have Closure in time, the construction method for just taking the inverted arch by side wall and middle hole to be once closed, naturally this method is when excavating inverted arch Sidewall bottom is in vacant state, is great security risk.
The above is the problem in this engineering method structure, and in addition to this, progress is also a serious problem, the engineering method Progress be the 1/4 of normal operation.The main reason for taking the engineering method is safety, is given way the problem of progress in safety, practical Effect is slow often caused by progress early period, causes overworking for later period, leaves all multimass, security risk, loses peace instead Entirely.
Summary of the invention
In order to overcome the above-mentioned deficiencies of the prior art, it digs and applies the object of the present invention is to provide a kind of tunnel middle drift bilateral Work method, the section or excavation width of middle drift are generally no greater than common two-wire or two-lane tunnel, benching tunnelling method are taken to construct, with Common two-wire or two-lane tunnel construction method are no different, and are construction method known to construction personnel, no difficulty of construction.At the beginning of middle drift It can be digged after at least 3 meters of phase supporting section closure, if side face is stable, overcome manually installed steelframe and anchor pole is applied The operation height problem of work, can once excavate and supporting, construction will be facilitated more;Otherwise side hole is opened according to two or three benching tunnelling methods It digs.Middle drift preliminary bracing can be closed in time;The connection of the preliminary bracing of side hole and middle drift preliminary bracing completely can with drop-over, And the deformation of various errors and country rock and supporting influence is stayed in into the processing of inverted arch position;Construction speed and common two-wire or two-way traffic Tunnel is no different substantially.
To achieve the goals above, the technical solution adopted by the present invention is that:
A kind of tunnel middle drift bilateral Enlargement excavation method, which comprises the following steps:
1) tunnel includes middle drift, two sides hole;
2) excavation width of middle drift undertakes entirely no more than common two-wire or the width of two-lane tunnel according to preliminary bracing Portion's design load is calculated according to the model of " load-structure " and is determined;
3) sky needed for space needed for side hole excavation width meets tunnel system anchor pole operation and dress slag Transport Machinery operation Between;
4) middle drift takes benching tunnelling method to construct, and distance maximum of the preliminary bracing apart from face should not exceed pilot drive 1.5 times of width;
5) middle drift is constructed in advance, and after its preliminary bracing is closure of more than 3 meters, the construction in starting side hole, side hole is taken It is symmetrical to excavate, Eccentric Load is born to avoid middle hole;If middle hole anchor bolt construction reliable in quality, adjoining rock stability, side hole can be with Consider to take the primary method construction for excavating simultaneously supporting, two or three benching tunnelling methods is otherwise taken to construct;
6) preliminary bracing closing distance face in side hole should not exceed middle hole excavation width.
The middle drift section is in symmetry status, and middle drift excavation width meets the stable structure needed for benching tunnelling method excavates Property and large tunnel excavate, dress slag, space needed for Transport Machinery operation;Its preliminary bracing do not conform to apart from face it is maximum away from From should not exceed 1.5 times of middle drift excavation width.
Space needed for the side hole excavation width meets tunnel anchor pole operation;Its preliminary bracing closing distance face Maximum distance 8 should not exceed middle drift excavation width.
In the described side hole face distance minimum range of hole preliminary bracing closure be side hole can excavate it is necessary most Small length.
The beneficial effects of the present invention are:
Middle drift preliminary bracing can be closed in time;The connection of the preliminary bracing of side hole and middle drift preliminary bracing completely can be with Drop-over, and the deformation of various errors and country rock and supporting influence is stayed in into the processing of inverted arch position;Construction speed and common two-wire or Two-lane tunnel is no different substantially.
Detailed description of the invention
Fig. 1 is the schematic diagram that the preliminary bracing of double -side approach in the prior art is not closed.
Fig. 2 is the preliminary bracing drop-over schematic diagram that the preliminary bracing of two sidewalls in the prior art can not be hit exactly with vault.
Fig. 3 is that sidewall bottom is in vacant state schematic diagram when inverted arch excavates in the prior art.
Fig. 4 is construction front schematic view of the invention.
Fig. 5 is construction side schematic view of the invention.
Fig. 6 is that the slump pitch of arch (load) of the invention changes schematic diagram.
Fig. 7 is middle drift Calculation of support illustraton of model of the invention.
Fig. 8 is the middle side hole Calculation of support illustraton of model of invention.
Wherein, 1 is middle drift;2 be left side hole;3 be right side hole;4 be middle drift excavation width;5 be the wide open digging of left and right side Width;6 be the maximum distance of middle drift preliminary bracing closing distance face;7 be hole preliminary bracing in side hole face distance The minimum range of closure;8 be the maximum distance of side hole preliminary bracing closing distance face.
Specific embodiment
The present invention is further discussed below below in conjunction with attached drawing.
As shown in Figure 4,5, the excavation width 4 of middle drift 1 is generally no greater than the width of common two-wire or two-lane tunnel, tool Body undertakes whole design loads according to preliminary bracing and calculates determination according to the model of " load-structure ";Side hole excavation width should expire Space needed for space needed for sufficient tunnel system anchor pole operation and dress slag Transport Machinery operation;Middle drift takes benching tunnelling method to construct, Distance maximum of its preliminary bracing apart from face should not exceed 1.5 times of pilot drive width;Middle drift is constructed in advance, to it Closure of more than after 3 meters, symmetrical excavation is taken in the construction in starting side hole, side hole for preliminary bracing, bears bias lotus to avoid middle hole It carries;If middle hole anchor bolt construction reliable in quality, adjoining rock stability, side hole can be considered the method for taking primary excavation and supporting and apply Otherwise work takes two or three benching tunnelling methods to construct;Preliminary bracing closing distance face in side hole should not exceed middle hole excavation width.
The sedimentation of control country rock and preliminary bracing is especially emphasized in middle drift construction, and concrete measure is designed system anchor bolt And lock foot anchoring stock should all make engineer testing at the scene in advance, the standard according to the pulling capacity minimum of anchor pole not less than 100kN is come true It is fixed;Enclosing rock measure is conscientiously performed in work progress, if any exception, should be taken immediate steps;The hole the excavation Ying Zhong country rock in side hole Stable premise is measured to carry out;The construction in side hole pays special attention to the anchoring of side wall.
Described " load-structure " the method computation model principle is as follows:
The determination of load, according to Pu Shi theory, the variation of the slump pitch of arch (load) is as shown in Figure 6.
The slump pitch of arch in figure is only related with country rock internalfrictionangleφ and Protodyakonov coefficient f and tunnel excavation width, figure In three kinds of slumps arch calculating take identical internalfrictionangleφ and Protodyakonov coefficient f.If taking full face tunneling, tunnel slump Encircle in (load) highly such as figure shown in (1);Middle drift bilateral expansion digging method is such as taken, then the slump of middle drift encircles (load) highly such as It is low compared with middle drift slump arch (load) height in the slump pitch of arch such as figure shown in (3) when side hole digs in figure shown in (2), but The maximum height during constructing tunnel is taken when calculating --- middle drift slump sagitta.It is concluded that in use by principles above Load caused by pilot tunnel bilateral expansion digging method is small compared with tunnel overall with total load head;The calculating load height of middle drift is to be opened by middle drift It digs height determined by width to determine, it is the safe practice that side hole, which also uses,.
Calculate load
Calculating payload values, chapter --- the regulation of design load is true by " Design of Railway Tunnel specification " TB10003-2016 the 5th It is fixed.Constraint due to structure side wall displacement by support, and the shift value very little between adjacent support, so country rock elastic reactance Power is negligible.
Computation model
Middle drift Calculation of support model
Due to the elastic resistance of soft rock is smaller and preliminary bracing structural section width is lesser, the elasticity branch of arch springing Seat is reduced to movable hinged-support;Consider the symmetry of structure and load;Anchor pole is hinged as the activity of constraint supporting construction displacement Seat;According to the 8.1.10 articles of TB10003-2016 of " Design of Railway Tunnel specification " regulation " when inverted arch after abutment wall when applying, It can not then consider the effect of inverted arch ".Consider factors above, following calculating " load-structure " model is established, using structural mechanics Force method principle calculates, and middle drift Calculation of support model is as shown in Figure 7.
Corresponding legislation equation are as follows:
In formula:
δij--- by unit force Xj=1 generate along XiThe displacement in direction;
ΔiP--- by load generation along XiThe displacement in direction.
In Force Method Equation, δij、ΔiPCalculating ignore the influence of shearing and axle power, only consider Moment Influence.
(1) side hole Calculation of support model
Due to the elastic resistance of soft rock is smaller and preliminary bracing structural section width is lesser, the elasticity branch of arch springing Seat is reduced to movable hinged-support;Upper seat 0 is hold-down support;Movable hinged-support of the anchor pole as constraint supporting construction displacement; " when inverted arch after abutment wall when applying, then may be used according to the 8.1.10 articles of TB10003-2016 of " Design of Railway Tunnel specification " regulation The effect of inverted arch is not considered ".Consider factors above, following calculating " load-structure " model is established, using structural mechanics force method Principle calculates.Side hole Calculation of support model is as shown in Figure 8.
Corresponding legislation equation are as follows:
In formula: δij--- by unit force Xj=1 generate along XiThe displacement in direction;
ΔiP--- by load generation along XiThe displacement in direction.
In Force Method Equation, δij、ΔiPCalculating ignore the influence of shearing and axle power, only consider Moment Influence.
The resultant force of two power at each activity hinged-support is the design anchor force of anchor pole, and the direction of resultant force is anchor pole Set direction;When specific design, trial can be carried out according to the accessible anchor force experience of the anchor pole of locating tunnel surrounding first Tentative calculation primarily determines anchor pole spacing (the movable hinged-support spacing i.e. in model), and after disclosing country rock to tunnel excavation, scene is real Anchor force design value, then the spacing (radical) of careful design anchor pole are used as after surveying the pulling capacity of anchor pole.
X at side hole structure upper and the moment of middle drift next door intersection, support2(i.e. Q0) value and N0It is worth in as External force suffered by pilot tunnel next door examines the bearing capacity for calculating median septum after the wide open digging in side with this.

Claims (4)

1. a kind of tunnel middle drift bilateral Enlargement excavation method, which comprises the following steps:
1) tunnel includes middle drift, two sides hole;
2) excavation width of middle drift undertakes according to preliminary bracing and all sets no more than common two-wire or the width of two-lane tunnel It counts load and calculates determination according to the model of " load-structure ";
3) space needed for space needed for side hole excavation width meets tunnel system anchor pole operation and dress slag Transport Machinery operation;
4) middle drift takes benching tunnelling method to construct, and distance maximum of the preliminary bracing apart from face should not exceed pilot drive width 1.5 times;
5) middle drift is constructed in advance, and after its preliminary bracing is closure of more than 3 meters, the construction in starting side hole, side hole is taken symmetrically It excavates, bears Eccentric Load to avoid middle hole;If middle hole anchor bolt construction reliable in quality, adjoining rock stability, side hole be can be considered The primary method construction for excavating simultaneously supporting is taken, two or three benching tunnelling methods is otherwise taken to construct;
6) preliminary bracing closing distance face in side hole should not exceed middle hole excavation width.
2. a kind of tunnel middle drift bilateral Enlargement excavation method according to claim 1, which is characterized in that led in described Hole section is in symmetry status, and middle drift excavation width width meets structural stability and large tunnel needed for benching tunnelling method excavates Space needed for excavating, filling slag, Transport Machinery operation;The maximum distance that its preliminary bracing does not conform to apart from face is led in should not exceed 1.5 times of hole excavation width.
3. a kind of tunnel middle drift bilateral Enlargement excavation method according to claim 1, which is characterized in that the side hole Space needed for excavation width meets tunnel anchor pole operation;The maximum distance 8 of its preliminary bracing closing distance face should not exceed Middle drift excavation width.
4. a kind of tunnel middle drift bilateral Enlargement excavation method according to claim 1, which is characterized in that the side hole The minimum range of hole preliminary bracing closure is the necessary minimum length that side hole can excavate in face distance.
CN201811382767.XA 2018-11-20 2018-11-20 Double-side expanding excavation construction method for pilot tunnel in tunnel Active CN109611100B (en)

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Cited By (2)

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Publication number Priority date Publication date Assignee Title
CN111305852A (en) * 2020-02-27 2020-06-19 中铁建大桥工程局集团第五工程有限公司 Construction method for excavating guide pits in double-track tunnel in advance and in back
CN113401586A (en) * 2021-06-26 2021-09-17 山东省公路桥梁建设有限公司 Tunnel excavation method

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CN102720504A (en) * 2012-06-13 2012-10-10 北京市公路桥梁建设集团有限公司 Double-side-wall-pilot-hole subsection bench cut method construction method
CN107288653A (en) * 2017-06-27 2017-10-24 中铁十局集团第四工程有限公司 A kind of the benching tunnelling method excavation supporting structure of weak surrounding rock large cross-section tunnel double -side approach three and construction method

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111305852A (en) * 2020-02-27 2020-06-19 中铁建大桥工程局集团第五工程有限公司 Construction method for excavating guide pits in double-track tunnel in advance and in back
CN111305852B (en) * 2020-02-27 2021-10-01 中铁建大桥工程局集团第五工程有限公司 Construction method for excavating guide pits in double-track tunnel in advance and in back
CN113401586A (en) * 2021-06-26 2021-09-17 山东省公路桥梁建设有限公司 Tunnel excavation method
CN113401586B (en) * 2021-06-26 2022-05-10 山东省公路桥梁建设集团有限公司 Tunnel excavation method

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