AU2021101941A4 - Construction System and Method of Shallow-Buried Deep-Tunnel under Existing Railway Line - Google Patents
Construction System and Method of Shallow-Buried Deep-Tunnel under Existing Railway Line Download PDFInfo
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- 238000010276 construction Methods 0.000 title claims abstract description 110
- 238000000034 method Methods 0.000 title claims abstract description 104
- 238000009412 basement excavation Methods 0.000 claims abstract description 50
- 239000011435 rock Substances 0.000 claims abstract description 19
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 3
- 230000000087 stabilizing effect Effects 0.000 claims abstract description 3
- 238000005728 strengthening Methods 0.000 claims abstract description 3
- 238000013459 approach Methods 0.000 claims description 37
- 229910000831 Steel Inorganic materials 0.000 claims description 21
- 239000010959 steel Substances 0.000 claims description 21
- 230000002787 reinforcement Effects 0.000 claims description 20
- 239000002689 soil Substances 0.000 claims description 17
- 230000000694 effects Effects 0.000 claims description 10
- 230000008569 process Effects 0.000 claims description 9
- 239000011521 glass Substances 0.000 claims description 8
- 230000008901 benefit Effects 0.000 claims description 6
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 230000007613 environmental effect Effects 0.000 claims description 3
- 230000006835 compression Effects 0.000 claims description 2
- 238000007906 compression Methods 0.000 claims description 2
- 238000005336 cracking Methods 0.000 claims description 2
- 238000009826 distribution Methods 0.000 claims description 2
- 230000005484 gravity Effects 0.000 claims description 2
- 238000004181 pedogenesis Methods 0.000 claims description 2
- 238000005516 engineering process Methods 0.000 abstract description 5
- 230000001808 coupling effect Effects 0.000 abstract description 2
- 230000003993 interaction Effects 0.000 abstract 1
- 230000009897 systematic effect Effects 0.000 abstract 1
- 239000004567 concrete Substances 0.000 description 16
- 241001669679 Eleotris Species 0.000 description 6
- 238000013461 design Methods 0.000 description 6
- 238000005457 optimization Methods 0.000 description 6
- 239000011378 shotcrete Substances 0.000 description 5
- 238000005422 blasting Methods 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 239000011150 reinforced concrete Substances 0.000 description 3
- 238000005507 spraying Methods 0.000 description 3
- 239000004568 cement Substances 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 230000005641 tunneling Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009933 burial Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000003203 everyday effect Effects 0.000 description 1
- 239000010438 granite Substances 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 239000011440 grout Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/14—Layout of tunnels or galleries; Constructional features of tunnels or galleries, not otherwise provided for, e.g. portals, day-light attenuation at tunnel openings
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/045—Underground structures, e.g. tunnels or galleries, built in the open air or by methods involving disturbance of the ground surface all along the location line; Methods of making them
- E02D29/05—Underground structures, e.g. tunnels or galleries, built in the open air or by methods involving disturbance of the ground surface all along the location line; Methods of making them at least part of the cross-section being constructed in an open excavation or from the ground surface, e.g. assembled in a trench
- E02D29/055—Underground structures, e.g. tunnels or galleries, built in the open air or by methods involving disturbance of the ground surface all along the location line; Methods of making them at least part of the cross-section being constructed in an open excavation or from the ground surface, e.g. assembled in a trench further excavation of the cross-section proceeding underneath an already installed part of the structure, e.g. the roof of a tunnel
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining 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
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/12—Consolidating by placing solidifying or pore-filling substances in the soil
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Structural Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Civil Engineering (AREA)
- Architecture (AREA)
- Paleontology (AREA)
- General Engineering & Computer Science (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
The present invention discloses a construction system and method of a shallow
buried deep-tunnel under an existing railway line and proposes reasonable pre
support and excavation construction technology to ensure the safety of construction
of the railway line under a tunnel. The present invention mainly includes the following
aspects: (1) optimizing a main construction method of tunnel excavation; (2) selecting
an appropriate support structure and auxiliary construction measures for the tunnel
excavation; (3) reinforcing a subgrade slope of the railway line under the tunnel; and
(4) strengthening and stabilizing a track of the railway line under the tunnel. The
construction system and method of the shallow-buried deep-tunnel under the existing
railway line proposed by the present invention fully considers interaction between a
newly built tunnel and the existing railway line, and a coupling effect of surrounding
rock and different support methods, optimizes a support and excavation solution, and
explores an efficient and systematic construction safety management mode of an
existing railway line project under a shallow-buried and underground excavation
tunnel.
1/3
FIGURES OF THE SPECIFICATION
r Optimize a main
construction method of
tunnel excavation;
?Select an appropriate
support structure and
auxiliary construction
excavation;
Reinforce a subgrade
under the tunnel;
under the tunnel.
FIG. 1
Description
1/3
r Optimize a main construction method of tunnel excavation;
?Select an appropriate support structure and auxiliary construction
excavation;
Reinforce a subgrade
under the tunnel;
under the tunnel.
FIG. 1
Construction System and Method of Shallow-Buried Deep-Tunnel under
Existing Railway Line
The present invention belongs to the field of tunnel crossing construction,
and particularly relates to a construction system and method of a shallow-buried
deep-tunnel under an existing railway line.
With the rapid development of highway and railway tunnel construction in
China, in some areas, due to the limitations of existing buildings (structures),
geological conditions, and the need for comprehensive development and
utilization of underground spaces, there are many phenomena such as
phenomenon that new tunnels pass through existing railway lines at a close
distance or other buildings (structures). When a tunnel encounters an existing
railway line underneath, it is not only necessary to ensure the safety of the tunnel
project itself, but also to focus on the public safety issues of a line traffic
operation.
When newly constructed tunnels often pass through an existing railway, the
original railway foundation is inevitably disturbed during the construction of new
tunnels, which causes the soil to settle to varying degrees and further causes
existing tracks and subgrades to deform. This has a negative impact on existing
transportation safety, and causes damage to existing railways in severe cases.
Due to the constraints of special geological conditions and diverse topographical changes, many highway tunnels have technical problems such as difficulty in determining support parameters and difficulty in selecting initial linings during a construction process. For example, in an entrance section of the tunnel, unfavorable conditions such as broken surrounding rock and shallow burial bias increase the difficulty in determination of support parameters and selection of excavation methods. In construction of tunnels crossing existing railway lines, complex construction environments lead to more factors that need to be considered. For weak surrounding rock and shallow-buried tunnels, a construction disturbance range is relatively large. The longer the action time, the easier it is to form a large yield area. This causes a large-scale settlement of the ground surface, which inevitably causes surface settlement or uplift, ground tilt and horizontal displacement, and even changes stress stability of the foundation of existing structures, and increases an additional stress of structures. In a gradual development process, undesirable consequences such as foundation instability and structural damage appear. Therefore, it is of great significance to study and select reasonable and effective construction techniques to ensure the safety of existing railway lines.
In view of the above defects or improvement needs of the prior art, the
present invention provides a construction system and method of a shallow-buried
deep-tunnel under an existing railway line. The objective of the present invention
is to effectively control ground surface settlement and track settlement, and to
ensure safety of a railway line under a tunnel by optimizing a construction method.
The technical problems to be solved by the present invention are realized by
the following technical solutions: a construction system and method of the
shallow-buried deep-tunnel under an existing railway line is provided, wherein the
method comprises the following steps:
(7) optimizing a main construction method of tunnel excavation; (2) selecting
an appropriate support structure and auxiliary construction measures for
the tunnel excavation; (3) reinforcing a subgrade slope of the railway line
under the tunnel; and (4) strengthening and stabilizing a track of the
railway line under the tunnel.
Further, step (1) is specifically as follows: using the "New Austrian Tunneling
Method" for construction and operation, wherein when an excavation method of
the tunnel is determined and a portal surface is excavated, a hydrogeological
conditions of the tunnel, distribution of surrounding buildings and structures, a
buried depth of the tunnel, construction operation, surrounding rock conditions
and bearing capacity, a technical capability of a construction worker, construction
period requirements, and other various factors should be fully considered, and it
is best to adopt the method of excavation in a partial area. Reinforcement is
performed first and then excavation is performed. Strong and reliable support is
carried out. The construction operation is timely. Support measures is taken for a
middle wall. In order to prevent displacement of a side wall due to compression,
effective measures is taken when an inverted arch is excavated, An operation
process mainly comprises a single-side-wall approach pit method and a double- side-wall approach pit method, and an optimal excavation method is determined from these two excavation methods.
Further, the single-side-wall approach pit method in step (1) specifically
refers to: the single-side-wall approach pit method also is called a CD method or
a CRD method. This method is widely used in poor surrounding rock conditions,
avoidance of poor control of settlement, or construction of a plurality of shallow
buried tunnels, The CD method is used for construction, first, the single-side
approach pit is excavated in advance. For the other side and the middle wall, a
positive step method is selected for operation. The objective of this is capable of
greatly reducing horizontal and vertical displacements of a vault and a side wall,
However, it is worth pointing out that this method also has certain disadvantages,
that is, a weak position of the inverted arch is prone to cracking and damage
during the construction process, and this construction method is not prone to
adjust when the surrounding rock changes.
Further, the double-side-wall approach pit method in the step (1) specifically
refers to the double-side-wall approach pit method, that is, a glasses method.
This method is more suitable for a large-span shallow-buried tunnel with strict
control of soil settlement and a multi-line tunnel with poor surrounding rock
conditions. The glasses method uses a small mechanical apparatus for
excavation, which has little effect on the stability of the surrounding rock, so the
glasses method is more reliable and safe. However, the glasses method also has
disadvantages such as complex construction engineering, slow construction
progress, and high costs.
Further, step (2) specifically comprises: auxiliary construction measures for
tunnel excavation comprises large pipe shed advanced support measures,
advanced small pipe pre-grouting and a rammed pipe curtain method, The pipe
shed support measures is very suitable for rock-soil formations where an arching
effect of the rock and soil is very bad, and can reduce the lateral pressure caused
by gravity of the soil to ensure stability of the front excavated soil. The advanced
pipe pre-grouting stabilizes loose soil in a vertical direction. The rammed pipe
curtain method is capable of well supporting and protecting a shallow-buried and
digging operation in a city, and has the advantages of little interference on ground
traffic, safety and reliability, low noise, green and environmental protection, The
support plan is selected according to different geological conditions, different
buried depths and types of surrounding rock.
Further, step (3) specifically comprises the most commonly used slope
reinforcement method. The method is capable of changing a sliding resistance of
a landslide body and a sliding force, so as to achieve balance requirements on a
sliding surface of a sliding soil body, Construction methods such as retaining wall
construction, ground surface anchor construction, and anti-slide pile hitting are
capable of improving an anti-sliding ability of slope soil.
Further, step (4) specifically comprises: in order to improve an overall rigidity
of the track system, controlling ground surface settlement caused by construction
of the existing railway line under the tunnel, wherein pre-reinforcement measures
often adopted is a buckle rail reinforcement method, a steel beam vertical picking
and transverse lifting method, and a steel temporary bridge overhead method.
The construction system and method of the shallow-buried deep-tunnel
under the existing railway line of the present invention has the following beneficial
effects: combining an actual state of the tunnel under the railway line project,
considering the coupling effect of the surrounding rock and different support
methods, and optimizing a tunnel pre-support method and excavation
construction technology to ensure that a construction process is in a safe, stable,
high-quality and controllable state. The present invention can provide reference
for similar projects.
FIG. 1 is a flow chart of a construction system and method for a shallow
tunnel under an existing railway line according to an embodiment of the present
invention.
FIG. 2 is a schematic diagram of a CRD construction method of Beijing
Baotou Railway section under Qinglong Bridge tunnel provided by an
embodiment of the present invention.
FIG. 3 is a schematic diagram of an upper blasting hole of a CRD method
provided by an embodiment of the present invention.
FIG. 4 is an illustration of a railway track rail fastening track reinforced track
provided by an embodiment of the present invention.
In order to make the objectives, technical solutions and advantages of the
present invention clearer, the following further describes the present invention in
detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.
The present invention will be further described below in conjunction with
specific embodiments and the accompanying drawings.
The present invention takes construction of existing Beijing-Baotou railway
line under Qinglong Bridge tunnel project of Badaling transit line as an example.
The project overview of this embodiment is specifically as follows: a starting point
of a tunnel starts under Qinglong Bridge of Badaling Expressway, and Beijing
Baotou Railway passes under the tunnel. An entrance section of the tunnel is
shallowly buried and geologically broken, especially the existing Beijing-Baotou
railway line "Zigzag railway" passes on the entrance side, which poses a greater
safety risk. During a construction period, four passenger trains passed through
the Beijing-Baotou railway line every day. One of the passenger trains was the
Beijing-Moscow international train, which requires high safety. The railway
authority stipulated that the limit value of the ground surface settlement of a
railway road base was 10mm, and a differential settlement limit value of two
tracks was 5mm. The differential settlement of a rail surface in a turnout area
should not exceed 4mm, which puts forward higher requirements for construction
control. According to results of engineering geological survey, surveying and
drilling, the tunnel site was filled with artificial soil at an entrance and an exit of
the tunnel and Quaternary loose stratum was accumulated in a valley. Most of
the bedrock in other sections was exposed and a lithology is Yanshanian
intrusion granite.
(7) Comparison and selection of construction solutions for undercutting and
reinforcement of a tunnel entrance
Based on the previous construction experience of similar projects, by
consulting relevant experts, conducting multi-solution demonstration and analysis,
comparison of the solutions is shown in Table 1. After comprehensive economic
and technical analysis, recommended solution III is an implementation solution.
Table 1 Comparison and selection of a preliminary construction solution for
undercutting and reinforcement
S/N Solution I Solution II Solution III Solution IV Box culvert Auxiliary support of Auxiliary support for Project name jack-in an arch with a an arch with a Lieajsmn construction 0159mm large pipe 0325mm rammed Lineadjustment shed pipe curtain 35 pipe sheds with 47 rammed pipes a diameter of with a diameter of In view of the (p159x7mm, section (p325x14mm and particularity of Ajack-in box lengths of 3m and section lengths of the location of 6m; circumferential 3m and 6m; each the tunnel culvert with a reinforced spacing of 40cm one is locked and entrance, Solution concrete closed and an inclination connected; an further description frame with a angle of 10. Double angle is parallel to a investigations wall thickness grout grouting of longitudinal axis. were conducted of90cm. 1:1 cement and Grouting of on the site in water glass. A slope unmixed cement order to obtain of a cave entrance mortar. The slope is better entry is reinforced with a reinforced with a conditions. 6m anchor bolt. 20m anchor cable. 1. A main 1. Pre-support in structure is a 1. Pre-support in advance can rigid frame, advance can basically prove which is easy to basically prove geological control during geological conditions, which Properposition large conditions, which has certain guiding adjustment can deformation has certain guiding significance for avoid railway Advantages asd significance fording utctofment. snrce f turnout area 2. Being construction of undercutting and reduce conducive to undercutting excavation. safety risks. groundwater excavation. 2. Fast construction control and 2. Fast construction speed. rainy season speed. 3. A buckle lock and construction. a hole lock beam can ensure that a pipe curtain is connected as a whole and increase overall rigidity. 1. The entrance of the tunnel is moved to the 1. A termination left by 30m, length is not which can easyto stagger the determine. 2. 1. A grouting effect railway turnout, The section determines an but lead connection is overall effect of indicators at the not beautiful, reinforcement, and entrance of the which is not it is difficult to tunnelcannot conducive to ensure that the 1. It is difficult to meet the subsequent grouting penetrates control a positioning specifications. ventilation evenly in soil. angle and interlock In addition, the monitoring 2. Due to a connection of the entrance design. continuous rammed tube. crosses a larger 3. There is a tino 2. A hitting process gully after Disadvantage gap between an vibration load of a is affected by entering the excavation ptrain,rigidity ofthe surrounding rock tunnel by 100 contour and a relatively small. and a depth is not m, which structure, which 3.Stronger easy to control. increases risks is easy to cause reinforcement 3. A construction of excavation settlement and measureseedto period is easy to safety. a speed is betakueonlne.4.t control. 2. Buildings on relatively fast. Anundercutting the right are 4. The back of aexcavationprocess dense with pusher is on the eedsvto sreh railway lines ground, which needsto strengthen and high-speed makes it invest supportinadvance, bridges; there is much and no operating makes it difficult space. to dismantle. 3. It takes too long to redesign and report for approval. (2) Optimization of construction plan
In order to further coordinate with the relevant railway authorities, the
optimization of the construction plan design is carried out, as shown in Table 2
below:
Table 2 Optimization table of construction plan
Optimization Online Auxiliary Supporting parameters Excavation project reinforcement construction method
1.3-5-3 A circular direction 20a 2-beam frame, 26cm ACD buckle rail of the arch is thick C20 shotcrete, 50cm construction reinforcement; supported by 47 thick C25 reinforced method is Before 2. Speed limit c325x14mm pipe concrete secondary lining. adopted for optimization measures is curtains, and a left Aside wall is routed with undercutting of taken and a hole is 1Om long. a c30 anchor pipe with a 40m tunnel speed is A right hole is circumferential spacing of underthe 45Km/h. 15m long. stemesgle-lcme railway line. 20a I-steel frame spacing 0.5m, 27cm thick C20 1.3-5-3 A circular direction shotcrete, 50cm thick C25 A CRD buckle rail of the arch is reinforced concrete construction reinforcement; supported by 47 secondary lining. The side method is After 2. Speed limit c325x14mm pipe wall is grouted with a c25 adopted for the optimization measures is curtains, and left hollow anchor rod, a undercutting of taken and a and right holes circumferential spacing is a 40m tunnel speedis are more than 1.0m. $8 double-layer underthe 15Km/h. 20m long. steel mesh, 20x2Ocm. A railway line. temporary inverted arch is increased. An interface of a A refined Effectively railway subgrade excavation Effcvite bedrockis method is of Effectenessobem ofthe infiltrated as much Being conduciveto great benefit to Effctvees prblm f heas possible, and aimproving an initial the control of analysis height reinforcement support effect. settlement and turnouttrack. range of a railway the safety of section is process lengthened. conversion. (3) A CRD method construction plan
Beijing-Baotou Railway under Qinglong Bridge tunnel was mainly excavated
by the CRD method to ensure the safety of railway operations, strengthen
monitoring and measurement, and optimize and adjust support parameters in
time based on feedback information. The specific construction operation
sequence is carried out in accordance with h part, @part, part, @ part,@
part, and @ part, as shown in FIG. 2. First, drilling and blasting, then carrying out
construction operation on lining, and finally carrying out a closed joint for a full
section primary lining. For the CRD method, t part, ©part, @part, @part, @ part, and @ part select a smooth surface controlled blasting method, and proceed with the construction in sequence. The blast hole positions of @ part and @ part are shown in FIG. 3.
When an approach pit is excavated, the approach pit is divided into two parts:
the first approach pit and the second approach pit, which are cross-operated. The
first and second approach pits divided upper, middle and lower platforms into six
parts by using a step method. As shown in FIG. 2, manual
excavation is used to reduce disturbance to the surrounding rock during
excavation. Upper steps are excavated first. The length of the steps cannot
exceed 8m. The construction sequence is as follows:
7. Using an advanced large pipe shed and an advanced small duct to
provide advanced support to a top of the tunnel and a middle wall. Using
a manual excavation method for an approach pit excavation of @ part,
wherein when excavation of 0.5 m is performed, I 20a steel frame and I
18 I-steel temporary steel frame are erected, and a locking anchor rod is
set.
When the approach pit is excavated and supported by 8m, the unexcavated
surface is sprayed with 8cm thick C25 concrete to seal and support a tunnel face.
Then constructing a preliminary support and a temporary support of part
around the approach pit, that is, 4 cm thick concrete is first sprayed. After part
of the approach pit bottom is leveled and compacted, constructing the temporary
inverted arch of @ part of the approach pit, and installing an 1 18I-beam cross
bracing. Finally, spraying the concrete again to meet design thickness
requirements.
2. After @ part of the approach pit is constructed for a certain distance (a
step length is 8m), using a manual excavation to carry out @ part of the
approach pit excavation.
I 20a steel frame and I 18I-beam temporary steel frame are erected every
0.5m of excavation, and anchor pipes for locking feet are installed. When the
approach pit is excavated by 8 m, an unexcavated surface is sprayed with 8 cm
thick C25 grade concrete to seal the tunnel face. Then constructing the
preliminary support and the temporary support of part @ around the approach pit,
that is, 4 cm thick concrete is first sprayed. After @ part of the approach pit
bottom is leveled and compacted, constructing the temporary inverted arch of 0 part of the approach pit, and installing the 118 I-beam cross bracing. Finally,
spraying a concrete to a design thickness.
3. When the excavation of @@parts lags behind @part by 30m, the
construction is carried out. When @@parts of the approach pit is excavated,
following an excavation method and sequence of 0@parts of the approach pit,
and performing the preliminary support and the temporary support around the
approach pit.
4. After lagging @@parts of the approach pit for a certain distance (30m),
carrying out excavation of @@parts of the approach pit. Manual and cross
excavation is still used during excavation, and a staggered distance is not less
than 3m. When @ part is excavated by 3m, spraying 8cm thick C25 concrete to
seal the tunnel face. A peripheral part of the tunnel bottom is initially sprayed with
4cm thick concrete, and is connected with a I 20a steel frame and a I 18I-steel temporary steel frame, and then concrete is sprayed to the design thickness.
After the excavation and support of @ part of the approach pit is completed, the
approach pit of @ part is excavated in the same way.
(4) Design of supporting parameters
The tunnel adopts composite lining and is designed according to the
principles of the New Austrian Tunneling Method. The preliminary support is
composed of a steel frame, an anchor rod, a steel mesh, and shotcrete to form a
combined support system. The second lining of the railway section is reinforced
concrete. The common support of the two linings is performed to withstand a
pressure load, thereby ensuring safety of tunnel construction.
Table 3 Table for composite lining support parameters
Preliminary support 06 steelSeco Linin Shotcrete steel Anchor rod Steel frame Advance support nd g Settin riSettin Settin lining type LGrideng spacing spaci Supp Location/spa Lining Partthickn g size th RingxVerti loaing ort cing (cm) ess (cm) Locati (c )Locati (m aI() locati () tp m on (cm) on (m) cal(m) on (m) type (m)
1V Arch, Arch, 25/2 Arch 3.0 1.2/1.2 Arch, 1.2 Anch Arch 0.4 40 wall/22 wall 5 wall or rod
Arch, 20/2 Side Full Small V Full ring/23 3.0 1.0/0.5 0.5 guidin Arch 0.4 45* 11wall 10 wall ringgpie g pipe Vj Full ring/27 Arch, 20/2 Side 3.0 1.0/0.5 Full 0.5 -- -- 50* wall 0 wall 30 1/.5 ring
Note: The lower corner mark j of the lining type is reinforced; the upper
corner mark* of the secondary lining is reinforced concrete, and the no corner
mark is plain concrete.
(5) Construction auxiliary measures
For this special section, first carrying out construction of auxiliary measures
for the pipe curtain and slope protection, and then carrying out buckle track
protection of a railway track, and reporting key points and speed limit for the
relevant department. A ballast bed is maintained in time in accordance with the
requirements of relevant railway regulations to ensure the smoothness of the
railway track and the normal operation of the railway.
7. Rammed pipe curtain
In this project, the rammed pipe curtain adopts a seamless steel pipe with a
diameter of 325mm and a wall thickness of 14mm. The construction of the pipe
curtain takes into account a 20cm error. An end of the rammed pipe is equipped
with a C20 shotcrete locking beam, and a steel grille is used to effectively
connect an end reinforcement of a pipe shed and an anchor rod at an outer circle
of the pipe shed to ensure stability of the pipe shed of the rammed pipe. A pipe
rammer uses the German TT company Grundoram-tube rammer for construction.
2. Reinforcement technology of the buckle track of the railway track
In order to ensure the safety of tunnel excavation, controlling the ground
surface settlement, and protecting safety of railway operations, wherein a buckle
track reinforcement length is 85.6m. As shown in FIG. 4.
(0) Replacing a wooden sleeper
Traveling slowly before reinforcement, replacing line concrete with the long
wooden sleeper, and adding a base plate at the bottom of the track to reinforce a
track surface. Replacing one wooden sleeper every six, and an area to be
replaced meets the requirements for the use of a reinforced length. When the replacement is completed, the wooden sleeper is vibrated to meet the compactness requirements, and then a nearby reinforced concrete sleeper is replaced. An exchanged route is operated in a symmetrical manner from both sides of a central axis of the tunnel. When work is completed, the entire route is reviewed to ensure that the result of the operation meets the corresponding specifications for track construction.
©Paving a hanging rail A method of assembly is to set up the hanging rail in the way of 3-5-3. Joints
of s steel rail is misaligned by more than one meter. The rail is 43 Kg/m rail, and
the hanging rail and the sleeper under the hanging rail are connected by a ©22-U
bolt.
(6) Construction of secondary lining
The minimum radius of the tunnel entrance curve is R=600m. In order to
ensure the smoothness of the secondary lining, a 6m long trolley is used for
integral molding. A concrete tanker is transported, pumped into the mold, and
attached vibration is combined with an inserted tamping rod for tamping. Before
pouring, the inverted arch filling, side wall foundation, a waterproof layer, a blind
ditch, pre-embedded pipelines, installation of pre-embedded parts, fixation of a
cover die of a reserved cavern, etc., are completed to ensure an appearance
quality of concrete.
The present invention takes the Qinglong Bridge tunnel project of existing
Beijing-Baotou Railway under Badaling Transit Line as an example to verify the
rationality and reliability of the proposed construction system and method of the shallow-buried deep-tunnel under the existing railway line. After verification, a construction effect is good, achieving an effect of controlling a construction impact within an acceptable range. The present invention provides a decision making basis and technical indicators for the selection of construction methods and technologies for existing railway lines under similar tunnels. The present invention promotes the progress of tunnel crossing engineering construction technology, with significant social and environmental benefits.
The forgoing are only the preferred embodiments of the present invention
and are not intended to limit the present invention. Any modification, equivalent
replacement and improvement made within the spirit and principle of the present
invention shall be included within the protection scope of the present invention.
Claims (7)
1. A construction system and method of a shallow-buried deep-tunnel under
an existing railway line, wherein the method comprises the following steps:
(1) optimizing a main construction method of tunnel excavation; (2) selecting
an appropriate support structure and auxiliary construction measures for the
tunnel excavation; (3) reinforcing a subgrade slope of the railway line under the
tunnel; and (4) strengthening and stabilizing a track of the railway line under the
tunnel.
2. The construction system and method of the shallow-buried deep-tunnel
under the existing railway line according to claim 1, wherein step (1) is
specifically as follows: using the "New Austrian Tunnelling Method" for
construction and operation, wherein when an excavation method of the tunnel is
determined and a portal surface is excavated, a hydrogeological conditions of the
tunnel, distribution of surrounding buildings and structures, a buried depth of the
tunnel, construction operation, surrounding rock conditions and bearing capacity,
a technical capability of a construction worker, construction period requirements,
and other various factors should be fully considered, and it is best to adopt the
method of excavation in a partial area, reinforcement is performed first and then
excavation is performed, strong and reliable support is carried out, the
construction operation is , timely support measures is taken for a middle wall, in
order to prevent displacement of a side wall due to compression, effective
measures is taken when an inverted arch is excavated, an operation process
mainly comprises a single-side-wall approach pit method and a double-side-wall approach pit method, and an optimal excavation method is determined from these two excavation methods.
3. The construction system and method of the shallow-buried deep-tunnel
under the existing railway line according to claim 1, wherein the single-side-wall
approach pit method in step (1) specifically refers to: the single-side-wall
approach pit method also is called a CD method or a CRD method, this method
is widely used in poor surrounding rock conditions, avoidance of poor control of
settlement, or construction of a plurality of shallow-buried tunnels, the CD method
is used for construction, first, the single-side approach pit is excavated in
advance, for the other side and the middle wall, a positive step method is
selected for operation, the objective of this is capable of greatly reducing
horizontal and vertical displacements of a vault and a side wall, however, it is
worth pointing out that this method also has certain disadvantages, that is, a
weak position of the inverted arch is prone to cracking and damage during the
construction process, and this construction method is not prone to adjust when
the surrounding rock changes.
4. The construction system and method of the shallow-buried deep-tunnel
under the existing railway line according to claim 1, wherein the double-side-wall
approach pit method in the step (1) specifically refers to the double-side-wall
approach pit method, that is, a glasses method, this method is more suitable for a
large-span shallow-buried tunnel with strict control of soil settlement and a multi
line tunnel with poor surrounding rock conditions, the glasses method uses a
small mechanical apparatus for excavation, which has little effect on the stability of the surrounding rock, so the glasses method is more reliable and safe, however, the glasses method also has disadvantages such as complex construction engineering, slow construction progress, and high costs.
5. The construction system and method of the shallow-buried deep-tunnel
under the existing railway line according to claim 1, wherein step (2) specifically
comprises: auxiliary construction measures for tunnel excavation comprises large
pipe shed advanced support measures, advanced small pipe pre-grouting and a
rammed pipe curtain method, the pipe shed support measures is very suitable for
rock-soil formations where an arching effect of the rock and soil is very bad, and
can reduce the lateral pressure caused by gravity of the soil to ensure stability of
the front excavated soil; the advanced pipe pre-grouting stabilizes loose soil in a
vertical direction; the rammed pipe curtain method is capable of well supporting
and protecting a shallow-buried and digging operation in a city, and has the
advantages of little interference on ground traffic, safety and reliability, low noise,
green and environmental protection, a support plan is selected according to the
specific construction conditions.
6. The construction system and method of the shallow-buried deep-tunnel
under the existing railway line according to claim 1, wherein step (3) specifically
comprises: the most commonly used slope reinforcement method, the method is
capable of changing a sliding resistance of a landslide body and a sliding force,
so as to achieve balance requirements on a sliding surface of a sliding soil body,
construction methods such as retaining wall construction, ground surface anchor construction, and anti-slide pile hitting are capable of improving an anti-sliding ability of slope soil.
7. The construction system and method of the shallow-buried deep-tunnel under
the existing railway line according to claim 1, wherein step (4) specifically
comprises: in order to improve an overall rigidity of the track system, controlling
ground surface settlement caused by construction of the existing railway line
under the tunnel, wherein pre-reinforcement measures often adopted is a buckle
rail reinforcement method, a steel beam vertical picking and transverse lifting
method, and a steel temporary bridge overhead method.
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| AU2021101941A AU2021101941A4 (en) | 2021-04-15 | 2021-04-15 | Construction System and Method of Shallow-Buried Deep-Tunnel under Existing Railway Line |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114692352A (en) * | 2022-04-06 | 2022-07-01 | 中南大学 | Intelligent layout method for highway network in mountain railway construction |
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2021
- 2021-04-15 AU AU2021101941A patent/AU2021101941A4/en not_active Ceased
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114692352A (en) * | 2022-04-06 | 2022-07-01 | 中南大学 | Intelligent layout method for highway network in mountain railway construction |
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