CN115613612A - Single-layer steel shell immersed tube for shield segment lining and construction method thereof - Google Patents

Abstract

The invention relates to the technical field of underwater tunnel immersed pipes, and provides a single-layer steel shell immersed pipe of a shield segment lining and a construction method thereof, wherein the single-layer steel shell immersed pipe of the shield segment lining comprises a steel shell structure which is a single-layer shell; the section of the steel shell structure is oval; the long axis of the ellipse is arranged along the horizontal direction; shield segments are arranged on the inner side of the steel shell structure; mortar is filled between the shield segment and the steel shell structure. The single-layer steel shell immersed tube for shield segment lining solves the problems that the existing immersed tube technology needs special dry dock or factory manufacturing and needs to excavate a special floating channel during transportation, can save construction cost and construction period and reduce the influence on the environment.

Description

Single-layer steel shell immersed tube for shield segment lining and construction method thereof

Technical Field

The invention relates to the technical field of underwater tunnel immersed tubes, in particular to a single-layer steel shell immersed tube for shield segment lining and a construction method thereof.

Background

In the current immersed tube tunnel construction projects at home and abroad, the main immersed tube structure types comprise a double-layer steel shell immersed tube structure and a reinforced concrete immersed tube structure, and the main body structures of the two types of immersed tubes are poured by self-compacting concrete and need to be prefabricated in a special prefabricated dry dock or a factory; and the concrete structure is heavy in self weight, the existing immersed tube usually has a draught depth of 8-9 m, and the immersed tube is transported to a tunnel site by floating through a special floating channel during transportation.

For the prior art, the construction masonry of immersed tube prefabricated dry dock, factory and floating channel not only has large engineering quantity and high construction cost, but also has great influence on the environment; and if the method is used in shallow and narrow water areas of inland rivers or limited water areas of bridge navigation, the excavation of the floating shipping channel and the floating transportation construction of pipe joints are accompanied by extremely high safety risks.

Disclosure of Invention

The invention aims to: the problems that in the existing immersed tube technology, a large amount of self-compacting concrete is adopted as a main body, the dead weight is too large, and a special floating channel needs to be excavated during transportation, so that the construction cost is high, the construction period is long, and the environmental damage is large are solved, and the single-layer steel shell immersed tube of the shield segment lining and the construction method thereof are provided.

In order to achieve the purpose, the invention adopts the technical scheme that:

a single-layer steel shell immersed tube for shield segment lining comprises a steel shell structure; the steel shell structure is a single-layer shell; the section of the steel shell structure is oval; the long axis of the ellipse is arranged along the horizontal direction; a shield segment is arranged on the inner side of the steel shell structure; mortar is filled between the shield segment and the steel shell structure.

The specific semi-major axis and semi-minor axis of the steel shell structure are matched with the size of a traffic lane and other auxiliary facilities such as anti-collision piers, which are expected to be arranged in the steel shell structure; except for the section shape of the steel shell structure and the use of the shield segment as the inner lining, other structures of the steel shell structure accord with the design of a common immersed tube, such as the steel shell structure has enough structural strength for resisting water pressure, enough anti-floating coefficient and the end provided with a water stop and a connecting structure.

The shield segment can adopt the existing mature shield segment.

Use steel-shelled structure and shield structure section of jurisdiction as the major structure of immersed tube, and establish the connection with the mortar, compare in the current scheme as major structure with cast-in-place concrete structure, under the same condition of tunnel inner space, this scheme dead weight is lighter, draft is littleer, require lowly to the superficial shipping channel, can not excavate special superficial shipping channel, thereby reduce the construction cost, the reduction of erection time, also alleviateed the environmental damage to tunnel site periphery simultaneously, the influence of steel-shelled structure transportation to other navigation along the line has been reduced.

Meanwhile, the main structure does not use a large amount of cast-in-place concrete structures, so that the manufacturing precision is easier to control, the relation between the dead weight and the volume is easier to adjust so that the dead weight and the buoyancy reach a balanced critical state, and the requirements of the immersed tube on the performance of other equipment such as ships during transportation, sinking and butt joint are reduced; in addition, the different sections of the immersed tube and the different reinforcement designs caused by different concrete ground materials in each region are not required to be considered, so that the section designs of the immersed tubes in each section can be unified, the design difficulty is reduced, and the standardization of the manufacturing template is facilitated; the construction process of the scheme is simple, the construction environment is good, and the construction period is short without using a large amount of concrete, so that the construction quality is ensured more easily, and the investment of management resources is reduced.

Compared with the circular steel shell structure with the oval section, the steel shell structure with the oval section is closer to the building boundary of the tunnel, so that the space utilization rate is higher, the section height can be relatively reduced, the excavation depth of a foundation trench is reduced, the masonry engineering quantity is reduced, the construction period is further shortened, and the construction cost is saved; compared with the square scheme, the scheme has more reasonable stress and can effectively reduce the phenomenon of stress concentration, thereby better resisting traffic load and earthquake impact load; meanwhile, the existing arc-shaped shield segment technology can be conveniently utilized by using the oval section, and other special-shaped shield segments do not need to be customized independently.

This scheme is compared in current double-deck box hat structure immersed tube, because only individual layer box hat structure does not have a large amount of steel storehouse check between the two-layer box hat structure of double-deck box hat structure immersed tube, therefore still less with the steel volume, the structure is simpler, can obviously reduce cost and shorten casing manufacturing period.

The shield segment is used as the immersed tube lining in the scheme, the technology is mature, the factorization degree is high, the quality is highly controllable, the assembling process is mature, and the engineering progress control, the quality control and the construction cost control are facilitated.

As a preferable scheme of the invention, the number of the steel shell structures is at least two; the steel shell structures are arranged side by side; two adjacent steel shell structures are connected through a support rod; the support rods are axially distributed at intervals along the steel shell structure.

The spacing and the number of the steel shell structures are designed according to the requirements of the traffic lanes of specific projects.

Compared with the scheme of a single steel shell structure, the scheme has lower section height under the condition of the same section area, so that the excavation depth of the foundation trench can be reduced, the masonry engineering amount can be reduced, the construction period can be shortened, and the construction cost can be saved.

The plurality of support rods arranged at intervals along the axial direction of the steel shell structure are used for connecting the steel shell structures, so that on one hand, the load is more dispersed, and the steel shell structures can be kept connected even if part of the support rods fail by setting a corresponding safety factor, so that the scheme has higher maintainability; on the other hand, if other structures are arranged among the steel shell structures, the supporting rods arranged at intervals also facilitate the construction of other structures among the steel shell structures.

As a preferred scheme of the invention, a partition plate structure is connected between two adjacent steel shell structures; the partition plate structure is equal to the steel shell structure in length; the partition plate structures are at least two and are distributed at intervals along the height direction of the steel shell structure.

The height direction of the steel shell structure refers to the direction parallel to the minor axis of the oval steel shell structure.

The partition plate structure can be mechanically connected to each steel shell structure, but the splicing seams are subjected to waterproof treatment; the baffle structure may also be welded to the steel shell structure to enhance water resistance.

The specific number and spacing of the baffle structures may be determined by the specific requirements for the enclosed space, e.g. if the space between the baffle structures is used as an access passage, the spacing of the baffle structures will be referenced to the size of the access equipment and personnel.

The partition plate structures distributed at intervals in the vertical direction can be used as a bottom template of concrete for ballast, and a closed space can be formed between two adjacent steel shell structures and can be used for accommodating other equipment or personnel, such as a pipeline channel or a maintenance channel; the partition plate structure can also assist the support rod to connect each adjacent steel shell structure.

In a preferred embodiment of the present invention, an external ballasting concrete structure is cast on an upper surface of the uppermost partition structure or a lower surface of the lowermost partition structure.

When the external ballasted concrete structure is arranged on the lower surface of the partition plate structure at the lowest part, the gravity center of the immersed tube structure can be lowered; when the external ballasting concrete structure is arranged on the upper surface of the uppermost partition plate structure, the pouring of the external ballasting concrete structure can be facilitated.

Because the immersed tube structure has the requirement of anti-floating coefficient of at least 10 percent after sinking, the thickness of the ballasted concrete structure is often larger; compared with the prior scheme that the ballasted concrete structure is completely arranged inside the immersed tube structure, the scheme has the advantages that the external ballasted concrete structure is poured outside the steel shell structure, so that the volume inside the immersed tube structure can be saved, the space utilization rate is improved, the section height is relatively reduced, the excavation depth of a foundation trench is reduced, the masonry engineering quantity is reduced, the construction period is shortened, and the construction cost is saved; and this scheme can directly regard as the template of concrete with the recess that baffle structure and the steel-shelled structure of connecting in its both sides formed when pouring outside ballast concrete structure, and the operation of pouring is convenient.

As the preferred scheme of the invention, the end surface of the steel shell structure is provided with a PC inhaul cable; the PC inhaul cable is used for connecting two longitudinally adjacent steel shell structures.

The longitudinal direction in the scheme refers to the axial direction of the steel shell structure.

Through setting up the PC cable, need not to set up sealed template and concreting when with each box hat structure end to can further reduce concrete placement's work load and simplify the connection process, reduce the time limit for a project.

As the preferred scheme of the invention, the upper part of the steel shell structure is provided with a ventilation channel clapboard; the length of the ventilation channel partition plate is equal to that of the steel shell structure; and the ventilation channel partition plate and a channel formed at the upper part of the corresponding steel shell structure are used for ventilation.

The ventilation channel partition plate can be a simple plane plate or a curved surface plate, and can also be a corresponding special-shaped plate for mounting other equipment such as lamps and ventilation equipment; the specific size of the ventilation channel formed by the ventilation channel partition plate corresponds to the ventilation requirement.

The ventilation channel clapboard of the scheme can divide a channel special for ventilation from the interior of a steel shell structure on one hand, and can be used as a mounting plate of other top equipment such as a lamp on the other hand; this scheme can also increase the compressive strength of box hat structure simultaneously.

As a preferable embodiment of the present invention, the present invention further includes a pavement structure; the pavement structure is connected with the shield segment through a pavement upright post.

The pavement structure may be a roadway, a sidewalk, or a combination thereof.

According to the scheme, the horizontal pavement structure is arranged on the inner wall of the oval steel shell structure through the pavement upright post, and the pavement structure can be lifted to the position near the long axis of the oval steel shell through the pavement upright post so as to increase the space utilization rate; the space between the pavement structure and the shield segment can also be used as a pipeline or a drainage channel.

A construction method of a single-layer steel shell immersed tube of a shield segment lining comprises the following steps:

A. sinking the steel shell structure to a tunnel site;

B. draining the underwater steel shell structure; installing shield segments in the steel shell structure; and pouring mortar between the shield segment and the steel shell structure.

Except that the assembly arrangement of shield segments sinks at the steel shell structure, the manufacturing, transportation, butt joint and backfilling of the single-layer steel shell immersed tube of the shield segment lining can refer to the construction steps of the existing immersed tube structure.

For example, when the steel shell structure is manufactured, a special dry dock or a factory can be built on site, and the existing factory can also be utilized; when the single-layer steel shell immersed tube of the shield segment lining is manufactured, other accessories of the single-layer steel shell immersed tube of the shield segment lining or other accessory equipment required by the subsequent steps, such as a measuring tower, a guy cable column and a ballast system, can be installed in a factory together or can be installed again when needed, besides the steel shell structure.

During floating transportation, temporary sealing doors can be added at two ends of the single-layer steel shell immersed tube of the shield segment lining so as to facilitate floating transportation.

When the steel shell structure is sunk to the bottom, all single-layer steel shell immersed tubes of the shield segment lining used for the tunnel can be sunk at one time and then the next operation is carried out, and the next operation can be carried out when one single-layer steel shell immersed tube of the shield segment lining is sunk.

During butt joint, corresponding butt joint modes such as welding, wet joint or mechanical connection can be adopted according to tunnel site conditions and construction equipment limitation.

During backfilling, the backfilling is carried out according to the conditions of the tunnel site and the restriction of construction equipment and by referring to the existing backfilling specification.

After the steel shell structures of all the sections are butted and drained, tunnel auxiliary equipment or structures such as driveways, lamps and cables can be installed and constructed.

After the shield segment of one of the main components of the single-layer steel shell immersed tube of the shield segment lining is assembled and arranged and then the steel shell structure is sunk, the weight of the single-layer steel shell immersed tube of the shield segment lining during transportation can be greatly reduced, so that the draft of the single-layer steel shell immersed tube of the shield segment lining during floating transportation is greatly reduced, and the requirement on the depth of the floating transportation channel is further reduced; and the weight of the single-layer steel shell immersed tube of the shield segment lining in the floating transportation process is reduced, and the mooring and positioning operation is more convenient.

As a preferable aspect of the present invention, when an external ballasted concrete structure is provided outside the steel shell structure, the external ballasted concrete structure is cast before step a.

Because outside ballast concrete sets up in the box hat structure outside, this scheme just pours outside ballast concrete structure before the box hat structure sinks the operation, can reduce outside ballast concrete structure's the degree of difficulty of pouring, avoids under water the construction.

As a preferable scheme of the invention, fine sand is adopted for backfilling the covering layer of the steel shell structure.

This scheme uses fine sand backfill to carry out the overburden and backfills, and the surface of steel-shell structure can more be laminated to the backfill to provide good support for the steel-shell structure.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. compared with the prior art, the invention uses the steel shell structure and the shield segment as the immersed tube main body, so that a large amount of concrete is not required to be cast in situ, the existing steel processing factory, such as a shipyard, can be used for processing, and the construction of temporary dry dock or factory at a tunnel site is avoided; the invention has lighter dead weight, shallow draft during floating transportation and small requirement on the depth of water in a floating transportation channel; the invention can save construction cost and shorten construction period in two links of manufacturing and transportation, and can reduce the damage to the tunnel site environment, thereby better meeting the increasing environmental protection requirements.

2. The construction method adopts the sequence of floating the steel shell structure, sinking the bottom and then installing the shield segments, and can greatly reduce the dead weight of the single-layer steel shell immersed tube lined by the shield segments during floating, thereby reducing the draft of the single-layer steel shell immersed tube lined by the shield segments during floating, reducing the requirement on the water depth of the floating channel, further saving the construction cost and shortening the construction period.

3. Compared with the circular steel shell structure, the steel shell structure with the oval section is closer to the building boundary of a tunnel, so that the steel shell structure has higher space utilization rate, can relatively reduce the height of the section, and can reduce the excavation depth of a foundation trench and reduce the masonry engineering quantity, thereby shortening the construction period and saving the construction cost; compared with the square structure, the invention has more reasonable stress and can effectively reduce the stress concentration phenomenon, thereby better resisting traffic load and earthquake impact load.

4. Compared with the existing double-layer steel shell immersed tube structure, the invention has only a single-layer steel shell structure and does not have a large number of steel storage lattices between the two-layer steel shell structure, so that the steel consumption is less, the structure is simpler, the cost can be obviously reduced, and the manufacturing period of the shell can be shortened.

5. The shield segment is a mature technology, has high industrial degree, controllable quality height and mature assembly process, and is convenient for engineering progress control, quality control and construction cost control.

6. Compared with the prior art, the method has the advantages of simpler process, good construction environment, easier guarantee of construction quality and reduction of investment of management resources because of no need of a large amount of concrete pouring operation.

Drawings

FIG. 1 is a schematic perspective view of a single-layer steel shell immersed tube for shield segment lining in example 1;

FIG. 2 is a schematic cross-sectional view of a single-layer steel shell immersed tube of the shield segment lining of example 1;

FIG. 3 is a schematic perspective view of a single-layer steel-shelled immersed tube of the shield segment lining of example 2;

FIG. 4 is a schematic cross-sectional view of a single-layer steel shell immersed tube of shield segment lining of example 2;

icon: 1-steel shell structure; 2-shield segment; 3-a support bar; 4-external ballasted concrete structure; 5-a separator structure; 6-pavement structure; 7-pavement upright posts; 8-anti-collision pier; 11-ventilation channel partition.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

Example 1

As shown in fig. 1 and 2, the single-layer steel shell immersed tube for shield segment lining adopted by the invention comprises a steel shell structure 1 and shield segments 2, wherein the shield segments 2 are laid on the inner wall of the steel shell structure 1; to this embodiment, shield segment 2 is the shield segment 2 that the customization is used for oval cross-section, and the fissure of displacement is assembled in 1 inner wall of steel-shelled structure.

Mortar is filled between the shield segment 2 and the steel shell structure 1, and for the embodiment, the mortar with the strength greater than or equal to 40MPa is filled.

The steel shell structure 1 is further provided with a PC cable, an end plate and a waterproof belt arranged on the end plate at two ends thereof for butt joint operation.

It should be noted that the PC cable in this embodiment is a single-layer steel shell immersed tube connecting each segment of the shield segment lining for simplifying the process, and other connecting methods such as welding or cast-in-place concrete joints may be adopted according to the needs and the scenes.

Example 2

As shown in fig. 3 and 4, on the basis of embodiment 1, the number of the steel shell structures 11 of the single-layer steel shell immersed tube for shield segment lining adopted by the invention is increased to two, and the steel shell structures are arranged side by side along the long axis direction of one steel shell structure 11; two steel shell structures 11 are connected through bracing piece 33 along 11 axis interval distribution of steel shell structure, and in order to guarantee the connection effect, 11 upper ends of steel shell structure, lower extreme all set up bracing piece 33.

A partition plate structure 55 is also arranged between two adjacent steel shell structures 11; for this embodiment, the partition structures 55 are plates parallel to the horizontal plane, the number of which is two, and the passage between two partition structures 55 serves as a service passage.

It should be noted that the embodiment includes two steel shell structures 11 corresponding to two lanes, and if the lanes have different requirements for installation space, the number of the steel shell structures 11 may be increased or decreased.

Example 3

As shown in fig. 1 to 4, on the basis of embodiments 1 to 2, a ventilation channel partition plate 11 is further arranged inside the steel shell structure 1;

for the present embodiment, the ventilation channel partition 11 is a horizontal plate disposed in the upper half of the steel shell structure 1, and is used for ventilation with the channel formed inside the steel shell structure 1.

Example 4

As shown in fig. 1 to 4, in addition to embodiments 1 to 3, the present invention further includes a road surface structure 6 as a traffic lane; the pavement structure 6 is connected to the shield segment 2 through a pavement upright post 7. Anti-collision piers 8 are further arranged at two ends of the pavement structure 6; a gap is arranged between the crash piers 8 and the pavement structure 6 for guiding water flow to enter below the pavement structure 6.

The embodiment is a specific scheme for installing the driveway in the single-layer steel shell immersed tube of the shield segment lining.

Example 5

As shown in fig. 1 to 4, the construction method of the single-layer steel shell immersed tube applied to the shield segment lining in any one of embodiments 1 to 4 adopted by the present invention includes the following steps:

s1, manufacturing a steel shell structure 1 of a single-layer steel shell immersed tube of a shield segment lining; when the single-layer steel shell immersed tube of the shield segment lining contains a plurality of oval steel shell structures 1, the support rod 3 and the partition plate structure 5 which are connected with the two adjacent steel shell structures 1 are also manufactured together, and the partition plate structure 5 and the groove formed by the steel shell structures 1 connected with the two sides of the partition plate structure can be directly used as a template of the external ballasting concrete structure 4, and the external ballasting concrete structure 4 can also be poured in the step to avoid underwater operation.

Other devices, such as a measuring tower, which need to be installed in the steel shell structure 1 during construction can be installed together in the step, or can be installed on site when needed.

S2, transporting the steel shell structure 1 to a tunnel site in a floating mode;

for the present embodiment, temporary sealing doors are installed at both ends of the steel shell structure 1 during the floating transportation so as to make the steel shell structure 1 float on the water.

S3, mooring and positioning the steel shell structure 1; after positioning, water is injected into the steel shell structure 1 to enable the steel shell structure to sink;

after the cable is transported to a designated place, positioning can be carried out by the aid of other equipment or vehicles, such as winching positioning by using anchor blocks and cables; for sinking, the present embodiment sinks the steel case structure 1 to a predetermined position by installing a water tank in the steel case structure 1 and injecting water into the water tank.

S4, repeating the steps S2-S3 until at least two sections of steel shell structures 1 are arranged underwater;

for the present embodiment, after the first section of steel shell structure 1 is sunk into water to be in place, the next steps are directly performed after each other section of steel shell structure 1 is sunk into water to reduce the waiting time.

S5, butting the steel shell structure 1 underwater;

for the embodiment, the two adjacent sections of the steel shell structures 1 are mutually pulled to be closed by mutually squeezing the waterproof belts on the end plates by adopting the pulling jack; after connecting the PC inhaul cables at the corresponding positions of the two adjacent sections of the steel shell structures 1, releasing the pressure of the pull-in jack and removing the pull-in jack; and finally, performing anticorrosive treatment on the PC inhaul cable to finish butt joint.

S6, backfilling a covering layer of the steel shell structure 1;

the backfilling of the covering layer can refer to the prior art, firstly, the two sides of the steel shell structure 1 are locked and backfilled to lock the position of the steel shell structure 1, and then, the bottom of the steel shell structure 1 is generally backfilled to enable the bottom of the steel shell structure 1 to be uniformly stressed; after the backfilling is generally completed, outfitting for installation of the steel shell structure 1 during transportation or positioning is removed, and the armor layer is backfilled to protect the steel shell structure 1 from the outside.

And to this embodiment, adopt fine sand as the backfill soil to make the backfill soil more laminate the outer wall of the shield segment lining's of this scheme individual layer steel shell immersed tube.

S7, draining the mutually connected steel shell structures 1;

s8, installing a shield segment 2 in the steel shell structure 1 and filling mortar between the shield segment 2 and the steel shell structure 1; and finishing the construction of the single-layer steel shell immersed tube of the shield segment lining.

And S8, finishing the inside of the single-layer steel shell immersed tube of the shield segment lining according to specific engineering requirements, and if the single-layer steel shell immersed tube of the shield segment lining needing to be communicated with a vehicle is provided with the pavement structure 6 and the pavement upright post 7, and the ventilation channel partition plate 11 is arranged on the steel shell immersed tube structure requiring ventilation.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalents and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A single-layer steel shell immersed tube of a shield segment lining comprises a steel shell structure (1), and is characterized in that the steel shell structure (1) is a single-layer shell; the section of the steel shell structure (1) is oval; the long axis of the ellipse is arranged along the horizontal direction; a shield segment (2) is arranged on the inner side of the steel shell structure (1); mortar is filled between the shield segment (2) and the steel shell structure (1).

2. The single-layer steel-shelled immersed tube for shield segment lining according to claim 1, wherein the number of the steel-shelled structure (1) is at least two; the steel shell structures (1) are arranged side by side; two adjacent steel shell structures (1) are connected through a support rod (3); the support rods (3) are axially distributed at intervals along the steel shell structure (1).

3. The single-layer steel shell immersed tube of the shield segment lining, according to claim 2, characterized in that a partition plate structure (5) is further connected between two adjacent steel shell structures (1); the partition plate structure (5) is equal to the steel shell structure (1) in length; the partition plate structures (5) are at least two and distributed at intervals along the height direction of the steel shell structure (1).

4. The single-layer steel-shell immersed tube of shield segment lining according to claim 3, characterized in that the upper surface of the uppermost partition plate structure (5) or the lower surface of the lowermost partition plate structure (5) is cast with an external ballasted concrete structure (4).

5. The single-layer steel shell immersed tube of shield segment lining according to any one of claims 1 to 4, characterized in that a PC inhaul cable is arranged on the end face of the steel shell structure (1); the PC inhaul cable is used for connecting two longitudinally adjacent steel shell structures (1).

6. The single-layer steel shell immersed tube of shield segment lining according to any one of claims 1 to 4, characterized in that the upper part of the steel shell structure (1) is provided with a ventilation channel clapboard (11); the length of the ventilation channel partition plate (11) is equal to that of the steel shell structure (1); and the ventilation channel partition plate (11) and a channel formed at the upper part of the corresponding steel shell structure (1) are used for ventilation.

7. The single-layer steel shell immersed tube of shield segment lining according to any one of claims 1 to 4, further comprising a pavement structure (6); the pavement structure (6) is connected with the shield segment (2) through a pavement upright post (7).

8. A construction method of a single-layer steel shell immersed tube of a shield segment lining is applied to the single-layer steel shell immersed tube of the shield segment lining in any one of claims 1 to 7, and is characterized by comprising the following steps:

A. sinking the steel shell structure (1) to a tunnel site;

B. draining the underwater steel shell structure (1); installing a shield segment (2) in the steel shell structure (1); and pouring mortar between the shield segment (2) and the steel shell structure (1).

9. The construction method of the single-layer steel-shelled immersed tube for shield segment lining according to claim 8, characterized in that when an external ballasted concrete structure (4) is arranged outside the steel-shelled structure (1), the external ballasted concrete structure (4) is cast before step A.

10. The method for constructing a single-layer steel shell immersed tube of a shield segment lining according to any one of claims 8 to 9, characterized in that fine sand backfill is adopted when backfilling the covering layer of the steel shell structure (1).

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