Highway tunnel expansion structure and construction method

Abstract

The application relates to the field of tunnel construction, and particularly discloses a highway tunnel expansion structure and a construction method, which comprises a tunnel lining on an old highway tunnel and further comprises: an upper traffic lane plate horizontally and fixedly arranged at the lower side of the edge of the tunnel lining; a plurality of pile columns supported at the lower side of the edge of the tunnel lining, a tunnel perimeter structure is cast between two adjacent pile columns, a lower traffic lane plate is horizontally arranged on the tunnel perimeter structure, and the lower traffic lane plate is located between the plurality of pile columns; and an expansion traffic space is formed between the pile columns, the upper traffic lane plate, the lower traffic lane plate and the tunnel perimeter structure. The tunnel lining on the original old highway tunnel in the scheme does not need to be newly built, compared with a newly-built tunnel, the tunnel lining, excavation and other operation steps and construction costs and the use of raw materials in the construction of the new tunnel can be effectively saved, the reconstruction can be quickly completed, and the reconstruction cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of tunnel structure design and construction technology, and in particular to the expansion structure and construction method of highway tunnels. Background Technology

[0002] With the rapid development of my country's highway transportation, the design and construction of early highway tunnels can no longer meet the needs of rapid traffic development, leading to frequent problems. The most significant issue is that the original design of older highway tunnels often featured single-lane dual carriageways with limited lanes. The designed traffic capacity of these lanes was significantly less than the actual traffic demand today, frequently resulting in congestion at highway tunnel locations. During peak hours, this can easily lead to traffic jams and accidents.

[0003] Therefore, it is necessary to renovate old highway tunnels. The renovation will generally adopt the following three schemes: (1) Reconstruct a single-bore two-way two-lane tunnel into a double-bore one-way two-lane tunnel; This is the simplest form of tunnel reconstruction and expansion operation. A new tunnel is built directly on the left or right side of the original tunnel at a certain distance.

[0004] (2) The double-bore single-direction two-lane tunnel is reconstructed into a double-bore single-direction four- or three-lane tunnel. This reconstruction method is relatively complicated and requires widening the existing tunnel. The widening methods are generally as follows: ① widening most of the left side of the original tunnel (for a single tunnel); ② widening most of the right side of the original tunnel; ③ the original tunnel is located in the middle of the widened section.

[0005] (3) The double-bore, one-way, two-lane tunnel will be converted into an eight-lane tunnel; there are two expansion methods: ① converting it into a double-bore, one-way, four-lane tunnel; ② converting it into a four-bore, one-way, two-lane tunnel.

[0006] All three options involve constructing new tunnels next to existing highway tunnels or expanding existing tunnels on the left and right sides. All three require rebuilding the tunnel lining and other structures. Widening the highway inside the tunnel significantly increases the vertical pressure on the mountain rock strata, making the structural design complex and subject to immense stress, resulting in a substantial increase in the manpower and material costs of highway tunnel reconstruction. Furthermore, horizontal widening or the construction of new highway tunnels is often hampered by limited surrounding geological space, making horizontal widening difficult. Even when there is sufficient space and terrain for widening, the long-term fixed residences and farmland of residents around the existing highway tunnels present challenges in terms of relocation and compensation, slowing down the highway tunnel reconstruction process and affecting the project's implementation. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the present invention provides a highway tunnel expansion structure and construction method to solve the problem that the manpower and material costs are too high when renovating old highway tunnels by building new tunnels.

[0008] To achieve the above objectives, the basic solution of the present invention is as follows: a highway tunnel expansion structure, including tunnel lining on an old highway tunnel, and further comprising:

[0009] The horizontal expansion and widening of the highway tunnel was changed to separate the upper and lower driving lanes to achieve the purpose of highway expansion.

[0010] A driving passage was excavated downwards beneath the old tunnel structure;

[0011] The old tunnel's driving lanes were converted into a bridge structure, and the piers adopted a pile-column structure to support the original tunnel structure during downward excavation; the horizontally set bridge pier cap beams can be used to resist the horizontal lateral pressure of the tunnel.

[0012] Several piles are supported on the lower side of the tunnel lining edge. A tunnel perimeter structure is poured between two adjacent piles. A lower driving lane slab is horizontally set on the tunnel perimeter structure. The lower driving lane slab is located between several piles. An extended driving space is formed between the piles, the upper driving lane slab, the lower driving lane slab and the tunnel perimeter structure.

[0013] The technical principle of this invention is as follows: the piles and the tunnel perimeter structure are stably supported at the extended driving space. Since the piles are stable on the lower side of the edge of the old tunnel lining, the extended driving space is located below the original old highway tunnel driving space. The lower driving lane slab and the extended driving space occupy less space, and have less impact on the surrounding environment, making it more practical to implement. At the same time, there is no need to occupy the land on the side of the old highway tunnel, and there is no need to solve the problem of demolition compensation difficulties, which can make the implementation of the renovation smoother and faster.

[0014] Meanwhile, since the extended driving space formed by the piles, upper driving lane slab, lower driving lane slab and the tunnel perimeter structure is located below the driving space of the original old highway tunnel, the tunnel lining on the original old highway tunnel does not need to be rebuilt. Compared with building a new tunnel, it can effectively save the operation steps, construction costs and raw materials used in the construction of new tunnels such as tunnel lining and excavation, and can quickly complete the transformation while reducing the transformation cost.

[0015] Furthermore, a horizontal beam is fixedly installed between the upper ends of the piles. The upper side of the beam abuts against the lower surface of the upper driving lane slab, and the axis of the beam intersects with the driving direction.

[0016] With the above configuration, the crossbeam can support the upper roadway slab and transfer its vertical load to the pile column. The pile column, together with the tunnel lining, provides stable support for the crossbeam and the upper roadway slab.

[0017] Furthermore, the piles are evenly arranged along the axis of the tunnel lining, and the piles on both sides of the tunnel lining correspond one-to-one, and the axis of the crossbeam is perpendicular to the direction of travel.

[0018] With the above setup, several piles can provide uniform support for the tunnel lining, and the crossbeams can also be evenly arranged on the lower surface of the upper roadway slab, so that the upper roadway slab can also receive uniform and stable support.

[0019] Furthermore, the upper carriageway slab includes a precast concrete slab and a cast-in-place treatment layer, with the cast-in-place treatment layer located on the precast concrete slab, and the precast concrete slab is fixedly connected to the crossbeams or tunnel lining.

[0020] With the above setup, precast concrete slabs can be quickly and directly installed onto the crossbeams on the construction site, enabling rapid construction of the upper driveway slab, shortening the construction cycle, and reducing labor costs. At the same time, the pouring treatment layer can reinforce and level the installation of the precast concrete slabs, making the final upper driveway slab more precise and stronger.

[0021] Furthermore, the upper driving lane slab is a cast-in-place reinforced concrete layer.

[0022] With the above-mentioned design, the cast-in-place reinforced concrete layer can be better adapted to the structure of old highway tunnels, and the cast-in-place reinforced concrete layer can be constructed in segments, thus enabling simultaneous construction of multiple segments, accelerating construction efficiency and shortening the construction cycle.

[0023] Furthermore, the piles are reinforced concrete columns.

[0024] With the above configuration, reinforced concrete columns have higher strength and support capacity than ordinary concrete columns, which can provide support for tunnel lining and prepare for safe stress resistance against lateral rock pressure during excavation to expand the driving space.

[0025] Furthermore, the upper driving lane is for passenger vehicles, and the lower driving lane is for commercial vehicles.

[0026] With the above configuration, the upper and lower driving lanes can separate passenger cars and commercial vehicles, allowing passenger cars to be diverted to the upper driving lane and commercial vehicles to be diverted to the lower driving lane. This can effectively reduce the traffic pressure and load on the upper driving lane, while reducing structural costs and improving the service life and safety of the upper driving lane slab.

[0027] This invention also aims to provide a construction method for highway tunnel expansion structures, including the highway tunnel expansion structure, and further includes the following steps:

[0028] Prepare for the installation of column and beam reinforcement, concrete, steel bars, and formwork for the tunnel perimeter structure pouring;

[0029] A column cavity is excavated on the lower side of the tunnel lining edge to accommodate the piles. The column cavities are excavated at intervals along the direction of traffic. After the column cavity reaches the design height, the installation column is installed in the column cavity. The beam reinforcement is welded to the top of the installation column. Then, concrete is poured into the column cavity and the beam reinforcement. After the installation column and the concrete solidify, a reinforced concrete column is formed, and the beam reinforcement and the concrete solidify to form a crossbeam.

[0030] After the reinforced concrete columns and beams are formed, the rock strata between the reinforced concrete columns and beams on the lower side of the tunnel lining are excavated; steel bars are tied on the rock strata between the reinforced concrete columns, and the tunnel perimeter structure casting formwork is installed at the steel bars. Concrete is poured between the rock strata and the tunnel perimeter structure casting formwork, and the tunnel perimeter structure is formed after the concrete solidifies.

[0031] The upper lane slab is laid on the crossbeam and is attached to the lower edge of the tunnel lining; the lower lane slab is laid horizontally between the tunnel perimeter structure and the side of the lower lane slab is attached to the lower end of the reinforced concrete column.

[0032] The technical principle of this invention is as follows: In the construction step of reinforced concrete columns, the column cavities are excavated at intervals along the driving direction, so that when the column cavities are excavated, other rock strata can still provide stable support for the tunnel lining; after this part of the reinforced concrete columns is formed, the column cavities between the reinforced concrete columns can be excavated again to improve the support strength for the tunnel lining; at the same time, the crossbeams can be constructed simultaneously in this step to prepare for the subsequent construction of the upper driving lane slab.

[0033] During the construction of the tunnel perimeter structure, after the mountain rock strata are excavated, the tunnel perimeter structure can be set up, which can prepare for the subsequent construction of the upper and lower roadway slabs.

[0034] Furthermore, when the upper driving lane slab is a precast concrete slab and a cast-in-place treatment layer, the precast concrete slab is transported into the tunnel and, assuming it is paved onto the crossbeams, concrete is used to fill the gaps between the precast concrete slabs to form the cast-in-place treatment layer; or when the upper driving lane slab is a cast-in-place reinforced concrete layer, the upper driving lane slab is constructed in segments, a cast-in-place reinforced concrete layer construction formwork is prepared, and steel bars are used to tie the cast-in-place reinforced concrete layer structure. The cast-in-place reinforced concrete layer construction formwork is wrapped around the steel bars, and concrete is poured into the cast-in-place reinforced concrete layer construction formwork. After the concrete solidifies, a segmented upper driving lane slab is formed. Several segmented upper driving lanes are assembled and solidified to form a segmented upper driving lane.

[0035] During construction, either precast concrete slabs or cast-in-place reinforced concrete layers can be selected according to usage requirements, and different construction methods will be adopted accordingly, all of which can achieve the goal of shortening the construction cycle of old highway tunnels.

[0036] Furthermore, several reinforced concrete columns can be constructed simultaneously or in batches at intervals.

[0037] With the above setup, the tunnel perimeter structure can be constructed in segments due to the phased construction of reinforced concrete columns and beams. This allows the construction steps of the tunnel perimeter structure to be staggered and carried out simultaneously with the construction steps of reinforced concrete columns and beams. At the same time, the construction of the lower and upper lane slabs can be carried out segmentally while the construction of a single tunnel perimeter structure is completed, which can significantly shorten the construction cycle of old highway tunnels. Attached Figure Description

[0038] Figure 1 This is a sectional view of the highway tunnel expansion structure in the main view direction in an embodiment of the present invention.

[0039] Figure 2 for Figure 1 Sectional view at point AA.

[0040] In the above attached diagram: tunnel lining 10, pile column 20, upper driving lane slab 30, crossbeam 301, lower driving lane slab 40, tunnel perimeter structure 50, and extended driving space 60. Detailed Implementation

[0041] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] This embodiment is basically as follows: Figure 1 and Figure 2 As shown, the present invention proposes a highway tunnel expansion structure, including a tunnel lining 10 on an old highway tunnel, an upper lane slab 30 horizontally fixed on the lower side of the edge of the tunnel lining 10, and a number of piles 20 supported on the lower side of the edge of the tunnel lining 10. The upper lane slab 30 is a cast-in-place reinforced concrete layer, and the piles 20 are reinforced concrete columns.

[0043] like Figure 1 As shown, a tunnel perimeter structure 50 is poured between two adjacent piles 20. The lower side of the tunnel perimeter structure 50 is a tunnel invert. A lower lane slab 40 is horizontally arranged on the tunnel invert. The lower lane slab 40 is located between the tunnel perimeter structure 50 and several piles 20. An extended driving space 60 is formed between the piles 20, the upper lane slab 30, the lower lane slab 40 and the tunnel perimeter structure 50.

[0044] like Figure 1 and Figure 2 As shown, the piles 20 are evenly arranged along the axis of the tunnel lining 10, and the piles 20 on both sides of the tunnel lining 10 correspond one to one. A horizontal beam 301 is welded between the upper ends of the piles 20. The upper side of the beam 301 abuts against the lower surface of the upper driving lane slab 30, and the axis of the beam 301 is perpendicular to the driving direction.

[0045] In addition, the upper driving lane slab 30 is a passenger vehicle driving lane slab, and the lower driving lane slab 40 is a commercial vehicle driving lane slab; the upper driving lane slab 30 includes a precast concrete slab and a pouring treatment layer, the pouring treatment layer is located on the precast concrete slab, and the precast concrete slab is fixedly connected to the crossbeam 301 or the tunnel lining 10.

[0046] The highway tunnel expansion structure in this embodiment is constructed using a construction method for highway tunnel expansion structures, including the highway tunnel expansion structure in this embodiment, and also includes the following steps:

[0047] Prepare to install column and beam reinforcement, concrete, steel bars, beam formwork, and 50mm pouring formwork for the tunnel perimeter structure;

[0048] A column cavity to accommodate the piles 20 is excavated on the lower side of the edge of the tunnel lining 10. The column cavities are excavated at intervals along the direction of traffic, or they can be excavated in batches according to the total number of column cavities, with 3-5 column cavities excavated in each batch. After the column cavity reaches the design height, the reinforcing steel of the installation column is installed in the column cavity. The beam reinforcing steel is welded to the top of the installation column. The crossbeam formwork is installed at the beam reinforcing steel. Then, concrete is poured into the column cavity and the crossbeam formwork. After the installation column and the concrete solidify, a reinforced concrete column is formed, and after the concrete at the beam reinforcing steel and the crossbeam formwork solidifies, a crossbeam 301 is formed. In this step, several reinforced concrete columns are constructed in batches at intervals.

[0049] After the reinforced concrete columns and beams 301 are formed, the rock strata between the reinforced concrete columns and beams 301 and the lower side of the tunnel lining 10 are excavated. Reinforcing bars are tied to the rock strata between the reinforced concrete columns, and the reinforcing bars are bundled to form the outline of the tunnel perimeter structure 50. Then, the casting template of the tunnel perimeter structure 50 is installed at the reinforcing bars, and concrete is poured between the rock strata and the casting template of the tunnel perimeter structure 50. After the concrete solidifies, the tunnel perimeter structure 50 is formed. In this step, the rock strata between the reinforced concrete columns and beams 301 and the lower side of the tunnel lining 10 are also excavated in a segmented manner. Excavation is carried out simultaneously from each segment along the axis of the tunnel lining 10 to the middle of the axis of the tunnel lining 10. The ends of multiple tunnel perimeter structures 50 are spliced ​​together at the middle node of the tunnel lining 10.

[0050] The lower carriageway slab 40 is laid horizontally onto the tunnel invert, with its side edge adhering to the lower end of the reinforced concrete column. The upper carriageway slab 30 is laid onto the crossbeam 301 and adhering to the lower edge of the tunnel lining 10. When the upper carriageway slab 30 uses precast concrete slabs and a cast-in-place treatment layer, the precast concrete slabs are transported into the tunnel and laid onto the crossbeam 301. Concrete is used to fill the gaps between the precast concrete slabs to form a cast-in-place treatment layer. When the upper carriageway slab 30 uses a cast-in-place reinforced concrete layer, the upper carriageway slab 30 is constructed in segments, assuming... Prepare formwork for the cast-in-place reinforced concrete layer construction. Use steel bars to tie and form the cast-in-place reinforced concrete layer structure. Wrap the formwork around the steel bars. Pour concrete into the formwork. After the concrete solidifies, it forms a segmented upper driving lane slab 30. Several segments of the upper driving lane are assembled and solidified to form a segmented upper driving lane. The construction of the lower driving lane slab 40 and the upper driving lane slab 30 in this step can be carried out immediately after the construction of the corresponding segments of the tunnel perimeter structure 50 is completed, so that this step can be carried out synchronously with the overall construction steps of the tunnel perimeter structure 50.

[0051] In the construction steps of reinforced concrete columns and beams 301, the column cavities can be excavated in batches, minimizing the impact on the support strength of the existing old highway tunnel lining 10. After the excavation of a single column cavity is completed, the column and concrete are installed and filled immediately, which facilitates the rapid solidification of the reinforced concrete column and provides rapid support and reinforcement to the lower side of the tunnel lining 10. The construction of beams 301 is completed simultaneously with the construction of reinforced concrete columns, which facilitates the rapid construction of the upper carriageway slab 30 in subsequent steps, making the connection between each construction step compact.

[0052] During the construction of the tunnel perimeter structure 50, influenced by the phased construction of reinforced concrete columns and beams 301, the tunnel perimeter structure 50 can be constructed in segments. This allows the construction steps of the tunnel perimeter structure 50 to be staggered and carried out simultaneously with the construction steps of reinforced concrete columns and beams 301. At the same time, while completing the construction of a single segment of the tunnel perimeter structure 50, the construction of the lower lane slab 40 and the upper lane slab 30 can be carried out segmentally, which can significantly shorten the construction cycle of old highway tunnels. Meanwhile, the sidewalls of the excavated mountain rock strata can also be promptly supported and sealed by the tunnel perimeter structure 50 and reinforced concrete columns, creating excellent conditions for the construction of the lower lane slab 40.

[0053] Compared to constructing new tunnels next to old highway tunnels or expanding existing tunnels on the left and right sides, the above construction methods reduce the cost of tunnel renovation per kilometer by about 55%; at the same time, the construction period is shortened by more than 70%, which can quickly complete the renovation while reducing the renovation cost, and has the value of widespread application.

[0054] When the renovated highway tunnel opens to traffic, the diversion lanes connecting to the highway at the tunnel's entrance and exit will separate passenger cars from commercial vehicles. These diversion lanes will connect to the upper driving lane slab 30 and the lower driving lane slab 40, respectively. This will allow passenger cars to be diverted to the upper driving lane slab 30 and commercial vehicles to be diverted to the lower driving lane slab 40, effectively reducing traffic pressure on the upper driving lane slab 30 and improving its service life and safety.

[0055] During the renovation of the entire highway tunnel, there is no need to occupy the land on the side of the old highway tunnel, thus avoiding the problem of demolition and compensation difficulties, which makes the renovation implementation smoother and faster. At the same time, after the highway tunnel is renovated, the lower driving lane slab 40 and the extended driving space 60 occupy less space and have less impact on the surrounding environment, making it more practical to implement.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A highway tunnel expansion structure, including tunnel lining for old highway tunnels, characterized in that, Also includes: The upper driving lane slab is horizontally fixed and installed on the lower side of the tunnel lining edge; A number of piles are supported on the lower side of the tunnel lining edge. A tunnel perimeter structure is cast between two adjacent piles. A lower driving lane slab is horizontally arranged on the tunnel perimeter structure. The lower driving lane slab is located between the piles. An extended driving space is formed between the piles, the upper driving lane slab, the lower driving lane slab and the tunnel perimeter structure. The piles are evenly arranged along the axis of the tunnel lining, and the piles on both sides of the tunnel lining correspond one to one. A horizontal beam is welded between the upper ends of the piles. The upper side of the beam abuts against the lower surface of the upper carriageway slab, and the axis of the beam is perpendicular to the direction of travel. The upper carriageway slab includes a precast concrete slab and a cast-in-place treatment layer. The cast-in-place treatment layer is located on the precast concrete slab, and the precast concrete slab is fixedly connected to the crossbeams or tunnel lining.

2. The highway tunnel expansion structure as described in claim 1, characterized in that, The upper side of the crossbeam abuts against the lower surface of the upper driving lane slab, and the axis of the crossbeam intersects with the driving direction.

3. The highway tunnel expansion structure as described in claim 2, characterized in that, The upper driving lane slab is a cast-in-place reinforced concrete layer.

4. The highway tunnel expansion structure as described in claim 3, characterized in that, The piles are reinforced concrete columns.

5. The highway tunnel expansion structure as described in claim 4, characterized in that, The upper driving lane is for passenger vehicles, and the lower driving lane is for commercial vehicles.

6. A construction method for the expansion structure of a highway tunnel, characterized in that, Including the highway tunnel expansion structure as described in claim 5, the method further includes the following steps: Prepare for the installation of column and beam reinforcement, concrete, steel bars, and formwork for the tunnel perimeter structure pouring; A column cavity is excavated on the lower side of the tunnel lining edge to accommodate the piles. The column cavities are excavated at intervals along the direction of traffic. After the column cavity reaches the design height, the installation column is installed in the column cavity. The beam reinforcement is welded to the top of the installation column. Then, concrete is poured into the column cavity and the beam reinforcement. After the installation column and the concrete solidify, a reinforced concrete column is formed, and the beam reinforcement and the concrete solidify to form a crossbeam. After the reinforced concrete columns and beams are formed, the rock strata between the reinforced concrete columns and beams on the lower side of the tunnel lining are excavated; steel bars are tied on the rock strata between the reinforced concrete columns, and the tunnel perimeter structure casting formwork is installed at the steel bars. Concrete is poured between the rock strata and the tunnel perimeter structure casting formwork, and the tunnel perimeter structure is formed after the concrete solidifies. The upper lane slab is laid on the crossbeam and is attached to the lower edge of the tunnel lining; the lower lane slab is laid horizontally between the tunnel perimeter structure and the side of the lower lane slab is attached to the lower end of the reinforced concrete column.

7. The construction method for the highway tunnel expansion structure as described in claim 6, characterized in that, When the upper driving lane slab is a precast concrete slab and a pouring treatment layer, the precast concrete slab is transported into the tunnel and laid on the crossbeams. Concrete is used to fill the gaps between the precast concrete slabs to form the pouring treatment layer. Alternatively, when the upper driving lane slab is a cast-in-place reinforced concrete layer, the upper driving lane slab is constructed in segments. A formwork for the cast-in-place reinforced concrete layer is prepared, and steel bars are used to tie the cast-in-place reinforced concrete layer structure. The formwork for the cast-in-place reinforced concrete layer is wrapped around the steel bars, and concrete is poured into the formwork for the cast-in-place reinforced concrete layer. After the concrete solidifies, a segmented upper driving lane slab is formed. Several segments of the upper driving lane are assembled and solidified to form a segmented upper driving lane.

8. The construction method for the highway tunnel expansion structure as described in claim 7, characterized in that, Several of the aforementioned reinforced concrete columns may be constructed simultaneously or in batches at intervals.

Images