CN-121993232-A - Tunnel lining reinforcing structure combined by steel arch frame and UHPC-RC and construction method

CN121993232ACN 121993232 ACN121993232 ACN 121993232ACN-121993232-A

Abstract

The invention relates to a tunnel lining reinforcing structure of a steel arch-UHPC-RC combination, which comprises a plurality of steel arches, a UHPC permanent bottom die and an RC reinforcing layer which are longitudinally distributed along a tunnel, wherein the steel arches comprise I-shaped steel beam sections, the UHPC permanent bottom die comprises UHPC section plates, the RC reinforcing layer comprises a reinforcement cage which is formed by binding and welding reinforcement cages, post-cast concrete is poured above the UHPC permanent bottom die during assembly, the RC reinforcing layer, the steel arches, the UHPC permanent bottom die and the existing lining layer after pouring jointly form a stressed whole.

Inventors

CHEN ZHIQING
SU JIAZHAN
YANG HONGHONG
DENG TAO
WANG YUCHEN
LIU XIAOFENG

Assignees

福建省高速路桥建设发展有限公司
福州大学

Dates

Publication Date: 20260508
Application Date: 20260209

Claims (10)

1. The tunnel lining reinforcing structure of the steel arch-UHPC-RC combination is characterized by comprising a plurality of steel arches (1), UHPC permanent bottom dies (2) and RC reinforcing layers (3) which are longitudinally distributed along the existing lining layer of a tunnel, wherein the steel arches (1) comprise a plurality of I-shaped steel beam sections, and the steel beam sections are connected through connecting pieces to form the steel arches (1) matched with the curvature of the existing lining layer of the tunnel; The UHPC permanent bottom die (2) is erected on the inner sides of two adjacent steel arches (1) in front and back, the UHPC permanent bottom die (2) comprises a plurality of UHPC segment flat plates (21), and the two adjacent UHPC segment flat plates (21) are connected through a flexible piece; the RC reinforcement layer (3) is attached to the outer side of an existing lining layer and is arranged above the UHPC permanent bottom die (2), the RC reinforcement layer (3) comprises a reinforcement cage formed by binding and welding a plurality of reinforcement cages (32), during assembly, post-cast concrete (31) is poured above the UHPC permanent bottom die (2), and the RC reinforcement layer (3), the steel arch (1), the UHPC permanent bottom die (2) and the existing lining layer after pouring form a stressed whole together.
2. A steel arch-UHPC-RC combined tunnel lining reinforcing structure according to claim 1, characterized in that the steel girder segments comprise one steel arch dome segment (11) at the top and two steel arch waisted segments (12) at the bottom.
3. A tunnel lining reinforcing structure of a steel arch-UHPC-RC combination according to claim 2, characterized in that the connection piece comprises a steel plate (16) with mounting holes and bolts (17) for connection; screw holes for matching are formed in the steel arch crown section (11) and the steel arch waist section (12); during assembly, a steel plate (16) is sleeved at the junction of the steel arch crown section (11) and the steel arch waist section (12), the bolts (17) are screwed into the steel plate (16) and are fixed on the other side by matching with nuts, and the steel plate (16) is welded at the junction after the bolts are fixed.
4. A tunnel lining reinforcing structure of a steel arch-UHPC-RC combination according to claim 3, characterized in that the steel arch dome section (11) comprises a steel arch upper flange plate (14) at the upper end, a steel arch lower flange plate (15) at the lower end and a steel arch web (13) for connection; The steel arch waisted section (12) also comprises a steel arch upper flange plate (14) arranged at the upper end, a steel arch lower flange plate (15) arranged at the lower end and a steel arch web (13) for connection; the steel arch upper flange plate (14) of the steel arch vault section (11) and the steel arch upper flange plate (14) of the steel arch loin section (12) are clamped by an upper steel plate (16) and a lower steel plate (16) and are matched and fixed with a screw cap by bolts (17); the steel arch lower flange plate (15) of the steel arch vault section (11) and the steel arch lower flange plate (15) of the steel arch loin section (12) are clamped by an upper steel plate (16) and a lower steel plate (16) and are matched and fixed with a screw cap by bolts (17); The steel arch web (13) of the steel arch vault section (11) and the steel arch web (13) of the steel arch waist section (12) are clamped by a front steel plate (16) and a rear steel plate (16), and are matched and fixed with a screw cap by bolts (17).
5. A steel arch-UHPC-RC combined tunnel lining reinforcing structure according to claim 4, characterized in that the steel arch crown sections (11) and steel arch waisted sections (12) are welded with a number of studs (18) at the steel arch web (13), which studs (18) are welded to the side close to the RC reinforcing layer (3).
6. The tunnel lining reinforcing structure of a steel arch-UHPC-RC combination according to claim 5, wherein jack bases (4) are provided at bottoms of both sides of the steel arch (1), jacks are detachably mounted on the jack bases (4), and after the steel arch crown sections (11) and the steel arch waist sections (12) are assembled, the steel arch (1) is provided with axial pressure by applying jack loads.
7. A tunnel lining reinforcing structure of a steel arch-UHPC-RC combination according to claim 6, characterized in that the top surface of the steel arch lower flange plate (15) is welded with reinforcing bars (19); The UHPC segment flat plates (21) are provided with arc-shaped notches (25) towards the bottoms of the front and rear adjacent steel arches (1), and the arc-shaped notches (25) on two sides are respectively clamped into the corresponding steel reinforcement bars (19) after being assembled; and a plurality of UHPC segment flat plates (21) are directly fixed on the steel arch (1) through straight bolts (26).
8. A tunnel lining reinforcing structure of steel arch-UHPC-RC combination according to claim 7, characterized in that the flexible members (22) for connecting adjacent UHPC segment slabs (21) are carbon fibre cloth.
9. The tunnel lining reinforcing structure of the steel arch-UHPC-RC combination according to claim 8, wherein the inside of the UHPC segment flat plate (21) is embedded with stress steel bars (23) arranged along the long side direction thereof and a '冂' shaped connecting steel bar (24) embedded in the UHPC permanent bottom die (2) and protruding upwards; A transverse steel bar (27) for reinforcement is arranged below the connecting steel bar (24), the transverse steel bar (27) is also embedded into the UHPC permanent bottom die (2), and the transverse steel bar (27) is perpendicular to the stress steel bar (23); the connecting steel bars (24) are hooked at the bottoms of a plurality of hooking bars (34) at the bottom of the steel reinforcement cage (32); The reinforcement cage (32) is arranged in the RC reinforcement layer (3) and is hung on the planted bars (33) at the bottom of the existing lining layer.
10. A construction method of a tunnel lining reinforcing structure combined by a steel arch and UHPC-RC is characterized by comprising the following steps: step S1, removing the inner surface which is possibly fallen off from the existing lining layer of the tunnel to be reinforced, and performing roughening and bar planting treatment; S2, prefabricating a steel arch crown section and a steel arch waist section of a steel arch according to the shape of an existing lining layer ring inner curve of a tunnel to be reinforced, welding studs at steel arch webs of the steel arch crown section and the steel arch waist section of the steel arch, and welding steel ribs on the top surface of a lower flange plate of the steel arch to strengthen the interface bearing capacity between the steel arch and post-cast concrete; Step S3, arranging jack pedestals at bottoms of the steel arch waisted sections at two sides, placing the steel arch waisted sections on the jack pedestals, assembling steel plates at junctions of the steel arch crown sections and the steel arch waisted sections, screwing nuts through bolts for fixation, and welding the steel plates at the junctions to realize connection of the steel arch crown sections and the steel arch waisted sections; s4, applying jack load to enable the steel arches to have certain axial pressure, so that the bearing capacity of the existing lining layer of the tunnel after reinforcement is enhanced, pouring concrete to a jack pedestal after the jack load is applied, and removing the jacks after the concrete reaches the designed target strength, so that a plurality of steel arches distributed longitudinally along the tunnel are formed; S5, dividing the manufacturing width of the UHPC section flat plate in a bending way according to the shape of the inner curve of the existing lining layer of the tunnel to be reinforced, and in the process of manufacturing the UHPC section flat plate, embedding flexible material carbon fiber cloth, stress steel bars, connecting steel bars and transverse steel bars into dies of adjacent UHPC section flat plates, wherein the dies comprise a steel bottom die and steel side dies arranged on two sides of the steel bottom die, and the steel bottom die is provided with a bulge matched with an arc-shaped notch of the UHPC section flat plate; S6, manufacturing a reinforcement cage with a corresponding size according to the thickness to be reinforced, binding and welding a plurality of reinforcement cages to form a reinforcement cage, hanging the reinforcement cage on the embedded bars on the lower surface of the existing lining layer, and hanging a plurality of hooking bars at the bottom of the reinforcement cage; S7, placing the UHPC segment flat plate into a lower flange plate of the steel arch from bottom to top, hooking the hooking ribs at the bottom of the reinforcement cage with the connecting reinforcements on the exposed surface of the top of the UHPC segment flat plate, and directly locking the UHPC segment flat plate at a plurality of positions on the steel arch through straight bolts; And S8, setting a temporary opening at the vault position of the steel arch frame by taking the UHPC permanent bottom die as the bottom, and pouring concrete after pouring, so that the steel arch frame, the UHPC permanent bottom die, the RC reinforcing layer and the existing lining layer are connected into a common stressed whole, and reinforcing the existing lining layer of the tunnel is realized.

Description

Tunnel lining reinforcing structure combined by steel arch frame and UHPC-RC and construction method Technical Field The invention relates to the technical field of tunnel construction, in particular to a tunnel lining reinforcing structure combined by a steel arch frame and UHPC-RC and a construction method. Background As a typical disease, concrete cracking not only weakens the bearing performance of the structure, but also can cause derivative problems such as water seepage and the like. Engineering practice shows that tunnel lining diseases mainly comprise crack damage, leakage, freeze thawing damage, chemical erosion and the like, wherein the influence of crack deformation on structural safety is particularly remarkable. Aiming at tunnel lining reinforcement, three technical schemes are mainly adopted, namely a steel plate reinforcement method, a steel plate is fixed on the inner side of a duct piece by using an adhesive, the structural rigidity can be improved, but the defects of complex process and poor economy exist, a sleeve arch reinforcement technology is mainly adopted, a concrete or steel-concrete combined structure is mainly adopted, the cost advantage is realized, the tunnel use space can be reduced, and a fiber cloth reinforcement method is adopted, and the composite material is adhered to a tension area for local reinforcement, so that the improvement effect on the whole bearing capacity is not obvious. It is worth noting that the reinforcement processes are all required to interrupt traffic during construction, and the normal operation of the tunnel is greatly influenced. Therefore, in order to solve the problems, the invention provides a tunnel lining reinforcing structure combined by a steel arch and UHPC-RC and a construction method. Disclosure of Invention (1) Technical problem to be solved The invention aims to provide a tunnel lining reinforcing structure combining a steel arch with UHPC-RC. The invention further aims to provide a construction method of the tunnel lining reinforcing structure combined by the steel arch and the UHPC-RC. In view of the defects of the prior art, the invention provides a tunnel lining reinforcing structure of a steel arch-UHPC-RC combination, which has reasonable structural design, fully utilizes the stress advantage of the steel arch, makes the steel arch have certain axial pressure by applying jack load, thereby enhancing the bearing capacity of the reinforced existing lining layer of the tunnel, simultaneously utilizes the characteristics of high strength, high durability, high toughness and the like of UHPC (ultra-high performance concrete), and takes a UHPC permanent bottom die formed by connecting UHPC segment flat plates with flexible materials such as carbon fiber cloth and the like as a permanent template of post-pouring concrete, thereby avoiding the traditional formwork supporting procedure, furthest reducing the influence on driving in the tunnel and having remarkable engineering application value. (2) Technical proposal In order to solve the above technical problem, a first aspect of the present invention provides: The tunnel lining reinforcing structure comprises a plurality of steel arches, a UHPC permanent bottom die and an RC reinforcing layer, wherein the steel arches, the UHPC permanent bottom die and the RC reinforcing layer are longitudinally distributed along the existing lining layer of a tunnel, the steel arches comprise a plurality of I-shaped steel girder sections, and the steel girder sections are connected through connecting pieces to form the steel arches matched with the curvature of the existing lining layer of the tunnel; The UHPC permanent bottom die is erected on the inner sides of two adjacent steel arches in front and back, and comprises a plurality of UHPC segment flat plates, and the two adjacent UHPC segment flat plates are connected through a flexible piece; the RC reinforcement layer is attached to the outer side of the existing lining layer and is arranged above the UHPC permanent bottom die, the RC reinforcement layer comprises a steel reinforcement framework formed by binding and welding a plurality of steel reinforcement cages, post-cast concrete is poured above the UHPC permanent bottom die during assembly, and the poured RC reinforcement layer, the steel arch, the UHPC permanent bottom die and the existing lining layer form a stressed whole together. Preferably, the steel beam section comprises one steel arch dome section at the top and two steel arch waisted sections at the bottom. Preferably, the RC reinforcement layer is a reinforced concrete reinforcement layer. Preferably, the hooking ribs are arranged in a double-hook mode, the hooking end on the upper side is hooked with the steel reinforcement framework, and the hooking end on the lower side is hooked with the connecting steel reinforcement. Preferably, the connecting member includes a steel plate with a mounting hole and a bolt for connection; screw