A construction method for installing an extra-long horizontal storage tank in a mountain circular tunnel

Abstract

The present invention provides a construction method for installing an extra-long horizontal storage tank in a circular mountain tunnel, comprising the following steps: Step 1: excavating and initially supporting the circular mountain tunnel, then constructing a secondary lining inverted arch surface within the tunnel. The inverted arch surface is constructed in predetermined segments, with its longitudinal highest point located below the tunnel centerline, and pre-embedded track fixing components and grouting pipes; Step 2: after the concrete of the secondary lining inverted arch surface reaches the design strength index, the arc-shaped surface of the inner side surface is roughened to strengthen the bonding strength of the contact surface between the new and old concrete; at the same time, a slide rail is provided in the middle of the secondary lining inverted arch wall; Step 3: dividing the storage tank into several segments, ensuring that the tail of each segment extends at least 1 meter beyond the corresponding secondary lining inverted arch segment. The method of the present invention not only solves the technical difficulties of installing extra-long horizontal storage tanks in circular mountain tunnels, but also achieves significant improvements in construction efficiency, safety, structural performance, and other aspects.

Description

Technical Field

[0001] The present invention relates to the technical field of building engineering construction, and in particular to a construction method for installing an extra-long horizontal storage tank in a circular tunnel in a mountain. Background Art

[0002] Storage tanks in mountain tunnels rely on the mountain for pressure, requiring reliable transfer of internal pressure to the mountain. The concrete lining between the tanks and the mountain must be uniform and reliable. However, the tanks' extreme length and width make entry into the tunnel difficult due to the limited space available. Once inside, the narrow working surface between the tanks and the mountain makes concrete placement difficult. Furthermore, the tanks' length makes concrete transportation difficult, the long pouring distance, and vibration challenging, making it prone to incomplete pouring and insufficient vibration. For example, a storage tank section in one project is 45 meters long and 5,600 mm in diameter. Construction involved a primary support layer: a 100 mm thick circular UHPC shotcrete ring; a secondary lining: a 700 mm thick circular UHPC reinforced concrete ring; and a 45 meter long, 4,000 mm diameter steel tank. As the distance between the storage tank and the initial support is only 700mm and the length is 45m, the conventional method of pouring the secondary lining layer after the storage tank is put in as a whole needs to be adopted. The horizontal passage needs to be laid in advance, and the circular opening needs to be changed to a circular arch. The overall length of the tunnel is 45m, and it is difficult to ensure the pouring density when pouring concrete over a long distance. In addition, the construction space is only 700mm, which is difficult to use for concrete construction. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies of the prior art and provide a construction method for installing an extra-long horizontal storage tank in a circular mountain tunnel.

[0004] The specific technical solutions are as follows:

[0005] A construction method for installing an extra-long horizontal storage tank in a circular mountain tunnel comprises the following steps:

[0006] Step 1: Excavate and initially support the mountain circular tunnel, then construct a secondary lining inverted arch surface inside the tunnel. The inverted arch surface is constructed in predetermined sections, with its longitudinal highest point located below the tunnel centerline. During the construction process, track fixing components and grouting pipes are pre-buried;

[0007] Step 2: After the secondary lining inverted arch concrete reaches the design strength index, the arc-shaped surface of the inner side is roughened to strengthen the bonding strength of the contact surface between the new and old concrete; at the same time, a slide rail is installed in the middle of the secondary lining inverted arch wall;

[0008] Step 3: Design and manufacture the tank, dividing it into several segments. Ensure that the tail of each segment extends at least 1 meter beyond the corresponding secondary lining arch section to serve as the welding preparation area for adjacent segments. Install a flotation stop and a sliding support device in the center of the tank's exterior.

[0009] Step 4: Use a trackless ground-level mobile vehicle to load the tank segment, and use the hydraulic crawler and hydraulic jack provided on the inverted arch surface of the secondary lining to push the tank to the predetermined position;

[0010] Step 4: After the initial positioning of the tank segment is completed, use the jack to lift the anti-floating device, remove the sliding support device, and place the tank segment securely on the inverted arch surface; then remove all temporary auxiliary facilities and lock the tank segment;

[0011] Step 5: Use steel formwork to cover the top gap between the tank segment and the primary support, and pour concrete in this area. Once the concrete has hardened to the required level, inject pressurized cement slurry through pre-installed grouting pipes to seal the gap between the tank and the lining.

[0012] Step 6. Repeat steps 3 to 5 until all tank segments are installed to form a complete and coherent extra-long horizontal storage tank.

[0013] Optionally, the segmented construction of the secondary lining is carried out synchronously and staggered with the installation of the tank segments to provide necessary concrete pouring operation space and ensure the quality of concrete pouring and the density of the structure.

[0014] Optionally, self-compacting high-strength grouting material can be used to fill the gaps between the top arch and the primary support, and between the tank and the secondary lining.

[0015] Optionally, the trackless ground moving vehicle is equipped with an arc-shaped support for supporting the tank segments.

[0016] Optionally, the segment length of the storage tank segment is designed to be 8-12 meters to facilitate flexible transportation and installation in the tunnel.

[0017] Optionally, the anti-floating device includes an anti-floating plate, and the anti-floating plate is located on the upper part of the inverted arch wall of the secondary lining.

[0018] Optionally, the sliding support device includes a sliding shoe, the bottom of which is equipped with a roller, and the roller is slidably connected to the sliding rail.

[0019] Optionally, at least two sets of anti-floating devices and sliding support devices are provided in the upper county of each section of the storage tank.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention divides the storage tank into several small sections that are easy to transport and install, and combines this with the segmented construction strategy of the tunnel secondary lining. This ensures the transportation flexibility of the storage tank, simplifies the on-site installation process, and improves construction efficiency and safety. Furthermore, by utilizing anti-floating devices, sliding support devices, and pre-buried tracks on the tunnel invert surface, a multi-level support and guidance mechanism is formed, effectively controlling the movement trajectory of the storage tank and ensuring the stability and accuracy of the tank during installation. Furthermore, by roughening the secondary lining invert surface, the adhesion between the new and old concrete is enhanced, improving the integrity of the structure. Simultaneously, a high-pressure grouting process is used to fill the gap between the storage tank and the lining, which not only enhances the sealing performance but also compensates for minor errors during construction, ensuring the long-term stability and waterproof performance of the storage tank. The use of modern mechanical equipment such as trackless ground-moving vehicles, hydraulic crawlers, and jacks greatly reduces the labor burden, improves the level of construction automation, shortens the construction period, and reduces construction risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the inverted arch operation in the cave of the present invention;

[0023] Figure 2 This is a schematic diagram of the in-hole storage tank section in place according to the present invention;

[0024] Figure 3 This is the completed construction drawing of the initial storage tank in the cave of the present invention;

[0025] Figure 4 This is a schematic diagram of the construction operation of adjacent sections of storage tanks in a cave according to the present invention;

[0026] Figure 5 This is a schematic diagram of the welding space of adjacent storage tanks in the cave of the present invention.

[0027] In the figure: 1. Tunnel; 2. Inverted arch surface; 3. Slide rail; 4. Storage tank; 5. Anti-floating device; 6. Sliding support device; 7. Trackless ground moving vehicle; 8. Hydraulic crawler; 9. Hydraulic jack; 10. Arc support; 11. Top arch surface. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0031] The construction method for installing an ultra-long horizontal storage tank in a mountain circular tunnel provided in the present invention is as follows: Figure 1-Figure 5 , including the following steps:

[0032] Step 1: Excavate and initially support the mountain circular tunnel 1, then construct the secondary lining inverted arch surface 2 inside the tunnel 1. The inverted arch surface 2 is constructed in sections with a horizontal length of 6-10m, with its highest point located 300mm below the centerline of the tunnel 1 (to facilitate the placement of the storage tank 4). During the construction process, track fixing components and grouting pipes are pre-buried;

[0033] Step 2: After the concrete of the secondary lining inverted arch surface 2 reaches the design strength index, the arc surface of its inner side is roughened to a depth of ≥50mm to ensure the thickness of the concrete protective layer and strengthen the bonding strength of the contact surface between the new and old concrete; at the same time, a slide rail 3 (43Kg steel rail is intended to be used) is installed in the middle of the secondary lining inverted arch wall;

[0034] Step 3: Design and manufacture the storage tank 4, dividing it into several segments, ensuring that the tail of each segment extends at least 1 meter beyond the corresponding secondary lining arch section to serve as a welding preparation area for adjacent segments; install an anti-floating device 5 and a sliding support device 6 in the central part of the exterior of the storage tank 4;

[0035] Step 4: Use a trackless ground-level mobile vehicle 7 to load the storage tank 4 segment, and use the hydraulic crawler 8 and hydraulic jack 9 provided on the inverted arch surface 2 of the secondary lining to push the storage tank 4 to the predetermined position;

[0036] Step 4: After the initial positioning of the tank 4 segments is completed, the anti-floating device 5 is raised with the help of four jacks, and the sliding support device 6 is removed, so that the tank 4 segments are securely placed on the inverted arch surface 2; then all temporary auxiliary facilities are removed and the tank 4 segments are locked;

[0037] Step 5: Use steel formwork to cover the arch space between the storage tank 4 segment and the initial support and reserve a grouting pipe on the arch surface 11. Carry out concrete pouring in this area. After the concrete hardens to the required level, inject pressurized cement slurry through the pre-installed grouting pipe to seal the gap between the storage tank 4 and the lining.

[0038] Step 6: Repeat steps 3 to 5 until all the sections of the storage tank 4 are installed to form a complete and coherent extra-long horizontal storage tank 4.

[0039] This method divides the storage tank 4 into several small, easily transportable and installable segments, combined with the segmented construction strategy of the tunnel 1 secondary lining. This ensures the transport flexibility of the storage tank 4, simplifies the on-site installation process, and improves construction efficiency and safety. Furthermore, utilizing the anti-floating device 5, the sliding support device 6, and the pre-embedded track on the tunnel 1 invert surface 2, a multi-level support and guidance mechanism is formed, effectively controlling the movement trajectory of the storage tank 4 and ensuring its stability and precision during installation. Furthermore, by roughening the secondary lining invert surface 2, the bond between the new and old concrete is enhanced, improving the structural integrity. Simultaneously, high-pressure grouting is used to fill the gap between the storage tank 4 and the lining, which not only enhances the sealing performance but also compensates for minor errors during construction, ensuring the long-term stability and waterproof performance of the storage tank 4. The use of modern mechanical equipment such as a trackless ground-level mobile vehicle 7, a hydraulic crawler 8, and a jack significantly reduces the labor burden, improves the level of construction automation, shortens the construction period, and reduces construction risks. Therefore, the method of the present invention not only solves the technical problem of installing an extra-long horizontal storage tank 4 in a mountain circular tunnel 1, but also achieves significant progress in construction efficiency, safety, structural performance, etc.

[0040] In step 4, refer to Figure 2 The trackless ground-moving vehicle 7 uses a trackless platform, which has a strong load-bearing capacity and maneuverability, adapting to the non-standard ground conditions within tunnel 1. The trackless platform slowly moves on the pre-laid trestle to the secondary lining invert arch section. After aligning the center of the tank body, the tank section 4 is slowly inserted into the invert arch surface 2. After the maximum insertion distance, the front anti-floating device 5 and sliding support device 6 of the tank 4 are connected to the track of the invert arch surface 2, forming the primary guide and support foundation. After the hydraulic crawler 8 is installed at the position of the front anti-floating device 5 on the secondary lining inverted arch section, the hydraulic jack 9 is used to lift the rear anti-floating device 5, the trackless leveler retreats a distance, and then the hydraulic jack 9 is retracted, and the storage tank 4 falls back onto the trackless leveler; the hydraulic crawler 8 and the trackless leveler continue to push the storage tank 4 section until the rear anti-floating device 5 and the sliding support device 6 are on the track of the inverted arch surface 2, and the trackless leveler completely retreats, and finally only the hydraulic crawler 8 is used to push the storage tank 4 to the designated installation position. The efficient cooperation between the trackless leveler and the hydraulic equipment in this method greatly shortens the transportation time and placement cycle of the storage tank 4 segments, while also ensuring the accuracy of the storage tank 4 during the installation process, reducing the additional adjustment time and labor consumption caused by inaccurate positioning.

[0041] In this embodiment, referring to Figure 3-Figure 5Based on the actual specifications of the tank 4 segment and the space limitations of tunnel 1, the secondary lining is designed in a segmented mode, with the length of each segment strictly matching the width of the tank 4 segment to be installed. This dynamic matching not only saves construction time, but also creates ample operating space for subsequent concrete pouring; the "tunnel first, tank later" cross-construction method is adopted, that is, a certain length of secondary lining is completed first, followed by the installation of the corresponding length of tank 4 segment, and then the next stage of secondary lining construction is carried out, and this cycle is repeated until the entire tank 4 is installed. This model effectively avoids construction conflicts and ensures that each link has sufficient space and time to execute, especially the critical concrete pouring operation. Thanks to the orderly connection between segmented construction and tank 4 installation, each concrete pouring is carried out in a relatively independent and undisturbed environment, which is conducive to controlling the fluidity and density of the concrete, reducing the generation of bubbles and cracks, and thus improving the integrity and durability of the structure.

[0042] Specifically, the present invention uses self-compacting high-strength grouting material to fill the gaps between the top arch and the initial support, and between the storage tank 4 and the secondary lining. The selected self-compacting high-strength grouting material has the characteristics of good fluidity, high strength and low shrinkage. These characteristics enable the grouting material to flow on its own and fill gaps of any shape, and the ideal density can be achieved without vibration. At the same time, the high-strength property ensures that the filler can withstand external loads and maintain structural stability. The grouting operation needs to be carried out under specific conditions, including but not limited to the selection of temperature, humidity and grouting pressure. Reasonable construction parameter setting can maximize the performance of the grouting material, ensure that the air is completely removed during the grouting process, prevent the formation of voids or weak areas, and thus improve the integrity and durability of the structure.

[0043] In this embodiment, referring to Figure 2 The trackless ground-moving vehicle 7 is equipped with curved supports 10 for supporting the segments of the tank 4. The curvature of the curved supports 10 matches the outer wall of the tank 4, forming a point-to-surface contact pattern. This not only maximizes load distribution and reduces local stress concentration, but also maintains the stability of the tank 4 during transportation, avoiding the risk of rolling or tipping.

[0044] Specifically, refer to Figure 3-Figure 5Due to the limited spatial dimensions of the mountain circular tunnel 1, overly long sections of tank 4 are difficult to transport directly into tunnel 1. Therefore, tank 4 is divided into shorter segments to facilitate passage through the tunnel 1 entrance and flexible movement within tunnel 1, ensuring the feasibility of the entire installation process. The segment length of tank 4 is designed to be 8-12 meters, which takes into account the capacity requirements of tank 4 and the transportation conditions of tunnel 1. Longer individual segments can increase the storage capacity of tank 4, but also require more advanced lifting and movement technology. Conversely, overly short segments, while easier to transport, increase the number of interfaces, affecting the sealing and structural strength of tank 4. The 8-12 meter range cleverly balances these two considerations, facilitating transportation while meeting the effective volume requirements of tank 4.

[0045] In this embodiment, referring to Figure 2 The anti-floating device 5 includes an anti-floating plate, which is located on the upper part of the secondary lining inverted arch wall. The main function of the anti-floating plate is to prevent the storage tank 4 from deviating from the predetermined trajectory due to tilting or vibration during installation or transportation. The anti-floating plate is placed on the top of the secondary lining inverted arch wall. Through physical constraints, it limits the freedom of movement of the storage tank 4 in the vertical direction, ensuring that the storage tank 4 will not drift laterally or float up and down during longitudinal movement, thereby maintaining a stable state; the sliding support device 6 is composed of a sliding shoe and a roller or slider installed at the bottom. The roller or slider is embedded in the pre-laid slide rail 3, forming an efficient linear motion guide system. When the storage tank 4 segment moves in the tunnel 1, the roller slides along the slide rail 3, greatly reducing the friction resistance and ensuring the smooth sliding of the storage tank 4 segment. At the same time, it also reduces the pressure on the storage tank 4 structure itself and avoids damage caused by friction or collision. Through the combined action of the anti-floating plate and the sliding support device 6, the storage tank 4 always maintains a high degree of stability during the movement, effectively preventing the storage tank 4 from swinging or losing control due to the complex and changeable environment of the tunnel 1.

[0046] In addition, refer to Figure 2 To further enhance the stability and control accuracy of the storage tank 4 during movement, each section of the storage tank 4 is equipped with at least two or more sets of anti-floating devices 5 and sliding support devices 6. In this embodiment, four sets are provided, two on each side of the storage tank 4. This layout design can be evenly distributed around the storage tank 4, forming a full-scale support system, effectively preventing the storage tank 4 from shaking or shifting in any direction, and ensuring the absolute stability of the storage tank 4 during transportation and installation in the tunnel 1. The precise layout of multiple sets of anti-floating devices 5 and sliding support devices 6 ensures the precise positioning and directional movement of the storage tank 4 in the tunnel 1, improves installation accuracy, and reduces the workload of subsequent debugging.

[0047] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for installing an extra-long horizontal storage tank in a circular mountain tunnel, characterized in that: The following steps are involved: Step 1: Excavate and initially support the mountain circular tunnel, then construct a secondary lining inverted arch surface inside the tunnel. The inverted arch surface is constructed in predetermined sections, with its longitudinal highest point located below the tunnel centerline. During the construction process, track fixing components and grouting pipes are pre-buried; Step 2: After the secondary lining inverted arch concrete reaches the design strength index, the arc-shaped surface of the inner side is roughened to strengthen the bonding strength of the contact surface between the new and old concrete; at the same time, a slide rail is installed in the middle of the secondary lining inverted arch wall; Step 3: Design and manufacture the tank, dividing it into several segments. Ensure that the tail of each segment extends at least 1 meter beyond the corresponding secondary lining arch section to serve as the welding preparation area for adjacent segments. Install a flotation stop and a sliding support device in the center of the tank's exterior. Step 4: Use a trackless ground-level mobile vehicle to load the tank segment, and use the hydraulic crawler and hydraulic jack provided on the inverted arch surface of the secondary lining to push the tank to the predetermined position; Step 4: After the initial positioning of the tank segment is completed, use the jack to lift the anti-floating device, remove the sliding support device, and place the tank segment securely on the inverted arch surface; then remove all temporary auxiliary facilities and lock the tank segment; Step 5: Use steel formwork to cover the top gap between the tank segment and the primary support, and perform concrete pouring in this area; After the concrete hardens to the specified level, pressurized cement slurry is injected through the pre-installed grouting pipe to seal the gap between the tank and the lining; Step 6. Repeat steps 3 to 5 until all tank segments are installed to form a complete and coherent extra-long horizontal storage tank.

2. The construction method for installing an extra-long horizontal storage tank in a mountain circular tunnel according to claim 1, characterized in that: The segmented construction of the secondary lining is carried out synchronously and staggered with the installation of the tank segments to provide the necessary concrete pouring operation space and ensure the quality of concrete pouring and the density of the structure.

3. The construction method for installing an extra-long horizontal storage tank in a mountain circular tunnel according to claim 1, characterized in that: Self-compacting high-strength grouting material is used to fill the gaps between the top arch and the primary support, and between the storage tank and the secondary lining.

4. The construction method for installing an extra-long horizontal storage tank in a mountain circular tunnel according to claim 1, characterized in that: The trackless ground-moving vehicle is provided with an arc-shaped support for supporting the tank segments.

5. The construction method for installing an extra-long horizontal storage tank in a mountain circular tunnel according to claim 1, characterized in that: The segment length of the storage tank segments is designed to be 8-12 meters to facilitate flexible transportation and installation in the tunnel.

6. The construction method for installing an extra-long horizontal storage tank in a mountain circular tunnel according to claim 1, characterized in that: The anti-floating device comprises an anti-floating plate, and the anti-floating plate is located on the upper part of the inverted arch wall of the secondary lining.

7. The construction method for installing an extra-long horizontal storage tank in a circular mountain tunnel according to claim 1, characterized in that: The sliding support device includes a sliding shoe, the bottom of the sliding shoe is equipped with a roller, and the roller is slidably connected to the sliding rail.

8. The construction method for installing an extra-long horizontal storage tank in a mountain circular tunnel according to claim 1, characterized in that: At least two sets of anti-floating devices and sliding support devices are provided in the upper county of each section of the storage tank.

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