Water delivery tunnel steel lining connecting structure of pumped storage power station

Abstract

The utility model provides a water delivery tunnel steel lining connecting structure of a pumped storage power station, which belongs to the technical field of water delivery tunnel engineering of pumped storage power stations and comprises a reinforced concrete lining section and a steel lining section, and further comprises a steel sleeve pre-buried in the reinforced concrete lining section, one end of the steel lining section is inserted into the steel sleeve, and the other end of the steel lining section is inserted into the steel sleeve. Oil hemp is arranged between the inner wall of the steel sleeve and the outer wall of the steel lining section, meanwhile, a baffle is welded to the end, away from the reinforced concrete lining section, of the steel sleeve, and a certain gap is formed between the inner wall of the baffle and the outer wall of the steel lining section. According to the utility model, the hard contact between the steel lining pipe and the reinforced concrete lining pipe is effectively solved, the interaction force is effectively released, and the problem of leakage at the connection interface is successfully solved.

Description

Technical Field

[0001] This utility model belongs to the technical field of pumped storage power station water conveyance tunnel engineering, and in particular relates to a steel lining connection structure for pumped storage power station water conveyance tunnels. Background Technology

[0002] Pumped storage power stations, as important peak-shaving and valley-filling energy facilities, rely on the water circulation between upper and lower reservoirs for their core function: during power generation, water from the upper reservoir flows into the lower reservoir through a water conveyance tunnel; during energy storage, water from the lower reservoir is pumped to the upper reservoir via pumps. Because the elevation difference between the upper and lower reservoirs can reach hundreds of meters, the water conveyance tunnel must withstand extremely high water pressure, and its structural reliability directly affects the safe operation of the power station.

[0003] Water conveyance tunnels are typically divided into different sections: the upper horizontal section, due to its lower water pressure, uses a reinforced concrete lining structure (referred to as "reinforced concrete lining section"), relying on the integrity of the concrete and the tensile strength of the steel bars to resist the water pressure; while the high-pressure section (such as the inclined shaft section and the lower horizontal section), which needs to withstand the high pressure of hundreds of meters of water head, uses a "steel lining pipe + backfill concrete" structure (referred to as "steel lining section"). The high strength of the steel lining pipe resists the radial water pressure, while the backfill concrete serves to fix and protect the steel lining pipe.

[0004] Leakage at the connection between the reinforced concrete lining section and the steel lining section has long been a critical problem plaguing the industry. Current technology typically involves welding a water-stop ring to the outer end of the steel lining section and then embedding the ring into the reinforced concrete lining section to form a rigid connection structure. However, this connection method has significant drawbacks:

[0005] On the one hand, during the filling and emptying water circulation of the water conveyance tunnel, the steel lining section will undergo radial expansion / contraction due to changes in water pressure, and longitudinal displacement due to temperature changes and water impact; while the reinforced concrete lining section has high rigidity and minimal deformation. The rigid connection between the two will result in huge additional stress at the connection point.

[0006] On the other hand, under long-term cyclic loading, fatigue failure is likely to occur between the rigidly connected wing ring and steel lining section, and between the wing ring and concrete, resulting in gaps. Under high pressure, water will seep along the gaps, which not only affects the safety of the tunnel structure, but may also cause seepage deformation of the surrounding rock mass, further aggravating the engineering risks.

[0007] Therefore, there is an urgent need for a connection structure that can adapt to the deformation difference between the steel lining section and the reinforced concrete lining section, avoid fatigue failure, and effectively stop water leakage, so as to solve the leakage and structural failure problems of existing rigid connections. Utility Model Content

[0008] This invention addresses the problems of leakage and structural failure associated with traditional rigid connections. It provides a steel-lined connection structure for water conveyance tunnels in pumped-storage power stations, effectively resolving the hard contact between the steel lining pipe and the reinforced concrete lining pipe, thus releasing the interaction force and successfully solving the leakage problem at the connection interface.

[0009] The technical solution adopted by this utility model for the steel lining connection structure of a water conveyance tunnel in a pumped storage power station is as follows:

[0010] A steel lining connection structure for a pumped storage power station water conveyance tunnel includes a reinforced concrete lining section and a steel lining section, and also includes a steel sleeve pre-embedded in the reinforced concrete lining section. One end of the steel lining section is inserted into the steel sleeve. Oil hemp is provided between the inner wall of the steel sleeve and the outer wall of the steel lining section. At the same time, a baffle is welded to the end of the steel sleeve away from the reinforced concrete lining section, and there is a certain gap between the inner wall of the baffle and the outer wall of the steel lining section.

[0011] A further improvement of this utility model is that the inner diameter of the steel sleeve is 100-140mm larger than the outer diameter of the steel lining section.

[0012] A further improvement of this utility model is that the width of the steel sleeve along its axial direction is 400-600mm.

[0013] A further improvement of this utility model is that the baffle is made of square steel, and the cross-sectional dimensions of the square steel are 25mm×25mm-45mm×45mm.

[0014] A further improvement of this utility model is that: the outer wall of the steel sleeve is provided with connecting bars, and the connecting bars are tied and fixed to the reinforcing bars in the reinforced concrete lining section.

[0015] A further improvement of this utility model is that the hemp is wound at least 5 turns between the steel sleeve and the steel lining section.

[0016] A further improvement of this utility model is that the baffle is continuously arranged along the circumference of the steel sleeve, and the gap between the inner wall of the baffle and the outer wall of the steel lining section is no greater than 25mm.

[0017] A further improvement of this utility model is that the length of the steel lining section inserted into the steel sleeve is 2 / 3-1 of the width of the steel sleeve.

[0018] The technological advancements achieved by this utility model due to the adoption of the above technical solution are as follows:

[0019] This invention uses tar-impregnated hemp as a sealing material, which expands rapidly upon contact with water, tightly filling the gap between the steel sleeve and the steel lining section, and actively blocking the seepage path; moreover, the tar component can improve the corrosion resistance and waterproofness of the hemp, ensuring a long-term water-stopping effect, and solving the leakage problem caused by fatigue gaps in existing rigid connections.

[0020] The hemp fiber in this invention has good elasticity and can absorb the radial expansion / contraction and longitudinal displacement of the steel lining section through its own deformation, effectively releasing the additional stress at the connection, avoiding fatigue damage caused by rigid contact, and significantly extending the service life of the connection structure.

[0021] This utility model can be installed through only three core steps: pre-embedded steel sleeve, filling with hemp, and welding baffle. No complicated processing equipment is required. The hemp filling can be manually wrapped and compacted, which is easy to operate, has high construction efficiency, and can adapt to the working environment of the narrow space of the tunnel.

[0022] Since hemp is a common building material, it is inexpensive and widely available; steel sleeves and baffles can be made from ordinary steel, resulting in low material costs. If localized wear occurs later, maintenance can be achieved by removing the baffles and replacing the hemp, without requiring large-scale modifications to the overall structure, thus reducing operation and maintenance costs. Attached Figure Description

[0023] Figure 1 This utility model provides a structural schematic diagram of a steel lining connection structure for a water conveyance tunnel in a pumped storage power station.

[0024] In the attached diagram: 1. Lining section; 2. Steel lining section; 3. Steel sleeve; 4. Oil hemp; 5. Baffle; 6. Connecting reinforcement. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. In the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concept of this utility model.

[0026] like Figure 1 As shown, this utility model provides a steel lining connection structure for a water conveyance tunnel of a pumped storage power station. The structure includes a reinforced concrete lining section 1, a steel lining section 2, a steel sleeve 3, hemp fiber 4, and a baffle 5.

[0027] Specifically, the reinforced concrete lining section 1 is a conventional upper horizontal section structure of a water conveyance tunnel, with internal reinforcing steel bars (not shown in the figure). Its inner diameter is matched with the inner diameter of the steel lining section 2 to ensure smooth water flow.

[0028] The steel lining section 2 is made of Q345R steel plate rolled and welded. The thickness is determined according to the design water pressure (usually 16-30mm). Its ends are ground to ensure that the outer wall is flat and easy to fit with the hemp 4.

[0029] The steel sleeve 3 is made of the same steel plate as the steel lining section 2, and its inner diameter is 120mm larger than the outer diameter of the steel lining section 2 (which can be adjusted within the range of 100-140mm according to actual working conditions). Its width along its own axis is 500mm (which can be adjusted within the range of 400-600mm). Six connecting ribs 6 with a diameter of 16mm and a length of 80mm are welded to the outer wall of the steel sleeve 3. The connecting ribs 6 are evenly distributed around the circumference of the steel sleeve 3 and are used to tie and fix it to the stressed reinforcing bars in the reinforced concrete lining section 1 to ensure that the steel sleeve 3 does not shift during concrete pouring.

[0030] In this invention, the hemp rope 4 is made of 10mm diameter tar-impregnated hemp rope with a tar content of not less than 30%. Before inserting the steel sleeve 3 into the steel lining section 2, the hemp rope 4 is wrapped around the outer wall of the insertion end of the steel lining section 2. During wrapping, the hemp rope 4 is gently tapped radially with a wooden mallet to ensure it fits tightly against the outer wall of the steel lining section 2, with an initial filling density of not less than 0.8g / cm³. 3 Ensure that the gaps are fully filled.

[0031] The baffle 5 of this utility model is made of square steel with a cross-sectional dimension of 25mm×25mm. It is continuously welded to the end of the steel sleeve 3 away from the reinforced concrete lining section 1 along the circumference, and the weld height is 8mm to ensure the connection strength. The gap between the inner wall of the baffle 5 and the outer wall of the steel lining section 2 is controlled within 25mm, which can avoid hindering the slight displacement of the steel lining section 2 and prevent the hemp fiber 4 from sliding out horizontally under water pressure.

[0032] The installation process of the connection structure in this embodiment is as follows:

[0033] During the construction of reinforced concrete lining section 1, the steel sleeve 3 is tied and fixed to the internal reinforcing bars through the connecting bars 6. After positioning, concrete is poured to ensure that the axis of the steel sleeve 3 coincides with the axis of the reinforced concrete lining section 1.

[0034] After the steel lining section 2 is prefabricated, its insertion end outer wall is derusted and polished, and then wrapped with hemp 4 and compacted.

[0035] Slowly push the insertion end of the steel lining section 2 into the steel sleeve 3, with an insertion length of 350mm - fully inserted, ensuring that the hemp 4 is completely within the gap between the steel sleeve 3 and the steel lining section 2.

[0036] A baffle 5 is welded to the outer end of the steel sleeve 3. A symmetrical welding process is used during the welding process to avoid deformation of the steel sleeve 3 due to welding stress.

[0037] The working principle of the steel lining connection structure for a water conveyance tunnel in a pumped storage power station in this embodiment is as follows:

[0038] When the water conveyance tunnel is filled with water, if a small amount of seepage flows along the gaps, the hemp fiber 4 will expand rapidly upon contact with water, tightly filling the gaps and blocking the leakage path. When the steel lining section 2 undergoes radial deformation due to changes in water pressure or temperature, the elasticity of the hemp fiber 4 can absorb the deformation through compression / tension. When the steel lining section 2 undergoes longitudinal displacement, the hemp fiber 4 can undergo slight axial slippage, releasing longitudinal stress and preventing fatigue failure at the connection.

[0039] In the above embodiments, this utility model provides a steel lining connection structure for a pumped storage power station water conveyance tunnel. This utility model uses tar-impregnated hemp as a sealing material, which expands rapidly upon contact with water, tightly filling the gap between the steel sleeve and the steel lining section, actively blocking the seepage path. Furthermore, the tar component enhances the corrosion resistance and waterproofness of the hemp, ensuring long-term water-stopping effects and solving the leakage problem caused by fatigue gaps in existing rigid connections. The hemp in this utility model has good elasticity, absorbing the radial expansion / contraction and longitudinal displacement of the steel lining section through its own deformation, effectively releasing additional stress at the connection point, avoiding fatigue damage caused by rigid contact, and significantly extending the service life of the connection structure. This utility model can be installed through only three core steps: pre-embedding the steel sleeve, filling with hemp, and welding the baffle, without requiring complex processing equipment. The hemp filling can be done manually by wrapping and compacting, making operation simple, construction efficient, and adaptable to the confined working environment of tunnels. Since hemp is a conventional building material, it is inexpensive and widely available; the steel sleeve and baffle can be made of ordinary steel, resulting in low material costs. If localized wear occurs later, maintenance can be achieved by removing the baffle and replacing the hemp fiber, without requiring large-scale modifications to the overall structure, thus reducing operation and maintenance costs.

[0040] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention should fall within the protection scope of the present invention. The technical content for which protection is sought in the present invention has been fully described in the claims.

Claims

1. A steel lining connection structure for a pumped storage power station water conveyance tunnel, comprising a reinforced concrete lining section (1) and a steel lining section (2), characterized in that: It also includes a steel sleeve (3) pre-embedded in the reinforced concrete lining section (1), one end of the steel lining section (2) is inserted into the steel sleeve (3), the inner wall of the steel sleeve (3) and the outer wall of the steel lining section (2) are provided with hemp (4), and at the same time, a baffle (5) is welded to the end of the steel sleeve (3) away from the reinforced concrete lining section (1), and there is a certain gap between the inner wall of the baffle (5) and the outer wall of the steel lining section (2).

2. The steel lining connection structure for a pumped storage power station water conveyance tunnel according to claim 1, characterized in that: The inner diameter of the steel sleeve (3) is 100-140 mm larger than the outer diameter of the steel lining section (2).

3. The steel lining connection structure for a pumped storage power station water conveyance tunnel according to claim 1, characterized in that: The steel sleeve (3) has a width of 400-600 mm along its axial direction.

4. The steel lining connection structure for a pumped storage power station water conveyance tunnel according to claim 1, characterized in that: The baffle (5) is a square steel, and the cross-sectional dimensions of the square steel are 25mm×25mm-45mm×45mm.

5. The steel lining connection structure for a pumped storage power station water conveyance tunnel according to claim 1, characterized in that: The outer wall of the steel sleeve (3) is provided with connecting bars (6), which are tied and fixed to the reinforcing bars in the reinforced concrete lining section (1).

6. The steel lining connection structure for a pumped storage power station water conveyance tunnel according to claim 1, characterized in that: The hemp fiber (4) is wound at least 5 turns between the steel sleeve (3) and the steel lining section (2).

7. The steel lining connection structure for a pumped storage power station water conveyance tunnel according to claim 1, characterized in that: The baffle (5) is continuously arranged along the circumference of the steel sleeve (3), and the gap between the inner wall of the baffle (5) and the outer wall of the steel lining section (2) is no greater than 25mm.

8. The steel lining connection structure for a pumped storage power station water conveyance tunnel according to claim 1, characterized in that: The length of the steel lining section (2) inserted into the steel sleeve (3) is 2 / 3 - 1 of the width of the steel sleeve (3).

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