T-shaped connection node construction structure for newly-built electric power tunnel and existing electric power tunnel

Abstract

The invention discloses a newly-built electric power tunnel and existing electric power tunnel T-shaped connection node construction structure which comprises a working well enclosure structure and two waterproof curtains, the working well enclosure structure comprises an underground diaphragm wall frame, one end of the underground diaphragm wall frame is used for being in butt joint with the newly-built electric power tunnel, and an underground wall notch is reserved in the other end of the underground diaphragm wall frame; the existing power tunnel penetrates through the ground wall gap; the two waterproof curtains are arranged at the two opposite ends of the ground wall notch correspondingly, each waterproof curtain is composed of a plurality of high-pressure jet grouting piles, and each waterproof curtain and the underground diaphragm wall frame define a reinforcing area; the existing electric power tunnel penetrates through the waterproof curtain, a first reinforcing soil layer is formed in the reinforcing area, and the first reinforcing soil layer wraps the existing electric power tunnel. The gap between the ground wall notch and the existing power tunnel can be sealed through mutual cooperation of the first reinforcing soil layer, the waterproof curtain and the underground diaphragm wall frame body of the working well enclosure structure, and therefore the problem that a foundation pit is poor in sealing performance around the existing power tunnel is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to a construction structure for a T-shaped connection node between a newly built power tunnel and an existing power tunnel. Background Technology

[0002] A certain project involves a T-shaped connection between a newly constructed power tunnel and an existing power tunnel, with a working shaft at the connection point. Because the existing power tunnel is still in operation, the retaining structure of the new working shaft conflicts with the existing tunnel structure. To ensure the safety of the existing power tunnel, it cannot be demolished in advance, and the diaphragm wall of the working shaft's retaining structure cannot be constructed normally. It is necessary to cut off the top of the existing power tunnel, creating a gap between the existing power tunnel and the retaining structure. This results in poor sealing around the existing power tunnel when excavating the foundation pit inside the retaining structure. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a construction structure for a T-shaped connection node between a newly built power tunnel and an existing power tunnel. This structure can seal the gap between the ground wall gap and the existing power tunnel through the cooperation of a first reinforced soil layer, a water-stop curtain, and a diaphragm wall frame of the working well retaining structure. This effectively avoids the problem of poor sealing around the existing power tunnel when excavating the foundation pit inside the retaining structure.

[0004] According to an embodiment of the present invention, a construction structure for a T-shaped connection node between a newly constructed power tunnel and an existing power tunnel includes a working shaft retaining structure and two water-stop curtains. The working shaft retaining structure includes a diaphragm wall frame, which is installed at the T-shaped connection node between the newly constructed power tunnel and the existing power tunnel. One end of the diaphragm wall frame in the length direction is used to connect with the newly constructed power tunnel, and the other end of the diaphragm wall frame has a ground wall gap in the width direction through which the existing power tunnel passes. The two water-stop curtains are respectively installed at opposite ends of the ground wall gap. The water-stop curtains are composed of multiple high-pressure jet grouting piles, and each water-stop curtain and the diaphragm wall frame enclose a reinforced area. The existing power tunnel passes through the water-stop curtains, and a first reinforced soil layer is formed in the reinforced area. The first reinforced soil layer covers the existing power tunnel, and the first reinforced soil layer, the water-stop curtains, and the diaphragm wall frame cooperate to seal the gap between the ground wall gap and the existing power tunnel.

[0005] The construction structure of the T-shaped connection node between the newly built power tunnel and the existing power tunnel according to the embodiments of the present invention has at least the following beneficial effects: The present invention can seal the gap between the ground wall gap and the existing power tunnel by the cooperation of the first reinforced soil layer, the water-stop curtain and the diaphragm wall frame of the working well retaining structure, forming a double waterproof structure, thereby effectively avoiding the problem of poor sealing around the existing power tunnel when the foundation pit is excavated inside the retaining structure.

[0006] According to some embodiments of the present invention, the water-stop curtain includes a first curtain, a second curtain, and a third curtain connected in sequence. The second curtain is located on the side of the first curtain away from the diaphragm wall frame. The existing power tunnel is located between the first curtain and the third curtain. Both the first curtain and the third curtain are composed of multiple high-pressure jet grouting piles arranged along the axial direction of the existing power tunnel. The third curtain is composed of multiple high-pressure jet grouting piles arranged radially along the existing power tunnel. The existing power tunnel passes through the third curtain. The bottom ends of the high-pressure jet grouting piles located above the existing power tunnel are constructed to the existing power tunnel. The bottom ends of the other high-pressure jet grouting piles are close to the bottom end of the diaphragm wall frame.

[0007] According to some embodiments of the present invention, the distance between the first curtain or the third curtain and the existing power tunnel is 2 to 4 m, and the distance between the second curtain and the diaphragm wall frame is 4 to 6 m.

[0008] According to some embodiments of the present invention, the diameter of the high-pressure jet grouting pile is 800 mm, and the center distance between two adjacent high-pressure jet grouting piles is 450 mm.

[0009] According to some embodiments of the present invention, the first reinforced soil layer is constructed using the MJS method, and the reinforcement range is within 3m on both sides of the existing power tunnel and within 5m above and below the existing power tunnel.

[0010] According to some embodiments of the present invention, the distance between the diaphragm wall on the upper side wall of the ground wall gap and the existing power tunnel is 1m.

[0011] According to some embodiments of the present invention, the working well enclosure structure further includes an internal support frame disposed inside the diaphragm wall frame.

[0012] According to some embodiments of the present invention, the construction method of the above-mentioned construction structure includes: Step 1: constructing the diaphragm wall frame of the working well enclosure structure; Step 2: constructing the water-stop curtain; Step 3: constructing the first reinforced soil layer in the reinforced area formed by the water-stop curtain and the diaphragm wall frame; Step 4: excavating the foundation pit and setting internal supports within the diaphragm wall frame; Step 5: demolishing the existing power tunnel located within the diaphragm wall frame.

[0013] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0014] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a top view of the construction structure of the T-shaped connection node between the newly built power tunnel and the existing power tunnel according to an embodiment of the present invention; Figure 2 for Figure 1 The diagram shows a cross-sectional view of the construction structure of the T-shaped connection node between the new power tunnel and the existing power tunnel at section AA, and a partial cross-sectional view at the junction of the new power tunnel and the working shaft retaining structure.

[0015] Figure label: The following components are included: working well enclosure structure 100, diaphragm wall frame 110, ground wall gap 111, internal support frame 120, embedded steel ring 130, rubber waterstop strip 140, waterstop curtain 200, first curtain 200a, second curtain 200b, third curtain 200c, high-pressure jet grouting pile 210, first reinforced soil layer 310, second reinforced soil layer 320, newly built power tunnel 400, and existing power tunnel 500. Detailed Implementation

[0016] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0017] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0018] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0019] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0020] Reference Figure 1 and Figure 2 According to an embodiment of the present invention, the construction structure for the T-shaped connection node between the newly built power tunnel 400 and the existing power tunnel 500 includes a working shaft retaining structure 100 and two water-stop curtains 200. The working shaft retaining structure 100 includes a diaphragm wall frame 110, which is used to be installed at the T-shaped connection node between the newly built power tunnel 400 and the existing power tunnel 500. One end of the diaphragm wall frame 110 in the length direction is used to connect with the newly built power tunnel 400, and the other end of the diaphragm wall frame 110 leaves a ground wall notch 111 in the width direction, through which the existing power tunnel 500 passes. The gap 111 passes through; two water-stop curtains 200 are respectively set at opposite ends of the gap 111 in the ground wall. The water-stop curtains 200 are composed of multiple high-pressure jet grouting piles. Each water-stop curtain 200 is enclosed with the diaphragm wall frame 110 to form a reinforced area. The existing power tunnel 500 passes through the water-stop curtains 200. The reinforced area forms a first reinforced soil layer 310. The first reinforced soil layer 310 covers the existing power tunnel 500. The first reinforced soil layer 310, the water-stop curtains 200 and the diaphragm wall frame 110 cooperate with each other to seal the gap between the ground wall gap 111 and the existing power tunnel 500.

[0021] The present invention can seal the gap between the ground wall gap 111 and the existing power tunnel 500 by the cooperation of the first reinforced soil layer 310, the water-stop curtain 200 and the ground wall frame 110 of the working well enclosure structure 100, forming a double waterproof structure, thereby effectively avoiding the problem of poor sealing around the existing power tunnel 500 when the foundation pit is excavated inside the enclosure structure.

[0022] Reference Figure 1According to some embodiments of the present invention, the water-stop curtain 200 includes a first curtain 200a, a second curtain 200b, and a third curtain 200c connected in sequence. The second curtain 200b is located on the side of the first curtain 200a away from the diaphragm wall frame 110. The existing power tunnel 500 is located between the first curtain 200a and the third curtain 200c. The first curtain 200a and the third curtain 200c are both composed of a plurality of high-pressure jet grouting piles arranged along the axial direction of the existing power tunnel 500. The third curtain 200c is composed of a plurality of high-pressure jet grouting piles arranged radially along the existing power tunnel 500. The existing power tunnel 500 passes through the third curtain 200c. The bottom end of the high-pressure jet grouting pile located above the existing power tunnel 500 is constructed to the existing power tunnel 500. The bottom end of the other high-pressure jet grouting piles is close to the bottom end of the diaphragm wall frame 110. Thus, the water-stop curtain 200 can form an effective waterproof and leak-proof barrier around the existing power tunnel 500 outside the gap 111 in the ground wall.

[0023] Reference Figure 1 According to some embodiments of the present invention, the distance between the first curtain 200a or the third curtain 200c and the existing power tunnel 500 is 2 to 4m, and the distance between the second curtain 200b and the diaphragm wall frame 110 is 4 to 6m, so as to ensure that the size of the reinforced area enclosed by each curtain is appropriate, taking into account the construction cost and the impact on the existing power tunnel 500.

[0024] According to some embodiments of the present invention, the diameter of the high-pressure jet grouting pile is 800 mm, and the center distance between two adjacent high-pressure jet grouting piles is 450 mm, thereby forming a sealed and seamless water-stop curtain 200.

[0025] According to some embodiments of the present invention, the first reinforced soil layer 310 is constructed using the MJS method, and the reinforcement range is within 3m on both sides of the existing power tunnel 500 and within 5m above and below the existing power tunnel 500. The MJS method (Metro JetSystem), also known as the all-round high-pressure jet grouting method, is a new type of foundation reinforcement technology developed on the basis of traditional high-pressure jet grouting technology. Its core advantage lies in forced grout drainage + real-time monitoring and control of ground pressure, which can accurately and with minimal disturbance reinforce the soil in a closed space.

[0026] Reference Figure 2 According to some embodiments of the present invention, the distance between the diaphragm wall on the upper side wall of the ground wall gap 111 and the existing power tunnel 500 is 1m.

[0027] Reference Figure 1According to some embodiments of the present invention, the working well enclosure structure 100 further includes an inner support frame 120 disposed inside the diaphragm wall frame 110. The inner support frame 120 is disposed after the foundation pit inside the diaphragm wall frame 110 is excavated, so as to provide internal support for the diaphragm wall frame 110 and enhance the ability of the diaphragm wall frame 110 to withstand soil compression.

[0028] According to some embodiments of the present invention, the construction method of the above-mentioned construction structure includes: Step 1: constructing the diaphragm wall frame 110 of the working well retaining structure 100; Step 2: constructing the water-stop curtain 200; Step 3: constructing the first reinforced soil layer 310 in the reinforced area formed by the water-stop curtain 200 and the diaphragm wall frame 110; Step 4: excavating the foundation pit and setting internal supports within the diaphragm wall frame 110; Step 5: demolishing the existing power tunnel 500 located within the diaphragm wall frame 110. Using the above configuration, the construction of the T-shaped connection node between the new power tunnel and the existing power tunnel can be completed, and the sealing of the foundation pit throughout the construction process can be ensured, effectively preventing accidents such as water and sand inrush around the existing power tunnel 500.

[0029] According to some embodiments of the present invention, in some embodiments, a maintenance station and a maintenance warehouse can be set up in the foundation pit within the working well retaining structure 100 so that workers can enter the power tunnel from the maintenance station entrance to carry out power maintenance.

[0030] Reference Figure 2 According to some embodiments of the present invention, a pre-embedded steel ring 130 is provided at one end of the diaphragm wall frame 110. An opening for the new power tunnel 400 to pass through is formed in the pre-embedded steel ring 130. The pre-embedded steel ring 130 is fully welded to the reinforcing cage of the diaphragm wall frame 110 and constructed simultaneously to ensure that the pre-embedded steel ring 130 and the wall share the load. A curtain rubber plate is installed on the inner wall of the pre-embedded steel ring 130 through a pre-embedded flange. The curtain rubber plate is a core dynamic water-stopping component and is made of wear-resistant and aging-resistant rubber. When the tunnel boring machine advances, the curtain rubber plate is squeezed and pressed tightly against the outer shell of the tunnel boring machine to prevent groundwater and soil from entering the foundation pit. A water-swellable rubber water-stop strip is attached to the outer periphery of the pre-embedded steel ring 130. 140, to fill the gaps in the concrete pouring, forming the first static water-stopping defense line; the inner wall of the pre-embedded steel ring 130 is pre-set with grouting holes for later gap filling grouting to form a seal; a second reinforcing soil layer 320 is set on the side of the pre-embedded steel ring 130 away from the diaphragm wall frame 110, the reinforcement range is 3-5m along the axis of the newly built power tunnel 400 outside the opening and 2-3m radially outward along the newly built power tunnel 400 outside the opening. Thus, the diaphragm wall frame 110, the pre-embedded steel ring 130, the curtain rubber sheet and the second reinforcing soil layer 320 work together to achieve sealing and waterproofing, ensuring the sealing of the foundation pit before the newly built power tunnel 400 connects with the diaphragm wall frame 110.

[0031] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0032] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A construction structure of a T-shaped connection node of a newly-built power tunnel and an existing power tunnel, characterized in that, include: The working shaft enclosure structure (100) includes a diaphragm wall frame (110), which is used to be installed at the node where the newly built power tunnel (400) and the existing power tunnel (500) are connected in a T-shape. One end of the diaphragm wall frame (110) in the length direction is used to connect with the newly built power tunnel (400), and the other end of the diaphragm wall frame (110) has a ground wall gap (111) in the width direction, through which the existing power tunnel (500) passes. Two water-stop curtains (200) are respectively set at opposite ends of the ground wall gap (111). The water-stop curtains (200) are composed of multiple high-pressure jet grouting piles. Each water-stop curtain (200) is enclosed with the ground wall frame (110) to form a reinforced area. The existing power tunnel (500) passes through the water-stop curtain (200), and the reinforcement zone forms a first reinforcement soil layer (310). The first reinforcement soil layer (310) covers the existing power tunnel (500). The first reinforcement soil layer (310), the water-stop curtain (200), and the diaphragm wall frame (110) cooperate to seal the gap between the ground wall gap (111) and the existing power tunnel (500).

2. The construction structure of a new power tunnel and an existing power tunnel T-shaped connection node according to claim 1, characterized in that, The water-stop curtain (200) includes a first curtain (200a), a second curtain (200b), and a third curtain (200c) connected in sequence. The second curtain (200b) is located on the side of the first curtain (200a) away from the diaphragm wall frame (110). The existing power tunnel (500) is located between the first curtain (200a) and the third curtain (200c). Both the first curtain (200a) and the third curtain (200c) are composed of multiple The third curtain (200c) consists of a number of high-pressure jet grouting piles arranged along the axial direction of the existing power tunnel (500). The existing power tunnel (500) passes through the third curtain (200c). The bottom end of the high-pressure jet grouting piles located above the existing power tunnel (500) is constructed to the existing power tunnel (500). The bottom ends of the other high-pressure jet grouting piles are close to the bottom end of the diaphragm wall frame (110).

3. The construction structure for a T-shaped connection node between a newly built power tunnel and an existing power tunnel according to claim 2, characterized in that, The distance between the first curtain (200a) or the third curtain (200c) and the existing power tunnel (500) is 2-4m, and the distance between the second curtain (200b) and the diaphragm wall frame (110) is 4-6m.

4. The construction structure for a T-shaped connection node between a newly built power tunnel and an existing power tunnel according to claim 2, characterized in that, The diameter of the high-pressure jet grouting pile is 800mm, and the center distance between two adjacent high-pressure jet grouting piles is 450mm.

5. The construction structure for a T-shaped connection node between a newly constructed power tunnel and an existing power tunnel according to claim 1, characterized in that, The first reinforced soil layer (310) is constructed using the MJS method, and the reinforcement range is within 3m on both sides of the existing power tunnel (500) and within 5m above and below the existing power tunnel (500).

6. The construction structure for a T-shaped connection node between a newly built power tunnel and an existing power tunnel according to claim 1, characterized in that, The distance between the diaphragm wall on the upper side of the ground wall gap (111) and the existing power tunnel (500) is 1m.

7. The construction structure for a T-shaped connection node between a newly built power tunnel and an existing power tunnel according to claim 1, characterized in that, The working well enclosure structure (100) also includes an inner support frame (120) disposed inside the diaphragm wall frame (110).

8. The construction structure for a T-shaped connection node between a newly built power tunnel and an existing power tunnel according to claim 1, characterized in that, Its construction methods include: Step 1: Construct the diaphragm wall frame (110) of the working well enclosure structure (100). Step 2: Construct the water-stop curtain (200); Step 3: Apply the first reinforcing soil layer (310) to the reinforcement area formed by the water-stop curtain (200) and the diaphragm wall frame (110). Step 4: Excavate the foundation pit and install internal supports within the diaphragm wall frame (110); Step 5: Destroy the existing power tunnel (500) located within the diaphragm wall frame (110).

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