Construction method for advance reservation of entrance of underground continuous wall in underground communication passage

Abstract

The application provides a construction method for early reserving an entrance of an underground continuous wall in an underground communication passage. First, the position, size and shape of the entrance of the underground communication passage in the underground continuous wall are determined according to engineering design drawings, measurement and line laying are completed, and a standardized steel structure reserved part is processed and manufactured. Grooving construction of the underground continuous wall is performed. A steel reinforcement cage is manufactured. The reserved part and the steel reinforcement cage are welded and fixed to form an integral whole, and are hoisted to a groove section for fixation. A concrete pouring guide pipe is installed in the groove section, concrete pouring of the underground continuous wall is performed, and it is ensured that the concrete can fully fill the groove section and the space around the reserved part. After the concrete of the underground continuous wall reaches the design strength, subsequent construction of the underground communication passage is directly performed based on the reserved entrance. The application reserves the entrance of the underground communication passage in the enclosure structure in advance, avoids the complicated process of breaking and reinforcing during the construction of the underground communication passage in the later period, and solves the problems of long construction period, high cost and safety hazards existing in the traditional construction method.

Description

Technical Field

[0001] This invention belongs to the field of building construction technology, and in particular relates to a construction method for pre-reserving entrances and exits in underground continuous walls in underground passages. Background Technology

[0002] With the deepening of urbanization, the scale of urban underground space development and utilization is expanding, and interconnection between group projects through underground passages has become a common requirement. During the construction of group projects, development and construction are usually carried out in zones according to plots. Under this model, the reservation of entrances and exits for underground passages becomes a key link in the construction process.

[0003] Currently, for projects involving basement excavation and the construction of retaining structures, the conventional construction method is to not reserve entrances / exits for connecting passages during the retaining structure construction phase, but only to reserve corresponding locations on the basement exterior walls. This approach necessitates the demolition of the existing retaining structure during the later construction of connecting passages, regardless of whether pipe jacking or open-cut construction is used. This not only increases the additional demolition workload and construction costs, but also, for structures where the diaphragm wall and basement exterior walls are combined, demolishing the retaining structure can damage the structure, significantly increasing the risk of structural leakage and seriously affecting project quality and safety. Furthermore, the later demolition process generates substantial dust and noise, polluting the surrounding environment and contradicting green construction principles. Therefore, a new construction method is urgently needed to address the numerous problems associated with traditional methods. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a construction method for pre-reserving entrances and exits in the diaphragm wall of underground connecting passages. Applied to the early stage of connecting passage construction, this method effectively avoids the cumbersome procedures of demolition and reinforcement during later connecting passage construction by pre-reserving entrances and exits in the retaining structure. It also solves the problems of long construction period, high cost, and safety hazards in traditional construction methods.

[0005] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0006] A construction method for pre-reserving entrances and exits in the diaphragm wall of an underground connecting passage includes the following process:

[0007] Step 1: Determine the location, size, and shape of the underground passage entrances and exits within the diaphragm wall based on the engineering design drawings; conduct surveying and layout; fabricate standardized steel structure pre-installed components;

[0008] Step 2: Use trenching equipment to perform trenching operations for the diaphragm wall according to the designed depth and width;

[0009] Step 3: Fabricate the reinforcing cage and connect the pre-installed parts to the reinforcing cage to form a whole;

[0010] Step 4: Hoist the integrated structure formed by the steel cage and the reserved parts into the trench section and fix it in place;

[0011] Step 5: Install concrete pouring guide pipes in the trench section and use the guide pipe method to pour concrete for the underground continuous wall, ensuring that the concrete fully fills the trench section and the space around the reserved parts.

[0012] Step 6: After the underground continuous wall concrete reaches the design strength, the subsequent construction of the underground connecting passage will proceed directly based on the reserved entrance and exit.

[0013] Furthermore, the reserved component includes a pre-embedded steel ring frame, and the inner ring of the pre-embedded steel ring frame is fixedly installed with a mud-blocking water flap by high-strength bolts.

[0014] Furthermore, in step 3, the reserved component and the steel cage are fixed together by welding or mechanical connection to form an integral structure, which jointly bears the force and ensures that the reserved component is accurately positioned and does not shift during subsequent construction.

[0015] Furthermore, in step 5, during the concrete pouring process, the concrete pouring speed is controlled within the range of 2 to 4 m³ / h, and the concrete is poured in layers, with the thickness of each layer meeting the design requirements, to ensure that the concrete fully fills the groove and the space around the reserved parts.

[0016] Furthermore, in step 6, the subsequent construction of the underground connecting passage includes: excavation, support, and structural construction of the passage;

[0017] Tunnel excavation: The tunnel excavation operation shall be carried out using appropriate excavation equipment and methods (including mechanical excavation and manual assistance). During the excavation process, attention shall be paid to controlling the excavation size and slope.

[0018] Channel support: Based on the geological conditions and design requirements of the channel, timely support construction shall be carried out. Support methods include anchor bolt support and shotcrete support to ensure the stability of the channel after excavation.

[0019] Structural construction: Complete the structural construction of the passage, including rebar tying, formwork installation, and concrete pouring, to form a complete underground connecting passage structure.

[0020] The present invention has the following beneficial effects:

[0021] This invention abandons the traditional post-construction excavation method, accelerating construction progress, reducing costs, and facilitating the construction of basement connecting passages. This solution has many significant advantages: it is convenient and quick, significantly shortening the construction cycle; it is safe and reliable, effectively reducing safety hazards during construction; and it also features cost savings and environmental friendliness. It is particularly suitable for the construction of connecting passages in group engineering projects.

[0022] This invention effectively avoids subsequent demolition work by reserving access passages during the pre-construction phase of the retaining structure, significantly reducing construction costs such as demolition equipment, labor, and waste disposal. This method not only ensures the integrity and durability of the structure and reduces quality risks such as leakage, but also improves construction efficiency, simplifies the installation process of pre-reserved components, shortens the construction period, and meets project schedule requirements. Simultaneously, it avoids dust and noise generated by demolition operations, contributing to environmental protection and aligning with green construction principles. It has a wide range of applications, particularly suitable for group projects with integrated underground diaphragm walls and basement exterior walls, demonstrating promising application prospects and significant technical advantages. Attached Figure Description

[0023] Figure 1 A schematic diagram of the plan for reserving parts for the opening;

[0024] Figure 2 A schematic diagram of the plan for the reserved parts at the entrance of the tunnel;

[0025] Figure 3 for Figure 1 Schematic diagram of the AA-direction section;

[0026] Figure 4 for Figure 2 A schematic diagram of the BB-direction cross section.

[0027] In the diagram: 1. Embedded nut (only at the opening); 2. Mud-blocking and water-retaining flap; 3. Embedded steel ring frame; 4. Rectangular jacking pipe; Detailed implementation method

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0029] Reference Figures 1 to 4 The construction method for pre-reserving entrances and exits in the diaphragm wall of the underground connecting passage described in this invention specifically includes the following process:

[0030] Step 1: Pre-construction preparations;

[0031] Based on the engineering design drawings, the precise location, size, and shape of the underground passage entrances and exits (including exit and entrance) within the diaphragm wall are determined. Simultaneously, surveying and layout work is completed. According to design requirements, standardized steel structure pre-fabricated components are fabricated. These components must meet strength, stiffness, and stability requirements, and their size and shape must match the designed entrances and exits. The pre-fabricated components include a pre-embedded steel ring frame 3, with a mud-blocking and water-retaining flap 2 fixedly installed within the inner ring of the pre-embedded steel ring frame 3 using high-strength bolts.

[0032] Step 2: Trenching construction of the diaphragm wall;

[0033] Using trenching equipment, trenching operations for diaphragm walls are carried out according to the designed depth and width. During the trenching process, various performance indicators of the slurry, including specific gravity, viscosity, and sand content, are strictly controlled to ensure the stability of the trench wall and prevent it from collapsing.

[0034] Step 3: Fabrication and installation of the reinforcing cage;

[0035] According to the design requirements of the diaphragm wall, standard-compliant steel bars are used to fabricate the steel cage, and nodes for connection with pre-installed components are reserved at corresponding positions within the steel cage. After the steel cage is fabricated, the pre-installed components are accurately hoisted to the design position using hoisting equipment. The pre-installed components are then connected to the completed steel cage using positioning devices and connecting components, which can be achieved through welding or mechanical connection. This ensures that the steel cage and the pre-installed components form a unified structure, sharing the load and guaranteeing the accurate positioning and stability of the pre-installed components during subsequent construction. Furthermore, during the fabrication of the steel cage, strict control must be exercised over the processing dimensions of the steel bars and the quality of welding or connection.

[0036] Step 4: Install and secure the pre-installed parts;

[0037] After the reserved parts are connected to the steel cage, the whole structure is lifted into the trench section again using lifting equipment. During the lifting process, care should be taken to keep it stable and avoid collisions. After being lifted to the design position, the construction personnel only need to follow the pre-established installation procedure and use conventional installation tools (such as wrenches) to complete the fixing of the reserved parts and the steel cage to the entrance and exit in a short time.

[0038] Step 5: Concrete pouring construction;

[0039] Concrete pouring guide pipes are installed within the trench section. The arrangement of the guide pipes must meet the requirements of concrete flowability and uniformity. The diaphragm wall concrete is poured using the guide pipe method. During the pouring process, the pouring speed (controlled within a suitable range, approximately 2-4 m³ / h, adjusted according to actual conditions), height (layered pouring, with each layer thickness meeting design requirements), and continuity of the concrete are strictly controlled to ensure that the concrete can fully fill the trench section and the space around the reserved components, guaranteeing the quality of the concrete pouring and avoiding quality defects such as voids, honeycombing, and pitting.

[0040] Step 6: Subsequent construction of connecting passages;

[0041] Once the concrete of the underground continuous wall has reached the design strength as determined by the concrete strength test, the subsequent construction of the underground connecting passage can be carried out directly based on the reserved entrance and exit, including the excavation, support, and structural construction of the passage, without the need to demolish the retaining structure.

[0042] Tunnel excavation: Use appropriate excavation equipment and methods (mechanical excavation, manual assistance, etc.) to carry out tunnel excavation operations, and pay attention to controlling the excavation size and slope during the excavation process;

[0043] Channel support: Based on the geological conditions and design requirements of the channel, timely support construction should be carried out. Methods such as anchor bolt support and shotcrete support can be used to ensure the stability of the channel after excavation.

[0044] Structural construction: Complete the structural construction of the passage, including rebar tying, formwork installation, concrete pouring, etc., to form a complete underground connecting passage structure.

[0045] The construction method described in this invention is applicable to the construction of underground connecting passages in various group projects. In particular, it has significant technical advantages and good application prospects for the construction of underground continuous walls and basement exterior walls in a combined structure.

[0046] The embodiments described above are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method of constructing an access opening in advance of a diaphragm wall in an underground tunnel, characterized by, The process includes the following: Step 1: Determine the location, size, and shape of the underground connecting passage entrances and exits within the diaphragm wall based on the engineering design drawings; conduct surveying and layout; fabricate standardized steel structure pre-installed components; Step 2: Use trenching equipment to perform trenching operations for the diaphragm wall according to the designed depth and width; Step 3: Fabricate the reinforcing cage and connect the pre-installed parts to the reinforcing cage to form a whole; Step 4: Hoist the integrated structure formed by the steel cage and the reserved parts into the trench section and fix it in place; Step 5: Install concrete pouring guide pipes in the trench section and use the guide pipe method to pour concrete for the underground continuous wall, ensuring that the concrete fully fills the trench section and the space around the reserved parts. Step 6: After the underground continuous wall concrete reaches the design strength, the subsequent construction of the underground connecting passage will proceed directly based on the reserved entrance and exit.

2. The method of claim 1, wherein the method further comprises: The reserved components include a pre-embedded steel ring frame (3), and the inner ring of the pre-embedded steel ring frame (3) is fixedly installed with a mud-blocking water flap (2) by high-strength bolts.

3. The method of claim 1, wherein the method further comprises: In step 3, the reserved parts and the steel cage are fixed together by welding or mechanical connection to form an integral structure, which shares the load and ensures that the reserved parts are accurately positioned and do not shift during subsequent construction.

4. The method of claim 1, wherein the method further comprises: In step 5, during the concrete pouring process, the pouring speed of the concrete is controlled within the range of 2 to 4 m³ / h, and the concrete is poured in layers, with the thickness of each layer meeting the design requirements, to ensure that the concrete fully fills the groove and the space around the reserved parts.

5. The method of claim 1, wherein the method further comprises: In step 6, the subsequent construction of the underground connecting passage includes: excavation, support, and structural construction of the passage; Tunnel excavation: The tunnel excavation operation shall be carried out using appropriate excavation equipment and methods (including mechanical excavation and manual assistance). During the excavation process, attention shall be paid to controlling the excavation size and slope. Channel support: Based on the geological conditions and design requirements of the channel, timely support construction shall be carried out. Support methods include anchor bolt support and shotcrete support to ensure the stability of the channel after excavation. Structural construction: Complete the structural construction of the passage, including rebar tying, formwork installation, and concrete pouring, to form a complete underground connecting passage structure.

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