Construction methods and waterproof structures to improve the waterproofing performance of construction joints in phased construction projects.

Abstract

This application discloses a construction method and a waterproof structure for improving the waterproofing performance of construction joints in phased implementation structures. The construction method includes: constructing a temporary support structure, which is set between the retaining transverse wall (1) and the initial structure (2) and is positioned on both sides of a waterstop (3) to provide temporary placement space for the waterstop (3), wherein the first end of the waterstop (3) is fixed in the initial structure (2); and constructing a waterproof structure, which is set in the construction joint of the phased implementation structure to prevent water from seeping from the water-facing side into the water-repellent side through the construction joint. By setting up a temporary support structure, on the one hand, support can be provided between the initial structure and the retaining transverse wall, and on the other hand, temporary placement space is provided for the reserved waterstop, thereby providing more options for the waterstops that can be used at the construction joint, thus improving the waterproofing effect of the waterproof structure at the construction joint of the phased implementation structure.

Description

Technical Field

[0001] This application relates to the field of tunnel construction, and more specifically, to a construction method and waterproof structure for improving the waterproof performance of construction joints in phased construction structures. Background Technology

[0002] Underground structures for rail transit are typically constructed using the open-cut method. Due to the complex and variable underground environment, high groundwater levels, and the risk of seepage, construction joints, as weak points where concrete connects different construction stages, are highly susceptible to water intrusion. Once leakage occurs, it not only affects the durability and safety of the tunnel structure but may also threaten internal facilities and track operation. Therefore, effective waterproofing at construction joints is a crucial measure to ensure the long-term stable operation of underground rail transit structures.

[0003] Currently, the waterproofing solution for circumferential construction joints at phased construction locations typically involves using water-swellable sealant combined with full-section grouting pipes. While this addresses the waterproofing issue to some extent, the sealant has poor adaptability to structural deformation and cracks, making it more susceptible to failure due to subsequent micro-displacements of the structure. It also requires high-quality concrete surface conditions and construction, as even slight oversights can lead to leakage. Furthermore, its durability and reliability under high water pressure and long-term service conditions are poor, making it difficult to meet high-standard waterproofing requirements and subsequent maintenance. In actual construction, to ensure stability between phased structures, a retaining wall is usually installed between the earlier and later phases, with the earlier structure tightly fitted to the retaining wall, making it impossible to pre-install a more effective waterproofing strip.

[0004] Therefore, how to provide a method that can provide sufficient space for reserving a waterstop with good waterproofing effect during phased structural construction has become a technical problem that needs to be solved in this field. Summary of the Invention

[0005] In view of this, this application proposes a construction method and waterproof structure to improve the waterproof performance of construction joints in phased construction structures.

[0006] According to one aspect of this application, a construction method for improving the waterproofing performance of construction joints in phased implementation structures is proposed. The construction method includes: constructing a temporary support structure, which is disposed between the retaining wall and the initial structure and is located on both sides of a waterstop to provide temporary placement space for the waterstop, wherein the first end of the waterstop is fixed in the initial structure; and constructing a waterproof structure, which is disposed in the construction joint of the phased implementation structure to prevent water from seeping from the water-facing side into the water-repellent side through the construction joint.

[0007] Preferably, the temporary support structure is located at the position of the base plate, side walls and top plate of the initial structure.

[0008] Preferably, the temporary support structure includes: a box-type component and jacks disposed in the box-type component to balance the soil pressure after unloading from the excavation of the foundation pit later.

[0009] Preferably, steel plates are provided around the radial perimeter of the box-shaped component; steel plates are provided at the top and bottom of the box-shaped component in the axial direction to prevent the jack from being suspended in the air; the box-shaped component is hollow inside to accommodate the jack.

[0010] Preferably, the distance between the enclosing transverse wall and the initial structure is 200mm-400mm.

[0011] Preferably, the construction waterproofing structure includes: a post-construction structure, which is the post-construction structure at the retaining transverse wall and between the retaining transverse wall and the initial structure; removal of the temporary support structure and the retaining transverse wall; the temporary support structure and the retaining transverse wall are removed sequentially from bottom to top; wherein, the second end of the waterstop is fixed in the post-construction structure.

[0012] Preferably, the waterstop is an embedded waterstop.

[0013] Preferably, the embedded waterstop is one of an embedded steel-edged rubber waterstop and a galvanized steel plate waterstop.

[0014] Preferably, the construction waterproofing structure further includes: setting a full-section grouting pipe, which is used to seal micro-cracks or leakage channels in the structure after construction is completed.

[0015] According to a second aspect of this application, a waterproof structure for phased construction joints is proposed, which is made using the aforementioned construction method.

[0016] According to the construction method for improving the waterproofing performance of construction joints in phased construction structures proposed in this application, by setting up temporary support structures, on the one hand, support can be provided between the initial structure and the retaining transverse wall, and on the other hand, space is provided for the temporary placement of the reserved waterstop, thereby providing more options for the waterstops that can be used at the construction joints, so as to improve the waterproofing effect of the waterproofing structure of the construction joints in phased construction structures.

[0017] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application, and the illustrative embodiments and descriptions thereof are used to explain this application. In the drawings:

[0019] Figure 1 This is a schematic diagram of the later structure before implementation of the preferred embodiment according to this application.

[0020] Figure 2 This is a cross-sectional schematic diagram of a box-type component according to a preferred embodiment of this application.

[0021] Figure 3 This is a side view of a box-type component according to a preferred embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the later structural construction according to the preferred embodiment of this application. Detailed Implementation

[0023] The technical solution of this application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] In this application, a circumferential construction joint in an underground structure constructed using the open-cut method is taken as an example.

[0025] In construction joints of phased construction structures, a common waterproofing solution involves both water-swellable sealant and full-section grouting. However, sealant has poor adaptability to structural deformation and cracks, making it more susceptible to failure due to micro-displacements in the later stages of construction. It also requires high-quality concrete surfaces and construction, as even slight oversights can lead to leakage. Furthermore, its durability and reliability under high water pressure and long-term service conditions are poor, making it difficult to meet high-standard waterproofing requirements and subsequent maintenance. On one hand, because the retaining transverse walls are closely attached to the initial structure, it is impossible to pre-install a centrally embedded waterstop with good waterproofing performance in the initial structure. On the other hand, if the distance between the retaining transverse walls and the initial structure is large, there will be no effective support between them during construction, resulting in poor stress and stability of the foundation pit, easily leading to excessive deformation or even local instability.

[0026] Therefore, as Figure 1 As shown, according to one aspect of this application, a construction method for improving the waterproofing performance of construction joints in phased implementation structures is proposed. The construction method includes: constructing a temporary support structure, which is set between the retaining transverse wall 1 and the initial structure 2, and is set on both sides of the waterstop 3 to provide temporary placement space for the waterstop 3, wherein the first end of the waterstop 3 is fixed in the initial structure 2; and constructing a waterproof structure, which is set in the construction joint 4 of the phased implementation structure to prevent water from seeping from the water-facing side into the water-repellent side through the construction joint 4.

[0027] The aforementioned temporary support structure is set in the space between the retaining transverse wall 1 and the initial structure 2. On the one hand, it plays a role in transmitting soil pressure during the excavation of the foundation pit of the initial structure 2 and before the implementation of the later structure 7. On the other hand, during the construction of the later structure 7, the support structure provides stable thrust to avoid the situation of uneven loading of the foundation pit in the later stage.

[0028] The aforementioned temporary support structure is set on both sides of the waterstop 3. The first end of the waterstop 3 is fixed in the initial structure 2, and the second end can be temporarily placed in the space formed by the temporary support structure, the initial structure 2, and the enclosure transverse wall 1.

[0029] The construction method proposed in this application for improving the waterproofing performance of construction joints in phased construction structures involves setting up a temporary support structure between the retaining structure and the initial structure 2. On the one hand, this provides support between the initial structure 2 and the retaining transverse wall 1, ensuring the stability of the construction structure. On the other hand, it provides temporary space for the reserved waterstop 3, thereby offering more options for the waterstop 3 that can be used at the construction joint 4, thus improving the waterproofing effect of the waterproofing structure at the construction joint 4 of the phased construction structure.

[0030] To provide stability to the retaining structure and the initial structure 2, the temporary support structure is preferably located at the bottom slab, side walls, and top slab of the initial structure 2. Positioning the temporary support structure at the bottom slab, side walls, and top slab can balance the soil pressure after unloading during later excavation, thereby enhancing the overall stability of the structure. During the construction of the later structure 7 at the retaining transverse walls and between the retaining transverse walls and the initial structure 2, the temporary support structure can be gradually dismantled from bottom to top as the later structure 7 is constructed. In areas where the later structure 7 has not yet been constructed, it can still transfer supporting forces, ensuring construction safety.

[0031] To transfer supporting forces to the retaining transverse wall 1 and the initial structure 2, the temporary support structure preferably includes: a box-type component 5 and jacks 6 disposed within the box-type component 5 to balance the soil pressure after unloading from the excavation of the foundation pit. The jacks 6 are disposed within the box-type component 5 at the locations of the bottom slab, side walls, and top slab of the initial structure 2, preventing the jacks 6 from being suspended in the air. The box-type component 5 is welded to steel plates embedded in the retaining transverse wall 1 and the initial structure 2; steel plates are arranged radially around the box-type component 5; steel plates are arranged axially at the top and bottom of the box-type component 5 to prevent the jacks 6 from being suspended in the air; the box-type component 5 is hollow inside to accommodate the jacks 6. This ensures that the jacks 6 are stable in position and accurate in direction of force during the stress process, preventing local structural damage or instability of the jacks 6 due to slippage or eccentric force. After welding and fixing, the box-type component 5 can better distribute the concentrated load, protect the concrete stress surface, and avoid local cracking and spalling. At the same time, it makes the force application of the jack 6 safer and more controllable, thereby improving the safety and stress effect of the structure during the construction stage.

[0032] The axial section of the aforementioned box-type component 5 can be of an appropriate shape, such as rectangular, square, or circular. In the construction field, square or rectangular shapes are generally used to make the load-bearing surface larger and easier to process.

[0033] like Figure 2 and Figure 3 As shown, the four radial edges of the aforementioned box-type component 5 are constructed using four L-shaped steel plates 51, which are welded together using connecting plates 52. The connecting plates are also steel plates. The top and bottom plates of the box-type component 5 are non-perforated steel plates 54, with perforated steel plates 53 spaced apart inside to accommodate jacks 6. The diameter of the perforated steel plates 53 is determined based on the diameter of the jacks 6, ensuring that the jacks can pass through and remain horizontal inside the box-type component 5. The number of perforated steel plates 53 is determined based on the actual length of the box-type component 5.

[0034] To ensure convenient placement of the jack 6 and prevent it from being suspended in mid-air, box-type components 5 are installed at both ends of the jack 6. During construction, the L-shaped steel plate 51 and the perforated steel plate 53 are first welded together, then the jack 6 is placed in the box-type component 5. Finally, the box-type component 5 is welded to the top plate (non-perforated steel plate 54) on the retaining wall 1 or the pre-construction structure 2. The jack 6 is adjusted, and the bottom plate (non-perforated steel plate 54) of the box-type component 5 is welded to the box-type component 5. Then, the steel plate at the bottom of the box-type component 5 is welded to the retaining wall 1 or the pre-construction structure 2, providing support or thrust to the retaining wall 1 and the pre-construction structure 2.

[0035] The number of temporary support structures is determined based on the width and height of the initial structure 2 or the enclosing transverse wall 1. Generally, the distance between adjacent temporary support structures in the horizontal direction is 3m; in the longitudinal direction, the distance between adjacent temporary support structures is 4m.

[0036] The aforementioned jack 6 can be of an appropriate type, such as a servo jack. The stroke of the jack can be adjusted according to changes in the force on the foundation pit support structure to balance the support force.

[0037] To allow sufficient space between the enclosing transverse wall 1 and the initial structure 2 for the temporary placement of the waterstop 3 and the provision of a temporary support structure, the distance between the enclosing transverse wall 1 and the initial structure 2 is preferably 200mm-400mm, and more preferably 400mm.

[0038] Preferably, the construction waterproofing structure includes: a post-construction structure 7, which is the post-construction structure 7 between the retaining transverse wall 1 and the initial structure 2; and the removal of the temporary support structure and the retaining transverse wall 1, which are removed sequentially from bottom to top; wherein the second end of the waterstop 3 is fixed in the post-construction structure 7.

[0039] During the construction of the later structure 7, the temporary support structure and the retaining transverse wall 1 are removed sequentially from bottom to top, so that the later structure 7 can be constructed between the earlier structure 2 and the later structure 7 which is far away from the earlier structure 2. During the construction process, at the construction site, the earlier structure 2 can be supported by the newly constructed later structure 7; at the unconstructed site, the earlier structure 2 can be supported by the thrust provided by the temporary support structure to ensure the stability of the earlier structure 2.

[0040] To improve the waterproofing effect of construction joint 4, preferably, the waterstop 3 can be a centrally embedded waterstop. A centrally embedded waterstop, embedded in concrete, forms a continuous, closed waterproof barrier, effectively resisting leakage and high water pressure, adapting to structural shrinkage, temperature differences, and minor deformations. It has excellent waterproofing effect and durability, making it suitable for basements, subways, tunnels, pools, and other structures with high waterproofing requirements. The aforementioned centrally embedded waterstop can take appropriate forms, such as a centrally embedded steel-edged rubber waterstop or a galvanized steel plate waterstop. In this application, a centrally embedded steel-edged rubber waterstop is used as an example. The rubber body adapts to structural shrinkage, temperature changes, and minor deformations, preventing leakage; the steel edge greatly improves the adhesion and sealing between the waterstop and the concrete, preventing the waterstop from loosening or leaking due to structural stress, shrinkage cracking, or local deformation, thus enhancing durability.

[0041] During construction, the waterstop 3 is placed in the middle of the horizontal direction of the initial structure 2. The steel edge of the waterstop 3 is welded and fixed to the main reinforcement of the initial structure 2 on the side of the initial structure 2, thereby pre-embedding the waterstop 3 in the initial structure 2. On the other side, before the construction of the later structure 7, it is placed in the space formed by the temporary support structure. When the later structure 7 is constructed, it is fixed in the later structure 7 using the same method.

[0042] like Figure 4 As shown, preferably, the construction waterproofing structure further includes: a full-section grouting pipe 8, which is used to seal micro-cracks or leakage channels in the structure after construction. After the later structure 7 and waterstop 3 are constructed, the full-section grouting pipe 8 is placed close to the construction joint 4 on both sides of the waterstop 3, with the water-facing side facing the joint, and concrete is poured. Concrete is also poured on both sides of the waterstop 3, and the grouting pipe is also pre-embedded in the concrete. In the event of leakage later, the grout quickly seals the leakage channel, achieving the best water-stopping effect.

[0043] The number of grouting pipes mentioned above is set according to actual needs, and the spacing between adjacent grouting pipes is 5m-6m.

[0044] According to a second aspect of this application, a waterproof structure for phased construction joints is proposed, which is made using the aforementioned construction method.

[0045] The construction method proposed in this application for improving the waterproofing performance at construction joints in phased construction structures is as follows:

[0046] 1. Construct the initial structure 2, fix the first end of the waterstop 3 on the initial structure 2; and implement a temporary support structure between the initial structure 2 and the retaining transverse wall 1.

[0047] 2. Excavate the deep foundation pit behind the retaining transverse wall 1 (away from the side of the initial structure 2), and construct the later structure 7 here. After the later foundation pit is excavated to the base, remove the retaining transverse wall 1 and the temporary support structure from bottom to top.

[0048] 3. As the retaining transverse wall 1 and the temporary support structure are demolished, the later structure 7 and the waterproof structure are gradually poured.

[0049] The preferred embodiments of this application have been described in detail above. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0050] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0051] Furthermore, various different embodiments of this application can be combined in any way, as long as they do not violate the spirit of this application, they should also be regarded as the content disclosed by this invention.

Claims

1. A construction method for improving waterproof performance at a construction joint in a structure constructed in stages, characterized by, The construction method comprises: construction of a temporary support structure, which is arranged between the retaining cross wall (1) and the early structure (2) and on both sides of the water stop belt (3) to provide a temporary space for the water stop belt (3), and the first end of the water stop belt (3) is fixed in the early structure (2); construction of a waterproof structure, which is arranged in the construction joint (4) of the staged structure to prevent water from penetrating from the water-facing surface into the water-backing surface through the construction joint (4); the temporary support structure is arranged at the positions of the floor, side wall and roof of the early structure (2); the temporary support structure comprises a box member (5) and a jack (6) arranged in the box member (5) to balance the earth pressure after the later foundation pit is excavated and unloaded; the box member (5) is provided with a steel plate around the radial direction; the top end and the bottom end of the box member (5) in the axial direction are provided with steel plates to avoid the jack (6) being suspended; the box member (5) is hollow inside to place the jack (6); the construction waterproof structure comprises: construction of a later structure (7), which is the later structure (7) at the retaining cross wall (1) and between the retaining cross wall (1) and the early structure (2); removal of the temporary support structure and the retaining cross wall (1); the temporary support structure and the retaining cross wall (1) are removed from bottom to top in sequence; wherein the second end of the water stop belt (3) is fixed in the later structure (7); the construction waterproof structure further comprises a full-face grouting pipe (8) arranged to seal the structure micro-cracks or leakage channels after the construction is completed.

2. The construction method for improving waterproof performance at a construction joint of a phased construction structure according to claim 1, characterized in that, The distance between the retaining cross wall (1) and the early structure (2) is 200-400 mm.

3. The construction method for improving waterproof performance at a construction joint of a phased construction structure according to claim 1, characterized in that, The water stop belt (3) is a middle-buried water stop belt.

4. The construction method for improving waterproof performance at a construction joint of a structure constructed in stages according to claim 3, characterized in that, The middle-buried water stop belt is one of a middle-buried steel edge rubber water stop belt and a galvanized steel plate water stop belt.

5. A waterproof structure of a construction joint executed in stages, characterized by The waterproof structure is made by the construction method of any one of claims 1-4.

Images