Bridge construction cofferdam inner support structure

Abstract

The utility model relates to bridge construction technology field, concretely relates to a kind of inner bracing structure for bridge construction cofferdam;Including: lock mouth steel pipe pile, the lock mouth steel pipe pile is vertically arranged, and the lock mouth steel pipe pile vertically arranged is parallelly arranged with two, and the opposite side of two lock mouth steel pipe piles is provided with inner bracing part, and the inner bracing part includes first section steel, second section steel and concrete support layer.The inner bracing structure for bridge construction cofferdam, first section steel, second section steel and concrete support layer formed 6 surrounding purlins in order parallelly arranged from top to bottom, the 1-3 surrounding purlins close to surface adopt section steel and can be quickly assembled and pre-axial force, timely resist shallow soil lateral displacement, reduce initial deformation of excavation, deep 4-6 adopt reinforced concrete surrounding purlin, utilize its high cross-section rigidity to resist deep water and soil pressure, inhibit foundation pit bottom upheaval, such design, realize rigidity strengthening and deformation collaborative control by material combination and stratification design.

Description

Technical Field

[0001] This utility model relates to the field of bridge construction technology, and in particular to an internal support structure for bridge construction cofferdams. Background Technology

[0002] A bridge construction cofferdam is a temporary water-retaining structure erected during bridge construction to build piers or foundations in water. Its core function is to create a dry and stable working environment for the construction area.

[0003] Steel pipe pile cofferdams are one type of existing cofferdam, characterized by good waterproofing and reusability. However, steel pipe pile cofferdams require internal support in their design when in use.

[0004] Therefore, how to provide an internal support structure for bridge construction cofferdams has become a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0005] This utility model provides a solution that is significantly different from existing technologies, addressing the problem that existing technologies are too simplistic. To overcome the aforementioned deficiencies of existing technologies, this utility model provides an internal support structure for bridge construction cofferdams, aiming to solve the problems mentioned in the background.

[0006] To achieve the above objectives, this utility model provides an internal support structure for a bridge construction cofferdam, comprising: interlocking steel pipe piles, wherein the interlocking steel pipe piles are arranged vertically, and two interlocking steel pipe piles are arranged in parallel, and an internal support part is provided on the opposite side of the two interlocking steel pipe piles. The internal support part includes a first type of steel, a second type of steel and a concrete support layer, and the first type of steel, the second type of steel and the concrete support layer are arranged in parallel from top to bottom.

[0007] The interlocking steel pipe piles are the main load-bearing components in the cofferdam structure. The internal support is a key component ensuring the overall stability and construction safety of the cofferdam, and its main functions are to resist lateral pressure, maintain structural stability, and optimize the load transfer path. Six walers are formed by parallel arrangement of the first and second steel sections and a concrete support layer from top to bottom. The first to third walers near the ground surface use steel sections that can be quickly assembled and pre-stressed to resist lateral displacement of shallow soil and reduce initial excavation deformation. The fourth to sixth walers in the deeper layers use reinforced concrete walers, utilizing their high cross-sectional stiffness to resist deep soil and water pressure and suppress bottom heave of the excavation pit. This design, through material combination and layered design, achieves synergistic control of stiffness enhancement and deformation.

[0008] Preferably, the interlocking steel pipe pile uses φ820x14mm steel pipe.

[0009] The φ820mm large diameter combined with the 14mm thick wall greatly increases the moment of inertia of the steel pipe pile section, which can effectively resist the water and soil pressure and lateral load generated by deep water, rapid current or complex strata (isolated rocks, sunken ship obstacles), and reduce the risk of cofferdam deformation.

[0010] Preferably, the first steel section is 2HN500×200mm steel with a cross section of 500×200mm.

[0011] The first type of steel forms the first waler, serving as the first support layer. Its large cross-section moment of inertia can efficiently bear the lateral load of the shallow soil and significantly suppress the horizontal displacement in the early stage of foundation pit excavation.

[0012] Preferably, there are two second-section steels distributed longitudinally, and both second-section steels are 2HN700×300mm steels with a cross-section of 700×300mm.

[0013] Two secondary steel sections form the second and third walers. Located in the lower part of the foundation pit, these secondary steel sections bear the increased lateral load from the deeper soil. Their large cross-section moment of inertia significantly improves bending stiffness, effectively suppressing deep displacement in the foundation pit, reducing the risk of deformation of the retaining structure, and dispersing and transferring water and soil pressure to the internal support system through the walers, avoiding local stress concentration that could lead to cracking of the retaining wall and ensuring overall stability.

[0014] Preferably, the concrete support layer has three longitudinally distributed layers, and the ring beam of the three concrete support layers has a cross section of 900mm*1000mm, the diagonal brace and horizontal brace have a cross section of 600mm*600mm, and the counter brace has a cross section of 900mm*900mm.

[0015] The design of the three-layer concrete support layer forms the fourth, fifth, and sixth walers. Through the sectional graded design, the support logic of "edge reinforcement, core bearing, and spatial coordination" is realized, taking into account both safety and economy, and demonstrating the practicality of this device.

[0016] Preferably, a connecting part is provided between the inner support part and the interlocking steel pipe pile. The connecting part includes a connector and a connecting rod. The connector is provided on the interlocking steel pipe pile and is located at the connection between the interlocking steel pipe pile and the first steel, the second steel and the concrete support layer. The connecting rod is vertically distributed between the first steel, the second steel and the concrete support layer, and the connecting rod is made of either 609*16mm steel pipe or 529*10mm steel pipe.

[0017] To facilitate the lowering of the internal support, a connecting part is welded onto the internal support. This connecting part, often a support bracket or welded base, is the core load-bearing component of the connecting part. The positional accuracy of the pre-embedded connecting part directly affects the installation efficiency of the internal support and must be perpendicularly aligned with the axis of the interlocking steel pipe pile. The connecting rod is the "skeleton" of the spatial force-bearing system, transferring the axial pressure / tension of the internal support to the steel pipe pile, reducing lateral displacement of the cofferdam. Furthermore, by adjusting the internal force of the connecting rod through prestressing tension, it actively controls uneven settlement of the foundation pit. In use, two types of connecting rods are alternately installed.

[0018] Preferably, it also includes a sealing layer, which is located below the concrete support layer, and the sealing layer is made of C30 underwater concrete with a thickness of 2m.

[0019] The cofferdam's bottom sealing layer, together with the internal support, forms a waterless space, providing stable working conditions for processes such as foundation pouring. After the bottom sealing concrete is completed and reaches its design strength, the cofferdam bonds with the steel casing through the bottom sealing concrete, thus possessing a certain degree of anti-buoyancy capability. Foundation construction can then proceed after dewatering.

[0020] The beneficial effects of this utility model are:

[0021] In use, this utility model consists of six walers arranged in parallel from top to bottom: a first steel section, a second steel section, and a concrete support layer. The first to third walers, which are closer to the ground surface, are made of steel sections that can be quickly assembled and pre-stressed to resist lateral displacement of shallow soil and reduce deformation in the early stages of excavation. The fourth to sixth walers, which are deeper, are made of reinforced concrete, which uses its high cross-sectional stiffness to resist deep soil and water pressure and suppress heave at the bottom of the foundation pit. This design achieves stiffness enhancement and deformation control in a coordinated manner through material combination and layered design. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a front view structural diagram of the entire embodiment of this utility model.

[0024] Part Name

[0025] 1. Locked steel pipe pile; 2. First type of steel; 3. Second type of steel; 4. Concrete support layer; 5. Connector; 6. Connecting rod; 7. Sealing layer. Detailed Implementation

[0026] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings. Preferably, 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 intended to explain this utility model, and should not be construed as limiting this utility model.

[0027] In the description of this utility model, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, in the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] Please see Figure 1 This utility model provides an internal support structure for a bridge construction cofferdam, comprising: interlocking steel pipe piles 1, which are vertically arranged, and two interlocking steel pipe piles 1 are arranged in parallel. An internal support section is provided on the opposite side of the two interlocking steel pipe piles 1. The internal support section includes a first steel section 2, a second steel section 3, and a concrete support layer 4, which are arranged in parallel from top to bottom. The interlocking steel pipe piles 1 are made of φ820x14mm steel pipes. The first steel section 2 is made of 2HN500×200mm steel with a cross-section of 500×200mm. Two second steel sections 3 are longitudinally distributed, and both second steel sections 3 are made of 2HN700×300mm steel with a cross-section of 700×300mm. The concrete support layer 4 is longitudinally... The structure consists of three layers. The ring beam of the three concrete support layers 4 has a cross-section of 900mm*1000mm, the diagonal and horizontal braces have a cross-section of 600mm*600mm, and the counterbracing has a cross-section of 900mm*900mm. A connection is provided between the inner support and the interlocking steel pipe pile 1. The connection includes a connector 5 and a connecting rod 6. The connector 5 is installed on the interlocking steel pipe pile 1 and is located at the connection between the interlocking steel pipe pile 1 and the first steel section 2, the second steel section 3, and the concrete support layer 4. The connecting rod 6 is vertically distributed between the first steel section 2, the second steel section 3, and the concrete support layer 4. The connecting rod 6 is made of either 609*16mm steel pipe or 529*10mm steel pipe. The sealing layer 7 is located below the concrete support layer 4 and is made of C30 underwater concrete with a thickness of 2m.

[0029] In this embodiment:

[0030] The first step is to maintain the normal water level during the construction of the internal support. After the cofferdam is closed, the first internal support connector 5 is installed at +2.5m, and a concrete pad is set between the first internal support and the interlocking steel pipe pile 1.

[0031] The second step involves pumping water into the cofferdam to -2.0m, removing the old bridge abutment, installing the second inner support connector 5 at -0.5m, and setting up a concrete pad between the second inner support and the locking steel pipe pile 1.

[0032] The third step is to pump water into the cofferdam to -4.0m, install the third inner support connector 5 at -3.5m, and set up a concrete pad between the third inner support and the interlocking steel pipe pile 1.

[0033] The fourth step is to pump water into the cofferdam to -6.9m (-6.4m), install the fourth inner support connector 5 at -6.5m (-6.0m), and set up a concrete pad between the fourth inner support and the interlocking steel pipe pile 1.

[0034] The fifth step is to pump water into the cofferdam to -9.9m (-8.9m), install the fifth inner support connector 5 at -9.5m (-8.5m), and set up a concrete pad between the fifth inner support and the interlocking steel pipe pile 1.

[0035] Step 6: Pump water into the cofferdam to -12.9m (-11.9m), install the sixth inner support connector 5 at -12.5m (-11.5m), and set up a concrete pad between the sixth inner support and the interlocking steel pipe pile 1.

[0036] Step 7: After the foundation pit is pumped down to the bottom layer 7, drainage measures should be taken on site to remove the seepage water in the foundation pit in a timely manner and create a dry working environment.

[0037] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Those skilled in the art can understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present utility model are still within the scope of the utility model.

Claims

1. An internal support structure for a bridge construction cofferdam, comprising: A lock-joint steel pipe pile (1) is arranged vertically, and two lock-joint steel pipe piles (1) are arranged in parallel, and an inner support part is provided on the opposite side of the two lock-joint steel pipe piles (1). The inner support part includes a first steel section (2), a second steel section (3) and a concrete support layer (4), and the first steel section (2), the second steel section (3) and the concrete support layer (4) are arranged in parallel from top to bottom.

2. The internal support structure for bridge construction cofferdams as described in claim 1, characterized in that, The lock-type steel pipe pile (1) uses φ820x14mm steel pipe.

3. The internal support structure for bridge construction cofferdams as described in claim 1, characterized in that, The first type of steel (2) is 2HN500×200mm steel with a cross section of 500×200mm.

4. The internal support structure for bridge construction cofferdams as described in claim 1, characterized in that, There are two second-section steels (3) distributed longitudinally, and both second-section steels (3) are 2HN700×300mm steels with a cross section of 700×300mm.

5. The internal support structure for bridge construction cofferdams as described in claim 1, characterized in that, The concrete support layer (4) has three longitudinal layers, and the ring beam section of the three concrete support layers (4) is 900mm*1000mm, the diagonal brace and horizontal brace section is 600mm*600mm, and the cross brace section is 900mm*900mm.

6. The internal support structure for bridge construction cofferdams as described in claim 1, characterized in that, A connection is provided between the inner support part and the lock-mouth steel pipe pile (1). The connection part includes a connector (5) and a connecting rod (6). The connector (5) is provided on the lock-mouth steel pipe pile (1) and is located at the connection between the lock-mouth steel pipe pile (1) and the first steel (2), the second steel (3) and the concrete support layer (4). The connecting rod (6) is vertically distributed between the first steel (2), the second steel (3) and the concrete support layer (4). The connecting rod (6) is made of either a 609*16mm steel pipe or a 529*10mm steel pipe.

7. The internal support structure for bridge construction cofferdams as described in claim 1, characterized in that, It also includes a sealing layer (7), which is located below the concrete support layer (4) and is made of C30 underwater concrete with a thickness of 2m.

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