Grating dam structure and construction method thereof

Abstract

The invention provides a grating dam structure and a construction method thereof.The grating dam structure comprises a plurality of herringbone frameworks, the lower portions of the herringbone frameworks are fixedly arranged in channel bed rock, the herringbone frameworks are arranged in the transverse direction of a channel at intervals, and the herringbone frameworks are formed by splicing rail profile steel and comprise upstream stand columns and downstream supporting columns; the tops of the upstream stand columns are connected with transverse connecting main beams, the adjacent downstream supporting columns are connected through transverse connecting secondary beams, longitudinal force transmission beams are connected between the upstream stand columns and the downstream supporting columns, transverse supports are connected between the upstream stand columns, and transverse connecting secondary beams are connected between the transverse supports. The transverse support is arranged on the upstream face which the upstream stand columns face jointly, and a flexible blocking protective net is further arranged on the upstream face of the transverse support. Large-area foundation excavation and concrete construction are omitted, construction is convenient, the construction period is shortened, and meanwhile the good blocking function is achieved.

Description

Technical Field

[0001] This invention relates to the field of debris flow prevention and control structure technology, specifically to a grid dam structure and its construction method. Background Technology

[0002] Grid dams are a common structure in debris flow control projects. Currently, grid dams used in debris flow prevention are generally made of concrete, with pre-reserved gaps within the concrete structure. These gaps are filled with embedded steel sections and reinforced mesh to create channels for filtering debris and allowing water to pass through. However, this type of grid dam is large in size, has a long construction period, and carries significant risks when constructed within the gully. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the first objective of this invention is to provide a grid dam structure. Compared to traditional concrete grid dam structures, this invention eliminates the need for large-scale foundation excavation and concrete construction, making construction easier, shortening the construction period, and providing excellent retaining capacity.

[0004] In a first aspect, the present invention provides a grid dam structure, comprising a plurality of herringbone-shaped frames fixedly disposed in the bedrock of a ditch and spaced apart along the transverse direction of the ditch. The herringbone-shaped frames are constructed by splicing together rail steel sections and include upstream columns and downstream support columns. Each upstream column is connected to a transverse connecting main beam at its top. Adjacent downstream support columns are connected by transverse connecting secondary beams. A longitudinal force transmission beam connects the upstream columns and the downstream support columns. A transverse support connects each upstream column. The transverse support is disposed on the upstream face that the upstream columns all face, and a flexible barrier net is also disposed on the upstream face of the transverse support.

[0005] As a preferred technical solution of the present invention: the grid dam structure further includes a strip concrete base disposed in the ditch and arranged along the transverse direction of the ditch, and the lower part of the upstream column has a pre-embedded section embedded in the strip concrete base.

[0006] As a preferred embodiment of the present invention: the upstream column is vertically fixed to the bedrock of the ditch, the downstream support column is obliquely fixed to the bedrock of the ditch, and a limiting plate is provided above the connection between the upstream column and the downstream support column.

[0007] As a preferred technical solution of the present invention: the upstream column and the downstream support column are buried in the pile hole in the bedrock of the ditch, and are anchored to the pile hole by mortar.

[0008] As a preferred embodiment of the present invention: the length of the upstream support column located in the bedrock of the ditch is not less than 1 / 2 of its exposed length, and the length of the downstream support column located in the bedrock of the ditch is not less than 1 / 4 of its exposed length.

[0009] As a preferred embodiment of the present invention: multiple transverse supports are provided and are arranged at intervals along the height direction of the upstream column, and the two ends of the transverse supports are fixedly connected to the strip concrete base.

[0010] As a preferred technical solution of the present invention: the pre-embedded section is provided with a through hole, the reinforcing bar is inserted into the through hole and forms an anchored connection with the strip concrete base.

[0011] As a preferred technical solution of the present invention: at least one layer of steel mesh is provided on the upper part of the strip concrete base.

[0012] As a preferred technical solution of the present invention: the strip concrete base is provided with a plurality of anchor piles in the bedrock of the ditch, the anchor piles are provided between adjacent upstream columns, and the top of the anchor bar inside the anchor pile is bent to form a hook and connected to the steel mesh layer of the strip concrete base.

[0013] Secondly, a second objective of the present invention is to provide a construction method for a grid dam structure, comprising the following steps:

[0014] S1. Excavate the strip concrete base. The minimum requirements for the foundation excavation are: when the thickness of the overburden is less than or approximately equal to the thickness of the strip concrete base, excavate the overburden down to the bedrock surface; when the thickness of the overburden is greater than the thickness of the strip concrete base, the excavation depth is approximately equal to the thickness of the strip concrete base; for exposed bedrock surfaces, only surface cleaning is required to directly serve as the foundation for the strip concrete base.

[0015] S2. Drill the upstream column, downstream support column and anchor pile holes on the foundation;

[0016] S3. Calculate the length of each upstream column and downstream support column based on the drilling depth. The cutting of the upstream column and downstream support column and the drilling of the through hole for the pre-embedded section of the upstream column are completed in advance in the factory.

[0017] S4. Install the upstream column and anchor pile, and seal the upstream column and anchor pile with mortar between the corresponding pile hole;

[0018] S5. Install the downstream support column, weld the top of the upstream column and the downstream support column, as well as the limit plate, and then anchor the downstream support column to the corresponding pile hole with mortar.

[0019] S6. Install the steel mesh layer and insert steel bars into the through holes of the upstream column;

[0020] S7. Construct strip concrete bases using formwork, and install transverse connecting main beams, longitudinal force transmission beams, transverse connecting secondary beams, transverse supports, and retaining netting.

[0021] The beneficial effects of the grid dam structure provided by this invention are as follows:

[0022] 1. This invention employs a "herringbone" frame as the core load-bearing structure, transforming the traditional vertical bearing mode into a more rational triangular stable structure. The upstream columns primarily bear impact and pressure, while the downstream support columns effectively provide resistance to horizontal thrust and stability, making the entire dam structure lighter yet more impact-resistant. The flexible retaining net not only effectively blocks solid materials of different particle sizes but also absorbs a large amount of energy through deformation and friction during large impacts, greatly reducing the impact force on the rigid main structure and extending the structural lifespan.

[0023] 2. Traditional concrete dams require extensive, deep foundation excavation to provide weight for slip resistance and overturning resistance. This invention, however, only requires localized excavation of the "strip concrete base," eliminating the need for extensive foundation excavation and directly reducing machinery operating costs, labor costs, and spoil disposal costs. The entire dam body can be constructed of steel sections, with concrete used only for localized foundations and anchoring. Compared to traditional dams constructed entirely of concrete, the amount of concrete used is reduced by orders of magnitude, significantly lowering material costs. This invention can adopt a "factory prefabrication, on-site assembly" model (e.g., steel cutting and drilling are completed in the factory), with on-site work mainly involving positioning, hoisting, welding, and anchoring. This avoids the long curing time problem in traditional concrete construction, resulting in faster construction speed and a significantly shorter construction period. This advantage is crucial for debris flow channels requiring rapid emergency treatment. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A cross-sectional view of a grid dam structure provided in an embodiment of the present invention;

[0026] Figure 2 This is an upstream vertical view of a grid dam structure provided in an embodiment of the present invention;

[0027] Figure 3 This is a cross-sectional schematic diagram of a strip concrete base provided in an embodiment of the present invention.

[0028] Attached reference numerals: 1. Upstream column; 2. Downstream support column; 3. Lateral connecting main beam; 4. Lateral support; 5. Longitudinal force transmission beam; 6. Lateral connecting secondary beam; 7. Limiting plate; 8. Pile hole; 9. Mortar; 10. Strip concrete base; 11. Barrier net; 12. Anchor pile; 13. Anchor pile hole; 14. Reinforcing mesh layer; 15. Through hole; 16. Reinforcing bar. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of the present invention, preferred embodiments of the present invention are described below in conjunction with specific examples. However, it should be understood that the accompanying drawings are for illustrative purposes only and should not be construed as limiting the present invention. For better illustration of this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable that some well-known structures and their descriptions may be omitted in the drawings for those skilled in the art. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting the present invention.

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0031] like Figure 1 and Figure 2 As shown, a grid dam structure includes several herringbone-shaped frames fixedly installed in the bedrock of a ditch and spaced at intervals along the transverse direction of the ditch (W). Specifically, a group of herringbone frames is arranged at intervals of 2-3 meters. The herringbone frames are constructed by splicing rail-shaped steel sections and include upstream columns 1 and downstream support columns 2. Each upstream column 1 is connected to a transverse connecting main beam 3 at its top. Adjacent downstream support columns 2 are connected by transverse connecting secondary beams 6. Multiple transverse connecting secondary beams 6 are provided and spaced at intervals along the height direction of the downstream support columns 2. Several longitudinal force transmission beams 5 connect the upstream columns 1 and the downstream support columns 2. The longitudinal force transmission beams 5 are spaced at intervals along the height direction of the downstream support columns 2. Transverse supports 4 connect each upstream column 1. The transverse supports 4 are located on the upstream face that the upstream columns 1 all face, and a flexible barrier net 11 is also provided on the upstream face of the transverse supports 4.

[0032] In this embodiment, the transverse connecting secondary beam 6, the longitudinal force transmission beam 5, and the transverse support 4 are all made of I-beams, while the transverse connecting main beam 3 is made of T-beams. The transverse connecting secondary beam 6, the longitudinal force transmission beam 5, the transverse support 4, and the transverse connecting main beam 3 are all connected to the upstream column 1 and the downstream support column 2 by welding.

[0033] The grid dam structure also includes a strip concrete base 10 installed in the ditch and arranged along the transverse direction of the ditch, and the lower part of the upstream column 1 has a pre-embedded section embedded in the strip concrete base 10.

[0034] In this embodiment, the thickness of the strip concrete base 10 is set to 1~2m, the minimum width is 2m, and the upstream column 1 extends through the middle of the strip concrete base 10 into the bedrock of the ditch below.

[0035] The upstream column 1 is vertically fixed to the bedrock of the ditch, and the downstream support column 2 is obliquely fixed to the bedrock of the ditch. The included angle between the upstream column 1 and the downstream support column 2 is not less than 30°. A limiting plate 7 is provided above the connection between the upstream column 1 and the downstream support column 2.

[0036] The upstream column 1 and the downstream support column 2 are embedded in the pile holes 8 in the bedrock of the ditch, and are anchored to the pile holes 8 by mortar 9.

[0037] The length of the upstream support column 1 located within the bedrock of the ditch is not less than 1 / 2 of its exposed length, and the length of the downstream support column 2 located within the bedrock of the ditch is not less than 1 / 4 of its exposed length.

[0038] Multiple transverse supports 4 are provided and are arranged at intervals along the height direction of the upstream column 1, with a spacing of 0.5~1.0m. The two ends of the transverse supports 4 are fixedly connected to the strip concrete base 10.

[0039] like Figure 3 As shown, the embedded section is provided with a through hole 15, and a reinforcing bar 16 is inserted through the through hole 15 and anchored to the strip concrete base 10. In this embodiment, the diameter of the through hole 15 is set to 30~35mm, the diameter of the reinforcing bar 16 is set to 28~32mm, the length of the reinforcing bar 16 is not less than 50cm, and the lengths of both ends of the reinforcing bar 16 anchored in the strip concrete are the same.

[0040] At least one layer of steel mesh 14 is provided on the upper part of the strip concrete base 10.

[0041] The strip-shaped concrete base 10 is equipped with several anchor piles 12 extending into the bedrock of the trench. The depth of the anchor piles 12 into the bedrock is determined by pull-out force calculation, but must extend at least 2 meters beyond the upstream column 1. Specifically, each anchor pile 12 includes anchor bars and mortar 9. Anchor pile holes 13 are drilled in the bedrock, and after the anchor bars are placed in the holes, mortar 9 is poured in to seal them. The anchor piles 12 are located between adjacent upstream columns 1. The top of the anchor bars inside the anchor piles 12 is bent to form hooks and connected to the steel mesh layer 14 of the strip-shaped concrete base 10.

[0042] The barrier net 11 is a passive protective net of appropriate size according to the diameter of the particles to be blocked. In this embodiment, a cable net is used. The net is fixed by steel strands and transverse support 4 plates, and the net is kept in a loose state.

[0043] A construction method for a grid dam structure, comprising the following steps:

[0044] S1. Excavate the foundation of the strip concrete base 10. The minimum requirements for foundation excavation are as follows: when the thickness of the overburden layer is less than or approximately equal to the thickness of the strip concrete base 10, excavate the overburden layer down to the bedrock surface; when the thickness of the overburden layer is greater than the thickness of the strip concrete base 10, the excavation depth is approximately equal to the thickness of the strip concrete base 10; for exposed bedrock surfaces, only surface cleaning is required to directly serve as the foundation of the strip concrete base 10.

[0045] S2. Drill the upstream column 1, the downstream support column 2 and the anchor pile 12 on the foundation and drill the pile hole 8.

[0046] For cases where the overburden has not been completely removed or the bedrock is relatively broken, root tube drilling is used, and the root tube is pulled out in time after the upstream column 1, downstream support column 2 and anchor bars are installed.

[0047] S3. Calculate the length of each upstream column 1 and downstream support column 2 based on the drilling depth. The cutting of upstream column 1 and downstream support column 2 is completed in advance in the factory, as well as the drilling of the through hole 15 of the pre-embedded section of upstream column 1.

[0048] S4. Install upstream column 1 and anchor pile 12. Seal the upstream column 1 and anchor pile with mortar 9 between the corresponding pile hole 8.

[0049] S5. Install the downstream support column 2, weld the top of the upstream column 1 and the downstream support column 2 and weld the limiting plate 7, and then anchor the downstream support column 2 to the corresponding pile hole 8 with mortar 9.

[0050] S6. Install the steel mesh layer 14, and insert steel bars 16 into the through hole 15 of the upstream column 1.

[0051] S7. Construct strip concrete base 10 using formwork, and install transverse connecting main beam 3, longitudinal force transmission beam 5, transverse connecting secondary beam 6, transverse support 4, and retaining net 11.

[0052] This invention replaces the traditional cast-in-place gravity concrete structure with a prefabricated steel structure. Through its herringbone frame, flexible retaining netting, and locally reinforced base, it offers advantages such as rapid construction, low cost, safety, reliability, and environmental friendliness. This invention addresses industry pain points mentioned in the background section, such as "massive size, long construction period, and high construction risks within the gully," providing a new approach for debris flow prevention and control projects.

[0053] Traditional methods of large-scale excavation and concrete pouring within trenches are highly susceptible to weather and geological disasters (such as sudden flooding during the rainy season), resulting in high construction risks. The structure of this invention features a shorter construction cycle, a smaller on-site work area, and significantly reduced personnel exposure to hazardous environments, greatly improving construction safety. Multiple technical means are employed to enhance the overall structural resistance. For example, both the columns and support columns are anchored into bedrock, utilizing the rock's strength for anchoring force rather than relying solely on their own weight. The steel mesh layer in the base, the steel bars inserted into the upstream columns, and the design connecting the anchor hooks to the steel mesh ensure that the upstream columns and the concrete base work together to form a unified whole, avoiding weaknesses at the joints.

[0054] Based on the description and accompanying drawings of this invention, those skilled in the art can easily manufacture or use a grid dam structure and its construction method according to this invention, and can achieve the positive effects described in this invention.

[0055] Unless otherwise specified, in this invention, terms such as "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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, the terms used to describe orientation or positional relationships in this invention are for illustrative purposes only and should not be construed as limiting this invention. For those skilled in the art, the specific meaning of the above terms can be understood in conjunction with the accompanying drawings and according to the specific circumstances.

[0056] Unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" in this invention should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A grid dam structure, characterized in that: The system includes several herringbone-shaped frames fixedly installed in the bedrock of the ditch and spaced apart along the transverse direction of the ditch. The herringbone-shaped frames are constructed by splicing together rail steel sections and include upstream columns and downstream support columns. Each upstream column is connected to a transverse connecting main beam at its top. Adjacent downstream support columns are connected by transverse connecting secondary beams. A longitudinal force transmission beam connects the upstream columns and the downstream support columns. Transverse supports connect the upstream columns and are located on the upstream face that the upstream columns all face. A flexible barrier net is also installed on the upstream face of the transverse supports.

2. The grid dam structure according to claim 1, characterized in that: The grid dam structure also includes a strip concrete base set in the ditch and arranged along the transverse direction of the ditch, and the lower part of the upstream column has a pre-embedded section embedded in the strip concrete base.

3. The grid dam structure according to claim 1, characterized in that: The upstream column is vertically fixed to the bedrock of the ditch, and the downstream support column is obliquely fixed to the bedrock of the ditch. A limiting plate is provided above the connection between the upstream column and the downstream support column.

4. The grid dam structure according to claim 1, characterized in that: The upstream column and downstream support column are embedded in the pile holes in the bedrock of the ditch and are anchored to the pile holes by mortar.

5. The grid dam structure according to claim 1, characterized in that: The length of the upstream support column located within the bedrock of the ditch shall not be less than 1 / 2 of its exposed length, and the length of the downstream support column located within the bedrock of the ditch shall not be less than 1 / 4 of its exposed length.

6. The grid dam structure according to claim 2, characterized in that: Multiple transverse supports are provided and are spaced apart along the height direction of the upstream column. The two ends of the transverse supports are fixedly connected to the strip concrete base.

7. The grid dam structure according to claim 2, characterized in that: The pre-embedded section is provided with a through hole, through which a steel bar is inserted and anchored to the strip concrete base.

8. The grid dam structure according to claim 2, characterized in that: At least one layer of steel mesh is provided on the upper part of the strip concrete base.

9. The grid dam structure according to claim 8, characterized in that: The strip concrete base is provided with a number of anchor piles in the bedrock of the ditch. The anchor piles are located between adjacent upstream columns. The top of the anchor bar inside the anchor pile is bent to form a hook and connected to the steel mesh layer of the strip concrete base.

10. A construction method for a grid dam structure, characterized in that, The construction of the grid dam structure as described in claims 1-9 includes the following steps: S1. Excavate the strip concrete base. The minimum requirements for the foundation excavation are: when the thickness of the overburden is less than or approximately equal to the thickness of the strip concrete base, excavate the overburden down to the bedrock surface; when the thickness of the overburden is greater than the thickness of the strip concrete base, the excavation depth is approximately equal to the thickness of the strip concrete base; for exposed bedrock surfaces, only surface cleaning is required to directly serve as the foundation for the strip concrete base. S2. Drill the upstream column, downstream support column and anchor pile holes on the foundation; S3. Calculate the length of each upstream column and downstream support column based on the drilling depth. The cutting of the upstream column and downstream support column and the drilling of the through hole for the pre-embedded section of the upstream column are completed in advance in the factory. S4. Install the upstream column and anchor pile, and seal the upstream column and anchor pile with mortar between the corresponding pile hole; S5. Install the downstream support column, weld the top of the upstream column and the downstream support column, as well as the limit plate, and then anchor the downstream support column to the corresponding pile hole with mortar. S6. Install the steel mesh layer, insert steel bars into the through holes of the upstream column, and install the upstream transverse connecting main beam and transverse support. S7. Construct strip concrete base using formwork, and install longitudinal load-bearing beams, transverse connecting secondary beams, and retaining netting.

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