Corrugated steel box culvert channel structure and construction method used in highway engineering

Abstract

The present invention discloses a corrugated steel box-type culvert channel structure and construction method for highway engineering, including: a corrugated arc plate structure, an arc-shaped T-shaped steel structure and a connecting angle transverse flange; the corrugated arc plate structure includes a first corrugated arc plate and a second corrugated arc plate; the first corrugated arc plate and the second corrugated arc plate are adjacently arranged, and the two first corrugated arc plates arranged opposite to each other are connected in sequence through the connecting angle transverse flange to form a circle of corrugated pipe box segments; any adjacent segments of several circles of the corrugated pipe box segments are fixedly assembled and connected through the arc-shaped T-shaped steel structure. The problem of complex technical requirements, high engineering costs, and susceptibility of structures to settlement damage in the prior art when constructing culverts and channels of reinforced concrete structures under complex geological environments is solved.

Description

Technical Field

[0001] The invention relates to the technical field of highway engineering, and in particular to a corrugated steel box culvert channel structure and a construction method used in highway engineering. Background Art

[0002] At present, with the development of highway construction and the improvement of grade, expressways have been continuously extended to mountainous areas, coastal areas, etc., and more and more special geological environments are encountered. In the prior art, when building culverts and passages in complex areas, conventional reinforced concrete structures are usually used, which have complex technical requirements, high engineering costs, and poor use of structures, and uneven settlement damage of culverts often occurs. Summary of the invention

[0003] To this end, the present invention provides a corrugated steel box culvert channel structure and construction method for use in highway engineering, so as to solve the technical problems in the prior art of constructing culverts and channels of reinforced concrete structures under complex geological environments, such as complex technical requirements, high engineering costs, and the structures being easily damaged by settlement.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A corrugated steel box-type culvert channel structure used in highway engineering, comprising: a corrugated arc plate structure, an arc-shaped T-shaped steel structure and a connecting angle transverse flange;

[0006] The corrugated arc plate structure comprises a first corrugated arc plate and a second corrugated arc plate;

[0007] The first corrugated arc plate and the second corrugated arc plate are arranged adjacent to each other, and the two first corrugated arc plates arranged opposite to each other are butt-jointed with the two second corrugated arc plates arranged opposite to each other in sequence through the connecting angle transverse flange to form a circle of corrugated pipe box segments; any adjacent segments of several circles of the corrugated pipe box segments are fixedly assembled and connected through the arc-shaped T-shaped steel structure.

[0008] On the basis of the above technical solution, the present invention is further described as follows:

[0009] As a further solution of the present invention, the arc-shaped T-shaped steel structure includes a T-shaped steel body and T-shaped steel connecting bolts.

[0010] The two side surfaces of the middle longitudinal plate of the T-shaped steel body are respectively arranged in one-to-one correspondence between the two adjacent corrugated arc plate structures, and corresponding first openings are reserved between the middle longitudinal plate of the T-shaped steel body and the two adjacent corrugated arc plate structures, and the T-shaped steel connecting bolts and nuts are correspondingly assembled at the first opening positions of the T-shaped steel body and the two adjacent corrugated arc plate structures.

[0011] As a further solution of the present invention, T-steel connection gaskets are provided between the T-steel connection bolts and the corresponding corrugated arc plate structures, and between the assembly nuts of the T-steel connection bolts and the corresponding corrugated arc plate structures.

[0012] As a further solution of the present invention, a T-shaped steel water-swellable rubber strip is sandwiched between the transverse plate surface and the two side surfaces of the middle longitudinal plate of the T-shaped steel body and the two adjacent corrugated arc plate structures, and inherent sealant is also coated on the end edges between the transverse plate and the middle longitudinal plate of the T-shaped steel body and the two adjacent corrugated arc plate structures.

[0013] As a further solution of the present invention, the connecting angle transverse flange includes a first transverse flange, a second transverse flange and flange connecting bolts.

[0014] The first transverse flange is respectively fixed to the two side ends of the first corrugated arc plate, and the second transverse flange is respectively fixed to the two side ends of the second corrugated arc plate.

[0015] The first corrugated arc plate and the second corrugated arc plate which are arranged adjacent to each other are connected by fixed assembly via the first transverse flange and the second transverse flange.

[0016] The first transverse flange and the second transverse flange are arranged in contact with each other, and a corresponding second opening is reserved between the first transverse flange and the second transverse flange.

[0017] The flange connection bolts and nuts thereof are correspondingly assembled at the second opening positions correspondingly arranged on the first transverse flange and the second transverse flange.

[0018] As a further solution of the present invention, the second opening corresponds to the concave position of the first corrugated arc plate and the second corrugated arc plate.

[0019] As a further solution of the present invention, flange connection gaskets are provided between the flange connection bolts and the corresponding second transverse flange, and between the assembly nuts of the flange connection bolts and the corresponding first transverse flange.

[0020] As a further solution of the present invention, a flange water-swellable rubber strip is sandwiched in the middle position between the first transverse flange and the second transverse flange, and a foam sealing gasket is sandwiched in the side end position between the first transverse flange and the second transverse flange.

[0021] As a further solution of the present invention, the first transverse flange and the second transverse flange are both arranged in a Z-shaped structure, and the end edges of the gaps formed by the first transverse flange and the second transverse flange arranged opposite to each other are both facing downward.

[0022] The connecting angle transverse flanges at both sides of the connecting angles of the first corrugated arc plate at the top are arranged in an inverted eight shape.

[0023] The bending angles of the Z-shaped first transverse flange and the Z-shaped second transverse flange are both obtuse angle structures.

[0024] A construction method for a corrugated steel box culvert channel structure applied to highway engineering comprises the following steps:

[0025] Before the corrugated pipe box culvert is put in place on site, first excavate to 30cm below the bottom of the culvert body according to the culvert layout diagram, and excavate within 1m of the outermost extension of the corrugated pipe box culvert. After the excavation is completed, the foundation bearing capacity is tested, and the foundation bearing capacity is not less than 200kpa;

[0026] When the foundation is a stable soil stratum and the foundation bearing capacity is greater than the design bearing capacity, the base is not replaced and a gravel cushion layer with a thickness of 30 cm is directly set up in the lower bearing layer. The gravel cushion layer is laid to the first transverse flange on both sides of the first corrugated arc plate at the bottom of the corrugated pipe box culvert;

[0027] When the underlying layer of the culvert 30cm below the bottom of the culvert body is a rock base, the surface rock is replaced and compacted through the replacement layer 8, with a thickness of 60cm; when the underlying layer is a swamp or silt poor foundation, the replacement is carried out and compacted through the replacement layer 8, with a thickness of 80cm; the replacement material is based on the source of the ground material, and natural gravel, graded gravel, mountain stone, crushed stone or crushed stone soil (volume ratio crushed stone: soil = 3:7) is used for mechanical compaction in layers, and the thickness of each layer does not exceed 20cm. The compaction degree is detected by sand filling method or settlement observation method;

[0028] The designed size of the corrugated steel box culvert is 4m×3m. The material of the corrugated steel box culvert is Q235, Q355 or S460 steel plate. After processing and forming, the surface is hot-dip galvanized. The single-side galvanizing amount is not less than 600g / m, and the average thickness is not less than 84μm. The corrugated steel box culvert is assembled by connecting a single corrugated arc plate structure with a waveform of 400mm*150mm through an arc-shaped T-shaped steel structure and a connecting angle transverse flange in sequence;

[0029] At the inner bottom plate of the corrugated steel box culvert, a 10cm thick concrete anti-scour layer is poured above the corresponding first corrugated arc plate, and 15cm*15cm steel mesh sheets are placed at equal intervals inside the concrete anti-scour layer;

[0030] Backfill within the excavation range on the outermost side of the corrugated box culvert to form a special backfill area, and excavate and backfill in the special backfill area and on the outside of the cushion layer and replacement layer to form a general backfill area; the special backfill area uses well-graded natural gravel, graded gravel or medium-coarse sand with a mud content of not more than 10%; the particle size is not more than 30mm, and it is compacted in layers, with each layer not higher than 30cm and a compaction degree of not less than 96%; the backfill material for the general backfill area is 4% cement soil, medium-coarse sand with a mud content of not more than 10% or natural gravel, and does not contain crushed stone or hard soil blocks with a particle size exceeding 75mm, and does not contain frozen soil, turf, coal slag or organic matter; the general backfill area is compacted symmetrically on both sides by machinery every 20cm layer, and the compaction degree is in accordance with the roadbed construction requirements, and the roller runs parallel to the culvert.

[0031] The present invention has the following beneficial effects:

[0032] The structure and its construction method are to assemble the corrugated arc plate structure by means of arc-shaped T-shaped steel structure and connecting angle transverse flange to form a corrugated pipe box culvert. The corrugated pipe box culvert structure is made of steel, aluminum and other materials. The existence of axial corrugation makes the corrugated pipe have good force characteristics, and the stress concentration of the load can be dispersed more, especially in various types of bad engineering rock and soil areas such as soft soil areas, expansive soil areas, and collapsible loess areas. At the same time, the cost of the corrugated pipe culvert is more economical than that of the traditional reinforced concrete structure, and it has the advantages of fast construction speed and little influence by temperature. It is a new corrugated steel box culvert design form with simple structure, convenient installation, high construction efficiency, economical and practical, and excellent construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the implementation mode of the present invention or the technical solution in the prior art, the drawings required for the implementation mode or the description of the prior art will be briefly introduced below. The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0034] Figure 1 A schematic diagram of the overall axonometric structure of a corrugated steel box culvert passage structure applied to highway engineering provided in an embodiment of the present invention.

[0035] Figure 2 A schematic diagram of the axonometric structure of a first corrugated arc plate and first transverse flanges on both sides of the first corrugated arc plate in a corrugated steel box culvert channel structure applied to highway engineering provided by an embodiment of the present invention.

[0036] Figure 3A schematic diagram of the axonometric structure of an arc-shaped T-shaped steel structure in a corrugated steel box culvert passage structure applied to highway engineering provided in an embodiment of the present invention.

[0037] Figure 4 A schematic diagram of the front structure of a first corrugated arc plate and first transverse flanges on both sides of the first corrugated arc plate in a corrugated steel box culvert channel structure for use in highway engineering provided by an embodiment of the present invention.

[0038] Figure 5 A schematic diagram of the front structure of a second corrugated arc plate and second transverse flanges on both sides of the second corrugated arc plate in a corrugated steel box culvert channel structure applied to highway engineering provided by an embodiment of the present invention.

[0039] Figure 6 A schematic diagram of the overall front structure of a corrugated steel box culvert passage structure applied to highway engineering provided by an embodiment of the present invention.

[0040] Figure 7 A schematic diagram of the connection structure of an arc-shaped T-shaped steel structure in a corrugated steel box culvert channel structure applied to highway engineering provided in an embodiment of the present invention.

[0041] Figure 8 The corrugated steel box culvert channel structure applied to highway engineering provided by the embodiment of the present invention is Figure 6 Schematic diagram of the connection structure of the connecting angle transverse flange at A in the middle.

[0042] Fig. 9 A schematic diagram of the overall application structure of a corrugated steel box culvert channel structure applied to highway engineering provided by an embodiment of the present invention.

[0043] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0044] Corrugated arc plate structure 1: a first corrugated arc plate 11 and a second corrugated arc plate 12;

[0045] Arc-shaped T-shaped steel structure 2: T-shaped steel body 21, T-shaped steel connecting bolts 22, T-shaped steel connecting gaskets 23, T-shaped steel water-expandable rubber strips 24, and sealant 25;

[0046] Connecting angle transverse flange 3: first transverse flange 31, second transverse flange 32, flange connecting bolts 33, flange connecting gasket 34, flange water-expandable rubber strip 35, foam sealing gasket 36;

[0047] Special backfill area 4; general backfill area 5; concrete anti-scour layer 6; cushion layer 7; replacement layer 8. DETAILED DESCRIPTION

[0048] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The terms such as "upper", "lower", "left", "right", and "middle" used in this specification are only for the convenience of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships should be regarded as within the scope of the invention without substantially changing the technical content.

[0050] like Figures 1 to 8 As shown, an embodiment of the present invention provides a corrugated steel box culvert channel structure applied to highway engineering, including a corrugated arc plate structure 1, an arc-shaped T-shaped steel structure 2 and a connecting angle transverse flange 3, which are used to connect and assemble the corrugated arc plate structure 1 through the arc-shaped T-shaped steel structure 2 and the connecting angle transverse flange 3 to form a corrugated pipe box culvert. The corrugated pipe box culvert structure is made of steel, aluminum and other materials as a whole. The presence of axial corrugations makes the corrugated pipe have good force characteristics, and the stress concentration of the load can be dispersed more. Especially in various types of poor engineering rock and soil areas such as soft soil areas, expansive soil areas, and collapsible loess areas, its advantages can be fully utilized. At the same time, the cost of the corrugated pipe culvert is more economical than that of the traditional reinforced concrete structure, and it has the advantages of fast construction speed and little influence by temperature. It is a new corrugated steel box culvert design form with simple structure, convenient installation, high construction efficiency, economical and practical, and excellent construction quality. The specific settings are as follows:

[0051] Please refer to Figure 1 and Figure 6 The overall model size of the corrugated pipe box culvert is a span of 400cm, a rise of 300cm, a wave height of 150mm, and a wave distance of 400mm, and the corrugated pipe box culvert is assembled by connecting a plurality of corrugated arc plate structures 1 with the help of an arc-shaped T-shaped steel structure 2 and a connecting angle transverse flange 3; specifically, the corrugated arc plate structure 1 includes a first corrugated arc plate 11 and a second corrugated arc plate 12; the first corrugated arc plate 11 and the second corrugated arc plate 12 are both formed by cold rolling of Q235, Q355 or S460 steel plates, and the surface is hot-dip galvanized, the galvanizing amount is not less than 600g / ㎡, and the average thickness is not less than 84μm.

[0052] The first corrugated arc plate 11 and the second corrugated arc plate 12 are arranged adjacent to each other, and the two first corrugated arc plates 11 and the two second corrugated arc plates 12 arranged opposite to each other are connected in sequence through the connecting angle transverse flange 3 to form a circle of corrugated pipe box segments, and an arc-shaped T-shaped steel structure 2 is fixedly connected between any adjacent segments of several circles of the corrugated pipe box segments.

[0053] For details, please refer to Figure 1 , Figure 3 and Figure 7 The arc-shaped T-steel structure 2 includes a T-steel main body 21, a T-steel connecting bolt 22, a T-steel connecting gasket 23, a T-steel water-expandable rubber strip 24 and a sealant 25; wherein, the two side surfaces of the middle longitudinal plate of the T-steel main body 21 are respectively arranged one-to-one with the two adjacent corrugated arc plate structures 1, and a first opening correspondingly arranged is reserved between the middle longitudinal plate of the T-steel main body 21 and the two adjacent corrugated arc plate structures 1, the T-steel connecting bolt 22 and its nut are correspondingly assembled at the first opening position of the T-steel main body 21 and the two adjacent corrugated arc plate structures 1, and the T-steel connecting bolt 22 The T-steel connecting gasket 23 is provided between the corresponding corrugated arc plate structures 1, and between the assembly nut of the T-steel connecting bolt 22 and the corresponding corrugated arc plate structure 1, so as to improve the seismic resistance of the T-steel connecting bolt 22; the transverse plate surface and the two side surfaces of the middle longitudinal plate of the T-steel main body 21 are respectively sandwiched between the two adjacent corrugated arc plate structures 1 with T-steel water-swellable rubber strips 24, and the transverse plate and the middle longitudinal plate of the T-steel main body 21 are respectively coated with inherent sealant 25 at the end edge positions between the two adjacent corrugated arc plate structures 1, so as to achieve double-layer protection and ensure its waterproof sealing.

[0054] Please refer to Figure 2 , Figures 4 to 6 , Figure 8The connecting angle transverse flange 3 includes a first transverse flange 31, a second transverse flange 32, flange connecting bolts 33, a flange connecting gasket 34, a flange water-expandable rubber strip 35 and a foam sealing gasket 36; wherein, the first transverse flange 31 is respectively fixed to the two side ends of the first corrugated arc plate 11, and the second transverse flange 32 is respectively fixed to the two side ends of the second corrugated arc plate 12, and the adjacent first corrugated arc plate 11 and the second corrugated arc plate 12 are connected and assembled by the first transverse flange 31 and the second transverse flange 32; the first transverse flange 31 and the second transverse flange 32 are both obtuse-angle structures, without the curvature limit of the arc angle, so that the corrugated steel plate with large wave height and large moment of inertia can be used, which can significantly improve the strength of the bellows box; the first transverse flange 31 and the second transverse flange 32 are arranged in contact with each other, and the first transverse flange 31 and the second transverse flange 32 are reserved for each other. A corresponding second opening is provided, and the second opening corresponds to the recessed position of the first corrugated arc plate 11 and the second corrugated arc plate 12; the flange connecting bolts 33 and their nuts are correspondingly assembled at the second opening positions corresponding to the first transverse flange 31 and the second transverse flange 32, and the flange connecting gasket 34 is provided between the flange connecting bolts 33 and the corresponding second transverse flange 32, and between the assembly nut of the flange connecting bolts 33 and the corresponding first transverse flange 31, so as to effectively improve the seismic resistance of the flange connecting bolts 33; the flange water-swellable rubber strip 35 is also sandwiched in the middle position between the first transverse flange 31 and the second transverse flange 32, and the foam sealing pad 36 is also sandwiched at the side end position between the first transverse flange 31 and the second transverse flange 32, so as to achieve double-layer protection for the connecting structure of the connecting angle transverse flange 3, thereby ensuring its waterproof sealing.

[0055] As a preferred solution of this embodiment, the first transverse flange 31 and the second transverse flange 32 are both arranged in a Z-shaped structure, so that the end edges of the gaps formed by the first transverse flange 31 and the second transverse flange 32 that are arranged opposite to each other are both facing downward, so as to ensure that after the first transverse flange 31 and the second transverse flange 32 are installed, water will not flow into the culvert along the gap, thereby improving its protection performance; at the same time, the coupling design of the Z-shaped flange reduces the shear force of the transverse flange on the flange connecting bolts 33, enhances the anti-slip ability of the transverse flange, and improves the seismic resistance of the culvert; in addition, the transverse flanges 3 at the connecting corners on both sides of the first corrugated arc plate 11 at the top are arranged in an inverted eight shape, which is easier to install and disassemble, and is more convenient to maintain when used in the pipe gallery structure. On the basis of ensuring the structural performance, the overall functional practicality is effectively improved.

[0056] Please refer to Fig. 9The embodiment of the present invention also discloses a construction method of a corrugated steel box culvert channel structure applied to highway engineering, which specifically includes the following steps:

[0057] Before the corrugated pipe box culvert is put in place on site, first excavate to 30cm below the bottom of the culvert body according to the culvert layout diagram, and excavate within 1m of the outermost extension of the corrugated pipe box culvert. After the excavation is completed, the foundation bearing capacity is tested, and the foundation bearing capacity is not less than 200kpa;

[0058] If the foundation is a stable soil layer and the foundation bearing capacity is greater than the design bearing capacity, the base is not replaced, and a gravel cushion layer 7 with a thickness of 30 cm is directly set up in the lower bearing layer. The gravel cushion layer 7 is laid to the first transverse flange 31 on both sides of the first corrugated arc plate 11 at the bottom of the corrugated pipe box culvert;

[0059] When the underlying layer of the culvert 30cm below the bottom of the culvert body is a rock base, the surface rock is replaced and compacted through the replacement layer 8, with a thickness of 60cm; when the underlying layer is a swamp or silt poor foundation, the replacement is completed and compacted through the replacement layer 8, with a thickness of 80cm. The replacement material is based on the source of the ground material, and natural gravel, graded gravel, mountain stone, crushed stone or crushed stone soil (volume ratio crushed stone: soil = 3:7) is used for mechanical compaction in layers, and the thickness of each layer does not exceed 20cm. The compaction degree is tested by sand filling method or settlement observation method.

[0060] The designed size of the corrugated steel box culvert is 4m×3m. The material of the corrugated steel box culvert is Q235, Q355 or S460 steel plate. After processing and forming, the surface is hot-dip galvanized. The single-side galvanizing amount is not less than 600g / m, and the average thickness is not less than 84μm. The corrugated steel box culvert is assembled by sequentially docking a single corrugated arc plate structure 1 with a waveform of 400mm*150mm through an arc-shaped T-shaped steel structure 2 and a connecting angle transverse flange 3.

[0061] At the inner bottom plate of the corrugated steel box culvert, a 10 cm thick concrete anti-scour layer 6 is poured above the corresponding first corrugated arc plate 11, and 15 cm*15 cm steel meshes are placed at equal intervals inside the concrete anti-scour layer 6.

[0062] The excavation range at the outermost side of the corrugated pipe box culvert is backfilled to form a special backfill area 4, and the special backfill area 4 and the outer side of the cushion layer 7 and the replacement layer 8 are excavated and backfilled to form a general backfill area 5. According to the source of the ground materials at the construction site, the special backfill area uses well-graded natural gravel, graded gravel or medium-coarse sand (mud content shall not exceed 10%); the maximum particle size is not more than 30mm, and it is compacted in layers, with each layer up to 30cm thick and a compaction degree of not less than 96%; the backfill material of the general backfill area 5 is 4% cement soil, medium-coarse sand (mud content shall not exceed 10%) or natural gravel, without crushed stone or hard soil blocks with a particle size exceeding 75mm, and does not contain frozen soil, turf, coal slag or organic matter; the general backfill area 5 is compacted symmetrically on both sides by machinery every 20cm layer, and the compaction degree is in accordance with the roadbed construction requirements, and the roller runs parallel to the culvert.

[0063] If materials are difficult to purchase at the construction site, after a backfill compaction test based on the existing materials on site, the materials at the construction site may be used provided that the backfill requirements are met.

[0064] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A construction method for a corrugated steel box-type culvert channel structure applied to a highway project, wherein the corrugated steel box-type culvert channel structure applied to a highway project comprises a corrugated arc plate structure, an arc-shaped T-shaped steel structure and a connecting angle transverse flange; The corrugated arc plate structure comprises a first corrugated arc plate and a second corrugated arc plate; The first corrugated arc plate and the second corrugated arc plate are arranged adjacent to each other, and the two first corrugated arc plates arranged opposite to each other are butt-jointed with the two second corrugated arc plates arranged opposite to each other in sequence through the connecting angle transverse flange to form a circle of corrugated pipe box segments; any adjacent segments of several circles of the corrugated pipe box segments are fixedly assembled and connected through the arc-shaped T-shaped steel structure; characterized in that, The construction method comprises the following steps: Before the corrugated pipe box culvert is put in place on site, first excavate to 30cm below the bottom of the culvert body according to the culvert layout diagram, and excavate within 1m of the outermost extension of the corrugated pipe box culvert. After the excavation is completed, the foundation bearing capacity is tested, and the foundation bearing capacity is not less than 200kpa; When the foundation is a stable soil stratum and the foundation bearing capacity is greater than the design bearing capacity, the base is not replaced and a gravel cushion layer with a thickness of 30 cm is directly set up in the lower bearing layer. The gravel cushion layer is laid to the first transverse flange on both sides of the first corrugated arc plate at the bottom of the corrugated pipe box culvert; When the underlying layer of the culvert 30cm below the bottom of the culvert body is a rock base, the surface rock is replaced and compacted through the replacement layer 8, with a thickness of 60cm; when the underlying layer is a swamp or silt poor foundation, the replacement is carried out and compacted through the replacement layer 8, with a thickness of 80cm; the replacement material is based on the source of the ground material, and natural gravel, graded gravel, mountain stone, crushed stone or crushed stone soil are used for mechanical compaction in layers, and the thickness of each layer does not exceed 20cm. The compaction degree is detected by the sand filling method or the settlement observation method, and the volume ratio of the crushed stone soil is crushed stone: soil = 3:7; The designed size of the corrugated steel box culvert is 4m×3m. The material of the corrugated steel box culvert is Q235, Q355 or S460 steel plate. After processing and forming, the surface is hot-dip galvanized. The single-side galvanizing amount is not less than 600g / m, and the average thickness is not less than 84μm. The corrugated steel box culvert is assembled by connecting a single corrugated arc plate structure with a waveform of 400mm*150mm through an arc-shaped T-shaped steel structure and a connecting angle transverse flange in sequence; At the inner bottom plate of the corrugated steel box culvert, a 10cm thick concrete anti-scour layer is poured above the corresponding first corrugated arc plate, and 15cm*15cm steel mesh sheets are placed at equal intervals inside the concrete anti-scour layer; Backfill within the excavation range on the outermost side of the corrugated box culvert to form a special backfill area, and excavate and backfill in the special backfill area and on the outside of the cushion layer and replacement layer to form a general backfill area; the special backfill area uses well-graded natural gravel, graded gravel or medium-coarse sand with a mud content of not more than 10%; the particle size is not more than 30mm, and it is compacted in layers, with each layer not higher than 30cm and a compaction degree of not less than 96%; the backfill material for the general backfill area is 4% cement soil, medium-coarse sand with a mud content of not more than 10% or natural gravel, and does not contain crushed stone or hard soil blocks with a particle size exceeding 75mm, and does not contain frozen soil, turf, coal slag or organic matter; the general backfill area is compacted symmetrically on both sides by machinery every 20cm layer, and the compaction degree is in accordance with the roadbed construction requirements, and the roller runs parallel to the culvert.

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