Overpass type construction method for underneath passing oil pipeline of ultra-large longitudinal slope comprehensive pipe rack

Abstract

The invention discloses an oversized longitudinal slope comprehensive pipe gallery underneath passing oil pipeline interchange type construction method, and belongs to the technical field of open cut tunnel construction. According to the method, an oil pipeline is suspended through concrete buttresses, bailey beams, suspenders and I-shaped steel, on the premise that normal operation of the oil pipeline is guaranteed, a longitudinal slope pipe gallery below is excavated, and the oil pipeline is constructed; during excavation, the form of a base plate of the ultra-large longitudinal slope pipe gallery structure is adjusted, a straight slope base plate is adjusted to be a step type slope, an anti-sliding key groove is additionally formed in the lower portion of the base plate, an open excavation method is adopted for constructing the pipe gallery structure below an oil conveying pipeline level crossing, the base plate of the pipe gallery structure is poured in a segmented mode, and in the time period of oil conveying pipeline suspension measure and backfill conversion, the anti-sliding key groove is formed. The brick foundation is additionally arranged at the bottom of the oil pipeline, it is guaranteed that the oil pipeline can be continuously kept stable after suspension measures are removed, the situation that due to the fact that backfill does not effectively support the oil pipeline, deflection of the oil pipeline is too large is avoided, the construction cost is saved, the construction period is shortened, and meanwhile normal operation of the oil pipeline is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of open-cut tunnel construction, and specifically relates to an overpass construction method for an oil pipeline under a super-large longitudinal slope comprehensive pipe gallery. Background Art

[0002] The underground integrated pipe gallery is an underground linear project, and during construction, it crosses various municipal roads and pipe networks. Especially in the complex terrain environment of the western region, the terrain difference is large. The underground integrated pipe gallery under the oil pipeline adopts the open excavation method for construction, and the longitudinal slope of the construction corridor is particularly large (the longitudinal slope reaches 33.18°, and there is no integrated pipe gallery with such a large slope in China at present). Figure 1 As shown, when the oil pipeline has been laid, it is necessary to excavate a large longitudinal slope integrated pipe gallery below the oil pipeline. The integrated pipe gallery and the oil pipeline are cross-distributed in the horizontal plane (there is a height difference in the vertical direction), which increases the difficulty of construction. And the construction plan of this large longitudinal slope integrated pipe gallery does not have the same experience reference. In addition, the large equipment and materials during the construction period will cause the operation safety of the oil pipeline above the pipe gallery to be difficult to ensure. At the same time, the integrated pipe gallery will also have the problems of slow construction speed, difficult to ensure construction quality, and difficult to ensure the safety of construction personnel. In view of this special construction situation, the present invention provides a method for constructing a large longitudinal slope pipe gallery under an overpass oil pipeline. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide an overpass construction method for an oil pipeline under an integrated pipeline corridor with a super-large longitudinal slope, so as to solve the problems of ensuring the operation safety of the upper oil pipeline and the construction quality and safety of the lower integrated pipeline corridor during the construction of the oil pipeline under an integrated pipeline corridor with a super-large longitudinal slope.

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

[0005] A construction method for an overpass type oil pipeline under a large longitudinal slope integrated pipe gallery, comprising the following construction steps:

[0006] Step S1, construction preparation: before construction, artificial trenching is used on both sides of the oil pipeline to determine the specific location and direction of the oil pipeline, and warning signs are set up on both sides of the pipeline construction;

[0007] Step S2, Bailey beam construction: after the deep trench is excavated, two concrete piers are respectively constructed and cast on both sides of the deep trench, the four concrete piers correspond to each other and are arranged opposite to each other along the length direction of the deep trench, a first Bailey beam arranged perpendicular to the length direction of the deep trench is installed and fixed between two adjacent concrete piers, and a second Bailey beam arranged along the length direction of the deep trench is installed and fixed between the two first Bailey beams;

[0008] Step S3, suspending the oil pipeline: a plurality of suspension rods are installed on the surface of the second Bailey beam at intervals along the length direction thereof, and each suspension rod is arranged vertically. At the same time, a plurality of brackets corresponding to the suspension rods are arranged at intervals along the length direction of the excavated deep trench, and each bracket is perpendicular to the length direction of the deep trench, and the brackets are all placed below the oil pipeline, the suspension rods are fixed to the corresponding brackets by bolts, and the oil pipeline is suspended below the second Bailey beam;

[0009] Step S4, excavation of the longitudinal slope pipe gallery: excavation of the longitudinal slope pipe gallery is performed below the oil pipeline, the longitudinal slope pipe gallery structure is stepped from top to bottom, and an anti-slip structure is provided at each step position;

[0010] Step S5, backfilling of the longitudinal slope pipe gallery: after the longitudinal slope pipe gallery structure reaches the design age, the backfilling construction of the longitudinal slope pipe gallery begins. The backfilling should be carried out in layers from bottom to top, and compaction is required after each backfilling is completed;

[0011] Step S6, construction of the oil pipeline protection culvert: when the longitudinal slope pipe gallery is backfilled to two meters below the oil pipeline, the oil pipeline protection cover culvert foundation, culvert body and cover plate construction are started on both sides along the length direction of the oil pipeline. First, two culvert body supports along the length direction of the oil pipeline are built and cast above the longitudinal slope pipe gallery backfill layer. The upper surfaces of the two culvert body supports are horizontally arranged, and the two culvert body supports are arranged on the inner sides of four concrete piers. Then, a vertically arranged culvert body structure is built and cast on the upper surfaces of the two culvert body supports. The height of the culvert body structure is higher than the oil pipeline. After the culvert body structure reaches the design age, the longitudinal slope pipe gallery and the gap between the two culvert body structures are continued to be backfilled until the backfill height is flush with the height of the culvert body structure.

[0012] Step S7, dismantling the Bailey beam: dismantling the first Bailey beam and the second Bailey beam by using a lifting device;

[0013] Step S8, installing the protection covers: using the lifting equipment to sequentially place multiple protection covers in an array on the top of two adjacent culvert structures, the length of each protection cover is perpendicular to the length of the oil pipeline, and any two adjacent protection covers are in contact with each other.

[0014] Furthermore, in step S3, when the bracket is placed on the lower surface of the oil pipeline, the soil under the oil pipeline should be hollowed out at intervals along the length of the oil pipeline for the bracket to be installed and fixed.

[0015] Furthermore, in step S4, when the longitudinal slope tunnel structure is excavated, layered excavation is adopted, and concrete pouring should also be carried out in sections. Slope support is constructed in time, and the depth of exposed bare soil during excavation shall not exceed 1m. A downward protruding anti-slip keyway is set at the position of each step. After excavation to the designed elevation, the concrete cushion layer, waterproof layer, protective layer, and tunnel floor structure are constructed in time, and the bottom of the pit is closed in time.

[0016] Furthermore, in step S5, due to the great depth of the excavation foundation pit of the longitudinal slope corridor, the backfill soil should be placed as low as possible into the foundation pits on both sides of the longitudinal slope corridor during backfilling. The backfilling should ensure that the backfilling progress on both sides is consistent, and the backfilling should be layered. The thickness of a single backfilling should not exceed 30 cm, and manual backfilling and compaction should be adopted within 50 cm of the walls on both sides.

[0017] Furthermore, in step S6, the culvert structure must be constructed in sections from bottom to top, and each section must be backfilled in time after completion. Fine sand is used to backfill the clearance space to ensure that it is filled solidly.

[0018] Further, in step S6, when the backfill height reaches 50 cm below the oil pipeline, piers are set below the oil pipeline and at intervals along its length, and asphalt hemp is used between each pier and the oil pipeline. Then, fine sand is backfilled below the oil pipeline and compacted with water. The backfill material is made of permeable materials that meet the design requirements, such as gravel and crushed stone. The permeable material has a reasonable gradation, the maximum particle size of the filler is not more than 50 mm, the loose laying thickness cannot exceed 150 mm, and all backfill work is done by manual compaction.

[0019] Further, in step S8, after the construction of the protective cover is completed, the opening should be sealed with bricks. After the protective cover is installed and the strength of the mortar and concrete reaches the designed strength, the two culvert structures are symmetrically backfilled on opposite sides at the same time, and the layers are rolled and their compaction degree is tested.

[0020] The beneficial effects of the present invention are:

[0021] 1. The invention adopts a construction process of suspended comprehensive protection of the oil pipeline during construction, and ensures "two-way safety" of the oil pipeline and the comprehensive pipeline corridor construction through the synchronous construction of the on-site underground comprehensive pipeline corridor and the overpass-type synchronous protection of the oil pipeline. This method can effectively improve the construction efficiency of the comprehensive pipeline corridor, and reduce the settlement of the oil pipeline when the foundation pit has a large span (27m), avoiding leakage or rupture of the oil pipeline due to large settlement during construction, ensuring the normal operation of the oil pipeline, and at the same time saving the construction period of the pipeline corridor project, improving the construction quality of the pipeline corridor project, ensuring the safety of the pipeline corridor project construction, reducing the investment in project measures, and saving the project cost compared with the underground excavation and underpass construction method;

[0022] 2. The present invention ingeniously adjusts the form of the floor plate of the super-large longitudinal slope corridor structure, adjusts the straight slope floor plate to a stepped slope, and adds an anti-slip key groove under the floor plate to increase the overall anti-slip ability of the longitudinal slope corridor. In addition, the corridor floor is quickly closed, and the longitudinal slope corridor structure floor is cast in sections to ensure the overall stability of the longitudinal slope corridor project quality. The longitudinal slope corridor operation scaffolding during construction adds connection measures (connection of scaffolding on both sides, connection of scaffolding and slope embedded parts) to ensure construction safety;

[0023] 3. During the period of suspension measures and backfill conversion of the oil pipeline, a brick foundation is added to the bottom of the oil pipeline to ensure that the oil pipeline can continue to remain stable after the suspension measures are removed, to avoid excessive deflection of the oil pipeline before the backfill soil forms an effective support for the oil pipeline, thereby affecting the safe operation of the oil pipeline. In addition, the Bailey beam is used as a material for protecting the oil pipeline. After the backfill is completed, the Bailey beam can be removed, which effectively reduces the generation of construction waste and effectively implements the concept of green construction. Compared with concrete beams, Bailey beams also have the advantages of fast installation and removal and a large number of turnover uses.

[0024] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0026] Figure 1 It is a partial cross-sectional view of the vertical section of the layout position of the super-large longitudinal slope integrated pipe gallery and the oil pipeline of the present invention;

[0027] Figure 2 It is a vertical cross-sectional view of the longitudinal slope pipe gallery of the present invention;

[0028] Figure 3 This is a schematic diagram of the installation positions of the first Bailey beam and the second Bailey beam of the present invention;

[0029] Figure 4 It is a vertical cross-sectional view of the protection duct of the present invention;

[0030] Figure 5 This is a schematic diagram of the installation covered by the present invention.

[0031] The following are marked in the accompanying drawings:

[0032] 1 oil pipeline, 2 concrete pier, 3 first Bailey beam, 4 second Bailey beam, 5 hanger, 6 bracket, 7 longitudinal slope corridor, 8 anti-slip keyway, 9 protection culvert, 901 culvert body support, 902 culvert body structure, 903 cover. DETAILED DESCRIPTION

[0033] like Figure 1 to Figure 5 As shown,

[0034] A method for constructing an overpass-type oil pipeline under a large longitudinal slope integrated pipe gallery, comprising the following construction steps:

[0035] Step S1, construction preparation: before construction, artificial trenching is used on both sides of the oil pipeline 1 along the length direction to determine the specific position and direction of the oil pipeline 1, and a special warning belt is set up along the entire line of the 10m area on both sides of the oil pipeline 1;

[0036] Step S2, Bailey beam construction: after the excavation of the deep trench is completed, two concrete piers 2 are respectively constructed and cast on both sides of the deep trench. During the construction of the foundation piles of the concrete piers 2, since the oil pipeline 1 passes through the middle of the pile foundation of the concrete piers 2, it is necessary to use a 4mm thick steel pipe to make a protective sleeve to protect the oil pipeline 1. The diameter of the steel sleeve is 20mm larger than the diameter of the oil pipeline 1 and the length is 2.5m. Among them, the four concrete piers 2 correspond to each other and are relatively arranged along the length direction of the deep trench. After the strength of the concrete piers 2 reaches 75% of the design strength, the first Bailey beam 3 perpendicular to the length direction of the deep trench is first installed and fixed between the two adjacent concrete piers 2, and then the second Bailey beam 4 arranged along the length direction of the deep trench is installed and fixed between the two first Bailey beams 3;

[0037] Step S3, oil pipeline suspension: a plurality of "U"-shaped threaded suspension rods 5 are installed on the surface of the second Bailey beam 4 at intervals along the length direction thereof, and each suspension rod 5 is vertically arranged, and the interval between any two adjacent suspension rods 5 is 3m. The bolts at the ends of the suspension rods 5 are made of Φ30 threaded steel bars bent. At the same time, a plurality of I18 I-beam brackets 6 corresponding to the suspension rods 5 are arranged at intervals along the length direction of the excavated deep trench, and each bracket 6 is perpendicular to the length direction of the deep trench, and the brackets 6 are all placed below the oil pipeline 1. When placing, the soil below the oil pipeline 1 should be dug out one by one in the direction of the length of the oil pipeline 1 (to prevent damage to the oil pipeline 1 due to the failure of individual suspension rods 5 to tighten the pipeline), and then the brackets 6 and the suspension rods 5 are fixed by double nuts, and the oil pipeline 1 is suspended below the second Bailey beam 4. After the oil pipeline 1 is suspended, the entire oil pipeline 1 is wrapped with fireproof cotton and fixed with cable ties every 20cm;

[0038] Step S4, excavation of the longitudinal slope corridor: excavation of the longitudinal slope corridor 7 is carried out below the oil pipeline 1, the longitudinal slope corridor 7 structure is stepped from top to bottom, and an anti-slip structure is set at each step position.

[0039] Among them, the excavation process of the longitudinal slope pipe gallery 7 includes foundation pit excavation, timely construction of slope support, the depth of exposed bare soil (unsupported part) shall not exceed 1m, the anti-slip key groove 8, the step-shaped platform, and the 30cm soil layer of the base are excavated manually, and multiple excavators are used to transfer the soil in the pit out of the foundation pit. After excavation to the designed elevation, the concrete cushion layer, waterproof layer, protective layer, and pipe gallery bottom plate structure are constructed in time, the bottom of the pit is closed in time, and the operation scaffolding outside the pipe gallery is set up. The scaffolding should be fixed to the embedded parts reserved on the slope, and the scaffolding on both sides also needs to be connected and fixed to increase the overall stability of the scaffolding;

[0040] Longitudinal slope corridor 7 structure construction: formwork support, steel bar binding, concrete pouring are carried out in succession. Note: Due to the large longitudinal slope of the foundation pit, concrete pouring should be carried out in sections to avoid excessive flow of concrete slurry to lower places during the pouring process. However, the next section of concrete should be poured before the previous section of concrete has finally set.

[0041] Step S5, backfilling of the longitudinal slope pipe gallery: when the longitudinal slope pipe gallery 7 structure reaches the design age, after the waterproofing and waterproof protective layer of the outer wall of the longitudinal slope pipe gallery 7 are completed, the backfilling construction of the longitudinal slope pipe gallery 7 begins. Because the foundation pit of the longitudinal slope pipe gallery 7 is deep, a long-arm excavator should be used to put the backfill soil as low as possible into the foundation pits on both sides of the longitudinal slope pipe gallery 7 during backfilling. The backfilling should ensure that the backfilling progress on both sides is consistent, and the backfilling is layered. The single backfilling thickness does not exceed 30cm. Manual backfilling and tamping are used within 50cm of the walls on both sides, and the backfilling is stopped after 2m below the oil pipeline 1;

[0042] Step S6, construction of the oil pipeline protection culvert: when the longitudinal slope pipe gallery 7 is backfilled to 2m below the oil pipeline 1, the oil pipeline 1 protection cover culvert foundation (culvert support 901), culvert body (culvert body structure 902) and cover (protection cover 903) are constructed on both sides along the length direction of the oil pipeline 1. First, two culvert body supports 901 along the length direction of the oil pipeline 1 are built and cast above the backfill layer of the longitudinal slope pipe gallery 7. The upper surfaces of the two culvert body supports 901 are horizontally arranged, and the two culvert body supports 901 are arranged on the inner sides of four concrete piers 2. Then, the vertically arranged culvert body structure 902 is built and cast on the upper surfaces of the two culvert body supports 901. The height of the culvert body structure 902 is higher than the oil pipeline 1. The culvert body structure 902 must be constructed in sections from bottom to top, and the gap between the two culvert body structures 902 should be backfilled in time after each section is completed. Fine sand is used to backfill the clearance, and it must be ensured that it is filled until the backfill height is flush with the height of the culvert body structure 902;

[0043] Among them, when the backfill height reaches 50cm below the oil pipeline 1, a pier with a height of 50cm and a width of 24cm is set at intervals of 3m below the oil pipeline 1 and along its length direction (the pier can be replaced by bricks or suitable stones, etc.), and asphalt hemp is used between each pier and the oil pipeline 1. Then, fine sand is backfilled under the oil pipeline 1 and filled with water. The backfill material is filled with permeable materials such as gravel and crushed stone that meet the design requirements. The permeable material has a reasonable gradation, the maximum particle size of the filler is not more than 50mm, and the loose laying thickness cannot exceed 150mm. All backfill work is done by manual compaction;

[0044] Step S7, dismantling the Bailey beam: first dismantle the suspended hanger 5 and bracket 6, ensuring that they are dismantled one by one to prevent damage to the oil pipeline 1 due to the loose support point below, and then dismantle the first Bailey beam 3 and the second Bailey beam 4 by hoisting equipment;

[0045] Step S8, installing the protective covers: using the lifting equipment to sequentially place multiple protective covers 903 in an array on the top of two adjacent culvert structures 902, the length of each protective cover 903 is perpendicular to the length of the oil pipeline 1, and any two adjacent protective covers 903 are in contact with each other. After the construction of the protective covers 903 is completed, the opening should be sealed with bricks. After the protective covers 903 are installed and the strength of the mortar and concrete reaches the designed strength, the two culvert structures 902 are symmetrically backfilled on opposite sides at the same time, and the layers are rolled and their compaction is tested.

[0046] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A construction method for an overpass type oil pipeline under a large longitudinal slope integrated pipe gallery, characterized in that: The construction steps include: Step S1, construction preparation: before construction, artificial trenching is used on both sides of the oil pipeline (1) to determine the specific location and direction of the oil pipeline (1), and warning signs are set up on both sides of the pipeline construction; Step S2, Bailey beam construction: after the deep trench is excavated, two concrete piers (2) are respectively constructed and cast on both sides of the deep trench, the four concrete piers (2) correspond to each other in pairs and are arranged opposite to each other along the length direction of the deep trench, a first Bailey beam (3) arranged perpendicular to the length direction of the deep trench is installed and fixed between two adjacent concrete piers (2), and a second Bailey beam (4) arranged along the length direction of the deep trench is installed and fixed between the two first Bailey beams (3); Step S3, suspending the oil pipeline: a plurality of suspension rods (5) are installed on the surface of the second Bailey beam (4) at intervals along the length direction thereof, and each suspension rod (5) is arranged vertically. At the same time, a plurality of brackets (6) corresponding to the suspension rods (5) are arranged at intervals along the length direction of the excavated deep trench, and each bracket (6) is perpendicular to the length direction of the deep trench, and the brackets (6) are all placed below the oil pipeline (1). The suspension rods (5) and the corresponding brackets (6) are fixed by bolts, and the oil pipeline (1) is suspended below the second Bailey beam (4); Step S4, excavation of the longitudinal slope pipe gallery: excavation of the longitudinal slope pipe gallery (7) is performed below the oil pipeline (1), the longitudinal slope pipe gallery (7) structure is stepped from top to bottom, and an anti-slip structure is provided at each step position; Step S5, backfilling of the longitudinal slope pipe gallery: after the longitudinal slope pipe gallery (7) structure reaches the design age, the backfilling construction of the longitudinal slope pipe gallery (7) is started. The backfilling should be carried out in layers from bottom to top, and compaction should be carried out after each backfilling is completed; Step S6, construction of the oil pipeline protection culvert: when the longitudinal slope pipe gallery (7) is backfilled to two meters below the oil pipeline (1), the oil pipeline (1) protection cover culvert foundation, culvert body and cover plate construction are started along both sides of the length direction of the oil pipeline (1). First, two culvert body supports (901) along the length direction of the oil pipeline (1) are built and cast above the backfill layer of the longitudinal slope pipe gallery (7). The upper surfaces of the two culvert body supports (901) are arranged horizontally, and the two culvert body supports (901) are arranged on the inner sides of four concrete piers (2). Then, a vertically arranged culvert body structure (902) is built and cast on the upper surfaces of the two culvert body supports (901). The height of the culvert body structure (902) is higher than the oil pipeline (1). After the culvert body structure (902) reaches the design age, the longitudinal slope pipe gallery (7) and the gap between the two culvert body structures (902) are continuously backfilled until the backfill height is flush with the height of the culvert body structure (902); Step S7, dismantling the Bailey beam: dismantling the first Bailey beam (3) and the second Bailey beam (4) by means of a lifting device; Step S8, installing the protective covers: using a lifting device to sequentially place a plurality of protective covers (903) in an array on the top of two adjacent culvert structures (902), the length of each protective cover (903) being perpendicular to the length of the oil pipeline (1), and any two adjacent protective covers (903) being in contact with each other.

2. The method for constructing an overpass-type construction of an oil pipeline under an ultra-large longitudinal slope integrated pipe gallery according to claim 1, characterized in that: In step S3, when placing the bracket (6) on the lower surface of the oil pipeline (1), the soil below the oil pipeline (1) should be hollowed out at intervals along the length direction of the oil pipeline (1) to provide space for the bracket (6) to be installed and fixed.

3. The method for constructing an overpass-type construction of an oil pipeline under an ultra-large longitudinal slope integrated pipe gallery according to claim 2 is characterized in that: In step S4, when the longitudinal slope pipe gallery (7) structure is excavated, layered excavation is adopted, and concrete pouring should also be carried out in sections. Slope support is constructed in time, and the depth of exposed bare soil during excavation shall not exceed 1m. A downward protruding anti-slip keyway (8) is set at the position of each step. After excavation to the designed elevation, the concrete cushion layer, waterproof layer, protective layer, and pipe gallery bottom plate structure are constructed in time, and the pit bottom is closed in time.

4. The method for constructing an overpass-type construction of an oil pipeline under an ultra-large longitudinal slope integrated pipe gallery according to claim 3 is characterized in that: In step S5, since the excavation depth of the foundation pit of the longitudinal slope pipe gallery (7) is large, when backfilling, the backfill soil should be placed as low as possible into the foundation pits on both sides of the longitudinal slope pipe gallery (7). The backfilling should ensure that the backfilling progress on both sides is consistent, and the backfilling should be layered. The single backfilling thickness does not exceed 30 cm, and manual backfilling and compaction are adopted within 50 cm of the walls on both sides.

5. The method for constructing an overpass-type construction of an oil pipeline under a large longitudinal slope integrated pipe gallery according to claim 4, characterized in that: In step S6, the culvert structure (902) must be constructed in sections from bottom to top, and each section must be backfilled in time after completion. Fine sand is used to backfill the clearance space to ensure that it is filled solidly.

6. The method for constructing an overpass-type construction of an oil pipeline under an ultra-large longitudinal slope integrated pipe gallery according to claim 5, characterized in that: In step S6, when the backfill height reaches 50 cm below the oil pipeline (1), piers are arranged below the oil pipeline (1) and at intervals along its length direction, and asphalt hemp is used as a cushion between each pier and the oil pipeline (1). Then, fine sand is backfilled below the oil pipeline (1) and compacted with water. The backfill material is made of permeable materials such as gravel and crushed stone that meet the design requirements. The permeable materials have a reasonable gradation, the maximum particle size of the filler is not more than 50 mm, and the loose laying thickness cannot exceed 150 mm. All backfill work is done by manual compaction.

7. The method for constructing an overpass-type construction of an oil pipeline under a large longitudinal slope integrated pipe gallery according to claim 6, characterized in that: In step S8, after the construction of the protective cover (903) is completed, the opening should be sealed with bricks. After the installation of the protective cover (903) is completed and the strength of the mortar and concrete reaches the designed strength, the two culvert structures (902) are symmetrically backfilled on opposite sides at the same time, and the layers are rolled and their compaction is tested.

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