SY/T 7366-2024 Specification for design of oil and gas transmission pipelinecrossing engineering by open cut method in water areas English, Anglais, Englisch, Inglés, えいご
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ICS
E
Professional standard of the People's Republic of China
SY/T 7366-2024
Replaces SY/T 7366-2016
Specification for design of oil and gas transmission pipeline crossing engineering by open cut method in water areas
油气输送管道工程水域开挖穿越设计规范
(English Translation)
Issue date: 2024-09-24 Implementation date: 2025-03-24
Issued by National Development and Reform Commission, P.R.C
Contents
1 General provisions
2 Terms
3 Basie requirement..
4 Crossing location
5 Engineering investigation and survey
6 Open cut design.
6.1 Vertical section design
6.2 Trench excavation, backfilling
7 Loads and combinations.
7.1 Loads classification
7.2 Loads combinations
8 Crossing pipe segment design .
8.1 Pipe wall thickness Calculation.
8.2 Stiffness, strength and stability calculat
8.3 Seismic Design
8.4 Pipeline stabilization design
9 Corrosion, welding and pressure test...
9.1 Anticorrosion.
9.2 Welding and inspection.
9.3 Pigging and pressure test.
10 Excavation measures without water...
10.1 Cofferdam diversion.
10.2 Precipitation and drainage
10.3 Excavation support and monitoring.
11 Excavation measures under water.
11.1 Trench excavation.
12 Protective Engineering..
12.1 General requirement.
12.2 Slope protection..
12.3 Pipeline protection.
Appendix A Trench excavation slope stability evaluation and calculation
Appendix B Trench inflow calculation.
Explanation of wording in this code
List of quoted standards .
Additon : Explanation of calculation.
1.0.1 This code is formulated with a view to implementing national laws and regulations in the design of open-cut water crossings for oil and gas pipeline engineering, ensuring project quality, and achieving safety, environmental protection, economy, and applicability.
1.0.2 This code is applicable to the design of open-cut water crossings for onshore oil and gas pipeline engineering.
1.0.3 In addition to complying with this code, the design of open-cut water crossings for oil and gas pipeline engineering shall also comply with the requirements of current relevant national standards.
2 Terms
2.0.1
open cut crossing in water areas
A crossing method where pipelines are laid by excavating a trench through water areas, hereinafter referred to as "open cut crossing".
2.0.2
water areas
Rivers, lakes, canals, reservoirs, or channels formed naturally or constructed artificially.
2.0.3
action
Concentrated or distributed forces applied to a structure, or causes of imposed deformations or constraint deformations on the structure. The former are direct actions, also known as loads; the latter are indirect actions.
2.0.4
limit state method
A design method that prevents the structure from exceeding specified ultimate limit states.
2.0.5
permissible (allowable) stress method
A design method where the stress generated in the structure under characteristic actions does not exceed the specified permissible stress (characteristic strength of the material divided by a safety factor).
3 Basic Requirements
3.0.1 Open cut crossing projects shall be classified according to Table 3.0.1, and the design flood frequency corresponding to the project class shall be adopted. For crossing projects within 300m upstream of a bridge, the design flood frequency shall not be lower than the design flood frequency of that bridge.
Table 3.0.1 Classification of Open Cut Crossing Projects
3.0.2 For seasonal rivers or rivers without data, the water surface width may be selected as the width of the main river channel excluding floodplains. For wandering rivers, the water surface width shall be selected based on the meander belt of the thalweg; if data is unavailable, it should be selected as the width between the main levees on both banks. For projects with special requirements, the project class may be raised.
3.0.3 In the design of crossing projects, the design of the crossing pipeline shall adopt the permissible stress method, while the design of other structures shall adopt the limit state method.
3.0.4 The pipeline crossing location, burial depth, and method of crossing embankments shall meet the requirements of the competent authorities and shall satisfy relevant evaluation requirements.
3.0.5 The security prevention design for open cut crossing pipelines shall comply with the relevant provisions of the current industry standard Requirements for Security Risk Grade and Security Protection of Oil and Gas Pipeline Systems GA 1166.
3.0.6 Steel pipes used in open cut crossing projects shall comply with the relevant provisions of the current national standards Code for Design of Oil Transmission Pipeline Engineering GB 50253, Code for Design of Gas Transmission Pipeline Engineering GB 50251, and Code for Design of Oil-Gas Gathering and Transportation Systems in Oilfield GB 50350. The type and steel grade of the steel pipe shall match those of the pipeline sections connected at both ends.
4 Crossing Location
4.0.1 The crossing location shall conform to the general route alignment. For large and medium crossing projects, the local route alignment shall be adjusted according to the selected crossing location.
4.0.2 The crossing location shall avoid primary drinking water source protection zones and core areas of aquatic life protection zones. It should avoid the following water areas:
1 Secondary drinking water source protection zones, buffer zones, and experimental areas of aquatic life protection zones.
2 Controlled river reaches such as bends, easily shifting sections, easily changing shoals, confluences, and diffluences.
3 River reaches with large amplitude of riverbed scouring and silting.
4 River reaches with active adverse geological effects that directly endanger or potentially threaten the stability of the crossing project.
5 River reaches within active faults and their influence zones.
6 Areas affected by existing or planned hydraulic structures, anchorage grounds; when the crossing is located within a reservoir area, areas affected by reservoir bank reconstruction.
7 Sand dredging areas, quarrying areas, mining areas.
4.0.3 The selection of the crossing location should preferably meet the following requirements:
1 It should preferably be selected in a straight river reach with a stable riverbed and banks.
2 It should preferably be selected in an area where the variation range of flow scouring and silting is not significant and does not affect the implementation of relevant river planning.
3 It should preferably cross perpendicularly to the river axis; if an oblique crossing is necessary, the intersection angle should not be less than 60°.
4 It should preferably be selected at a location convenient for construction site access and mobilization of personnel and equipment.
4.0.4 The minimum distance between the centerline of the open cut crossing pipeline and existing structures such as railways, highways, ports, and docks shall comply with the provisions of the current national standard Code for Design of Oil and Gas Pipeline Crossing Engineering GB 50423.
4.0.5 Open cut crossing should avoid waterways of Class IV and above. Approval from the competent waterway authority shall be obtained before crossing waterways using the open cut method.
5 Engineering Investigation
5.1 Engineering Survey
5.1.1 The engineering survey for open cut crossing projects shall, in addition to complying with the provisions of this code, also be carried out in accordance with the current national standard Code for Survey of Oil and Gas Transmission Pipeline Engineering GB/T 50539.
5.1.2 The scope of the survey mapping shall meet the following requirements:
