NB/T 1002-2012Guides for preparation of preliminary design of underground oil storage in rock caverns project of national oil strategic reserve (provisional) (English PDF)

Foreword

This document was issued on 29 October 2012 by the National Energy Administration of the PRC and takes effect on 1 March 2013.

It is a NB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

It is classified under ICS 75.010, Chinese classification P71.

This specification was organized by the National Energy Administration and completed by a drafting group led by China International Engineering Consulting Corporation, together with Haigong Yingpaier Engineering Co., Ltd. and China Petroleum Pipeline Engineering Co., Ltd.

In 2010 construction started on the national oil strategic reserve underground oil storage in rock caverns (water-sealed cavern storage) projects. To unify and standardize the construction standards and technical level of water-sealed cavern storage, to guide the design and construction of such projects so that they comply with national policies and achieve safety and environmental protection, energy saving, advanced technology and economic rationality, the drafting group carried out extensive investigation of water-sealed cavern storage in China and abroad, drew on existing domestic construction standards for similar projects and on foreign construction experience, listened carefully to the opinions of the departments, organizations and experts concerned, discussed and revised the specification several times, and finalized it after a review organized by the National Energy Administration.

The specification consists of 22 chapters and 1 appendix. Chapters 17 to 22 are the special volumes submitted for review by the competent government administrative departments: the fire-fighting design volume, the environmental protection volume, the safety facilities design volume, the occupational hazard protective facilities design volume, the seismic fortification volume and the energy conservation volume. Each volume shall be bound as a separate book.

The specification is under the day-to-day administration of the Oil Reserve Office of the National Energy Administration, and China International Engineering Consulting Corporation is responsible for the explanation of its specific technical contents. Comments and suggestions arising during implementation should be sent to the Oil and Gas Division, Petrochemical, Light Industry and Textile Development Department, 18th Floor, Zhongzi Building, No. 32 Chegongzhuang West Road, Haidian District, Beijing, postcode 100048.

Drafting organizations: China International Engineering Consulting Corporation; Haigong Yingpaier Engineering Co., Ltd.; China Petroleum Pipeline Engineering Co., Ltd.

The Foreword also lists the principal drafters of the specification and the principal reviewers who examined it.

Publication data: energy industry standard of the People's Republic of China NB/T 1002-2012, record number J1500-2013, issued by the National Energy Administration on 2012-10-29 and implemented from 2013-03-01; approving department: National Energy Administration; published in Beijing, 2013.

1 Scope

NB/T 1002-2012 fixes the content and the level of detail of the preliminary design for underground crude oil storage in unlined rock caverns built for China's national strategic petroleum reserve. It is a provisional regulation. Water-sealed rock cavern storage holds crude in large excavated galleries below the water table: the groundwater pressure around the cavern is kept higher than the pressure of the oil inside, so the water seals the rock and the oil cannot escape. The design therefore depends on hydrogeology and on the water curtain system as much as on the excavation. The regulation sets the general provisions and defined terms, then specifies chapter by chapter what the preliminary design report must contain: the project basis and scale, the site conditions with the geological and hydrogeological investigation, the general layout of caverns, shafts and access tunnels, the water curtain system with its boreholes and the monitoring that proves the seal, the oil storage and transfer process with the pumps installed at the bottom of the shafts, the surface facilities and the connection to pipelines or terminals, the electrical, instrumentation and control systems, fire protection, building and structural works, heating, ventilation and air conditioning, water supply and drainage, safety and environmental protection, energy conservation, organisation and staffing, and the investment estimate. For each chapter the drawings and calculations to be presented are listed. It applies to the national strategic reserve projects of this type.

1.0.1 This specification is formulated in order to unify the content and depth of preliminary design documents for national oil strategic reserve underground oil storage in rock caverns projects.

1.0.2 This specification is applicable to the preliminary design of newly built national oil strategic reserve underground oil storage in rock caverns projects.

1.0.3 Preliminary design documents shall be prepared on the basis of the design commission, the feasibility study report, the approval documents of the competent government departments, the geotechnical investigation report, the basic design data and similar documents.

1.0.4 The depth of the preliminary design documents shall meet the requirements of review by the relevant national departments, of carrying out construction drawing design, of procurement of engineering materials and of construction preparation; the underground works part shall in addition meet the requirements of construction bidding.

1.0.5 This specification does not prescribe uniform formats for the drawings and tables of the preliminary design; the design organization may prepare them according to its own rules.

1.0.6 The arrangement of chapters and sections of the preliminary design documents may refer to this specification.

2 Terms

2.0.1 underground oil storage in rock caverns: an underground space system excavated in rock mass at a certain depth below a stable groundwater table, which stores crude oil by the principle of water sealing; also called underground water-sealed rock cavern oil depot, or water-sealed cavern storage for short.

2.0.2 cavern: an underground space excavated in rock mass and used for storing crude oil.

2.0.3 cavern tank: an underground space consisting of several interconnected caverns.

2.0.4 connecting tunnel: a passage connecting caverns with each other.

2.0.5 access tunnel: a dedicated passage from the ground surface to the caverns, meeting the needs during construction for equipment passage, muck removal, ventilation, water supply and drainage, power supply, personnel passage and the like.

2.0.6 shaft: a vertical connecting passage from the top of a cavern to the ground surface or to an operation tunnel.

2.0.7 shaft operation area: the area around the shaft head used for operation, maintenance and management of oil pumps, water pumps, instruments, electrical equipment and the like.

2.0.8 water curtain hole: a borehole drilled for artificial water injection in order to ensure the groundwater sealing conditions.

2.0.9 water curtain tunnel: a passage used for construction of the water curtain holes and for water injection.

2.0.10 operation tunnel: a passage leading from the ground surface to each shaft operation area.

2.0.11 concrete plug: a reinforced concrete member placed in a tunnel or shaft and used for plugging the cavern tank.

2.0.12 pump pit: a pit below the shaft in which submerged oil pumps, submerged water pumps and instruments are installed.

2.0.13 water bed: a water layer maintained to a certain height at the bottom of a cavern, used for settling impurities in the crude oil and collecting water seeping from the surrounding rock.

2.0.14 groundwater logging hole: a borehole used for monitoring the groundwater level and water quality.

2.0.15 wanter curtain logging hole (water curtain monitoring well): a well hole used for replenishing water to the water curtain system and for monitoring the water level and water quality within the water curtain system.

2.0.16 seepage water: groundwater contained in fissures of the rock mass.

2.0.17 storage perimeter: the boundary line of the construction protection zone required to keep the underground structures of the water-sealed cavern storage stable.

2.0.18 hydrogeological perimeter: the hydraulic protection boundary required to keep the groundwater level of the water-sealed cavern storage stable.

2.0.19 vapor recovery unit: a device that treats the oil vapour generated during oil receiving operations of the cavern tanks.

3 General Specification

3.0.1 The general description of the preliminary design shall include (but is not limited to): overview, design basis, design principles, main codes and standards applied, design scope and division of work, main technical schemes, environmental protection, safety facilities design, occupational health, energy saving measures, seismic fortification, main technical and economic indicators, main quantities table, personnel, vehicles and maintenance, project schedule, explanation of inconsistencies with the feasibility study scheme, existing problems and suggestions, attached drawings and attachments.

3.0.2 The overview shall mainly describe the construction scale, regional location, oil receiving and dispatching modes and site construction conditions of the depot.

3.0.2 item 1: The construction scale shall list the crude oil storage scale, the number of cavern tanks and the capacity of a single tank, the crude oil receiving and dispatching flow rates and the turnover rate.

3.0.2 item 2: The regional location shall describe the geographical position, surrounding resources, distance from sensitive areas and whether relocation is required.

3.0.2 item 3: The oil receiving and dispatching modes shall describe the means of transporting crude oil, such as oil pipelines or ship transport.

3.0.2 item 4: The site construction conditions shall describe the meteorological conditions, geological conditions, supporting conditions and similar contents.

3.0.3 The design basis shall list the names, document numbers and approving authorities of the feasibility study report and its approval, the environmental impact assessment report, the safety assessment report, the geological hazard assessment report, the water resources demonstration report, the occupational hazard pre-assessment report, the project energy-saving assessment opinion and its approval, the seismic safety evaluation report of the site, the design contract or commission letter and other documents.

3.0.4 The design principles shall describe how the national basic construction guidelines and policies are implemented, and the local supporting conditions.

3.0.5 The main standards and codes applied shall list the main general codes and the main discipline design codes applied to the project.

3.0.6 The design scope and division of work shall describe the design scope and content of each design organization and the design interface points.

3.0.7 The main technical schemes shall briefly describe the design schemes for storage and transportation, underground works, general layout and transportation, instrumentation and automatic control, electrical, telecommunications, architecture and structure, heating, ventilation and air conditioning, thermal engineering, water supply, drainage and fire protection, analysis and laboratory testing, anticorrosion and cathodic protection, personnel, vehicles and maintenance, and off-site works.

3.0.7 item 1: The storage and transportation design scheme shall describe the design technical parameters (crude oil physical properties, receiving and dispatching flow rates, cavern tank design temperature and design pressure, etc.), the main process flow, the selection of main equipment (including submerged oil pumps, submerged water pumps, transfer pumps and vapour treatment facilities) and the pipeline laying method.

3.0.7 item 2: The underground works technical scheme shall describe the capacity and number of crude oil cavern tanks, the plan layout of the cavern tanks (cavern axis direction, spacing, length, etc.), the cross-section dimensions of cavern tanks and tunnels, the elevations of caverns and water curtain tunnels, shaft diameters and numbers, the composition of the water curtain system, and the number and gradient of access tunnels and the number of monitoring holes.

3.0.7 item 3: The general layout and transportation scheme shall describe the regional location of the depot, the general plan layout, vertical planning, roads and rainwater drainage (road arrangement and widths, rainwater drainage and flood discharge design principles), and the main technical and economic indicators (total depot area, permanent land, temporary land, internal road length, area of main buildings and structures, green area, earth and rock volume).

3.0.7 item 4: The instrumentation and automatic control scheme shall describe the level of automation (the control system adopted and its main functions, and monitoring and control of surrounding rock stability, seepage pressure, vapour treatment, etc.).

3.0.7 item 5: The electrical design scheme shall describe the electrical load and load class, the power supply source, the arrangement of substations and distribution rooms, power supply and lighting, and lightning protection, anti-static and earthing.

3.0.7 item 6: The telecommunications design scheme shall briefly describe the telecommunication systems such as the automatic telephone system, production dispatching telephone system, wireless intercom, computer local area network, explosion-proof paging and intercom system, industrial CCTV monitoring system, automatic fire alarm system, intrusion alarm system and smart card management system.

3.0.7 item 7: The architecture and structure design scheme is divided into an architectural scheme and a structural scheme. The architectural scheme shall describe the floor area, structural form and storey height of each building; the structural scheme shall describe the foundation treatment scheme and similar contents.

3.0.7 item 8: The heating, ventilation and air conditioning scheme shall describe the heating and ventilation methods and similar contents.

3.0.7 item 9: The thermal engineering scheme shall describe the supply mode and scale of inert gas and heat sources.

3.0.7 item 10: The water supply, drainage and fire protection scheme shall describe the water source and supply capacity, the composition of the drainage system, the sewage treatment capacity, the discharge indicators achieved and the discharge destination; and the fire protection support, fire-fighting flow, and the configuration of fire equipment and main fire-fighting equipment.

3.0.7 item 11: The analysis and laboratory scheme shall describe the analysis contents and the main analytical instruments.

3.0.7 item 12: The anticorrosion and cathodic protection scheme shall describe the anticorrosion schemes for metal structures in the depot, the shaft area and the pipelines.

3.0.7 item 13: The off-site works scheme shall describe the off-site oil pipeline system, power supply, water supply and drainage, gas supply, heat supply, roads and similar schemes.

3.0.8 The environmental protection design shall describe the main pollutants, the main pollution sources, the environmental protection measures and their expected effects.

3.0.9 The safety facilities design shall describe the analysis of hazardous and harmful factors and the safety facilities and measures.

3.0.10 The occupational hazard protective facilities design shall describe the analysis of the influence of occupational hazard factors and the protective measures adopted for occupational health.

3.0.11 The energy-saving design shall describe the energy consumption analysis, energy-saving measures and their expected effects.

3.0.12 The seismic fortification design shall describe the seismic design group and fortification category, the seismic design measures and the expected effects of the seismic fortification.

3.0.13 The main technical and economic indicators are given in Table 3.0.13, with columns for serial number, unit (item) name, quantity (unit) and remarks. The rows are: total storage capacity; consumption indicators (fresh water, circulating cooling water where necessary, electricity, steam where necessary, fuel where necessary, nitrogen); total land area (permanent land in the depot and off-site, temporary land); area of main buildings and structures; discharge of the three wastes (waste water, waste gas, waste residue); total staffing; total energy consumption; consumption of the three main materials (reinforcing steel, timber where necessary, cement); and construction investment.

3.0.14 The main quantities are given in Table 3.0.14, with columns for serial number, engineering item, unit, quantity and remarks. Group I, water-sealed cavern storage: storage caverns, underground rock excavation, shotcrete, steel, rock bolts and water curtain holes. Group II, depot process: cavern tanks, export pumps, submerged oil pumps, submerged water pumps, slop oil pumps, inert gas injection system, flow meters, filters, valves, insulating equipment and vapour treatment units. Group III, line works: pipeline length and pipe material. Group IV, general layout and transportation: depot land acquisition area, green area, earth (rock) works, roads and boundary walls.

Table 3.0.14 (continued): Group V, instrumentation and automatic control: control system and instrument detection and regulation system. Group VI, communication: data transmission system, program-controlled dispatching switching system, industrial CCTV monitoring system, intrusion alarm system, electronic patrol system, office network system and structured cabling system. Group VII, power supply and distribution: cable lines, substation and transformers. Group VIII, fire protection: fire pump house, fire water pond, fire extinguishing devices, fire water pumps, fire pressure-stabilizing equipment and fire hydrants.

Table 3.0.14 (continued): Group IX, buildings (main buildings): integrated office building, substation, nitrogen generation station, fire pump house and integrated equipment room, oil transfer pump house, gatehouse and metering calibration room. Group X, water supply and drainage: oil separation tank, oily wastewater treatment room, oily wastewater equalization tank, sewage storage pond, slop oil pit, oily wastewater treatment unit and reinforced concrete septic tank. Group XI, heat supply, heating and ventilation: heating network (seamless steel pipe), entry wells, valve wells, electric heaters and ventilators. Note: the items in the table are for reference only and may be added or deleted according to actual conditions.

3.0.15 Personnel, vehicles and maintenance shall describe the staffing, vehicle configuration and maintenance and emergency repair conditions.

3.0.16 The project schedule shall describe the preliminary arrangement of project construction, with a construction schedule table or Gantt chart attached, stating the starting point of work (contract effective), and the progress of the main construction stages such as preliminary design, construction drawing design, procurement of equipment and materials, bidding, construction and trial operation.

3.0.17 Where major changes have occurred compared with the scheme of the feasibility study stage, the reasons shall be stated briefly and clearly.

3.0.18 The existing problems and suggestions shall describe the problems in the project design and put forward rational suggestions for the construction of the underground water-sealed cavern storage.

3.0.19 The attached drawings shall include the project regional location map, the general plan layout, the crude oil flow diagram, the process flow diagram and similar drawings.

3.0.20 The attachments shall include the various approval documents (evaluation opinions on and replies to the feasibility study report, etc.).

4 Oil Storage and Transportation

4.1 Storage and transportation within the depot area.

4.1.1 The preliminary design documents for storage and transportation within the depot area shall include (but are not limited to) the design description, equipment summary list, material summary list, technical specifications, piping and instrument diagrams, piping and equipment plan layouts and shaft piping layouts.

4.1.2 The design description shall include the design principles, design scope, supporting conditions, storage and transportation scheme, process flows, equipment selection, process piping design, list of main quantities, existing problems and suggestions.

4.1.2 item 1: The design principles shall state the principles followed in the design, based on relevant national guidelines, policies and regulations and the specific conditions of the project.

4.1.2 item 2: The design scope shall describe the composition of the project.

4.1.2 item 3: The supporting conditions shall describe the present state of the facilities on which the underground water-sealed cavern storage relies and the quantities of work required for their modification.

4.1.2 item 4, depot storage and transportation scheme: 1) briefly describe the start and end points, length, throughput, design pressure and transport mode of the external oil pipelines; 2) determine the burial depth of the storage caverns according to the hydrogeological conditions and required safety margin, and determine the maximum and minimum storage pressure according to the burial depth and the saturated vapour pressure of the stored oil.

4.1.2 item 4 (continued): 3) briefly describe the oil receiving rate, storage pressure, vapour evaporation and vapour treatment scheme of the storage; where a vapour recovery scheme is adopted, describe the calculation of recovered vapour, design scheme, process flow, land occupied and the selection of recovery and auxiliary equipment; where waste gas incineration is adopted, describe the waste gas generation, the models, specifications and numbers of incineration and auxiliary equipment, fuel consumption and source, and the size, number, location, storage time and transport mode of fuel tanks; 4) briefly describe the inert gas injection system scheme, mainly the gas supply parameters, supply mode, inert gas consumption, design scheme, process flow, equipment specifications and numbers, and the main parameters of the gas supply network.

4.1.2 item 5: The depot process flows shall include: 1) crude oil receiving and unloading flow; 2) crude oil storage flow; 3) crude oil export flow, either jetty ship-loading or pipeline export; 4) tank-to-tank transfer flow.

4.1.2 item 6, equipment selection: 1) equipment selection principles; 2) selection calculations for export pumps, submerged oil pumps and submerged water pumps, including flow, head, NPSH check and driving power; 3) determination from those calculations of pump models, specifications, numbers, driving power and mode, and standby arrangement.

4.1.2 item 6 (continued): 4) selection of filters for their different duties, stating connection diameter and design pressure; 5) selection of valves and actuators according to valve type and function, actuator performance, parameters and control mode, and the requirements of the process flows, stating their types and specifications, and giving reasons where imported items are required; 6) specifications and number of insulating equipment according to the cathodic protection requirements of the depot; 7) purpose, specifications and number of each non-standard equipment item.

4.1.2 item 7, depot process piping design: 1) determine the diameters and wall thicknesses of process piping, which may be tabulated with diameter, material, wall thickness and applicable standards; 2) laying methods and requirements of the piping in the depot.

4.1.2 item 8: The main quantities of storage and transportation are given in Table 4.1.2, listing cavern tanks (capacity, units), export pumps, submerged oil pumps, submerged water pumps and slop oil pumps (each with flow, head and driving power, units), vapour treatment unit (sets), inert gas injection system (sets), piping (m), flow meters, filters, valves and insulating equipment. Note: the items are for reference only and may be adjusted according to actual conditions.

4.1.3 The equipment summary list shall state the equipment type, name and tag number, and the numbers of each type ordered domestically and from abroad.

4.1.4 The material summary list shall be arranged in order of material grade from high to low, pressure from high to low, size from large to small and thickness from thick to thin, and shall state the specification, material and corresponding standard number.

4.1.5 Technical specifications (to be prepared for pumps, vapour treatment units and main valves) shall include: 1 general, project description; 2 standards, codes and technical documents; 3 basic engineering data; 4 technical requirements; 5 factory acceptance tests and site acceptance tests; 6 coating, packing, transport and nameplate; 7 personnel training requirements; 8 appendices and attached drawings; 9 documents to be submitted and technical services.

4.1.6 Piping and instrument diagrams may be divided by function into depot process flow diagrams, vapour recovery system flow diagrams, inert gas injection system flow diagrams and so on. They shall represent the complete production process and indicate equipment and valve numbers, a detailed flow description, the diameters and pressure classes of main process piping and the main equipment parameters.

4.1.7 Piping and equipment plan layouts are generally drawn per unit, showing the plan arrangement of equipment and piping, with elevations where necessary. They shall show: 1 locating dimensions of equipment with tag numbers; 2 maintenance spaces, access ways and roads; 3 names, outlines, location and form of buildings and structures within the unit or area; 4 routing, width, column spacing and tier elevations of pipe racks (belts, bridges), with dimensions.

4.1.7 (continued): 5 extent and dimensions of the unit battery limit or area, and coordinates of the battery limit or area; 6 description of the units of dimensions and coordinates and the related drawing numbers; 7 the building north arrow of the unit or area.

4.1.8 The existing problems and suggestions shall describe the problems in the storage and transportation design and put forward rational suggestions for the construction of the underground water-sealed cavern storage. Where there are major differences from the feasibility study scheme, the reasons shall be explained in detail.

4.2 Off-site storage and transportation: the preliminary design documents of off-site stations shall be prepared according to the requirements of 4.1; those of off-site oil pipelines shall follow the relevant provisions of current national standards.

5 Underground Engineering

5.0.1 The preliminary design documents for the underground works shall include (but are not limited to) the design description and the following drawings: general plan layout; cavern tank plans and sections; access tunnel, shaft, water curtain tunnel and connecting tunnel plans and sections; water curtain hole layout; crude oil cavern tank safety monitoring layout; support longitudinal profiles of main caverns, access tunnels, shafts, water curtain tunnels and connecting tunnels; typical shotcrete-bolting and grouting drawings for each of these; portal excavation and support drawing of access tunnels; pump pit reinforcement drawing; concrete plug plans, sections and support reinforcement drawings; hydrogeological monitoring layout; vibration (rockfall) monitoring layout; general construction layout plan; soil and water conservation layout; and construction control schedule.

5.0.2 The design description shall include the design basis, design principles, underground works layout, site conditions, description of surrounding rock stability and support design, grouting design, water curtain system design, concrete plug design, main materials, cleaning, washing, floor treatment, gas tightness test and volume measurement of the cavern tanks, monitoring of surrounding rock stability and water sealing conditions, construction organization design, bill of quantities, and existing problems and suggestions.

5.0.2 item 1: The design basis shall list the basis of the design, such as the detailed geological investigation report, the feasibility study report and its approval, and current relevant codes and regulations.

5.0.2 item 2: The design principles shall describe the general principles followed in structural design, mainly technical, economic and design service life aspects.

5.0.2 item 3, underground works layout: 1) principles for determining the cavern axes and the axis direction, with an explanation of the preliminary design choice if it differs from the feasibility study; 2) determination of cavern burial depth, for both the feasibility study and preliminary design stages; 3) arrangement, number and volume of cavern tanks, storage perimeter, hydrogeological perimeter and measures to adjust volume changes; 4) determination of cavern geometry, including cross-section shape and size, cavern length and spacing.

5.0.2 item 3 (continued): 5) number, cross-section shape and size, gradient, length and position of access tunnels, position and number of concrete plugs and treatment of tunnel portals; 6) position, number, cross-section, length of water curtain tunnels and position, length and number of water curtain holes; 7) position, number, cross-section and length of connecting tunnels; 8) position, function, number, cross-section and depth of shafts and pump pits, and elevation and number of concrete plugs.

5.0.2 item 4, site conditions: 1) natural conditions, including meteorology and topography; 2) regional geology and seismicity; 3) engineering geology, including lithology, geological structure, in-situ stress, adverse geology and physical-mechanical properties of rock; 4) hydrogeological conditions, including occurrence and distribution of groundwater, groundwater level and dynamics, recharge, runoff and discharge of bedrock fissure water, hydrogeological tests and rock permeability, groundwater chemistry and its corrosiveness to construction materials.

5.0.2 item 4 (continued): 5) evaluation of geological conditions, including surrounding rock quality classification, rockburst analysis, burial depth analysis of main caverns and sectional evaluation of their engineering geology; 6) engineering geological evaluation of access tunnels, water curtain tunnels and shafts, including surrounding rock class and support type; 7) evaluation of water sealing conditions, including design groundwater level and inflow prediction for access tunnels, water curtain tunnels and shafts; 8) conclusions and suggestions on seismic influence, cavern layout, water sealing performance, surrounding rock stability and groundwater corrosiveness, and on design optimization and monitoring.

5.0.2 item 5, surrounding rock stability and support design: 1) stability analysis, including deformation stability and block stability, with conclusions, process and method; 2) cavern support design, covering general principles, support of main caverns, access tunnels, water curtain tunnels and shafts, cavern intersections, treatment of adverse geology, support grouting at concrete plugs, treatment of unstable blocks and side walls of main caverns, rockburst prevention, treatment of adverse geology sections in water curtain tunnels, shafts and access tunnels, and treatment of seepage and water inflow in the underground caverns.

5.0.2 item 6: The grouting design shall describe the grouting principles, pre-grouting and post-grouting (preconditions, grout parameters, grouting pressure, duration, etc.) and the final seepage rate of the cavern tanks.

5.0.2 item 7, water curtain system design: 1) principle and function of the water curtain; 2) seepage field analysis, including natural, construction period and operation period seepage fields, with conclusions and suggestions; 3) layout of water curtain tunnels and holes; 4) drainage and water replenishment design; 5) water curtain system tests and commissioning.

5.0.2 item 8, concrete plug design: 1) access tunnel plugs, including geometry, manhole design, plug and surrounding rock reinforcement (pre- and post-grouting) and reinforcement layout; 2) shaft plugs, including geometry, steel formwork under the plug, openings for process piping, plug and surrounding rock reinforcement and reinforcement layout; 3) grouting design, including grout holes, grouting pressure and grout material selection.

5.0.2 item 9: The main materials shall list rock bolts, reinforcing steel, steel sections, concrete, cement mortar, prestressed anchor cables and similar materials.

5.0.2 item 10: Cleaning, washing, floor treatment, gas tightness test and volume measurement of the cavern tanks shall describe the design of cleaning, washing, floor treatment, test pressure and duration, the volume measurement requirements, methods and quality control.

5.0.2 item 11, monitoring of surrounding rock stability and water sealing: 1) monitoring purpose, design principles and basis; 2) main monitoring items and data acquisition; 3) design of safety monitoring points, including cavern safety monitoring (monitoring sections, rock deformation, anchorage stress, concrete lining support, construction period), water sealing control monitoring (groundwater level and quality, sealing pressure) and water curtain tunnel water pressure; 4) automated monitoring system design; 5) patrol inspection, items, records and reports; 6) selection of main instruments and the automated monitoring system.

5.0.2 item 12, construction organization design: 1) construction conditions, including project overview, hydrology, meteorology, topography and geology, supply of external materials, construction power, water supply, drainage and muck disposal; 2) construction scheme, including planning, sequence and methods, adverse geology measures, ventilation, power, water and communication during construction; 3) advance geological prediction, monitoring and dynamic construction measures; 4) key and difficult points and risk countermeasures.

5.0.2 item 12 (continued): 5) general construction layout, including site planning (material storage, prefabrication, equipment parking and repair, utilities, offices and living areas), traffic (external, on-site and in-tunnel), spoil and transfer yards and land occupied; 6) resource supply of main materials, machinery and personnel; 7) overall schedule, including basis and principles, preparatory works, main caverns schedule analysis and measures to accelerate progress; 8) construction and acceptance requirements, including recommended codes, key technical points and basic acceptance requirements.

5.0.2 item 13: The bill of quantities shall include rock excavation, shotcrete, rock bolts, grouting and similar quantities; the summary of excavation and support quantities may refer to Table 5.0.2, whose columns are main caverns, water curtain tunnels, shafts, access tunnels and connecting tunnels, and whose rows are open excavation and underground rock excavation (in ten thousand cubic metres, solid volume), shotcrete, cast concrete, pavement concrete and slope protection concrete (m3), reinforcing steel and steel sections (t), grouting (m3), rock bolts of all types (pieces), boreholes of all types (m), turf (m2), mortar rubble (m3), prestressed anchor cables (pieces) and cleaning area (m2).

5.0.2 item 14: The existing problems and suggestions shall describe the problems in the underground works design and put forward rational suggestions; where there are major differences from the feasibility study scheme, the reasons shall be explained in detail.

5.0.3 The general plan layout shall show topography, main geological structures, boundary wall and land acquisition line, hydrogeological perimeter, positions of main caverns, access tunnels, water curtain system and connecting tunnels with locating dimensions, overall dimensions and numbering, the north arrow, and the positions and coordinates of boreholes and shafts.

5.0.4 Cavern tank plans and sections shall show the length and spacing of each main cavern, the layout and elevations of connecting tunnels and the positions of concrete plugs.

5.0.5 Sections of access tunnels, shafts, water curtain tunnels and connecting tunnels shall show the main cross-section dimensions and elevations.

5.0.6 The water curtain hole layout shall show the plan locating dimensions, diameter and spacing of water curtain holes and the arrangement of turning caverns.

5.0.7 The crude oil cavern tank safety monitoring layout shall show the types of instruments, their arrangement and installation methods.

5.0.8 Support longitudinal profiles, typical shotcrete-bolting and typical grouting drawings of main caverns, access tunnels, shafts, water curtain tunnels and connecting tunnels shall show for each section the surrounding rock class, longitudinal gradient and chainage, cross-section support type, shotcrete thickness and rock bolt diameter and spacing for each rock class, the grout hole layout and sections, and the grouting reinforcement procedure.

5.0.9 The portal excavation and support drawing of access tunnels shall show the portal pavement elevation, layout of locking bolts (diameter, length, spacing, extent), layout and cross-section of drainage ditches at the portal, slope gradient and support form and parameters (where shotcrete-bolting is used, bolt diameter, length and spacing).

5.0.10 The pump pit reinforcement drawing shall show the pit dimensions and elevations, the diameter and spacing of reinforcing bolts and the thickness and strength grade of shotcrete.

5.0.11 Concrete plug plans and sections shall show the basic dimensions of the plug, the arrangement of reserved sleeves (manhole) and the formwork arrangement at the plug bottom (for shaft plugs).

5.0.12 The concrete plug support reinforcement drawing shall show the rock bolt parameters and layout and the reinforcement types of the strengthened sections on both sides.

5.0.13 The concrete plug reinforcement drawing shall show the basic dimensions of the plug and a schematic of reinforcement.

5.0.14 The general construction layout plan shall show the construction areas by function, including the construction substation, muck yard, reinforcement workshop, timber workshop, equipment warehouse, general warehouse and compressor station.

5.0.15 The soil and water conservation layout shall show the arrangement and cross-sections of intercepting drains and the protection design of slopes and muck yards.

5.0.16 The underground works construction control schedule shall show each construction process and the planned duration, and calculate the total construction period of the underground works.

6 Plot Plan & Transportation

6.0.1 The preliminary design documents for general layout and transportation shall include (but are not limited to) the design description, regional location map, general plan layout, vertical layout, depot pipeline composite plan, earthwork drawing and off-site road drawing. Where necessary, a depot road plan, depot rainwater drainage plan and a plan of depot retaining walls and slope protection may be drawn.

6.0.2 The design description shall include the design basis, project overview, general plan layout, vertical layout, roads and traffic, depot greening, general layout quantities, and existing problems and suggestions.

6.0.2 item 1, design basis: 1) the approval of the feasibility study by the competent departments or other planning land use permit conditions (road red lines, building red lines or land boundary lines, building height control, plot ratio, building density, green ratio, parking spaces, etc.), and special requirements for general layout, surrounding environment, spatial treatment, traffic organization, environmental protection, cultural relics protection and phased construction; 2) documents, reports and agreements related to general layout and transportation.

6.0.2 item 2, project overview: 1) depot location and its relation to surrounding residential areas, towns, villages and major economic and cultural facilities; 2) present state and planning of local transport, and the supporting and supply of municipal infrastructure and public service facilities; 3) topography and site type of the depot, highest and lowest elevations, gradient and slope direction; 4) land area occupied by the depot and farmland occupied; 5) relocation of existing residential houses and other facilities.