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Terms

2.0.1　underground water-sealing oil-storage rock cavern（storage cavern）

Oil-storage cavern excavated under a stable groundwater level，including facilities such as oil storage cavern groups，access tunnels，shafts，water curtain holes，water curtain tunnels，as well as transportation facilities and control facilities at the ground surface.

2.0.2　Advance geological prediction

Timely and accurate scientific forecast of the position，size and nature of the unfavorable geological body or strip ahead of the cavern excavation working face that affects the construction safety，progress and structural stability，which is performed by using geological methods as well as various geophysical prospecting and drilling methods during the cavern construction.

2.0.3　monitoring measurement

Monitoring of the surrounding rock changes，support structure's working state，underground hydrological conditions，relevant blasting vibrations，air quality，etc.by means of various measurement instruments and tools，to obain the related data and information for the construction.

2.0.4　caverns group

Underground oil storage cavern group consisting of one or more caverns that are interconnected and having the similar function of groundsurface oil tank.

2.0.5　cavern

Underground space excavated in the rock mass to store crude oil or its product（s）.

2.0.6　access tunnel

Tunnel allowing people and equipment to pass and providing ventilation，water supply and drainage，and power supply during construction.

2.0.7　shaft

Vertical passageway from the ground surface or the operation tunnel to the cavern.

2.0.8　shaft operation area

Area around the shaft，where the oil pump，water pump，instruments and electrical devices are maintained，operated，and managed.

2.0.9　water curtain system

An artificial water supply system used to keep the water sealing condition，typically consisting of water curtain tunnels，water curtain holes，monitoring devices，etc.

2.0.10　water curtain hole

Borehole used inject water for the water curtain system.

2.0.11　water curtain tunnel

Tunnel used for water curtain hole construction，water injection and water storage.

2.0.12　plug

Reinforced concrete structure built in the access tunnel or in the shaft to seal the storage cavern.

2.0.13　key groove

Triangular or trapezoid slot set on the surface of the transverse joint or longitudinal to form a monolock after grouting or to effectively transfer the shearing force even without grouting.

2.0.14　pump pit

Pit just below the shaft，which is used for equipment installation.

2.0.15　water bed

A layer of water of certain depth at the bottom of the cavern，which is used to deposit impurities in the crude oil or oil product and to absorb the water seeping out of the surrounding rock.

2.0.16　observationborehole

Borehole used for monitoring the level and quality of groundwater during construction and operation.

2.0.17　instrumentation borehole

Passageway to take out the cables of the sensors and devices used for monitoring the rock mass stabiilty and groundwater pressure.

2.0.18　full-face excavation method

Construction method to excavate the full face of caverns in one time.

2.0.19　bench cut method

Construction method of dividing the full face of caverns into serveral parts according to the height and excavating the upper part first and then excavating the lower parts.

2.0.20　ring cut method

Construction method of firstly excavating the ring-shaped pilot heading around the upper part of the designed cross-section and timely providing support and then excavating the core soil and the lower parts.

2.0.21　centra heading excavation method

Construction method of excavating a pilot tunnel at the center of the top heading according to the designed cross-section and width，then enlarging the pilot tunnel to the designed cross-section and providing support.

2.0.22　smooth blasting

Blasting operation during which blastholes are densely arranged along the excavation contour，noncoupled charging is adopted or less powerful explosive is charged，and the blasting is executed from the center of the excavation face toward the contour，thus developing a smooth contour surface.

2.0.23　presplit blasting

Blasting operation during which blastholes are densely arranged along the excavation contour，noncoupled charging is adopted or less powerful explosive is charged，these blastholes are blasted in sequence before the main blastholes so as to develop penetrating fractures of certain width，therefore smooth contour surface is developed due to the reducing of the damage of the main blastholes on the reserved rock body.

2.0.24　shotcrete and anchor bolt support

Support structure consisting of shotcrete，anchor bolts，metal meshes and steel arches etc.

2.0.25　advanced support

Structure consisting of anchor bolts，forepoling，pipe roof，etc.，which provides pre-supporting for the surrounding rock ahead of the excavation face.

2.0.26　grouting

Construction technique of injecting cement grout or other grout into the ground that contains water-bearing fissures or caves or into unstable ground，in order to decrease the leakage or reinforce the ground.

2.0.27　contact grouting

A method of grouting for the gap between the concrete and the rock formed due to the concrete shrinking，so as to increase the bonding capability of the contact surface and sealing the gap.

2.0.28　lining

Permanent support structure built along the cavern contour by using reinforced concrete，etc.，in order to prevent the surrounding rock from being deformed or collapsing.