Storage coefficient calculation model of coal mine underground reservoir considering the effects of coal mine water velocity and time
Coal mine underground reservoir proposed 22614 working face is selected as the research back-ground,upon which similar experiment of working face mining and loading experiment of mine water soa-king sandstone are conducted,and motion law of overlying strata and stress distribution status are simula-ted.Further,overlying strata structure of goaf is analyzed,and storage coefficient calculation model of coal mine underground reservoir is set up concerning the effects of coal mine water velocity and time.The results show that the old roof first caving step in the model working face is 46 cm and periodic caving step is 7-16 cm.There are only fracture zone and caving zone in the overlying strata of goaf,and there are a large number of incompletely contact cavities,voids and cracks undercompacted between rock blocks in caved zone,which are the main water storage space of underground reservoir of coal mine.The rock bear-ing stress in goaf has a"∩"shape distribution along goaf strike,and the maximum stress reaches 1.5 MPa.The overlying strata displacement of goaf shows a"U"shape change with the symmetry axis of goaf strike center line,and the maximum displacement is-2.5 cm.Based on the key strata motion trail,its bottom surface subsidence curve function equation is built,and caving zone volume,void volume and water quantity of rock in caving zone are quantified mathematically.Storage coefficient calculation model of coal mine underground reservoir is established with some parameters such as rock hulking coefficient.By clarifying the mathematical relationship between sandstone hulking coefficient and coal mine water ve-locity and time,the storage coefficient calculation model of coal mine underground reservoir is further im-proved,and calculated by examples and verified by experiments.Storage coefficient calculated by the model is 0.196 5,while storage coefficient measured by experiment is 0.210 4,which proves the accuracy of the calculation model.It could provide an important theoretical basis for storage capacity design and wa-ter storage scheduling of coal mine underground distributed reservoir.
key stratarock hulking coefficientcoal mine water velocitytime effectstorage coefficient
万方数据
维普
