WANG Bei-fang, JIANG Jia-qi, LIU Xue-sheng, et al. Analysis and application of sheared and fallen roof structure during shallowly buried fully mechanized mining under thick loose bed and thin base rock[J]. 2023, 44(10): 3011-3021.
DOI:
WANG Bei-fang, JIANG Jia-qi, LIU Xue-sheng, et al. Analysis and application of sheared and fallen roof structure during shallowly buried fully mechanized mining under thick loose bed and thin base rock[J]. 2023, 44(10): 3011-3021.DOI: 10.16285/j.rsm.2022.1042.
Analysis and application of sheared and fallen roof structure during shallowly buried fully mechanized mining under thick loose bed and thin base rock
Severe ground pressure problem during shallowly buried fully mechanized mining under thick loose bed and thin base rock is increasingly prominent
which has seriously threatened safety and efficient production in coal mine. This study took 22614 working face in Shendong mining field as engineering background
adopted the combination research method of field monitoring
similar experiment and mechanical modeling to analyze the characteristics of its strong ground pressure
to reveal cause of mining-induced roof broken and instability
to build mechanical model of roof broken structure
to determine working resistance of hydraulic support in working face
and finally to perform field example application. The study results showed that: based on field monitoring
the average roof broken length of 22614 working face was 11.2 m; the average working resistance of hydraulic support was 8 450.1 kN
and the maximum working resistance was 11 857 kN. In similar materials simulation experiment
the average caving length was 12.5 m
and roof sheared and broke as short suspension beams
crack extended to surface
which led to the whole sheared roof falling behind coal wall. As well plane mechanical model of sheared and fallen roof structure was established
then the structure instability criterion was put forward
the positive correlation between instability coefficient and roof sheared and fallen angle
bearing capacity of hydraulic support was pointed out. Certainly
working resistance calculation formula of hydraulic support in working face was given and calculated average bearing capacity of hydraulic support was 8 364.22 kN
which is in good agreement with the field monitoring results. The results provided important theoretical basis for support selection and roof control of shallowly buried fully mechanized mining under thick loose bed and thin base rock in China.