Study On The Failure Mode Of Straight Wall Arch Roofway With Different Stress Environment In Deep

With the increase of the buried depth of the roadway,the engineering mechanics and safety problems caused by the high ground stress are also significantly different from the shallow rock mass engineering,which restricts the construction of the project.To this end,the project is under the action of ultra-high ground stress(the ground stress load is more than one to two times the uniaxial compressive strength of the rock mass),and the deformation of the surrounding rock of the deep chamber under different opening loads and different maximum load directions.A systematic study was carried out with the damage pattern,and the study found that:(1)The extent and extent of damage to deep surrounding rock is much larger than that of shallow diverticulum.Studies have shown that for a straight-walled dome-shaped diverticulum,the deep diverticulum with a geostress load of 1.0 times the uniaxial compressive strength of the rock mass and the shallow diurnal chamber with a ground stress load of 0.5 times the uniaxial compressive strength of the rock mass The damage depth is 3.5 times that of the shallow diverticulum,and the surrounding rock failure is a typical shear-slip failure.(2)The maximum ground stress direction is different from the angle of the diverticulum axis,and the surrounding rock stress and failure modes are also different.When the angle between the maximum load and the axis of the diverticulum is greater than 45 degrees,changing the angle between the maximum load and the axis of the diverticulum will not fundamentally change the deformation characteristics and failure modes of the surrounding rock of the chamber;when the maximum load and the diverticulum When the angle of the axis is zero,that is,when the maximum load is parallel to the axis of the chamber,the fracture crack around the chamber is generated after excavation,forming a zone rupture.This form of failure has certain positive significance to the deep roadway engineering.New anchoring techniques,such as long-short interphase anchor(cable)reinforcement,are required.Figure[112]Table[38]Reference[34].