针对巷道松动圈的影响因素与松动圈的大小进行正交试验,综合考虑围岩级别、侧压力系数、埋深、高跨比、跨度5个主要影响因素,利用FLAC3D数值软件对16个方案进行数值模拟.正交试验结果表明:对巷道综合位移影响程度最大的因素为围岩级别,其次为埋深.在描述松动圈时引入松动圈系数,将其与最大松动圈厚度进行比较后发现:引入松动圈系数后,对巷道松动圈的描述更加完善.对巷道两侧及前方的应力分析后可知,巷道两侧及前方的切向应力随围岩强度的降低和埋深的增加,应力峰值减小,巷道侧边的应力曲线出现明显的平直段,巷道两侧及前侧岩体的破裂始于距巷道内侧一定距离.
For the influence factors of roadway loose circle and its size,this paper takes into consideration the levels of surrounding rock,lateral pressure coefficient,burying depth,and height- span ratio by using the FLAC3 Dnumerical software to analyze the 16 numerical computation schemes based on the orthogonal test. The orthogonal test results show that the level of surround rock is the important factor for total displacement,followed by depth. By introducing loose circle coefficient,and compared with maximum loose circle thickness,it can be seen that loose circle coefficient and maximum loose thickness can better describe the roadway loose circle. By analyzing both sides and front stress of roadway,it can also be seen that the tangential stress peak decreases,with the increase of the surrounding rock strength and the burying depth,stress of roadway appears the straight section,and rock fracture of the two sides and the front starts from the inside of the roadway at a distance.