摘要
本文从围岩弹塑性理论基本方程出发,考虑形变压力,松动压力和塑性区围岩粘结力c值降低的影响,通过弹塑性理论推导,建立了塑性区半径与维持围岩塑性极限平衡所需支护抗力的关系,进一步导出了最小支护抗力和最大允许变形的计算公式,并举例说明了计算公式的应用.分析计算表明,是否考虑塑性区围岩c值降低和松动压力,对园形洞室最小支护抗力和最大允许变形计算结果有明显的影响.
Taking account of the loosening pressure as well as the decreasing of cohesion which actually exist in the plastic zone of surrounding rocks,the author deduced the relations between the radii of plastic zone.and support resistances on the top,sides and bottom of a tunnel. Based on these relations,the formulas for calculating the minimum support resistance and maximum allowable deformation of a circular tunnel are obtained.Analyses and calculation show that whether the decreasing of cohesion and the loosening prssure are considered or nothas an obvious influence on the calculating results of the minimum support resistance and maximum allowable deformation of circular tunnels.
关键词
隧洞
围岩
支护抗力
允许变形
tunnel
surrounding rocks
cohesion
loosening pressure
support resistance
radius of plastic zone
plastic deformation
