砂卵石地层物理力学特性对盾构隧道管片内力的影响

以呼和浩特地铁穿越的典型砂卵石地层为例,选取6个地层物理力学参数作为影响因素,采用单因素变量法,分析各因素对管片内力的影响,并通过敏感性系数判断管片内力对各因素的敏感程度。结果表明:管片内力随重度增大而增大;黏聚力、垂直基床系数对管片内力影响不显著;轴力随内摩擦角增大而减小,弯矩随之增大而增大;轴力随静止侧压力系数、水平基床系数增大而增大,弯矩随之增大而减小;偏心距随重度、静止侧压力系数、水平基床系数增大而减小,随黏聚力、内摩擦角增大而增大,但受垂直基床系数影响不大;管片内力对各因素的敏感程度排序为水平基床系数>静止侧压力系数>内摩擦角>重度>黏聚力>垂直基床系数。

Influence of Physical and Mechanical Properties of Sandy Pebble Stratum on Internal Force of Shield Tunnel Segment

Taking the typical sandy pebble stratum crossed by Hohhot metro as an example,six physical andmechanical parameters of the stratum were selected as influencing factors and the influence of each factor on the internalforce of the segment was analyzed by using single factor variable method.Through the sensitivity coefficient,thesensitivity level of the segment internal force to each factor was judged.The results show that the internal force of thesegment increases as the gravity increases.Cohesion and vertical bed coefficient have no significant influence on theinternal force of the segment.With the increasing of internal friction angle,the bending moment increases,while theaxial force decreases.As the static side pressure coefficient and horizontal bed coefficient increase,the axial forceincreases,while the bending moment decreases.The eccentricity decreases with the increase of gravity,static sidepressure coefficient,and horizontal bed coefficient,and increases with the increase of cohesion and internal frictionangle,but it is not greatly affected by the vertical bed coefficient.The order of the sensitivity level of the segmentinternal force to those factors is horizontal bed coefficient>static side pressure coefficient>internal friction angle>gravity>cohesion>vertical bed coefficient.