【摘要】 针对工程中大量涉及的孔收缩问题,推导了排水条件中不考虑塑性区弹性变形的球形空腔收缩的应力场和位移场,讨论了各种参数的影响,并揭示了钻孔开挖形成的塑性区范围与应力释放程度之间的关系。研究表明:同一深度下,随着钻孔孔径的减小,其塑性区范围也将减小,圆拱效应逐渐增强;在同一孔径下,随着钻孔深度的增加,形成的塑性范围也将逐渐减小;随着支护压力的逐渐减小,产生塑性变形后,其塑性区范围逐渐增大;位移主要发生在塑性区,最大位移发生在钻孔周边,随着深度的增大,位移减小;剪胀角对钻孔周边位移有显著影响,随着剪胀角的增大,钻孔周边的位移逐渐减小,在弹塑性交界处附近影响很小。更多还原

【Abstract】 The stress and displacement solutions of contraction of spherical cavity under drainage are obtained by neglecting the influence of the elastic deformation in plastic zone. The effects of corresponding parametersdiscussed. The relationship between the support pressure and the radius of the elasto plastic boundary is revealed. It is shown that the smaller the radius of cavity is,the smaller the plastic region is for the same depth and the arching effect is more obvious. The deeper the borehole is,the smaller the plastic region is for the same radius. When support pressure is decreased,the plastic region is increased. The maximum displacement occurs at the cavity wall. The dilation angle has an obvious effect on the cavity displacement and little effect nearby theboundary. With the increment of dilation angle,the cavity displacement is increased.更多还原