地下工程围岩的平面应变实验技术

软岩和深埋地下工程的围岩一般要进入峰后阶段，大量裂缝的衍生、扩展、错动和张开是围岩变形、承栽力下降的主要原因，单轴实验已不能反映峰后围岩的变形本质。平面应变压缩实验与围岩的应变状态相似，但其要求实验台具有极大的侧向刚度，一般均不能满足。本项目利用高强混凝土和槽钢浇铸平面应变实验台，已开展了大量的平面应变实验，获得了成功。此外，峰后的体积应变和侧向应变也一直是难以获得的实验数据，项目通过相应的实验设计也成功获得。

Plane-strain model test rig for surrounding rock in underground engineering

Generally surrounding rock will enter into its post-peak phase in soft rock or deep underground engineering,a large quantity of cracks appear,spread,stagger and stretch,which is the main reason for the deformation and bearing capacity decreasing of surrounding rock,therefore uniaxial experiment can not reflects the essence of surrounding rock deformation in its post-peak phase.Plane-strain experiment is similar to the strain course of surrounding rock,however which demands its rig must have extreme rigidity,and generally the rigidity is not enough.In our project a kind of new rig has been designed and built,and a lot of plane-strain experiments have been completed successfully.