大型三维土与结构接触面试验机的研制与应用

已有的土与结构接触面试验研究集中在二维加载条件下的接触面力学特性,而实际工程中接触面的受载条件大多为三维的,即接触面的剪应力方向在剪切过程中是不断变化的。针对粗粒土与较粗糙结构面的大型三维接触面的试验手段目前较为缺乏,自主设计研制了一台用于土与结构接触面特性试测的大型三维加载试验机。该试验机具有高加载能力,提供大试样截面,能够进行较大粒径土体与较粗糙接触面在较大应力变化范围内的单调和循环加载试验;采用液压伺服控制系统,法向可提供应力、常位移、常刚度等边界条件;切向两个方向均可按应力或位移控制,能够实现接触面上单向往返、十字、圆形、椭圆等不同的任意设定的加载路径。试验表明,该试验机能够很好地再现粗粒土与结构接触面在上述的复杂加载条件下的力学响应,为接触面的三维力学特性的研究提供了基础。

Development and application of 3D soil-structure interface test apparatus

A new 3D soil-structure interface test apparatus,which was capable of applying monotonic and cyclic loading in three perpendicular directions,was designed and developed to investigate the mechanical characteristics of the interface between coarse grained soil and structure under 3D loading conditions in most practical projects.Monotonic and cyclic tests could be carried out on large section interface sample by this apparatus with high loading capability.Hydraulic servo system was adopted on each loading direction to generate the desired load or displacement paths on the interface.In the normal direction,three boundary conditions including the constant normal stress,the constant volume and the constant normal stiffness could be imposed,while in the two perpendicular tangential directions,numbers of different loading paths,i.e.,cross,circular and elliptical etc.could be imposed.It was shown that this apparatus could be employed to represent the response of the interface under various loading paths.