矩形基础地基破坏机理细观模型试验

Mesoscopic Model Test on Failure Mechanism of Rectangular Foundation

采用自行研制的土体数字化变形测量装置,对承受中心荷载的矩形基础进行了室内细观模型试验,重点研究矩形基础沿着长边和短边剖面上土体位移发展直至破坏的全过程。研究结果表明:矩形基础下地基土位移的影响范围随着荷载增加而不断向竖向及水平方向扩展,沿着矩形基础长度和宽度方向竖向位移的影响深度在破坏时趋于一致,而基础宽度方向的水平位移影响范围约为长度方向的1.5倍,且沿着基础宽度方向地表隆起变形比长度方向大,沿着长度方向滑动面主要由基础两边的剪切滑动区及基础正下方的倒梯形弹性平衡区构成,沿着宽度方向弹性平衡区为三角形,矩形基础下弹性核的形状为横置的三棱台。研究结果为矩形基础地基破坏模型的建立提供了理论依据。

Using the self-developed soil digital deformation measurement device,mesoscopic tests on rectangular foundation under vitical load are carried out to study the whole process of soil displacement development. It shows that soil displacement influence region under rectangular foundation extends to a vertical and horizontal direction as the load increases,the vertical displacement influence depth tends to consistently along length and width direction when rectangular foundation is destroyed,but the horizontal displacement influence region along width direction is about 1. 5 times of length direction,surface uplift along width direction is larger than the length direction.Sliding surface along length direction is mainly composed of two shear sliding zone and a inverted trapezoidal elastic equilibrium area,the elastic equilibrium area along width direction presents triangle,and the shape of the elastic equilibrium area under rectangular foundation is a three trustum of pyramid. These research results provide some theoretical basis for the establishment of rectangular foundation failure model.