论文部分内容阅读
“立体加筋”体系的核心就是在传统水平筋条的基础上布置不同形状的竖向筋条或三维形式的空间加筋。作为一种典型的立体加筋方式,刚性筋材的条带式带齿加筋土经三轴压缩试验、拉拔试验以及挡墙和地基模型试验证明,可以显著地提高加筋土体的强度和地基极限承载力,增强土筋的综合摩擦特性,限制土体变形。采用染色砂法,对带齿筋材的平面应变拉拔试验过程进行了观察。通过分析齿筋前方染色砂土标记线的运动情况和水平标记线的变化情况,发现在拉拔过程中,齿筋前方土体会首先被挤密加强,成一个刚性的楔体,然后周围其他土体会产生绕刚性楔体与齿筋的流动。根据齿筋的宽高比,假定了刚性楔体的形状,从而确定了绕流阻力的分布情况。借鉴沈珠江院士对于抗滑桩阻力的分析方法,推导了刚性条带式带齿加筋土的拉拔阻力模型。在应变控制式拉拔试验机上,进行了法向应力分别为25,50和75kPa的条带式带齿加筋土的拉拔试验,将试验结果与模型计算值进行比较,二者比较接近。
“Three-dimensional stiffened ” The core of the system is to arrange the vertical ribs of different shapes or three-dimensional space stiffeners on the basis of the traditional horizontal stiffeners. As a typical three-dimensional reinforcement method, the three-axis compression test, the pull-out test and the retaining wall and foundation model tests show that the strip-type toothed reinforced soil with rigid reinforcement can significantly improve the strength of reinforced soil And the ultimate bearing capacity of the foundation to enhance the comprehensive friction characteristics of the soil to limit soil deformation. The dyeing process was used to observe the plane strain drawing test of tooth with gear. By analyzing the movement of marked sanding marks and the change of horizontal marking line in front of the tooth, it was found that in the process of drawing, the soil in front of the tooth was first compacted to form a rigid wedge and then surrounded by other soil Experience the flow around a rigid wedge and toothing. According to the aspect ratio of the tooth reinforcement, the shape of the rigid wedge is assumed, thus determining the distribution of resistance around the flow. Drawing on the analysis method of resistance of anti-slide piles by academician Shen Zhujiang, the drawing resistance model of rigid strip-type geogrid reinforced is deduced. In the strain controlled pullout test machine, the pullout test of strip-type toothed reinforced earth with normal stress of 25, 50 and 75 kPa respectively is carried out. The test results are compared with the calculated values of the model, and the two are close to each other.