基于特征分离原则的大比例砂土类缩尺模型相似材料配比研究

Similar material of large-scale model of the sandy soil based on feature separation principle

为了获得砂土类大比例缩尺模型相似材料配比,选取福建厦蓉高速漳州段原型砂土作为骨料,石英砂、滑石粉为填充材料,膨润土为添加剂。基于特征分离原则及正交设计方法,进行了3因素5水平共25组固结压缩和直接剪切试验,得到了不同配比相似材料的力学参数值。结果表明:1)基于特征分离原则的试验配比基本能满足大比例模型试验对砂土类相似材料的要求。2)砂土和滑石粉含量与砂土、石英砂和滑石粉总重的比值对材料黏聚力和内摩擦角起主要控制作用,而滑石粉含量与砂土和滑石粉总重的比值对材料的压缩模量起主要控制作用。3)当滑石粉的含量分别占砂土和滑石粉总含量的4%和6%时,对黏聚力和压缩模量的影响均达到峰值;而掺入膨润土可以降低压缩模量,当膨润土掺量为3%时,黏聚力达到最小值;添加石英砂可以降低内摩擦角,而对其他指标影响呈现无规律波动。成果可为其他砂土类大比例缩尺模型相似材料的配制提供参考。

In order to obtain the similar material ratio of large-scale model of the sandy soil,the prototype sand of Zhangzhou section of Xiamen-Chengdu expressway of Fujian is selected as aggregate.In addition,quartz sand and talcum powder are used as filling materials,while bentonite is used as additive.Based on the principle of feature separation and orthogonal design,25 sets of 3 factors and 5 levels of consolidation,compression and direct shear tests were carried out,and the mechanical parameters of similar materials with different proportions were obtained.The results show the follows.1）Based on the principle of feature separation,the test ratio can basically meet the requirements of large scale model test for similar materials of sandy soil.2）The ratio of sand and talcum powder content to the total weight of sand,quartz sand and talcum powder mainly controls the cohesion and internal friction angle,while the ratio of talcum powder content to the total weight of sand and talcum powder plays a major role in controlling the compression modulus of the material.3）When the content of talcum powder for sand and talcum powder content of 4% and 6%respectively,the influence on the cohesive strength and compression modulus reached peak;while the incorporation of bentonite can reduce the compression modulus,when the bentonite content is 3%,the cohesion reaches the minimum value;The addition of quartz sand can reduce the internal friction angle,while the influence on other indicators shows irregular fluctuations.The results can be used as reference for the preparation of similar materials of sand scale model.