Sun Zhenxing, Wang Rongchang, Yang Zhongnian, Lv Jianhang, Shi Wei, Ling Xianzhang
School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China.
College of Civil Engineering, Tongji University, Shanghai 200092, China.
Polymers (Basel). 2024 Oct 4;16(19):2817. doi: 10.3390/polym16192817.
Large volumes of waste tires are generated due to the rapid growth of the transportation industry. An effective method of recycling waste tires is needed. Using rubber from tires to improve problematic soils has become a research topic. In this paper, the dynamic response of rubber fiber-reinforced expansive soil under freeze-thaw cycles is investigated. Dynamic triaxial tests were carried out on rubber fiber-reinforced expansive soil subjected to freeze-thaw cycles. The results showed that with the increase in the number of freeze-thaw cycles, the dynamic stress amplitude and dynamic elastic modulus of rubber fiber-reinforced expansive soils first decrease and then increase, and the damping ratio first increases and then decreases, all of which reach the turning point at the 6th freeze-thaw cycle. The dynamic stress amplitude and dynamic elastic modulus decreased by 59.4% and 52.2%, respectively, while the damping ratio increased by 99.8% at the 6th freeze-thaw cycle. The linear visco-elastic model was employed to describe the hysteretic curve of rubber fiber-reinforced expansive soil. The elastic modulus of the linear elastic element and the viscosity coefficient of the linear viscous element first decrease and then increase with the increase in the number of freeze-thaw cycles; all reach the minimum value at the 6th freeze-thaw cycle. The dynamic stress-dynamic strain curve calculation method is established based on the hyperbolic model and linear visco-elastic model, and the verification shows that the effect is better. The research findings provide guidance for the improvement of expansive soil in seasonally frozen regions.
由于交通运输业的快速发展，产生了大量废旧轮胎。需要一种有效的废旧轮胎回收方法。利用轮胎橡胶改良问题土壤已成为一个研究课题。本文研究了橡胶纤维加筋膨胀土在冻融循环作用下的动力响应。对经历冻融循环的橡胶纤维加筋膨胀土进行了动三轴试验。结果表明，随着冻融循环次数的增加，橡胶纤维加筋膨胀土的动应力幅值和动弹性模量先减小后增大，阻尼比先增大后减小，均在第6次冻融循环时达到转折点。在第6次冻融循环时，动应力幅值和动弹性模量分别降低了59.4%和52.2%，而阻尼比增大了99.8%。采用线性粘弹性模型描述橡胶纤维加筋膨胀土的滞回曲线。线性弹性元件的弹性模量和线性粘性元件的粘性系数随冻融循环次数的增加先减小后增大；均在第6次冻融循环时达到最小值。基于双曲线模型和线性粘弹性模型建立了动应力-动应变曲线计算方法，验证表明效果较好。研究结果为季节性冻土地区膨胀土的改良提供了指导。
