干湿交替条件下膨胀围岩胀缩规律的试验研究

发布时间：2018-04-03 16:29

本文选题：膨胀土隧道　切入点：胀缩演变规律　出处：《铁道科学与工程学报》2017年01期

【摘要】：为研究干湿交替条件下膨胀围岩的胀缩演变规律,利用南宁地区的膨胀土制作了膨胀土隧道物理模型。通过对隧道模型进行五个循环的干湿交替试验,得出了围岩在吸水及失水条件下的应力—时间关系曲线,并对围岩在吸水及失水过程中的力学响应及行为表现进行了分析与描述。结果表明:随循环次数的增加,各应力—时间关系曲线趋于平缓,各阶段围岩应力变化值呈减小及各阶段循环所耗时间呈逐渐短化的趋势。说明干湿交替作用,使围岩的胀缩能力减弱,渗透性提高。此外,在围岩湿胀引起的洞周总围岩应力增加值中,底板处最大约为40kpa,因此在隧道设计和施工时应注意底板的变形。
[Abstract]:In order to study the expansion and shrinkage evolution of expansive surrounding rock under the condition of alternate dry-wet conditions, a physical model of expansive soil tunnel was made by using expansive soil in Nanning area.The stress-time curves of surrounding rock under the condition of water absorption and water loss are obtained through the dry and wet alternating test of five cycles on the tunnel model.The mechanical response and behavior of surrounding rock in the process of water absorption and water loss are analyzed and described.The results show that with the increase of cycle times, the stress-time relation curves tend to be gentle, the stress changes of surrounding rocks decrease and the cycle time of each stage becomes shorter gradually.It shows that the capacity of expansion and shrinkage of surrounding rock is weakened and the permeability is improved by the alternating action of dry and wet.In addition, the maximum value of stress increase in surrounding rock surrounding rock caused by surrounding rock swelling is about 40 kpa.Therefore, attention should be paid to the deformation of bottom slab in tunnel design and construction.
【作者单位】：桂林理工大学广西岩土力学与工程重点实验室;贺州市住房和城乡建设局;
【基金】：国家自然科学基金资助项目(51368014)
【分类号】：U451.5

【相似文献】