摘要
应用室内强度试验确定富水卵砾石层相似材料配合比,并进行冻结温度场、水分场与应力场的相似准则推导,设计研发出以物理模型箱,包括加载、制冷、监测系统为一体的多功能物理模型试验平台,根据等散热能量原则设计冻结管布置方案,研究了富水卵砾石层冻结过程中冻结壁温度及变形规律。通过模型试验监测模拟富水卵砾石地层冻结壁形成、地层冻胀及开挖过程中温度场与位移场变化,发现距离冻结管近端温度下降比远端快,随着时间的不断增加,冻结壁冻胀位移一直增大,最后达到峰值,不同位置由于冻胀引起的位移还是存在稍许差异,具体表现在拱顶冻胀位移最大,拱角次之,拱底最小。结果表明:冻结壁内侧温度下降比外侧下降快,离冻结管越远的测点差异性也越大,距离冻结管近端温度下降比远端快;冻胀阶段位移拱顶处最大,其次为拱角,拱底最小,而开挖阶段拱底处位移变化最大,其次为拱角,拱顶最小。两阶段位移都是先增大而后趋于平缓,但开挖位移开挖断面处有突变。
The mixture ratio of similar materials in the water-rich gravel layer was determined by the indoor strength test,and the similarity criteria of freezing temperature field,moisture field and stress field were derived.A multifunctional physical model test platform was designed and developed,including loading,cooling and monitoring systems.The arrangement scheme of freezing pipes was designed according to the principle of equal heat dissipation energy.The temperature and deformation law of frozen wall during freezing of water-rich gravel layer are studied.The formation of frozen wall,frost heaving of formation and changes of temperature field and displacement field during excavation of water-rich gravel layer are monitored and simulated through model test.It is pointed out that the temperature at the near end of the freezing tube drops faster than that at the far end.With the increase of time,the frost heaving displacement of the freezing wall increases all the time and finally reaches the peak value.The displacement caused by frost heaving in different positions still has a slight difference,which is manifested in the largest frost heaving displacement in the vault,the second in the arch angle and the smallest in the arch bottom.The results indicate that the temperature inside the freezing wall drops faster than the outside,the difference between the measuring points farther away from the freezing tube is also greater,and the temperature near the freezing tube drops faster than that at the far end.In frost heaving stage,the displacement of arch top is the largest,followed by arch angle and arch bottom being the smallest,while in excavation stage,the displacement of arch bottom is the largest,followed by arch angle and arch top being the smallest.The displacement in both stages increased first and then leveled off,but there was a sudden change in the excavation section.
作者
高志宏
胡双平
张晓峰
胡智民
田俊峰
刘忠祥
谢腾飞
GAO Zhi-hong;HU Shuang-ping;ZHANG Xiao-feng;HU Zhi-min;TIAN Jun-feng;LIU Zhong-xiang;XIE Teng-fei(State Key Laboratory of Rail Transit Engineering Informatization,China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an 710054,China;Shaanxi Railway and Underground Traffic Engineering Key Laboratory,China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an 710054,China;College of Civil and Architectural Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)
出处
《西安科技大学学报》
CAS
北大核心
2020年第3期408-416,共9页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金资助(41672305)。
关键词
富水卵砾石层
模型试验
冻结壁
温度
变形
water-rich gravel stratum
model test
frozen wall
temperature
deformation
