川藏铁路季节性粗颗粒冻土边坡破坏模式的模型试验研究

发布时间：2018-01-03 23:02

本文关键词：川藏铁路季节性粗颗粒冻土边坡破坏模式的模型试验研究　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：新建的川藏铁路由于受到线路坡度和地形的影响,川藏铁路在穿越以新都桥为代表的山区时大多只能以路堤形式通过,线路基本都位于较厚的季节性粗颗粒冻土边坡上,观测表明,这类粗颗粒冻土边坡在季节冻融作用下会发生缓慢滑移或流动。模型试验对于研究那些尚未或很难建立数学模型的试验对象是最佳选择。由于粗颗粒冻土边坡模型实验的研究较少,本文提出了一套适合川藏铁路季节性粗颗粒冻土边坡模型实验研究的方法。本文在建立该模型试验研究方法的过程中主要进行了以下方面的工作。对现场的32处边坡进行了调查,并对边坡破坏模式和破坏因素进行了总结。通过积分类比法推导了冻土边坡模型的相似比。结合理论计算和实际测试方法结合确定了模型试验的保温材料。设计了模型监测方案并选择了监测元件。研究了数据采集的方法。最后结合现场监测结果,证明该套模型试验方法的可行性。在进行模型试验研究过程中得到如下结论。根据现场边坡调查统计表明季节性粗颗粒冻土边坡的破坏多以坡表浅层土体发生破坏为主,破坏范围为坡体表层0.2～1.5m的土体。采用现场工作为模型主体材料时,当长度比尺cl=15时得到cτ=225。土体中的电阻值跟土体含水率成反比,得出自制电阻传感器用于监测边坡湿度场是可行的。该实验成功的将摄影测量方法应用于监测边坡冻胀量位移。模型试验结果表明,坡顶处的冻胀位移最大,沿坡顶至坡脚位置处边坡冻胀位移依次减小,坡脚位置处的冻胀位移最小。同时得出边坡破坏是由于积雪融化入渗到土体导致边坡冻胀量增大而引起的。通过与现场监测的结果对比发现模型试验结果符合现场监测结果。本次模型试验的不足之处是只针对有无积雪工况边坡进行了模型试验研究,建议根据其他不同工况对模型试验进行进一步的研究。
[Abstract]:The new Sichuan Tibet railway line due to the impact of slope and terrain, the mountains in the cross as the representative of the Sichuan Tibet railway to Xinduqiao mostly only by embankment, seasonal permafrost slope line of coarse particles are located in the thick, these observations show that the coarse particles of frozen soil slope in seasonal frozen or slow slip flow will be thawing. Model test is the best choice for the study of those who have not yet or is difficult to establish mathematical model of the test object. Because of the coarse particles of permafrost slope model experiment is less, this paper puts forward a set of suitable for the experimental study of the Sichuan Tibet Railway permafrost slope model of seasonal coarse particle method. This paper focuses on the following aspects of the work in the the process of establishment method of the model test. The investigation was made in 32 at the scene of the slope and the slope, failure mode and failure factors are summarized through. Integrated analogy method is used to derive a similarity model of permafrost slope ratio. According to the theoretical calculation and practical test method of combination to determine the insulation material model test. The design scheme of monitoring model and select the monitoring element. Method of data acquisition. Finally, combined with the field monitoring results, prove the feasibility test method of the model. The conclusions are obtained as follows in the process of model test. According to the field investigation of Slope Statistics show that seasonal frozen soil coarse slope on slope surface of shallow soil damage, the damage range for the soil slope surface of 0.2 ~ 1.5m. The field work model of the main material, when the length scale is obtained when the cl=15 resistance C the =225. value in the soil with soil water content is inversely proportional to the resistance sensor for monitoring the slope humidity field is feasible. The success of the photogrammetry Applied to the monitoring of slope displacement. The frost heave model test results show that the top of the frost heave displacement along the top to the foot position of slope heave decrease slope position. At the same time that the minimum frost heave displacement of slope failure is due to snow melt infiltration to the soil slope leading to increased frost heave caused by comparison with. The on-site monitoring results showed that the model test results accord with the field monitoring results. The shortcomings of the model test is carried out only for model tests without snow slope conditions, according to the different conditions of other suggestions for further study on the model test.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.14;U213.14

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