岩质隧道冻胀力计算及冻害等级划分研究

发布时间：2018-03-26 13:42

本文选题：隧道工程　切入点：积水冻胀模型　出处：《东北大学》2014年硕士论文

【摘要】：随着我国改革开放步伐的加快,中国交通基础建设工程全面展开,而公路、铁路隧道更是在东北、华北、西北、西南等高海拔地区新建消息频出。这一方面标志全国交通系统更加全面有效,而另一方面却带了人们对隧道冻害问题的深思。本文通过查阅国内外相关文献,对隧道冻胀力计算方法、隧道冻害机理、隧道冻害等级划分及隧道冻胀防治措施四个方面研究现状进行了总结归纳,在此基础之上重点对岩质隧道冻胀力计算模型以及冻害等级划分方法深入分析,主要工作内容如下：(1)综述积水冻胀理论,修正已有积水冻胀模型不足之处：该模型建立时忽略了围岩本身低温膨胀作用；计算过程未考虑积水结冰弹性体变形影响；未提及参数取值问题,工程使用困难。基于弹性力学理论,建立新的局部积水冻胀模型,并推导出冻胀力计算表达式。然后提出各参数取值方法,包括：冻胀围岩沿隧道径向深度、局部积水沿隧道径向深度、围岩弹性抗力系数、衬砌和冰的弹性当量系数以及围岩冻胀率。引入工程算例,计算衬砌背后无积水时所受冻胀力大小并与冻融岩石圈整体冻胀理论冻胀力弹性表达式计算结果对比,验证新建积水冻胀模型合理性。(2)采用有限元数值分析方法,分析新建局部积水冻胀模型的合理性,并讨论冻胀力与相关参数的关系。利用ANSYS有限元软件模拟隧道工程算例得出衬砌背后出现局部积水时所受冻胀力大小与局部积水冻胀模型分析结果比较,证明新建局部积水冻胀模型的合理性。然后通过参数调整分析冻胀力与围岩冻胀率、衬砌刚度以及水体纵向深度之间的关系。(3)提出新建隧道冻害等级划分标准以及各指标评价方法。在量化分析地下水、温度、围岩属性三指标前提下,采用加权平均综合评价方法提出新建隧道冻害等级划分标准；对隧道防冻害施工预防措施进行总结：保温加热措施、防排水措施、混凝土低温施工,并以施工预防措施有效性对新建隧道冻害等级划分标准进行修正。(4)基于新建局部积水冻胀模型,建立既有隧道冻害等级划分标准并明确各指标评价方法。提出以混凝土长期强度增长值为指标来区分新建和既有隧道的方法；以混凝土衬砌最小、最大配筋率作为冻胀力等级弱中强的划分标准,计算冻胀力界限值；之后量化洞内结冰影响正常使用情况和衬砌结构劣化程度,采用综合定性评价原则：量化指标、单指标评价、最值优先、定性评价,建立既有隧道冻害等级划分标准。(5)依据大苇沟隧道工程,应用新建局部积水冻胀模型计算该隧道衬砌所受冻胀力；根据新建隧道和既有隧道判别标准,分析该隧道所属类型,并采取对应类型隧道冻害等级划分标准进行评价。
[Abstract]:With the acceleration of the pace of reform and opening up in China, China's transportation infrastructure projects have been carried out in an all-round way, and highway and railway tunnels are located in the Northeast, North China, and Northwest China. News of new construction in high altitude areas such as southwest China is frequent. On the one hand, this indicates that the national transportation system is more comprehensive and effective, while on the other hand, it brings people to ponder over the problem of tunnel freezing injury. This paper refers to the relevant literature at home and abroad. In this paper, the methods of calculating the frost heaving force of the tunnel, the mechanism of the tunnel frost damage, the classification of the tunnel frost damage grade and the prevention and cure measures of the tunnel frost heave are summarized and summarized. On this basis, the calculation model of frost heave force of rock tunnel and the classification method of frost damage grade are deeply analyzed. The main work is as follows: 1) summarizing the theory of hydrofreeze heave. The shortcomings of the existing hydrofreeze heaving model were corrected: the low-temperature expansion of surrounding rock itself was neglected when the model was established; the deformation of hydrofreeze elastomer was not taken into account in the calculation process; the problem of parameter selection was not mentioned. Based on the theory of elastic mechanics, a new local hydrofreeze heave model is established, and the calculation expression of frost heave force is derived. Then, a method for determining the values of various parameters is put forward, including the depth of frost heave surrounding rock along the radial direction of tunnel. The local water accumulated along the radial depth of the tunnel, the elastic resistance coefficient of surrounding rock, the elastic equivalent coefficient of lining and ice, and the frost heaving rate of surrounding rock. By calculating the magnitude of frost heave force when there is no water behind the lining and comparing with the calculation result of frost heave force elastic expression of whole frost heaving theory of freeze-thawing lithosphere, it is proved that the new hydrofreeze heaving model is reasonable, and the finite element numerical analysis method is adopted. The reasonableness of the new model of local water frozen-heaving is analyzed. The relationship between frost heaving force and relevant parameters is discussed. By using ANSYS finite element software to simulate tunnel engineering example, the magnitude of frost heave force when local hydrops appear behind the lining is compared with the analysis results of local hydrofreeze model. It is proved that it is reasonable to build a new model of local water frozen-heaving, and then the frost heave force and the frost heave rate of surrounding rock are analyzed by adjusting the parameters. The relationship between lining stiffness and longitudinal depth of water body. (3) the classification standard of frost damage grade and the evaluation method of each index are put forward. Under the premise of quantitative analysis of groundwater, temperature and surrounding rock properties, By using the weighted average comprehensive evaluation method, the classification standard of frost damage grade of new tunnel is put forward, and the preventive measures are summarized, such as heat preservation measures, drainage prevention measures, low temperature concrete construction, etc. Based on the frost heaving model of the new local water, the classification standard of the frost damage grade of the new tunnel is revised by the effectiveness of the construction prevention measures. The criteria for classification of frozen damage grade of existing tunnels and the evaluation methods for each index are established. The method of distinguishing new and existing tunnels with long-term strength growth value of concrete is put forward, and the minimum concrete lining is used. The maximum reinforcement ratio is used as the dividing criterion of weak, moderate and strong frost heaving force, and the limit value of frost heave force is calculated, then the ice in the tunnel affects the normal use and the deterioration degree of lining structure, and the comprehensive qualitative evaluation principle is adopted: quantitative index. Single index evaluation, the best value first, qualitative evaluation, established the existing tunnel frost damage grade classification standard. 5) according to the Dawegou tunnel project, the frost heave force of the tunnel lining was calculated by using the newly built local water frost heave model. According to the criterion of judging the new tunnel and the existing tunnel, the type of tunnel is analyzed, and the classification standard of freezing damage grade of the tunnel of corresponding type is adopted to evaluate it.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U457

【参考文献】