重庆地区缓倾顺向泥岩斜坡稳定性判别研究
发布时间：2019-02-14 21:55
【摘要】：重庆地区在城市建设过程中形成较多缓倾顺向泥岩斜坡,其强度低、易风化,因其稳定性评价指标取值不准确常造成治理工程设计失误,发生斜坡变形和工程投资增加的实例多,损失大。在重庆地区缓倾顺向泥岩斜坡勘察过程中,由于斜坡潜在结构面的复杂性及泥岩本身的低强度、易风化和蠕变等特性,导致缓倾顺向泥岩斜坡稳定性评判时,勘察人员不能准确掌控其评价指标,常常是根据有限的室内试验结合工程经验进行取值。评判指标直接影响斜坡稳定性判别结果,且稳定性状态对评判指标敏感性较强(结构面c、?值),其稳定性评判结果与实际情况有不少偏差,造成部分治理工程的设计安全储备较大,工程投资增加。本文针对重庆地区典型的缓倾顺向泥岩斜坡进行勘察、设计资料收集并展开较为全面的现场调研,通过对勘察、设计阶段提供的抗剪强度参数分析,研究参数对已失稳缓倾顺向泥岩斜坡实际情况的符合程度、参数折减时的不合理性等,并对不同缓倾顺向泥岩斜坡破坏模式进行分类研究。其次,通过对泥岩自身力学特性研究,分析缓倾顺向泥岩斜坡不同模式的破坏机制,并应用权重分析等数学分析方法对其稳定进行判别,与采用规范方法计算的稳定性判别结果进行对比,综合全面对比分析,提出缓倾顺向泥岩斜坡的抗剪强度指标折减方法。最后,应用有限元分析软件对不同类型的缓倾顺向泥岩斜坡进行数值模拟分析,研究斜坡应力场的演变模式和应力-应变区域。主要成果如下:(1)重庆地区泥岩力学特性:研究了泥岩在降雨、风化等外力地质条件作用下,强度衰减、大变形、风化时效和蠕变等特性。(2)重庆地区缓倾顺向泥岩斜坡结构面抗剪强度指标折减系数:依据搜集的工程实例资料和现场调研,结合对泥岩力学特性的研究认识成果,建立了缓倾顺向泥岩斜坡坡体泥岩力学衰减联系,依照此联系提出较为准确的结构面抗剪强度指标折减系数。(3)分类别的重庆地区缓倾顺向泥岩斜坡稳定性评判结构面抗剪强度指标值:对重庆地区缓倾顺向泥岩斜坡不同破坏模式进行分类、分阶段研究,最后得到每种破坏模式各个阶段的结构面抗剪指标,进而确定其稳定性状态,形成图表。(4)分类别的缓倾顺向泥岩斜坡应力场的演变模式、应变区域图集。
[Abstract]:In the process of urban construction in Chongqing area, there are more gently inclined forward mudstone slopes, which are low in strength and easy to weathering, because of the inaccuracy of the evaluation index of its stability, which often results in the failure of the design of the treatment project. There are many examples of slope deformation and project investment increase, and the loss is large. In the process of the investigation of the slope of the gentle downward direction mudstone in Chongqing area, due to the complexity of the potential structural surface of the slope and the characteristics of low strength, easy weathering and creep of the mudstone itself, the stability of the slope of the gentle downward direction of mudstone is evaluated. The surveyor can not control the evaluation index accurately, and usually takes the value according to the limited indoor test and engineering experience. The evaluation index has direct influence on the judging result of slope stability, and the stability state is more sensitive to the evaluation index. There are many deviations between the results of stability evaluation and the actual situation, which results in a large design safety reserve and an increase in project investment in some treatment projects. In this paper, the typical sloping mudstone slopes in Chongqing are surveyed, the design data are collected and a comprehensive field investigation is carried out. Through the analysis of the shear strength parameters provided in the survey and design stage, The degree of conformity of the parameters to the actual condition of the slope of the progressive mudstone slope and the irrationality of the parameter reduction are studied, and the failure modes of the slope are classified and studied. Secondly, through the study of the mechanical characteristics of mudstone itself, the failure mechanism of different models of gently inclined forward mudstone slope is analyzed, and the stability of mudstone slope is judged by using the mathematical analysis method such as weight analysis. Compared with the stability discriminating results calculated by the standard method and comprehensive comparison and analysis, a reduction method of shear strength index of the slope with gentle forward direction mudstone is put forward. Finally, the numerical simulation of different types of gentle forward mudstone slopes is carried out by using finite element analysis software, and the evolution model and stress-strain region of slope stress field are studied. The main results are as follows: (1) the mechanical properties of mudstone in Chongqing area: the strength attenuation and large deformation of mudstone under the action of external forces such as rainfall and weathering are studied. Characteristics of weathering aging and creep. (2) the shear strength index reduction coefficient of the structural plane of gently inclined downstream mudstone slope in Chongqing area: based on the collected engineering data and field investigation, combined with the results of the study on the mechanical properties of mudstone, The mechanical attenuation relation of mudstone on slope of gently inclined mudstone slope is established. According to this relation, a more accurate shear strength index reduction coefficient of the structural plane is put forward. (3) the index value of shear strength of the structural plane for the evaluation of the stability of the gently inclined forward mudstone slope in Chongqing area: the value of the shear strength index of the structural plane in the Chongqing area. Different failure modes of mudstone slopes are classified, Finally, the shear resistance index of each stage of each failure mode is obtained, and the stability state is determined. (4) the evolution model of the stress field and the strain region atlas of the gentle downward slope of mudstone.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45
本文编号：2422645
[Abstract]:In the process of urban construction in Chongqing area, there are more gently inclined forward mudstone slopes, which are low in strength and easy to weathering, because of the inaccuracy of the evaluation index of its stability, which often results in the failure of the design of the treatment project. There are many examples of slope deformation and project investment increase, and the loss is large. In the process of the investigation of the slope of the gentle downward direction mudstone in Chongqing area, due to the complexity of the potential structural surface of the slope and the characteristics of low strength, easy weathering and creep of the mudstone itself, the stability of the slope of the gentle downward direction of mudstone is evaluated. The surveyor can not control the evaluation index accurately, and usually takes the value according to the limited indoor test and engineering experience. The evaluation index has direct influence on the judging result of slope stability, and the stability state is more sensitive to the evaluation index. There are many deviations between the results of stability evaluation and the actual situation, which results in a large design safety reserve and an increase in project investment in some treatment projects. In this paper, the typical sloping mudstone slopes in Chongqing are surveyed, the design data are collected and a comprehensive field investigation is carried out. Through the analysis of the shear strength parameters provided in the survey and design stage, The degree of conformity of the parameters to the actual condition of the slope of the progressive mudstone slope and the irrationality of the parameter reduction are studied, and the failure modes of the slope are classified and studied. Secondly, through the study of the mechanical characteristics of mudstone itself, the failure mechanism of different models of gently inclined forward mudstone slope is analyzed, and the stability of mudstone slope is judged by using the mathematical analysis method such as weight analysis. Compared with the stability discriminating results calculated by the standard method and comprehensive comparison and analysis, a reduction method of shear strength index of the slope with gentle forward direction mudstone is put forward. Finally, the numerical simulation of different types of gentle forward mudstone slopes is carried out by using finite element analysis software, and the evolution model and stress-strain region of slope stress field are studied. The main results are as follows: (1) the mechanical properties of mudstone in Chongqing area: the strength attenuation and large deformation of mudstone under the action of external forces such as rainfall and weathering are studied. Characteristics of weathering aging and creep. (2) the shear strength index reduction coefficient of the structural plane of gently inclined downstream mudstone slope in Chongqing area: based on the collected engineering data and field investigation, combined with the results of the study on the mechanical properties of mudstone, The mechanical attenuation relation of mudstone on slope of gently inclined mudstone slope is established. According to this relation, a more accurate shear strength index reduction coefficient of the structural plane is put forward. (3) the index value of shear strength of the structural plane for the evaluation of the stability of the gently inclined forward mudstone slope in Chongqing area: the value of the shear strength index of the structural plane in the Chongqing area. Different failure modes of mudstone slopes are classified, Finally, the shear resistance index of each stage of each failure mode is obtained, and the stability state is determined. (4) the evolution model of the stress field and the strain region atlas of the gentle downward slope of mudstone.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45
【参考文献】
相关期刊论文 前3条
1 杨志法,尚彦军,刘英;关于岩土工程类比法的研究[J];工程地质学报;1997年04期
2 万玲,彭向和,杨春和,郭开元;泥岩蠕变行为的实验研究及其描述[J];岩土力学;2005年06期
3 吕玉香;罗顺清;樊新庆;温金梅;胡伟;;重庆市红层承压水分布特征与富集规律研究[J];中国农村水利水电;2010年09期
，本文编号：2422645
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