基于有限差分强度折减法及其改进折减法的对比研究
发布时间：2018-10-08 15:20
【摘要】：关于边坡的稳定性研究一直以来都是工程领域的热点问题,而我国工程建设迅猛发展、地形地质情况复杂,此问题变得尤为突出。从事边坡研究的工作者很多,但由于涉及到岩土类问题的研究本身就有其复杂性,加之边坡体的不规则外形以及易受到来自外界的干扰,致使边坡稳定的研究一直比较缓慢。而随着工程开展速度的不断提高,相关的理论研究已经落后于工程实际。由于计算机具有强大的数据处理能力,越来越多的学者开始将边坡稳定的研究理论与计算机技术相结合,用来对边坡体的破坏情况进行模拟。现今的数值计算软件,其边坡理论主要是基于强度折减法来进行仿真计算。传统的强度折减法对于整个边坡的土体抗剪参数(c粘聚力、φ内摩擦角),采用同一个折减系数F进行强度折减。而实际工程中,当边坡体发生破坏时,滑坡面上下的岩土体其对边坡滑动的抵抗能力所发挥的程度必然是不同的,所以对于滑坡面以上的滑体、滑坡面下的滑床,二者应该有各自的折减系数F1、F2。正是鉴于此,本文拟利用FLAC3D软件对边坡问题进行分析,进而提出改进的强度折减法。由于此方法处于起步阶段,从计算效率的角度考虑,本改进的强度折减方法更适用于,潜在滑坡面已知的边坡体。本文的主要研究过程如下：一、对FLAC3D有限差分数值计算软件以及强度折减法进行了简单介绍。通过自编的强度折减方法,选取安全系数大于1以及安全系数小于1的理想边坡进行分析研究。对于一个边坡体分别对其滑体、滑床进行单独折减,通过对比分析提出改进的强度折减方法。二、本文对提出的改进强度折减法的可靠性进行了研究分析。以传统的强度折减法的结果为基准,通过改变影响边坡体稳定性的两个主要参数粘聚力c、摩擦角の的值,来讨论改进的强度折减法是否能够稳定的对边坡体进行评价。并得到了以下几个结论：1、粘聚力和摩擦角对边坡的稳定性影响较大；2、改进的强度折减法得到的综合安全系数与传统强度折减法得到的结果的最大偏差小于5%,即可认为运用该改进的强度折减法进行边坡稳定性分析是正确的；3、对于自然状态下可以稳定的边坡体,传统的强度折减法得到的稳定性评价偏高,对于自然状态下无法稳定的边坡体,传统的强度折减法过低的评价了边坡的安全稳定性。因而,对于边坡的稳定性分析采用改进的强度折减法更为合理。三、本文将提出的改进强度折减法,应用于右所屯滑坡的稳定评价中。选取右所屯滑坡最危险的剖面进行分析,得到的滑动面位置与前期提供的潜在滑动面位置是一致的。四、由于抗滑桩具有抗滑能力强、适应能力强、施工周期短等优点,使其在工程中得到了广泛的认可。本文采用双排抗滑桩对右所屯滑坡的典型剖面进行加固处置,通过单因素分析法研究桩间距、桩位对边坡稳定性的研究,最后归纳总结出本模型抗滑桩的最优加固方案。五、最后对本文的成果进行了总结,并对今后要开展有关方面研究的学者提出了自己的建议。
[Abstract]:The stability of the slope has always been a hot issue in the engineering field, and the construction of China's engineering construction has developed rapidly. There are many workers engaged in slope research, but because of the complexity of the research involved in rock and soil problems, along with the irregular shape of the slope body and the disturbance from the outside world, the research on slope stability has been relatively slow. With the increasing speed of the project, the relevant theoretical research has lagged behind the engineering practice. Due to the powerful data processing ability of the computer, more and more scholars begin to combine the research theory of slope stability with the computer technology, which is used to simulate the damage of the slope body. Today's numerical calculation software, its theory of slope is mainly based on the strength reduction method to carry on the simulation calculation. In this paper, the shear parameters (c-adhesive force and internal friction angle) of the soil body of the whole slope are reduced by the traditional strength reduction and subtraction. In the practical engineering, when the slope body is damaged, the degree of resistance of the rock-soil body under the landslide surface to the slope sliding must be different, so for the sliding body above the landslide surface and the sliding bed under the landslide surface, the two should have respective reduction coefficients F1 and F2. In view of this, this paper intends to use FLAC3D software to analyze the slope problems, and then put forward the improved strength reduction and subtraction. Since the method is in the initial stage, the improved strength reduction method is more suitable for the side slope body known to the potential landslide surface from the angle of calculation efficiency. The main research process of this paper is as follows: 1. Simple introduction of FLAC3D finite difference numerical calculation software and strength reduction and subtraction is carried out. By means of self-made intensity reduction method, an ideal slope with a safety factor greater than 1 and a safety factor of less than 1 is selected for analysis and study. For one side slope body, the sliding body and slide bed are separately reduced, and the improved strength reduction method is put forward through comparative analysis. Secondly, the reliability of the proposed improved intensity reduction is studied in this paper. Based on the results of traditional strength reduction and subtraction, the paper discusses whether the improved strength reduction and subtraction can be used to evaluate the slope body stably by changing the value of two main parameters affecting the stability of the slope body. The following conclusions are obtained: 1. The influence of cohesive force and friction angle on the stability of side slope is larger; 2. The maximum deviation of the comprehensive safety coefficient obtained by the improved strength reduction and subtraction is less than 5% with the result obtained by traditional intensity reduction and subtraction. it can be concluded that the slope stability analysis is correct by using the improved strength reduction and subtraction method, The traditional strength reduction method has evaluated the safety stability of the slope. Therefore, it is more reasonable for the stability analysis of the slope to adopt improved strength reduction and subtraction. Thirdly, the improved strength reduction method proposed in this paper is applied to the stability evaluation of the right Shantun landslide. The most dangerous section of the right Titun landslide is selected for analysis, and the position of the sliding surface is consistent with the position of the potential sliding surface provided in the prior period. 4. Owing to the advantages of strong anti-skid ability, strong adaptability and short construction period, it has been widely recognized in the project. In this paper, the typical cross section of the right Lutun landslide is reinforced and treated by double-row method. Through single-factor analysis, the study of pile spacing and pile position on slope stability is studied. Finally, the optimal reinforcement scheme of this model is summarized. Finally, the results of this paper are summarized, and their suggestions are put forward in the future.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU43
本文编号：2257259
[Abstract]:The stability of the slope has always been a hot issue in the engineering field, and the construction of China's engineering construction has developed rapidly. There are many workers engaged in slope research, but because of the complexity of the research involved in rock and soil problems, along with the irregular shape of the slope body and the disturbance from the outside world, the research on slope stability has been relatively slow. With the increasing speed of the project, the relevant theoretical research has lagged behind the engineering practice. Due to the powerful data processing ability of the computer, more and more scholars begin to combine the research theory of slope stability with the computer technology, which is used to simulate the damage of the slope body. Today's numerical calculation software, its theory of slope is mainly based on the strength reduction method to carry on the simulation calculation. In this paper, the shear parameters (c-adhesive force and internal friction angle) of the soil body of the whole slope are reduced by the traditional strength reduction and subtraction. In the practical engineering, when the slope body is damaged, the degree of resistance of the rock-soil body under the landslide surface to the slope sliding must be different, so for the sliding body above the landslide surface and the sliding bed under the landslide surface, the two should have respective reduction coefficients F1 and F2. In view of this, this paper intends to use FLAC3D software to analyze the slope problems, and then put forward the improved strength reduction and subtraction. Since the method is in the initial stage, the improved strength reduction method is more suitable for the side slope body known to the potential landslide surface from the angle of calculation efficiency. The main research process of this paper is as follows: 1. Simple introduction of FLAC3D finite difference numerical calculation software and strength reduction and subtraction is carried out. By means of self-made intensity reduction method, an ideal slope with a safety factor greater than 1 and a safety factor of less than 1 is selected for analysis and study. For one side slope body, the sliding body and slide bed are separately reduced, and the improved strength reduction method is put forward through comparative analysis. Secondly, the reliability of the proposed improved intensity reduction is studied in this paper. Based on the results of traditional strength reduction and subtraction, the paper discusses whether the improved strength reduction and subtraction can be used to evaluate the slope body stably by changing the value of two main parameters affecting the stability of the slope body. The following conclusions are obtained: 1. The influence of cohesive force and friction angle on the stability of side slope is larger; 2. The maximum deviation of the comprehensive safety coefficient obtained by the improved strength reduction and subtraction is less than 5% with the result obtained by traditional intensity reduction and subtraction. it can be concluded that the slope stability analysis is correct by using the improved strength reduction and subtraction method, The traditional strength reduction method has evaluated the safety stability of the slope. Therefore, it is more reasonable for the stability analysis of the slope to adopt improved strength reduction and subtraction. Thirdly, the improved strength reduction method proposed in this paper is applied to the stability evaluation of the right Shantun landslide. The most dangerous section of the right Titun landslide is selected for analysis, and the position of the sliding surface is consistent with the position of the potential sliding surface provided in the prior period. 4. Owing to the advantages of strong anti-skid ability, strong adaptability and short construction period, it has been widely recognized in the project. In this paper, the typical cross section of the right Lutun landslide is reinforced and treated by double-row method. Through single-factor analysis, the study of pile spacing and pile position on slope stability is studied. Finally, the optimal reinforcement scheme of this model is summarized. Finally, the results of this paper are summarized, and their suggestions are put forward in the future.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU43
【参考文献】
相关期刊论文 前1条
1 郑颖人,雷文杰,赵尚毅,邓卫东;抗滑桩设计中的两个问题[J];公路交通科技;2005年S1期
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