【作者】 毛泽宇；

【导师】 姚令侃；

【作者基本信息】 西南交通大学 ， 道路与铁道工程， 2008， 硕士

【摘要】 由于地震触发的崩塌灾害分布广,又多以一次性快速滑动方式出现。因此,在震区已经成为一种不可忽视的次生灾害。正如地震灾害一样,人类不可能完全避免地震崩塌灾害,但可以采取积极的、有效的措施来减轻这种灾害。特别是近年来,随着我国城市化进程的加快、大型水利水电工程的兴建、经济发展战略向西部的转移,对地震崩塌灾害预测研究发展的要求更为迫切。松散堆积体边坡在地震作用下失稳模式主要体现为崩塌,而松散介质边坡崩塌规模是崩塌灾害的重要指标,也是崩塌灾害中有待研究的科学问题,但国内外对此的研究甚少。本文采用离心模型实验和数值模拟相结合的方法,研究了不同地震烈度作用下松散堆积体崩塌规模;以此为基础,在拟静力法思想框架下,以松散介质边坡为研究对象,根据力的平衡原理,推导出在不同地震烈度作用下临界状态失稳范围的简化公式。以边坡底板为模型,通过离心试验和PFC2D数值模拟(按重力相似准则,高度达20.4m),对此简化公式的正确性进行比较验证,得出该简化公式的适用范围。最后以国道318线川藏公路整治改建工程通麦至105道班段实际工点为例,对此研究方法的应用模式进行说明。主要工作及研究结论如下:(1)采用大型离心模型实验,研究了均匀颗粒堆积体和非均匀颗粒堆积体在地震作用下的崩塌。(2)运用离散单元法颗粒流程序PFC2D,通过大量内摩擦角φ与摩擦系数μ关系的数值模拟,完成了实测数据内摩擦角φ与PFC2D中摩擦系数μ的对应,达到了实际散粒体工点在PFC2D中能够进行模拟的目的,为下一步在PFC2D中进行地震作用下散粒体颗粒崩塌数值模拟提供必要条件。(3)通过对地震作用下松散堆积体崩塌在PFC2D中的数值模拟,研究松散堆积体边坡的崩塌现象及规律,并将模拟结果与离心模型实验结果比较。(4)在上述离心模型实验和数值模拟研究崩塌的基础上,建立了一种基于拟静力法原理的边坡松散堆积体在不同强度地震作用下崩塌方量估算的简化公式。根据该简化公式,完成了川藏公路通麦至105道班沿线各典型边坡工程在小、中、大震作用下崩塌体积的计算。更多还原

【Abstract】 Collapse and landslide which are triggered by earthquake with the characteristics of wide distribution often occur under sliding rapidly one off mode, therefore,they have become an unneglectable secondary disaster in earthquake region. Just as disasters triggered by earthquake, the human can’t avoid disasters of collapse and landslide under earthquake completely, but we can take positive and effective measures to reduce the disaster. Especially in recent years, with the process of urbanization accelerating in our country, large water conservancy and hydropower projects establishing, strategies of economic development transfer to western,the requirement of developing the research of forecasting disasters of collapse and landslide under earthquake is more urgent.Under earthquake , surface collapse often occurs when the loose slope is in the instability mode and the collapse size of loose medium slope is an important index in collapse hazards. The collapse size in collapse hazards is also a scientific question for future study, but there are few studies at home and abroad. The loose particle of slop body is chosen as research object in pseudo-static method framework. According to the balance principle of force, the simplified formulae in instability of critical state is derived under different effects of earthquake intensity in this paper. The simplified formulae was validated by the centrifugal model test result (according to the criterion of gravitational force similarity, its height attains 20.4m) which uses slope body floor as the experimental model. Taking real underground projects of Tongmai to 105 Maintenance in the project of the treatment and reconstruction of Sichuan-Tibet highway at highway section of National Road 318 as an example , this paper will carry out an explanation of application mode in this research method.The main work and conclusion is as follow: (1) Geotechnical centrifuge model tests were adopted to study the accumulation ’s collapse under earthquake which is formed by uniform and non-uniform particles.(2) Adopting the traditional mechanics method to study the relation between friction coefficient and internal friction angle using PFC2D procedure , and study the accumulation ’s internal friction angle is affected by grain diameter ,density, and gradation.(3) By changing the angle of the slope corresponding to different sizes of earthquake intensity, numerical simulations of the accumulation ’s collapse could be realized in PFC2D procedure,and compare the difference between simulation results and results of geotechnical centrifuge model tests.(4) Having established a simplified formulae which is used to estimate the collapse ’s volume of loose slope under earthquake by using pseudo-static method for principle. According to this simplified formulae, the collapse ’s volume of loose slope of real underground projects of Tongmai to 105 Maintenance in the project of the treatment and reconstruction of Sichuan-Tibet highway at highway section has been calculated under large , middle, small earthquake.更多还原