摘要
“三段式”岩质边坡的动力响应试验研究
摘要
近年来，地震作用下岩质边坡的稳定性研究是地质工程和岩土工程研究的热点问题之一。地震灾害在我国频发，常常造成巨大的毁灭性灾难，地震造成的原生次生灾害，是一种诱发滑坡、崩塌、泥石流的主要因素，极大地威胁到人民的生命安全和财产安全，严重地损害了国民的经济建设。我国地震灾害频发，且西南地区存在着大量的高山地貌，随着西部大开发战略的进一步实施，西南崛起的进行，地震灾害问题日益显著，影响了基础建设的实施和工程项目的开展。这是在进行西部建设中所面临的重大挑战之一，西南地区广泛存在着“三段式”锁固段滑坡。为了探究地震灾害形成及发展的理论依据，为防震、抗震提供工程实践意义，加强地震作用下“三段式”岩质边坡的动力响应规律的研究至关重要。本文基于振动台模型试验，采集、分析、研究了不同工况条件下，不同位置的PGA 数据，得出了“三段式”岩质边坡的动力响应规律如下：
（1）通过对模型边坡进行振动台试验，得到不同输入波作用下，坡表及坡内测点的加速度放大系数均随坡高的增加而增大，整体表现出高程放大效应，沿坡表近似于线性放大，坡内同一竖直方向则呈现“鱼腹形”增大；同时，在位于相同高程的测点，坡面测点处加速度放大系数总是大于坡体内部测点的加速度放
大系数，呈现出趋表效应。
（2）试验过程中采用了正弦波和El Centro波进行激振，通过对比不同类型输入波作用下边坡坡面处加速度放大系数的变化规律，得出了输入波波形对加速度放大系数的变化存在着明显的差异，总体表现出正弦波在相同测点处的放大系数要明显高于El Centro地震波，其原因是地震波在输入过程中峰值出现的次数存在差异；此外，通过改变同一波形的加载振幅和频率发现，随着振幅与频率的增大，加速度放大系数均呈现出先增加后减小的变化规律。
（3）通过对不同结构类型的边坡模型进行地震波激振，发现：蠕滑段的存在，使得该结构下部测点的加速度放大效果有轻微的增大现象，原因是地震波在传播过程中，在蠕滑段处发生折射和散射；而在蠕滑段上部测点的加速度放大系数要小于均质边坡，其原因是单一蠕滑段边坡模型中蠕滑段材料与坡体材料不同，在其分界面处由于材料的改变而存在较大的滤波作用；此外，裂缝的存在也会使得其附近测点的加速度放大系数减小。
关键字：“三段式”岩质边坡；模型试验；蠕滑段；动力响应
I
ABSTRACT
Experimental study on dynamic respon of
"three-gment" rock slope
ABSTRACT
In recent years, the rearch on the stability of rock slope under earthquake is one of the hot topics in geological engineering and geotechnical engineering. Earthquakes are one of the most common and harmful natural disasters. Their primary and condary disasters are huge. They are the main factors inducing landslides, collaps and debris flows. They greatly threaten people's life and property safety, and riously damage the national economic construction. Earthquake disasters occur frequently in China, and there are a large number of Alpine landforms in southwest China. With the deepening development of the Western Regions and the ri of Southwest China, the problem of earthquake disasters has become increasingly prominent, affecting the implementation of infrastructure construction and the development of Engineering projects. This is one of the major challenges in the construction of the western region. There are many "three-gment" clavicular landslides in southwest China widely. In order to explore the theoretical basis for the formation and development of earthquake disasters and provide engineering practical significance for earthquake p
revention and earthquake resistance, it is very important to strengthen the study of dynamic respon law of "three-gment" rock slope under earthquake action. Bad on shaking table model test, PGA data at different locations under different working conditions are collected, analyzed and studied in this paper, and the dynamic respon law of "three-gment" rock slope are as follows:
(1)Through shaking table tests on model slopes, it is found that under different input waves, the acceleration amplification coefficients of the measured points on the slope surface and in the slope increa with the increa of the slope height, showing the elevation amplification effect as a whole, approximating to linear amplification along the slope surface, and increasing "fish belly" in the same vertical direction within the slope; at the same elevation measuring point, the acceleration at the measured points on the slope surface increas. The magnification factor is always greater than the acceleration magnification factor of the measured points inside the slope, showing a trend table effect.
(2)Sinusoidal wave and El Centro wave are ud to excite the slope during the test. By comparing the law of the variation of the acceleration amplification
华北水利水电大学硕士学位论文
coefficient at the slope surface under different input waves, it is concluded that there are obvious differences in the variation of the acceleration amplification coefficient between the input wave waveforms, which generally shows the amplification system of sinusoidal wave at the same measuring point. The number of ismic waves is significantly higher than that of El Centro ismic waves, which is due to the difference in the number of peak values of ismic waves in the input process. In addition, by changing the loading amplitude and frequency of the same waveform, it is found that with the increa of amplitude and frequency, the acceleration amplification coefficient increas first and then decreas.
(3)Through ismic wave excitation of slope models of different structural types, it is found that the existence of creep ction makes the acceleration amplification effect of the lower measuring points of the structure slightly increa, becau the ismic wave refracts and scatters in the creep ction during the propagation process. The acceleration amplification factor of the measured points in the upper part of the creep ction is smaller than that of the homogeneous slope. The reason is that the creep ction material in the single creep ction slope model is different from that of the slope body material, and there exists a large filtering effect at its interface due to the change of the material. In addition, the existence of cracks also reduces the acceleration amplification factor of the measured points nearby.
暴露拼音
Key words: "three-gment" rock slope; model test; creep ction; dynamic respon
目录
目录
摘要............................................................................................................................... I ABSTRACT ................................................................................................................. III 1 绪论.. (1)
1.1 研究背景和意义 (1)
1.2 国内外研究现状 (3)
养什么猫最好
1.2.1 “三段式”锁固段滑坡的发展历程 (4)
1.2.2边坡动力响应及稳定性分析 (5)
1.3 论文主要研究内容 (7)
1.4 技术路线 (8)
2 振动台设备及模型试验原理 (9)
2.1 概述 (9)
2.2 振动台试验设备及采集系统 (9)
2.3 模型试验的理论依据 (11)
2.3.1 相似定理 (13)
2.3.2 相似准则 (14)
熟牛肉2.3.3 振动台中模型与原型的相似关系 (19)
2.3.4 模型相似材料及相关力学性质 (20)
2.4 小结 (22)
3 振动台模型试验设计 (23)
艾敬为什么被禁3.1 振动台模型试验设计方案 (23)
3.1.1 模型箱的设计与制作 (23)
3.1.2 边坡模型的设计与制作 (24)ssid
3.1.3 试验方案的设计与制定 (28)
3.2 传感器的布置与地震波的选取 (29)
建国大业手抄报3.2.1 传感器的布置 (29)
3.2.2 地震波的选取 (30)
3.3 振动台试验加载过程及记录 (32)
3.3.1 试验加载方案 (32)
华北水利水电大学硕士学位论文
3.3.2 振动试验过程及记录 (33)
3.4 小结 (34)
心志4 振动台试验结果分析 (35)
4.1 概述 (35)
4.2 边坡动力响应的基本规律 (35)
4.3 波形对边坡动力响应特性的影响 (38)
4.4 幅值对边坡动力响应特性的影响 (38)
4.5 频率对边坡动力响应特性的影响 (39)
4.6 坡体结构对边坡动力响应特性的影响 (40)
4.7 小结 (43)
5结论与展望 (45)
5.1 结论 (45)
5.2 展望 (46)
攻读学位期间参加的科研项目及发表的学术论文 (47)
致谢 (49)
香蕉饼的做法大全参考文献 (51)
