交通工程边坡在振动力作用下行为特征研究

发布时间：2018-04-27 03:42

本文选题：工程边坡 + 变形破坏机制　；参考：《西南交通大学》2013年博士论文

【摘要】：交通工程边坡在地震作用下的行为特征研究,是近年来研究的热点问题。随着国家工程建设的投入,我国大量线路工程将会不可避免的穿越地震活跃区,科研人员将会遇到大量复杂边坡问题,而边坡问题将会伴随着工程建设的进行而变得日益突出。本学位论文在全面研究现代交通线路工程的各类边坡破坏模式的基础上,利用室内物理模型试验和数值模拟算等手段开展了边坡工程地质问题动力学的理论研究,为交通工程边坡治理防护和交通工程边坡地质灾害预测评价提供了动力学理论依据。主要研究成果如下： (1)按照机械设计原理和结构动力学原理,设计了二维单向振动试验台。利用位移传感器和动态采集系统对模型箱的位移时程曲线进行了采集,并且通过结构动力学理论计算,获取了理想状态下单向振动的位移时程曲线,通过两条曲线对比发现,振动试验台整体性能稳定,能够满足小型荷载的振动试验。 (2)边坡坡面形态对边坡的变形破坏有着直接的影响；凸面边坡由于滑动体质量大,所以在振动力施加时能够瞬问发生整体的变形破坏,而凹面边坡由于滑体质量较小,在振动力作用下容易造成滑体的分段下滑,位于滑体下部的块体先行下滑,进而带动整个滑体的滑动破坏,由此造成的宏观现象是凹面边坡坡面的裂隙要早于边坡坡顶的裂隙产生,而凸面边坡则与此相反。凹凸组合面边坡的变形破坏受坡面上凸起部分的影响。 (3)边坡的变形破坏程度以及滑动面倾角与边坡坡面的凹凸程度直接相关；边坡凹陷或凸出程度越强烈的边坡,振动试验结束后其坡顶剩余的部分就越少；同时分析发现,滑动面滑床倾角随着边坡坡面凹陷或者凸出程度的减缓而逐渐增大。 (4)边坡坡面形态对坡面加速度分布有直接影响；边坡加速度放大系数在坡而凹陷和凸起区域达到局部最大,并且逐步向外减小,在同等情况下,凸而坡坡面的加速度放大效应要强于凹面坡坡面放大效应。在凹凸组合面边坡中,加速度放大效应也在边坡坡面凹陷处和凸起处达到最大。加速度在边坡内部都有随着坡高的增高而增高的趋势,而且处于同一高程的边坡坡面放大效应趋势要大于边坡内部,但不同坡面形态边坡坡体内部加速度分布并未出现不同规律,说明边坡坡面形态对边坡内部加速度的分布影响较小。 (5)通过对层状岩石边坡物理模型试验发现,受结构面的影响,顺层模型边坡的变形破坏主要是沿着固定层面的滑动破坏,反倾向模型边坡的变形破坏主要是以崩塌体的形式破坏。 (6)高程位置较高的隧道口由于滑体将其包含其中而容易造成隧道口的整体破坏,而高程较低的隧道口由于滑塌体堆积而容易造成隧道洞口堵塞。 (7)结构面参数对边坡动力响应规律的影响较大；结构面刚度较小的边坡下部坡体的三量峰值较小,而上部坡体三量峰值较大；结构面越靠近边坡坡顶,结构面上部坡体的三量放大系数就越高；随着结构面倾角的增加,顺层结构面边坡加速度放大系数随之增大,反倾向结构面边坡加速度放大系数随之减小,顺层结构面边坡加速度放大系数整体大于反倾向结构面边坡加速度放大系数；结构面厚度较小的边坡其动力响应较为强烈,结构面厚度较大的边坡动力响应较弱；不同结构面连通率的边坡,加速度峰值的差异较为明显,在结构面位置处,连通率较大的结构面放大效应较强。 (8)通过总结太平隧道出口边坡工程地震安全性分析发现,太平隧道出口边坡受结构面的影响较大,在地震来临时,结构面切割块体会受到拉张剪切应力作用而发生整体和单个块体的下滑,但是由于隧道洞口位置适中,滑体滑动面位于隧道洞口以上,并且滑体滑落后不会出现堵塞洞口的现象,这一规律给隧道出口边坡震后的迅速通车提供了可贵的先前条件。整体而言,太平隧道出口边坡选址较为可观。
[Abstract]:The research on the behavior characteristics of traffic engineering slope under the earthquake action is a hot issue in recent years. With the investment of national engineering construction, a large number of line projects in China will inevitably cross the active area of the earthquake, and the researchers will encounter a large number of complicated slope problems, and the slope problem will be accompanied by the construction of the project. On the basis of all kinds of slope failure modes of modern traffic line engineering, this dissertation has carried out the theoretical study of the dynamics of slope engineering geology by means of indoor physical model test and numerical simulation, for the prevention and protection of the slope of the traffic engineering slope and the prediction of the geological disaster of the slope of the traffic engineering. The evaluation provides a theoretical basis for dynamics. The main research results are as follows:
(1) according to the principle of mechanical design and the principle of structural dynamics, a two-dimensional unidirectional vibration test rig is designed. The displacement time history curve of the model box is collected by the displacement sensor and the dynamic acquisition system, and the displacement time history curve of the unidirectional vibration under the ideal state is obtained by the structure dynamics theory, and the two curve pairs are used. It is found that the overall performance of the vibration test stand is stable, and it can meet the vibration test of small load.
(2) the slope surface shape has a direct influence on the deformation and failure of the slope; because the mass of the sliding body is large, the convex side slope can instantly ask for the whole deformation and failure when the vibration force is added, while the concave slope is easy to make the slide block slide under the action of the vibration force, and the block in the lower part of the slide is first. The sliding failure of the whole slide will lead to the sliding failure of the whole body, and the macroscopic phenomenon is that the crack of the concave slope surface is earlier than the crack in the top of the slope, while the convex side slope is opposite to this. The deformation and failure of the concave and convex side slope is affected by the convex part on the slope.
(3) the degree of deformation and failure of the slope and the dip angle of the sliding surface are directly related to the degree of the concave and convex of the slope, and the more strong slope of the slope, the more the remaining part of the slope is on the top of the slope after the end of the vibration test. At the same time, it is found that the dip angle of sliding surface slide with the slope of the slope or the degree of protruding slows down gradually. Enlarge.
(4) the slope surface morphology has a direct influence on the acceleration distribution of the slope; the acceleration amplification factor of slope acceleration reaches a local maximum in the slope and the concave and convex regions, and gradually decreases outward. Under the same circumstances, the acceleration amplification effect of the convex and sloping slopes is stronger than the magnification effect of the concave slope surface. The large effect also reaches the maximum in the slope and the protruding. The acceleration is increasing with the increase of slope height, and the trend of amplification effect on the same elevation is larger than that in the slope, but the distribution of the acceleration distribution in the slope of different slope forms does not appear in different laws, indicating the side of the slope. The slope surface morphology has little effect on the acceleration distribution inside the slope.
(5) through the physical model test of the layered rock slope, it is found that the deformation and failure of the bedding model slope is mainly along the fixed plane, and the deformation and failure of the anti tendency model slope is mainly destroyed by the form of the collapse.
(6) the tunnel mouth is prone to damage the tunnel entrance due to the inclusion of the slide body in the tunnel with high elevation position, and the lower height of the tunnel is likely to cause the tunnel opening to be blocked due to the accumulation of the slump.
(7) the structural plane parameters have great influence on the dynamic response law of the slope; the three peak value of the lower slope with the smaller structural surface is smaller, while the three peak value of the upper slope is larger; the closer to the top of the slope, the more the three magnification coefficient of the upper slope of the structure surface is higher; with the increase of the structure surface angle, the bedding structure side edge is increased. The amplification coefficient of slope acceleration increases, and the acceleration magnification coefficient of the side slope decreases, and the acceleration magnification factor of the slope acceleration is larger than that of the reverse inclined structural side slope; the dynamic response of the slope with smaller structural surface thickness is stronger, and the dynamic response of the slope with a larger structural surface thickness The difference of acceleration peak value between slopes with different structural plane connectivity is more obvious. At the location of structural plane, the enlargement effect of structural plane with larger connectivity is stronger.
(8) through the analysis of the seismic safety of the exit slope engineering of the Taiping tunnel, it is found that the influence of the structural plane on the exit slope of the Taiping tunnel is larger. When the earthquake comes, the structure face cutting block is subjected to the tension and shear stress, which occurs as a whole and a single block, but it is due to the moderate position of the tunnel hole, and the sliding surface of the slide is located in the tunnel. There is no phenomenon of blocking the hole after the slide of the tunnel, and this rule provides a valuable prior condition for the rapid transit of the tunnel exit slope after the earthquake. In general, the location of the exit slope of the Taiping tunnel is relatively considerable.

【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：U213.13;U416.14;P642.2

【参考文献】