EPS颗粒轻质混合土挡墙大型振动台试验研究

发布时间：2018-04-10 14:31

本文选题：EPS颗粒轻质混合土 + 挡土墙　；参考：《南京工业大学》2015年硕士论文

【摘要】：在大规模的基础建设过程中往往会伴随着大量的地基土体的填挖,特别是在山区修建道路桥梁,需要大规模修筑挡土结构。近年来,我国地震灾害愈发频繁,对于挡墙稳定性是一个巨大的考验,已有的挡墙抗震研究还不够深入,因此挡墙地震荷载下稳定性研究显得十分紧迫。课题基于EPS颗粒轻质混合土(EPS composite soil)在工程领域可行性的研究,开展了EPS颗粒轻质混合土的基本物理力学性质试验,并结合挡墙失稳研究现状,设计完成了一组几何相似常数为1/4的回填EPS颗粒轻质混合土挡墙的抗震性能研究的大型振动台试验。文章主要工作及结论如下：(1)开展了EPS颗粒轻质混合土的基本物理力学性质试验,包括密度试验、压缩试验、直剪试验。试验结果表明,EPS颗粒轻质混合土的密度主要受EPS颗粒含量影响,且随着EPS颗粒含量增大而减小；抗剪强度随水泥含量增大而增大,并在EPS颗粒含量取3%左右取得一个相对较大值。(2)设计了一组EPS轻质土挡墙的大型振动台试验,包括根据原型和试验目的设计模型结构和模型地基；选择对应试验装置且合理布置试验传感器；试验过程中对各部分工作协调安排。(3)分析了EPS轻质土挡墙的大型振动台试验结果,研究了EPS轻质土作为挡墙背后填土,在地震荷载作用下的动力特性。结果表明,相对普通回填土,EPS轻质土对于地震动的耗能效果明显,有效地降低了地震动的加速度峰值；作用于挡墙背后的主动土压力分布规律差异明显；相同位置,回填EPS轻质土的挡墙应变更小,加速度峰值较小,墙顶端位移也更小。回填EPS颗粒轻质混合土能够减少地震荷载对挡墙稳定性的影响。
[Abstract]:In the process of large-scale infrastructure construction, it is often accompanied by a large number of subgrade soil fill and excavation, especially in the mountains to build roads and bridges, it is necessary to build a large scale retaining structure.In recent years, earthquake disasters become more and more frequent in China, which is a great test for the stability of retaining wall. The existing seismic research of retaining wall is not enough, so the research on the stability of retaining wall under earthquake load is very urgent.Based on the feasibility study of EPS granular lightweight mixed soil (EPS composite soil) in the field of engineering, the basic physical and mechanical properties of EPS granular lightweight mixed soil are tested, and the research status of retaining wall instability is combined.A set of large-scale shaking table tests with a geometric similarity constant of 1 / 4 for the seismic performance of backfilled EPS particle lightweight mixed soil retaining wall were designed and completed.The main work and conclusions are as follows: (1) the basic physical and mechanical properties of EPS granular lightweight mixed soil are tested, including density test, compression test and direct shear test.The results show that the density of light mixed soil is mainly affected by the content of EPS particles, and decreases with the increase of EPS particle content, and the shear strength increases with the increase of cement content.A relatively large value of about 3% of EPS particles was obtained.) A group of shaking table tests of EPS light soil retaining wall were designed, including the design of model structure and model foundation according to prototype and test purpose.Selecting the corresponding test device and arranging the test sensor reasonably, the test results of the large scale shaking table of EPS lightweight soil retaining wall are analyzed, and the EPS lightweight soil as the backfill of the retaining wall is studied.Dynamic behavior under earthquake load.The results show that compared with ordinary backfill soil, EPS light soil has obvious energy dissipation effect on ground motion, effectively reduces the acceleration peak value of ground motion, and the distribution of active earth pressure acting on the back of retaining wall is obviously different.The strain of retaining wall is smaller, the peak of acceleration is smaller, and the displacement of the top of the wall is smaller than that of the backfilled EPS lightweight soil.Backfilling EPS granular lightweight mixed soil can reduce the influence of seismic load on the stability of retaining wall.
【学位授予单位】：南京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU476.4

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