强夯法加固湿陷性黄土地基的应用研究

发布时间：2018-04-04 23:12

本文选题：强夯法　切入点：地基处理　出处：《西安工业大学》2011年硕士论文

【摘要】：近年来强夯的应用越来越广泛,现阶段针对强夯法方面的研究大多是以现场试验为主要的研究手段。虽然前人的研究成果积累了宝贵且丰富的试验研究数据,但是针对强夯施工在湿陷性黄土地区应用的系统研究还有所不足,所以强夯法在湿陷性黄土地基应用的进一步研究显得十分重要。本文总结了国内外的研究成果,并主要进行了以下几项研究工作：总结、分析国内外关于强夯加固机理的研究成果,并结合黄土的特殊性提出强夯加固湿陷性黄土地基的机理；通过具体工程的试验研究,对强夯加固湿陷性黄土地基的加固效果进行评价,并通过试验数据的分析证实强夯的加固机理；通过数值模拟,对比分析试验数据及理论结果,证明LS-DYNA3D应用于强夯加固的可靠性。最后通过改变相应的施工参数对强夯过程进行模拟,通过模拟结果对设计、施工参数进行优化。研究的基本结论：LS-DYNA3D程序应用于强夯的数值模拟,具有较强的可靠性与适用性,在今后的强夯工程中可用于预测或分析；数值模拟和试验结果表明在强夯过程中地基土具有明显的波动性,反映出强夯作用于地基土时,夯击能量是以震动波的形式传播,最后被地基土吸收,改变了黄土的原有结构,黄土在震动波作用下被压密；在同能量级条件下,采用重锤低落距和底面积大而密度小的施工参数的加固效果要优于轻锤高落距和底面积小而密度大的组合；通过增大能量级,可以增大竖向加固影响深度,同时通过合理布置夯点间距,使深层地基土的位移产生叠加,可以达到提高深层土层的均匀性和强度目的。论文的研究成果对于强夯法在湿陷性黄土地区应用中的加固效果的预测或分析提供了很有参考价值的素材,同时对强夯应用于湿陷性黄土地基处理时设计及施工参数的优化有着积极的指导意义。
[Abstract]:In recent years, the application of dynamic compaction is more and more extensive.Although the previous research results have accumulated valuable and abundant experimental data, the systematic research on the application of dynamic compaction in collapsible loess areas is still insufficient.So it is very important to study the application of dynamic compaction method in collapsible loess foundation.This paper summarizes the research results at home and abroad, and mainly carries out the following research work: summing up, analyzing the research results of dynamic compaction reinforcement mechanism at home and abroad, and combining the particularity of loess, puts forward the mechanism of dynamic compaction strengthening collapsible loess foundation;The reinforcement effect of dynamic compaction on collapsible loess foundation is evaluated through the experimental study of concrete engineering, and the reinforcement mechanism of dynamic compaction is confirmed by the analysis of test data, and the experimental data and theoretical results are compared and analyzed by numerical simulation.The reliability of LS-DYNA3D used in dynamic compaction reinforcement is proved.Finally, the dynamic tamping process is simulated by changing the corresponding construction parameters, and the design and construction parameters are optimized by the simulation results.The basic conclusion of the study is that the application of the # LS-DYNA3D program to the numerical simulation of dynamic compaction has strong reliability and applicability, which can be used to predict or analyze the dynamic compaction in the future.The numerical simulation and experimental results show that the dynamic compaction of the foundation soil has obvious fluctuation, which reflects that when the dynamic compaction acts on the foundation soil, the tamping energy propagates in the form of vibration wave, and finally is absorbed by the foundation soil, which changes the original structure of loess.Loess is compacted under the action of vibration wave; under the condition of same energy level, the reinforcement effect with heavy hammer drop distance and construction parameters with large bottom area and low density is better than that with light hammer height drop distance and low bottom area and high density; by increasing the energy level, the reinforcement effect is better than that of light hammer high drop distance and low bottom area.The influence depth of vertical reinforcement can be increased and the displacement of deep foundation soil can be superimposed by reasonable arrangement of compaction point spacing which can improve the uniformity and strength of deep soil layer.The research results of this paper provide reference material for the prediction or analysis of the reinforcement effect of dynamic compaction method in collapsible loess area.At the same time, the application of dynamic compaction in the treatment of collapsible loess foundation design and construction parameters optimization has a positive guiding significance.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TU753.8

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