【作者】 和民锁；

【导师】 李亮；

【作者基本信息】 中南大学 ， 岩土工程， 2010， 博士

【摘要】 路基的压实质量是保证路基的工程性能、路基长期稳定、工后沉降控制的重要环节。从高速铁路的路基填筑质量保证方面来讲,除了选择合适的填料、在施工过程中的合理的过程控制外,路基压实质量检测和评价是保证路基填筑质量的关键措施之一。尽管现有规范对路基的压实质量检测方法、控制标准及质量评价等都做过相关的规定,但由于路基填料本身的不均匀性和现有检测方法的局限性,路基的填筑质量仍旧不能很好的控制,因此进而影响道路的使用寿命,并造成巨大的经济损失。同时,现有的高速铁路建设采用多重检测指标来确保路基的压实质量。但是,这些措施不仅影响路基的施工进度,而且远不能适应现代化的施工要求及合理地控制路基填筑质量。并且,在路基使用粗颗粒填料时,这些缺陷更加显著。在高速铁路路基的研究领域中,研究快速合理的压实质量检测方法、控制标准及质量评价方法在国内外都属于一个全新的课题。本文基于我国高速铁路的建设实践,通过现场试验与理论分析,进一步完善和发展了路基压实质量检测方法、控制标准及质量评价方法。得到一些创新性研究成果,其概括为以下四个方面：(1)结合对比中、德两国路基压实质量检测方法、控制指标,对武广高铁岳阳段全风化砂砾岩与碎石改良两种典型填料的室内外实验结果进行深入分析,建立了中国压实度与德国压实系数之间的内在关系；为适应高速铁路大颗粒填料日益广泛使用的趋势,提出了在室内试验中增加大型击实设备以反映粗颗粒填料的真实工程特性的重要建议；基于现有规范中采用孔隙率控制指标不能有效控制路基压实质量的缺陷,提出了采用压实度作为路基压实的控制指标,以满足客运专线路基的密实度要求,并成功应用于武广高铁路基填筑压实工程,该建议即将被行业规范采纳；获得了K30与Ev2的相关性,提出了可以选择其中一个检测指标来衡量路基压实质量的重要建议,以简化压实检测程序。(2)根据路基不同压实阶段的力学性质,建立了反映路基压实状态的压路机-路基简化的动力学计算模型,获得了不同路基刚度下振动轮的动态响应、动态响应与路基刚度的相关性；据此提出了路基压实过程中的动态监控方法。(3)在哈大高速铁路与向莆铁路进行了现场试验,进行了传统的路基压实质量和连续动态检测,对不同检测方法的结果进行对比分析,建立了动态连续检测指标CMV与K30等之间的关系。获得了动态连续检测指标与传统检测指标之间具有较好的相关性的重要结论；提出连续动态检测指标能很好的反应路基压实质量,具有较高的可靠度的重要建议。(4)以连续动态检测的大量数据为基础,对检测数据进行了统计分析,得到了路基连续动态检测压实度的分布规律,分析了影响分布规律的主要因素。此外,基于概率和统计学理论,提出了压实均匀性的评价概念和路基不均匀沉降控制的思路。更多还原

【Abstract】 Compaction quality of the embankment is a crucial link to ensure its engineering performance and long-term stability as well as reduce the post-construction settlement. Besides proper selection of soil and control of the construction, some influence factors (e.g. compaction quality, inspection and evaluation) are important measurements to guarantee the embankment quality required for a high quality embankment, especially for high-speed railway subgrade.Although there are requirements in specifications for the test methods, acceptance criteria and evaluation system of the compaction quality, there are still difficulties to control the compaction quality of subgrade due to the inhomogeneity of filling material and the limitations of test and evaluation methods. These kinds of disadvantages which may further influence the riding performance as well as reduce the service life of the road and then will result in great economic loss. As a matter of fact, in order to guarantee the compaction quality, many inspect methods were employed in high-speed railway construction in China to guarantee the compaction quality, which may delay the construction process schedule and are not adaptable to the requirement of modern construction including the compaction quality controlling of subgrade. These disadvantages are more evident when the coarse filling material is used in practice.It is a novel task, home and abroad, to study on high-speed railway subgrade to obtain the rapid and reasonable inspects method, rational control indexes and evaluation method with respect to compaction. Based on the practice of high-speed railway construction in China, this dissertation made an improvement and development in the test methods, acceptance criteria and evaluation system through theoretical analysis and field test. The innovational research achievements are summarized as follows:(1) According to deep analysis of laboratory and field test of compaction experiment with respect to two classical types of filling materials (e.g. completely decomposed sandy conglomerate and modified gravel) at Yueyang section of Wu-Guang High-speed railway as well as based on the comparison between China and Germany in terms of test measurement of compaction quality and controlling index, the correlation of the compaction degree applied in China and Germany was established. In order to adapt the development that the large-particle filling material is increasingly popular to be used in filling subgrade of hing-speed railway, a significant advice was presented that large scale compaction device should be added and applied in laboratory experiment to reflect the real engineering characteristics of large-particle filling material. Further, on the basis of the limitation of controlling index of porosity in current specification which cannot be efficient to control the compaction quality of subgrade, we presented another controlling index of compaction degree to control the compaction quality to satisfy the requirement of compaction required by subgrade of passenger dedicated line. This controlling index has been applied successfully in the practice of subgrade compaction engineering of Wu-Guang high-speed railway, and it will be included in the specification, Moreover, we obtained the correlation of K30 and Ev2, and presented another significant suggestion that we can simply select either K30 or Ev2 to weigh the compaction quality of subgrade, which can simplify the test procedures.(2) According to the different mechanical properties of subgrade in obvious compaction stages, the simplified roll-embankment integrated dynamic model to simulate the condition of subgrade compaction was presented. Based on the calculation of this model, we obtained the dynamic response of subgrade with obvious stiffness; also the correlation between dynamic response and stiffness of subgrade was obtained. Then, the method to monitor the compaction process dynamically was presented.(3) Based on the field experiment at Ha-Da high-speed railway and Xian-Pu railway, the roll-integrated compaction measurements and conventional measurements were conducted. Then, the relationship between CMV with respect to Roll-integrated compaction measurement and K30 was established in terms of comparison results between different detection measurements.(4) On the basis of numerous data of roll-integrated compaction measurements, the distribution of subgrade-compaction degree was obtained after analyzing the detection data statistically. Then, the main influence factors were analyzed. Further, the conception to evaluate the uniformity of compaction and the thought to control the non-uniformity of settlement were presented.更多还原