不同测试方法下碎石土、黄土路基模量对比研究

发布时间：2018-07-31 05:08

【摘要】：路基是路面结构的重要基础,它支撑着路面结构及之上的所有荷载,路基承载力的高低直接决定着公路的整体使用性能,而其路基质量的好坏会影响到路面结构的性能、病害的发生及程度等。公路在使用过程中,路面经常会出现多种的病害,而这些病害当中大部分原因是因为路基强度不足导致的。因此,坚实稳定且满足使用需求的路基是保证路面整体良好性能、确保交通运输安全的关键。回弹模量作为公路路基设计、施工控制、验收检测的重要指标,能够很好的对路基的质量性能做出准确的评价。但回弹模量受到土质、含水量、压实度等多种因素的影响,其数值的确定比较困难,尤其是特殊土路基回弹模量,规范当中并未给出推荐值,再加上在实际检测时所用的检测方法会有所不同,这就为结果的统一造成了困扰。因此,有必要专门对特殊土路基回弹模量进行研究,并将常用检测方法的检测结果对比分析,得出它们适用性和准确性的结论。本文分析了含水率、压实度对回弹模量的影响关系,并以陕西某高速公路为研究载体,对碎石土、黄土路基进行落锤式弯沉仪(FWD)检测,并与承载板法和贝克曼梁法所测结果对比分析。建立不同的回归模型,进行相应指标的相关性分析,并且通过回归方程得出了不同检测指标之间的转换关系,结果表明三种检测方法所测模量变化具有一定的一致性,能够客观的对路基性能做出准确评价。以本工程实际情况作为基础,分别使用FWD、承载板和贝克曼梁对相同的碎石土路基测点和黄土路基测点进行了检测,证明该路段使用的此种碎石土填筑成的路基质量、性能远优于黄土路基。通过简单的经济对比,虽使用碎石土作为路基填料,施工成本较使用黄土少许提高,但路基质量得到明显增强,更大程度的保证了公路的使用功能、延长了使用寿命,降低了后期的养护频次和费用。
[Abstract]:The subgrade is the important foundation of the pavement structure, it supports the pavement structure and all the loads on it. The bearing capacity of the roadbed directly determines the overall performance of the highway, and the quality of the subgrade will affect the performance of the pavement structure. Occurrence and extent of disease. Many kinds of pavement diseases often occur in the process of highway use, and most of these diseases are caused by insufficient roadbed strength. Therefore, the solid and stable subgrade is the key to ensure the overall good performance of the pavement and ensure the transportation safety. As an important index of highway roadbed design, construction control and acceptance inspection, the modulus of resilience can make an accurate evaluation on the quality and performance of roadbed. However, the modulus of resilience is affected by many factors, such as soil quality, water content, compaction degree, etc. It is difficult to determine its value, especially the modulus of resilience of special soil subgrade, which is not recommended in the code. In addition, the detection methods used in the actual detection will be different, which causes confusion for the unity of the results. Therefore, it is necessary to study the resilience modulus of special soil subgrade, and compare and analyze the test results of common testing methods, and draw the conclusions of their applicability and accuracy. In this paper, the influence of water content and compaction on the modulus of resilience is analyzed. Taking a highway in Shaanxi as the research carrier, the falling weight deflectometer (FWD) is used to detect the gravel and loess subgrade. The results are compared with those measured by bearing plate method and Beckman beam method. Different regression models are established and the correlation analysis of the corresponding indexes is carried out. The conversion relationship between the different detection indexes is obtained by regression equation. The results show that the changes of the measured modulus of the three detection methods are consistent to a certain extent. Can make the accurate appraisal to the roadbed performance objectively. Based on the actual situation of the project, FWD, bearing plate and Beckman beam are used to detect the same site of gravel subgrade and loess subgrade, which proves the quality of the roadbed filled with this kind of gravel soil. The performance is much better than the loess subgrade. Through simple economic comparison, although gravel soil is used as filling material for roadbed, the construction cost is slightly higher than that of loess, but the quality of roadbed is obviously enhanced, which ensures the use function of highway to a greater extent and prolongs the service life. The maintenance frequency and cost of the later period are reduced.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.1

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