【作者】 许学民；

【导师】 朱浮声；

【作者基本信息】 东北大学 ， 结构工程， 2009， 博士

【摘要】 宁夏六盘山地区海拔高,降雨量大、地下水丰富,土质特殊、路用材料缺乏。为加快该地区高等级公路的建设速度,提高工程质量,节约基本建设投资,针对该地区公路建设中的过湿土处治与合理路面结构进行了研究,对该地区高等级公路的发展具有重要的现实意义和长远意义。六盘山区公路修筑技术中,过湿土处治技术是关键技术问题之一。本文结合六盘山地区过湿土特性,从理论、试验、施工等多方面对过湿土处治技术进行了研究：(a)提出了过湿土的界定方法并开发了GSCP沉降计算软件；(b)针对过湿土的特点提出了石灰土、土工格栅、石灰土+土工格栅等三种处治方法,提出了以工后沉降量、沉降速率和不均匀沉降率三个指标作为过湿土地基处治效果的评价指标及控制标准。根据六盘山地区气候、交通组成、材料特性等特点,开展了公路基层、面层材料气候适应性研究,对提高公路的使用品质,延长使用寿命起着至关重要的作用。由于六盘山地区气候因素显著差异,材料类型区域性特点显著,路面结构组合方式多样,所以重点对以下7个方面进行研究：(a)对六盘山地区所涉及的5个区县进行了气候调查和分析,并按SHRP的PG分级标准对六盘山地区进行了气候分区,并结合当地实测温度场资料,对当地沥青路面不同层位进行了PG分区。在此基础上,提出了适应于六盘山地区沥青的种类和标号；(b)针对六盘山地区阴湿多雨,上面层集料呈酸性的特点,论文就工程中改善混合料水稳定性的措施进行了较系统的探讨,比较了这几种措施的优劣；(c)对六盘山地区常用的几种筑路材料进行了粘附性方面的研究,并提出了改善其粘附性的最佳措施；(d)对添加矿粉及水泥和消石灰后沥青胶浆高低温性能的变化进行了研究,在此基础上对外掺剂种类、添加剂量及合理粉胶比范围的选择进行了研究；(e)对新的施工规范中AC级配及Superpave级配两种设计方法,采用不同成型方法,从路用性能方面着手进行了对比研究,在此基础上结合当地实际情况,提出了适合于六盘山地区高等级公路使用要求的沥青混合料类型及设计方法；(f)针对半刚性基层的缺点,研究立足于提高水泥稳定基层材料的部分路用性能,从改善混合料设计方法和内在路用性能着手,采用水泥稳定类结构掺粉煤灰的方法,详细研究材料各项路用性能指标的变化,并着重研究了材料的收缩性能及抗裂评价指标；(g)在面层和基层混合料类型确定的情况下,考虑高等级公路行车条件、路用性能、品质等的要求,以及当地气候、材料、交通组成等条件,初步提出了两种路面结构形式,并采用国内设计方法对所提出的两种结构进行了使用寿命预测。更多还原

【Abstract】 Liupanshan Mountain Area in Ningxia is high altitude with rich rainfall and underground water resource. The material for road construction is shortage due to its special soil condition. In order to speed up the high-grade highway construction, improve the quality of works and save construction cost, the research on over-wet soil and reasonable road pavement structure is proposed to be carried out, which has long-term and practical implications for high-grade highway development in this region. For road construction technologies in Liupanshan Mountain area, over-wet soil treatment technology is one of key technical problem. Taking into account the over-wet features in Liupanshan Mountain area, the research on over-wet soil treatment technology is carried out in terms of theoretical, test and construction:(a) defining method of over-wet is put forward and GSCP settlement software is developed; (b) three methods including lime soil, geo-grid and lime soil plus geo-grid are proposed based on over-wet soil features; settlement volume, settlement speed and non-uniform settlement ratio are suggested to assess and control the over-wet soil treatment results.The research, based on the features in Liupanshan Mountain area including climate, traffic composite and material characteristics, is carried out with respect to adaptability of base and surface materials to climate and it plays vital role in improving highway service and extending life cycle. Due to the remarkable differences of climate factors, obvious characteristics of material dividing areas and various pavement structures in Liupanshan Mountain area, the research focuses on seven respects:(a) The climates in five counties of Liupanshan Mountain area have been investigated and analyzed. The climate dividing is done for Liupanshan Mountain area based on PG dividing standard of SHRP. PG dividing is also done for different layers of asphalt pavement in local area according to the field temperature data. The asphalt types and marks which are compatible to Liupanshan Mountain are further recommended; (b) Taking into account the rich rainfall and humidity in Liupanshan Mountain and acid nature of aggregate of upper layer, exploration on measures to improve the stability of mixture is undertaken. The advantages and disadvantages of measures are compared; (c) The adhesive property of common used road materials in Liupanshan Mountain area are studied and optimal measures of improvement are recommended; (d) The temperature property change of asphalt slurry after being added with mineral powder, cement and hydrated lime is studied. Based on this, the types and doses of admixtures as well as rational scope of dosage of mine powder and asphalt are studied; (e) For AC graduation and Superpave graduation which are covered in the new Construction Specifications, the different methods are used respectively to study road performance. Based on the study and local actual situation, the asphalt mixture type and design method which meet the requirements of high-grade highways in Liupanshan Mountain area are further recommended; (f) In terms of disadvantages of semi-rigid base, the research aims to improve partial road performance of cement stabilized base material and begins from improving mixture design method and road performance. The method of adding flash for cement stabilized type is used, various road performance index are studied in detail focusing on material shrinkage property and anti-cracking assessment index;the adhesive property of common used road materials in Liupanshan Mountain area is studied and the optimal measures to improve adhesive property are suggested.; (g) Under the fixed base and surface mixtures, given travel conditions of high-grade highway, road performance, quality, local climate, material and traffic composite, two kinds of pavement structures are proposed initially and service life is forecasted for the structures based on the domestic design methods.更多还原