【作者】 张永清；

【导师】 王选仓；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2009， 博士

【摘要】 近年来,我国公路建设发展迅猛,尤其是高等级公路建设取得了长足发展。随着东部经济发达地区高速公路建设的饱和,今后我国高等级公路建设的重点逐渐移向中西部等多山地区。在山区高速公路建设过程中,由于地形起伏大、地质构造复杂,路堤填筑较高,路基工程竣工后容易发生差异沉降。过大的路基差异沉降使得路面结构发生开裂破坏,形成裂缝、错台等病害,直接影响路面结构的使用性和耐久性,路基沉降控制是工程建设中的重要内容。因此,有必要对山区高速公路路基差异沉降特性与控制措施进行深入研究。本文主要研究内容如下：(1)山区高速公路路基沉降模式与特性分析在调研国内外高速公路工程差异沉降病害的基础上,分析了山区高速公路路基沉降机理与沉降模式,针对山区高速公路路基差异沉降影响因素,建立有限元分析模型,对各种条件下的差异沉降进行量化计算,分析地基土性质、地基压缩模量、路基填土高度、路基填料性质、路面结构、填土前后挖方部分沉降变化规律、施工时间等因素对路基沉降的影响,并对其敏感性进行研究。(2)基于结构与功能的路基差异沉降控制指标与标准通过建立路面结构有限元模型对差异沉降作用下路面结构层附加应力进行分析,综合考虑路面结构抗拉破坏性能及抗疲劳破坏性能,并结合道路平整度、排水等功能性要求,提出了基于结构与功能的山区高速公路差异沉降控制标准,并对路基差异沉降进行分级,便于对不同等级的沉降采取合理的处理措施,达到差异沉降主动控制的目的。(3)山区高速公路路基差异沉降处治措施研究结合具体工程实践,在对差异沉降进行分级的基础上,提出了路基差异沉降强夯处理措施、构造物处沉降控制措施、填挖结合部差异沉降土工格栅处治措施,并针对不同级别的差异沉降提出了相应的沉降处治方案。(4)土工格栅处治路基不均匀沉降试验研究以依托工程为基础,选取了试验路段,采取多种土工格栅方案进行沉降处理,埋设沉降观测仪器,通过理论分析与现场试验及观测相结合,研究了降低山区高速公路路基差异沉降的主要技术及其效果；同时结合试验路不同方案,采用离心模型试验对填挖结合处路基土工合成材料的加筋方案进行了观测及对比分析;并对多种方案进行了比选,提出了合理的技术方案。(5)试验路铺筑与沉降观测根据对路基差异沉降处治措施的分析结果,选择相应依托工程进行试验路铺筑,并且制定了施工期及工后沉降观测方案,对山区高速公路沉降变化规律及差异沉降处治措施效果进行观测,为沉降处治措施的推广应用提供依据。论文所分析及提出的针对山区高速公路路基差异沉降特性及沉降控制措施的研究,为以后相关项目的科研、设计、施工及规范的编制提供了较为有价值的技术参考与依据,具有一定的经济效益和社会意义。更多还原

【Abstract】 During the process of highway construction in mountainous areas, the subgrade is vulnerable to differential settlement after completion of the project, because of the rugged ground, complicated geological structure and high embankment. Excessive differential settlement of the subgrade makes the pavement accrue cracking damage, it impacts on the use of pavement and highway durability. Therefore, it is necessary to study on characteristics and control measure of differential settlement in highway subgrade. The content of this paper are as follows:(1) Settlement pattern and the characteristic analysis of highway subgrade in mountainous areaThe subgrade settlement mechanism and pattern were analysised on the basis of investigating and studing in the domestic and foreign highway project differential settlement disease. A finite element analysis model was established to comput differential settlement under each kind of condition,then the influence to subgrade settlement of many factors was analysised,such as the ground properties of soil, the ground compression module, the depth and nature of fill, the pavement structure and construction time,finaly its sensitivity were analyzed.(2) Study of differential settlement control indicator and standard based on the structure and functionA pavement structure finite element model was established to analyze the additional stress of pavement structure. Highway differential settlement control standard based on the structure and function was proposed by considering anti-pulls the destruction performance, the anti-fatigue failure performance, requests of pavement roughness and draining water.The subgrade differential settlement were classified into many level, it is advantageous for taking the reasonable processing measure to the different rank subsidence, achieves the goal of initiative control to the differential settlement.(3) Differential settlement treatment measures and effect analysis of highway subgrade in mountainous areas.According to the specific engineering, on the basis of differential settlement classification we proposed dynamic measures and geogrid measures to control the differential settlement. For every level of differential settlement we presented corresponding treatment program, and analyzed the effect of various plans in reducing the differential settlement.(4) Experimental study of subgrade differential settlement treatment by geogrid and optimization of settlement treatment programe.Taking depends on the project as a foundation, selected experimented the road section, used many kinds of geogrid plan to carry on settlement processing, embedded settlement observation instrument, unified the theoretical analysis, the field test and the observation, studied differential settlement reducing technology and the effect; Simultaneously unified the different plan of experimental road, used gentrifugalism model experiment to carry on the observation and the contrast analysis of the reinforcement plan using earthwork composition material; and carried on many kinds of plans compared to propose the reasonable technical plan.(5) Test Road Paving and Settlement ObservationAccording to the analysis results of differential settlement treatment, we selected the appropriate section to pave test road and layed a settlement observation plan during construction period and after completion of the project, in order to observe highway settlement changes and the effect of treatment measures, it can provide a basis to promote the application.The study of highway subgrade differential settlement characteristic and control measure in the mountainous area will provide valuable technical reference and basis to scientific research, project design, construction and standard establishment, it has certain economic efficiency and the social significance.更多还原