【作者】 魏强；

【导师】 赵国堂； 李成辉；

【作者基本信息】 西南交通大学 ， 道路与铁道工程， 2013， 博士

【摘要】 台后锚固结构是纵连板式无砟轨道的重要组成部分。目前国内外没有对台后锚固结构的作用机理和受力规律进行系统的理论分析,更缺乏试验研究支持。国内京津城际铁路等采用倒T型主端刺锚固结构,施工工序多,工艺复杂,锚固结构区采用水泥级配碎石,成本较高,长期性能需进一步观测研究。本文以京沪高速铁路为研究对象,从理论和试验两方面进行系统研究,提出了适用于AB组填料路基、施工方便并满足相关要求的锚固结构。论文根据纵连板式无砟轨道结构和台后锚固结构组成,分析了台后锚固结构受力机理,建立了台后锚固结构、轨道结构及路基本体相互作用的一体化计算模型,对相关输入参数进行了理论或者试验验证。其中应用Mohr-Coulom (M-C)准则描述岩土材料的强度特性建立了路基承受水平荷载的模型,路基水平土体弹性模量和摩擦板与底座板摩擦系数模型均通过现场实验取值,使所建模型更能反映实际情况。应用所建模型,通过对公路CRCP锚固结构分析,结合我国CRTS Ⅱ型板式无砟轨道台后锚固结构的设置经验,计算分析了锚固结构的受力规律,进行了不同类型的主端刺结构分析,提出了锚固地梁的结构形式,计算对比了单、双锚固地梁的受力和位移约束效果,提出了Π型主端刺锚固结构设计方案。对锚固结构设计参数影响规律分析结果表明：摩擦系数对结构的纵向位移影响不大,但对整个锚固结构力的分配有较大的影响；主端刺与底座板之间不同的锚固方式对端刺整体结构的影响较大；Π型主端刺间连接板尺寸越大,对端刺整体结构受力和约束变形越有利,连接板尺寸存在最优取值；端刺间距对结构受力和纵向位移的影响不大；摩擦板尺寸对结构受力和纵向位移的影响较大,同样存在最优取值。最后根据设计参数影响规律分析结果,进行了主端刺结构组合分析,设计了最优结构形式。设计了现场试验方案,通过n型主端刺结构现场顶推试验,得出不同荷载作用下,端刺结构的位移、应力及土体压力的变化规律：端刺及摩擦板在荷载作用下,纵向位移变化较大,横向和垂向位移变化较小；端刺纵向位移随荷载增加不断增大,主端刺的纵向位移变化较明显,小端刺纵向位移变化稍小,端刺变形为弹性变形；纵向力大部分由主端刺承担；试验结果还表明端刺侧土体变形较小,处于弹性范围。对端刺结构的失稳状态分析表明,目前采用的倒T型端刺结构,当底座板刚度折减大于30%或者路基采用普通A、B组填料时,不满足使用要求。现场对倒T型端刺的顶推试验也表明：倒T型主端刺纵向变形基本由其结构倾斜和弯曲变形组成；水平板与竖板尤其竖板与底板固结面积较小,在固结点形成集中力,单位面积分布力较大,可能导致混凝土产生裂纹、裂缝,影响端刺正常使用,建议对固结点加强设计；水泥级配碎石填料易发生开裂现象,产生塑性破坏,导致出现残余变形,难以恢复,并进一步分析提出了预防开裂的设计与施工控制措施。更多还原

【Abstract】 Anchoring structure behind abutment is an important part of the longitudinal connected slab ballastless Track. No theoretical model at home and abroad to the mechanism and stress law of anchorage structure, the more the lack of test studies support. Down T main end thorn anchorage structure was used in the beijing-tianjin inter-city railway at domestic.Construction process and technology is very complex, at the same time,anchorage structure zone use cement grading-macadam and cost is higher, long-term performance need further observation and research. The anchorage structure was put forward which suitable for AB group packing roadbed, construction-convenient and satisfing the relevant requirements. In this paper, theoretical analysis and experimental research was put on by the research object of the beijing-shanghai high-speed railway.According to the composition of longitudinal connected slab ballastless Track structure and anchoring structure behind abutment, this paper analyzes the stress mechanism of the anchor structure,sets up the integration calculation model around interaction among the anchor structure, track structure and subgrade ontology, and tests the related parameter on the theory or experiment. In this paper, the application of Mohr-Coulom(M-C)criterion can describe the intensity of geotechnical material character, and establish the subgrade-model under horizontal load. Subgrade soil modulus of elasticity commonly under horizontal and the coefficient of friction model between friction plate and base plate adopted the field test results to make the model better reflect the actual situation.Using the established model, based analysis of CRCP anchorage structure on highway, and combining with setting-experience of anchoring structure behind abutment of CRTS II slab ballastless Track,the stress rule of the anchorage structure and the different types of main end thorn structure were calculated and analysed,As the result, the pepers put forward the anchorage ground beam structure form, as the same time, compared with single, double and three anchorage ground beam stress andt constraint effect and put forward the II type main end thorn anchorage structure design plan.The results obtained by analysing influenced law of designed parameters of the anchor structure show that effect of the friction coefficient to the longitudinal displacement of the structure is not big, but for the whole anchor structure force distribution have bigger influence;Different anchoring way between main end thorn and base plate affectes the whole structure of the thorn; The connections plate size between II type main end thorns is larger,structure stress and restrained deformation more favorable, at the same time,connecting plate size exists optimal datas; The impact of end-thorn’spacing to the structure stress and longitudinal displacement is not big; The influence of friction-plate size to the structure stress and longitudinal displacement is bigger,and friction-plate size exists optimal datas. At the last, according to analysed results of the designed parameters and influenced law, the papers analysed the primary end thorn structure combination and designed the optimal structure form.The field test scheme was designed. Through the Ⅱ type main end thorn structure field pushing test, changed rule of the end thorn structure of the displacement,stress and soil pressure under different loads was obtained:In the loads, the longitudinal displacement change of end thorn and friction plate is bigger and horizontal and vertical displacement change is smaller; End thorn longitudinal displacement is continuously increasing with the load increase, and the main end thorn longitudinal displacement change is more apparent and small end thorn a little small, and deformation is elastic; Longitudinal force is most bear by the end thorn;Test results also show that soil deformation around the end thorn is small, in it’s elastic range.The analyses of instability condition of the end thorn structure show that it is not satisfy the use requirement to the inverted T end thorn structure used at present, when the base plate stiffness reduces more than30%or subgrade using common A or B group of packing. The down T end thorn pushing test also shows:Longitudinal deformation of the down T main end thorn basic is made up its structure tilt and bending deformation; The lesser concretion-area of horizontal plate and vertical plate forming concentrated force and distribution force in the unit area is bigger, what can lead to concrete crack and affects the end thorn normal use. So the suggestion to strengthening design the concretion-point was drown; Cement graded gravel is vulnerable to cracking phenomenon and takes place the plastic damage, what leads to appear residual deformation, difficult to recover. And the design and construction’s controllable measures are further analysed and put forward to prevent cracking.更多还原