针对重载铁路小半径曲线地段钢轨波磨严重的问题,通过建立基于semi-Hertzian轮轨接触算法的小半径曲线地段敞车动力学模型与三维钢轨弹塑性循环加载模型,分析重载塑流型波磨演化过程中波谷、波峰区域塑性行为特征,并对比和分析外轨超高、曲线半径等线路要素对波磨发展的影响.研究结果表明:钢轨表面在轮轨循环荷载作用下将迅速达到安定状态,且在安定状态下波磨波谷的塑性累积变形比波峰的塑性累积变形大,波磨轨波峰、波谷的塑性累积特征的差异促进了钢轨波磨病害的进一步发展;在不同的曲线半径条件下,波磨波谷区域塑性累积沿深度方向差异明显,当曲线半径较小时,最大累积塑性应变出现在钢轨表面;当曲线半径较大时,钢轨表面塑性特征不显著,最大塑性累积点出现在轨面下2～3 mm处;较小的曲线半径与线路过超高对钢轨波磨病害的发展具有显著的促进作用,因此,在线路设计过程中,应尽量避免选择小于500 m的曲线半径;而对于既有线而言,线路过超高将促使波磨病害的进一步发展,在运营过程中应保证车辆运营速度.

软土地基因其承载力低、压缩性强、沉降量大、稳定性差等不利特点,常常给道路路基工程施工和运营造成很大危害.针对云南省某高速公路河谷区复杂沉积环境多层软土地基采用强夯垫层法处理的加固效果与沉降变形进行了研究,在地基处理及路基填筑期间,获得了不同观测断面布设的沉降管、土压力盒、孔隙水压力计等的监测数据,分析了不同类型软土地基土体的变形、应力和孔隙水压力等数据随时间的变化规律,揭示了强夯垫层法处理不同类型软土地基的加固效果、有效加固深度和范围,提出了强夯处理后静置期的合理时间及填筑速率等控制参数等.

通过考虑活动断层引起的地震作用下断裂错动的双台联动振动模型试验,研究跨越活动断裂的高铁桩承式加筋路基结构与下部地基的加速度、孔隙水压、桩土应力、桩身应变、边坡位移和沉降等变化规律,获得高铁桩承式加筋路基在活动断裂影响下的受力变形特性与工作状态.研究结果表明:走滑运动对跨越活动断裂的高铁路基结构及下部地基的影响比逆冲运动产生的影响更加显著,且两者产生的协同作用将加剧路基的变形与受力,加剧路基的变形与受力;为应对跨越活动断裂的地基液化,路堤工程必须得到重视并采取有效的排水措施;中震量级以上的活动断裂错动作用会对桩承式全断面加筋路基的工作性能产生显著影响,路基面最大沉陷可达1.2 m.

针对当前对锚桩分离式组合结构的协调作用分析和评价尚未完善的问题,开展交通荷载作用下桩锚分离组合结构协同机制研究.从力学角度揭示桩锚协调规律,阐明二者对边坡下滑的分担机制.首先采用三维有限元数值模拟方法,对边坡桩锚组合结构进行自由振动分析.利用Lysmer的曲面黏性边界与传统地面支撑边界相结合的方式,求解坡顶交通荷载动力学模型的时域方程,精确描述桩锚组合结构的内力响应规律.其次提出桩锚组合结构通过各自内力的增量以抵抗边坡下滑的机制,其中抗滑桩占73.4％,锚索占26.6％,桩锚结构呈现了对下滑力的协调分担.下排锚索内力平均比上排锚索内力增大89.48 kN,内力增量增大4倍,说明固坡效应下排锚索比上排锚索明显增大,而坡顶的剪应变更大,建议在桩锚组合结构抗滑设计时,增加上排锚索的预应力张拉值,以降低下排锚索的内力增量,避免锚索的"连锁失效".最后提出一种桩锚分离组合结构的设计思路,即将边坡加固前剩余下滑力的0.2～0.3倍作为预应力锚索的设计值,从而减少抗滑桩截面的设计尺寸,为组合抗滑结构优化设计提供理论支持.

研究目的:在当前国内高等级铁路大规模建设,不可避免需穿越活动断裂区域的背景下,为综合考察断层蠕滑位移与粘滑震动叠加作用下高铁路基结构的变形响应特征,分析铁路服役年限内地震发生时机对路基工程变形特征的影响,本文建立考虑活断层不同运动类型的三维数值模型,分析多种工况下路基变形特征.研究结论:(1)断层蠕滑运动作用下路基变形主要表现为随基岩运动同方向的整体平动;(2)线路纵向影响范围对于逆冲型蠕滑量较为不敏感,对平移断层的蠕滑发展却较为敏感;(3)逆断层的影响范围显著大于正断层;(4)已有蠕滑累积量是震动发生后路基变形的重要影响因素,且逆断层与走滑断层较正断层对时间更为敏感;(5)从铁路抗震抗断角度出发,徐宿淮盐铁路跨越郯庐活动断裂宜采用有砟轨道路基,相应计算结果可为高铁跨越活断层路基工程的加固设计与实施提供计算依据.

为评价二维建模方法在高速铁路站场宽路基复合地基中的适用性,以京沪高铁济南西站站场路基为例,根据5种方法建立相应二维模型分析复合地基受力及变形特征,并与三维模型计算结果及实测结果进行对比.研究表明:在分析地基沉降、桩土应力和路基坡脚水平位移时,等弹性模量法计算结果精度最高;但在分析地基超静孔隙水压力和边桩弯矩时,所有二维模型结果均不可靠,此时须采用三维模型进行分析.

为厘清中俄高速铁路路基主要技术标准的异同,增进对俄罗斯技术标准的了解,更好地服务中国高铁“走出去”战略,结合中俄两国高速铁路路基设计施工相关规范,从计算荷载、路基结构、路基填料及压实标准、变形要求4个方面进行对比分析,得出以下研究结论:(1)莫喀高铁在设计时速、行车条件等方面相比我国高铁情况复杂,两国标准下的路基面计算荷载、边坡设计参数等存在差异;(2)中俄两国高速铁路路基结构形式基本类同,基床底层厚度中国标准比俄罗斯标准大0.5m;(3)两国标准在技术体系上总体相近,但在部分技术指标上存在差异,俄罗斯在制订技术标准的过程中对我国技术标准有所借鉴;(4)中俄两国路基填料采用不同的标准,有较大差异,在应用中值得注意.

为了制备高速铁路岩溶地基加固工程及高性能水泥基材料,研制一种改性高聚物即水泥基(HPC)注浆材料,对其与常规水泥浆液(Blank)、水泥?水玻璃(C?S)的力学性能及体积稳定性等进行室内试验对比分析;运用压汞测试技术(MIP)探究其硬化后浆体微观组构与宏观力学性能间的本质关联性.研究结果表明:在28 d龄期下,Blank,C?S和HPC试件单轴抗压强度与龄期为7 d的相比分别增大77％,20％和78％,体积损失率分别为18.3％,4.9％和1.2％;聚合物体系的协调效应减小了传统水泥基注浆材料体积失稳及因单掺速凝剂导致后期强度发展缓慢的缺陷;复合掺用多高聚物显著降低了硬化水泥浆体内部孔隙直径即孔径,使孔径分布趋于细化;在28 d龄期下,不同体系的HPC浆体抗压强度与材料内部孔隙率、阈值孔径均呈指数关系,与平均孔径呈线性负相关,揭示其孔隙结构分布特征可有效反映HPC浆体力学性能的变化规律,降低孔径有利于提升其力学性能.

为制备满足复杂地层加固工程需求的高性能水泥基注浆材料,探究以偏铝酸钠(SA)、聚羧酸(Sp)及高吸水性树脂(SAP)为组分的聚合物体系及其掺量对新拌水泥浆体流变特性与泌水率的影响,并采用水化放热监测与倒置荧光显微技术,对不同体系下水泥浆体早期水化进程及微米级颗粒的悬浮分散形态进行分析.结果表明:新拌水泥浆液流动性和泌水率与SA、SAP掺量呈负相关,随Sp掺量增加而提高.Sp及SAP延缓了水泥早期水化进程,改性样延迟近1 h进入水化诱导期,诱导期内水化放热速率显著降低.在不同掺量SA的促凝效应、Sp的分散效应以及SAP的"水库"作用下,新拌水泥浆液表现为初始及经时流动度大于200 mm的高流态期可分别被控制在10、20、30 min内且析水率小于5％(稳定性浆液),接近临界期时流动度陡降、流变参数突增并迅速凝结的流变特性.结合微观结构观测结果,建立了新拌水泥浆体流变演化模型,揭示多聚合物协调效应下水泥浆体呈现分散-储水-流变-水化的早期流变机制.

从微观孔结构角度探究以偏铝酸钠(SA)速凝剂、聚羧酸减水剂(Sp)、高吸水性树脂(SAP)保水剂为组分的外加剂体系对硬化水泥浆体强度及水化特征的影响机理,揭示其宏观性能与微观结构间的本质关联.结果表明:SA的溶解-沉淀、Sp的分散效应以及SAP的“水库”作用分另提高了水泥的早期水化速率、后期水化面积与水化程度;水泥水化加速期内最大放热峰峰值显著提高;28 d龄期时改性水泥浆体抗压强度较7d时增长78％,多外加剂的协调效应改善了因单掺速凝剂所导致的水泥基注浆材料后期力学性能发展缓慢的缺陷;复合掺用SA,Sp及适量SAP可显著降低水泥浆体孔径尺寸,使其孔径分布趋于细化;SAP存在阈值掺量,其释水后大尺寸空孔的堆积导致水泥浆体孔结构及力学性能劣化;28 d龄期时各体系平均孔径差异与强度试验结果一致,孔径分布规律可有效反映硬化水泥浆体力学性能的变化特征.

Slope instability under dynamic load is the technical difficulty in the engineering; the evaluation of slope stability under dynamic load and the control of dynamic load is particularly important. In this paper, taking the right side slope of K27+140 m~380 m typical section (K27 slope for short) in Chongqing Fuling-Fengdu-Shizhu expresses highway as an example to calculate and analyze. The K27 slope is under sinusoidal vehicle load and supported by anchor cable and antislide pile to resist downslide strength; at the same time, the combined effect of them is studied. Three-dimensional finite element methodology (FEM) is used to simulate the bedding slope with piles and anchor cable support; furthermore, the eigenvalue can be obtained. In order to reduce error of the elastic boundary conditions caused by the reflection effect of wavelengths, the combination of Lysmer surface viscous boundary and traditional ground support boundaries is utilized to analyze and calculate the time-histories during bedding slope under dynamic load. The dynamic response of pile anchor support to resist sliding force is obtained. The concept of the pile anchor supporting coordinate interval is put forward. Furthermore, it is verified that the pile anchor supporting coordinate interval can be used to evaluate the stability of the slope under dynamic load and provide a new method for the control of the dynamic load.

In this paper, taking Lushan West Sea highway green rest area in Jiangxi Province of China as the case study, the suitable types, applicability, advantages, and effective methods of solar lighting technologies for highway rest area were determined based on the analysis of characteristics of highway green rest area. It was proved that solar lighting technologies including the natural light guidance system, solar LED lighting, and maximizing natural light penetration were quite suitable for highway rest area in terms of lighting effects and energy and economic efficiency. The illuminance comparison of light guidance system with electrical lighting was made based on the on-site experiment. Also, the feasibility of natural light guidance system was well verified in terms of the lighting demand of the visitor centre in the rest area by the illuminance simulation analysis. The evaluation of the energy saving, economic benefits, and environmental effects of solar lighting technologies for highway rest area was, respectively, made in detail. It was proved that the application of solar technology for green lighting of highway rest facilities not only could have considerable energy saving capacity and achieve high economic benefits, but also make great contributions to the reduction of environment pollution.

For solving the collapsible loess foundation instability problem in practical engineering, we use dynamic compaction in foundation treatment. By the way of optimizing dynamic design and construction scheme, we can remove the compaction of collapsible loess, eliminate collapsibility effectively and improve the bearing capacity of foundation greatly. We often use the traditional detection techniques for analyzing, such as standard penetration test and static cone penetration test. In addition, the finite element method is a very effective numerical analysis method for extremely complex engineering structure. From the perspective of the stress and subgrade settlement, we can use it to analyze the effect of dynamic compaction by the ABAQUS finite element software. The results show that using the method of dynamic compaction to treat the collapsible loess foundation can greatly reduce the settlement of roadbed and increase the stability of the subgrade. Therefore, in the area of collapsible loess, dynamic compaction method is a kind of effective method for foundation treatment, it should be vigorously promoted.

In China, with the development of the high speed railway, subgrade settlements control has been a key factor of railway operation and safety. Based on the study of field test data of settlement plate surface subsidence and magnetic ring subsidence in deep layer, using ABAQUS FE simulation method, the settlements of composite foundation of wide yard station were calculated, the finite element settlement control model was established, and the regularity of composite foundation settlements and its relation with stress variation were analysed in this paper. The simulation results of settlement regularity matches well with observation results of field test data, verified the reliability of the model.

结合京沪高速铁路济南西客站工程实际,对站场咽喉区深厚软土大面积堆载预压下复合地基的工程特性开展现场试验研究,分析不同位置和深度的超孔隙水压力、沉降变形以及桩土应力等参数随时间和填土高度的变化规律,为该地区同类工程设计和施工提供科学依据.研究结果表明:站场咽喉区复合地基内的超孔隙水压力随着荷载的增加而增大,达到峰值后消散,其变化略滞后于荷载的变化;超孔隙水压力的最大值出现在下卧层上部;在下卧层中,随着深度的增加,超孔隙水压力逐渐减小.站场咽喉区复合地基最大沉降发生在25mCFG桩加固区的中部,35mPHC管桩有效减小了站场中心区的沉降.主要压缩量发生在加固区底部和下卧层.站场咽喉区复合地基由路堤中心向外,桩应力、桩间土应力及桩土应力比总体呈减小趋势.在路堤填筑和预压中,站场咽喉区复合地基桩间土应力向桩传递,桩间土应力逐渐减少,桩顶应力逐渐增大,并逐渐趋于稳定.

提出一种路基表面沉降和动位移光学测量方法,具有自动标定等优点,在此基础上构建了基于无线网络传输的铁路路基关键参数远程监测系统.该系统主要由路基动位移自动测量、表面沉降自动测量、路基动应力与含水量自动测量及数据采集与无线传输等部分组成.监测系统经实验室验证后,分别在大秦重载铁路大同路段及茶坞路段进行了现场安装调试和试验,实现了对路基含水量、动应力、动位移和沉降的长时间自动远程监测.

Ground penetrating radar is a new implement in railway subgrade inspection, it has the specialty of speedy, non-destructive and little impact in the operating of the train. The paper discusses the application of RIS ground penetrating radar of Italy, which has the technology of multifrequency in aerial. The technology solves the contradiction in present situation between the depth of detection and the resolution power of the detection, improving the precision and the efficiency of the detection. Kinds of the aerial transmitting the signal and receiving intercross, which augment the angle of the radar, has the best effect in the complex objects which very close to each other in horizontal or lap over. Field test accurately detects the subgrade disease type, location and depth, which provides the basis for Maintenance.

Experimental study was carried out on settlement characteristics of the preloaded PHC pipe pile and CFG pile composite foundation of the JinanWest Railway Station of the Beijing-Shanghai High-speed Railway . Surface settlement and layer settlement of the composite foundation with different widths and with piles of dif-ferent types and lengths were observed . The changing law of settlement deformations with embankment fill heights and time was analyzed . The influence of subgrade widthson the settlement magnitude and shape of set-tlement curve was investigated . The research results show as follows :The settlement-time curve of station subgrade includes the settlement development stage(the subgrade construction stage) , the rapid settlement de-velopment stage(the stage from soil preloading to 2~3 months standing ) and the basically stable settlement stage ;For the PHC pipe pile and CFG pile composite foundation of a large station ,a settlement depression ar-ea appears around the center of the station and secondary settlement depression areas appear on both sides of the center settlement depression area ;For the PHC piple pile and CFG pile composite foundation of a large sta-tion , the additional stress is large , its attenuating speed is low and settlement affects deeply ;settlement of foundation below 30~50 m takes up about 75% to 85% of the total settlement and settlement within the rein-forced areas takes up 5% to 10% of the total settlement .

As large civil engineering construction and building, bedding rock slope has been given sufficient attention, but due to lack of sufficient knowledge of bedding slope, bedding slope caused by major accidents are common. The combination structure of anchor framework beam and pile as slope governance of a new method, in slope governance gradually get application, this article relays on Chongqing Fuling-Fengdu-Shizhu Highway research topics, in integrated consider has slope geological features and engineering, through on anchor stretching force, anti-sliding pile of anti-sliding force and slope internal deformation of monitoring and the analysis, this combination can effectively govern sand-mudstone sustained pour high slope and provide basis to for similar slope problem.

The stability analysis and evaluation on high slope is of great significance. The stability analysis on the slope of ZHANG-ZHUO highway is carried on in this paper by using the strength reduction method and ABAQUS software. According to the stress and plastic deformation calculated by ABAQUS software, the paper gives evaluations for the stability of slope. It turns out that safety factor of the slope is greater than three; the stability of the slope is well.