【作者】 曹周阳；

【导师】 王晓谋；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2013， 博士

【摘要】 在秦巴山区修建高速公路必然要穿山越岭，跨越河谷，因此，在修筑过程中将会产生大量的变质软岩隧道弃渣、削坡弃方和路堑挖方，弃料外运堆积要占用土地且需要防护措施，与此同时，还存在路堤填土缺少，运输便道修筑困难，取土距离远等问题，如果要用砂砾作为路堤填料，则须从河道中挖取，这就会破坏河床及当地环境，若能将这些变质软岩用作路堤填料，不仅可降低公路建设成本，还可保护生态环境，具有明显的经济与社会效益。然而，变质软岩具有遇水后强度降低、易风化、受压易破碎等不良性质，变质软岩填料在碾压后，粗颗粒填料级配变化较大，路堤遇水还会产生湿化沉降，其中不均匀沉降可导致路面不平整和结构反射裂缝等病害，而现有的《公路路基设计规范》（JTGD302004）和《公路路基施工技术规范》（JTGF102006）对变质软岩能否用作高速公路路堤填料及相应的施工工艺都没有明确的标准和方法。因此，论文结合西部交通建设科技项目《秦巴山区变质软岩路基修筑关键技术研究》（2009318812004），依托十（堰）天（水）和柞（水）小（河）高速公路的建设，通过室内与现场试验，结合数值模拟及理论计算分析，对秦巴山区变质软岩的工程特性及其填料的路用性能、振动压实工艺及检测方法与标准进行了比较深入系统地研究，取得了以下主要成果：1.通过岩石的磨片与偏光显微镜试验，对高速公路建设中遇到的变质岩进行了成分分析及定名，研究了变质岩的内部结构成分及其是否含有亲水性矿物；通过膨胀试验和耐崩解试验，研究了变质岩的自由膨胀率和压力膨胀率及循环耐崩解指数规律；对风干与不同浸水时间的变质岩进行了点荷载强度试验，对变质岩的点荷载强度做了四级划分，即坚硬岩Is（50）≥5.0MPa，较坚硬岩2.5MPa≤Is（50）<5.0MPa，软岩0.4MPa≤Is（50）<2.5MPa，极软岩Is（50）<0.4MPa，由此可知，除长英质斑状糜棱片岩以外，其它的变质岩在浸水饱和后全部为软岩；点荷载强度能比较客观地反映实际工程中人工破碎后不规则岩块的强度，避免了选取可加工成规则试件所需的较大岩块而引起的单轴抗压强度偏高的问题。2.通过变质软岩填料的击实试验和振动台试验，以功能原理为基础，提出了击实试验和振动台试验中的单位体积击实能量（击实功）和振动能量计算公式，分析了能量大小对变质软岩填料最大干密度及其变化规律的影响，得到了在标准击实能量下粗颗粒含量不同时的最大干密度值；通过承载比（CBR）试验，分析了击实功对CBR值的影响，得到了填料CBR值及其随击实功的变化规律，这为评价变质软岩填料的路用性能提供了依据。3.通过室内大型压缩试验，采用单线法、双线法与循环加载法分别研究了变质软岩填料在不同荷载下的浸水湿化沉降规律，得到了三种荷载下的湿化应变值及相应填高荷载下的湿化沉降量，并建议了最大填料高度。运用有效应力原理，根据颗粒接触面积与总面积之比，结合压缩试验所加荷载，估算了颗粒间的接触压应力。对变质软岩填料的大型压缩试验进行了颗粒流模拟，基于赫兹接触理论，在一定的假设条件下，得到了颗粒内部强弱力链接触情况、孔隙率变化规律、平均接触力、最大接触力和顶部颗粒压缩位移的变化规律，这为解释压缩试验过程中填料内部颗粒间的相互作用提供了一种分析方法。4.通过室内大型三轴试验，研究了风干和饱和状态时变质软岩填料在四种围压下的应力应变规律，分析了偏差应力和围压对湿化应变的影响。针对路堤填料的湿化沉降，基于不同的计算步骤，将单线法与双线法在有限元模型中分别给予了实现，以编制的邓肯-张模型有限元子程序为基础，采用单线法模拟了不同工况下路堤湿化沉降，并与室内大比例浸水载荷试验路堤的沉降进行了对比，单线法能较好地反映路堤的湿化沉降规律，用浸水载荷试验结果估算的现场路堤湿化沉降量可满足规范对路堤沉降的要求。5.根据振动压路机的基本原理，以功能原理为基础，推导了单位体积填料压实所需振动压实能量的计算公式，结合击实试验和振动台试验结果，认为变质软岩填料路堤的压实度能满足《公路路基设计规范》（JTGD302004）的要求时，压路机的振动能量应大于相应压实度下的击实功和室内振动能量，通过计算压路机振动压实能量并与之相比较后，可选取合适吨位的碾压机械及强振压实参数（松铺厚度、碾压遍数、碾压速度和轮迹重叠系数），通过现场试验结果验证了计算公式的合理性和实用性，公式为强振压实参数的选取提供了一种计算方法。更多还原

【Abstract】 Freeway construction must be through the mountains and across the valley in Qin-Bamountain, therefore, a lot of metamorphic soft rocks such as tunnel, slope cutting andexcavation waste would be generated in the construction process, discarded materials needto be outward transported and piled up, the waste accumulation need to occupy the land andtake protective measures, in the meantime, there were existing lack of embankment fill, thetransportation road construction is difficult, the long distance borrowing soil is hard and soon, If to use gravel as embankment filling, must digging gravel from the river bottom, itwould destroy the river beds and the local environment. If the metamorphic soft rocks canbe used as embankment filling, not only reducing the cost of road construction, alsoprotecting the ecological environment, having obvious economic and social benefit.However, metamorphic soft rocks with adverse properties such as the strength would bereduced after wetting, weathering easily, compression crushing easily, after rolling coarseparticle filling grading of metamorphic soft rocks embankment changes greatly, wettingsettlement would occur with the influence of water, and uneven settlement would lead topavement structure uneven and reflective cracking disease etc, while whether metamorphicsoft rock can be used as highway embankment filling and it is not clear about compactiontechnology and testing standards for soft rock filling in the existing 《Specifications forDesign of Highway Subgrades》(JTGD30-2004) and 《Tcchnical Specification forConstruction of Hithway Subgrades》(JTGF10-2006). Therefore, the paper combined withscience and technology project of Western Transportation Construction《The key TechnologyResearch on Metamorphic Soft Rock Filler Embankment Construction in Qin-Ba MountainAreas》（2009318812004）, relying on Shi(Yan)-Tian(Shui) and Zha(Shui)-Xiao (He)highway construction, through the indoor experiments and field tests, combining withnumerical simulation and theoretical calculation analysis, studied deeply and systematicallyon road engineering properties test of metamorphic soft rock used as embankment filler inQin-Ba mountain areas, vibration compaction technology research and testing technologyspecification,the main results are obtained as follows: 1. By grinding and polarizing microscope experiment of rocks, in the highwayconstruction, carried out component analysis and naming of metamorphic rock；Studied theinternal structure composition of metamorphic rock and whether it contains hydrophilicmineral; Through the expansion experiment and resistant to disintegration tests, studied thefree and pressure expansion rate of metamorphic rocks, and cycle resistant to disintegrationindex law; Conducted point load strength test of metamorphic rocks in the dry and differentsoaking time condition, mading for four grade classification of metamorphic rocks point loadstrength, such as: the hard rock Is（50）≥5.0Mpa, relatively hard rock2.5MPa≤Is（50）<5.0Mpa,soft rock0.4MPa≤Is（50）<2.5MPa，exceedingly soft rock Is（50）<0.4Mpa，it can be seen, otherrocks are all soft rocks after water saturated in addition to felsic porphyritic mylonite schist;Point load strength can objectively reflect irregular rock strength after artificial broken in theactual engineering, avoided the problem of uniaxial compressive strength was higher thatcaused by selecting regular specimen from a large rock.2. Through compaction and shaking table test of metamorphic soft rock filling, based onthe work and energy principle, proposed compaction energy (compaction work) andvibrational energy per unit volume calculation formula,analyzed the energy size impact onmaximum dry density of metamorphic soft rock filling and its variation rule; obtained fillingmaximum dry density value when different coarse particle content in standard compactionenergy; By bearing ratio (CBR) test, analyzed the impact of the CBR value with compactionwork, got the filling CBR value with the compaction work and its changing rule, it provided abasis for evaluating highway filling engineering properties.3. Through indoor large-scale compression test，used single-line method,double-linemethod and cyclic loading method, studied wetting settlement rule of metamorphic soft rockfilling under different loading, respectively obtained wetting strain values under three loadingmethods and wetting settlement values of the corresponding loading filling height, andsuggested that the maximum filling height value. Using the principle of effective stress,according to the ratio of particle contact area and total area, combined with the compressiontest loading, estimated the contact stress between the particles. Adopted particle flow methodto simulate large-scale compression test of metamorphic soft rock filling，based on Hertz contact theory，under some hypotheses，got changing rule of aggregation internal particlestrong and weak contact force chain,porosity, mean contact force, maximum contact forceand displacement of the top particle compression, it provided an analysis method forexplaining interaction of filling internal particle in the compression test process.4. Through indoor large-scale triaxial test, studied stress-strain law of metamorphic softrock filling under four confining pressure in the dry and saturated state, analyzed theinfluence of the deviation stress and confining pressure with wetting strain, for embankmentfilling wetting settlement, based on different calculation steps,the single line and double linemethod are respectively realized in the finite element model, based on compiledDuncan-Chang model finite element subroutine,used the single line method and simulatedembankment wetting settlement under different working conditions, and compared withsettlemen of the indoor large-scale embankment loading test, the results show that,singlemethod can better response of embankment wetting settlement rule, field embankmentwetting settlement estimated value from indoor soaking-water loading test results can met thespecification requirements of embankment settlement.5. According to the basic principle of vibratory roller, based on the work and energyprinciple,derived vibration compaction energy per unit volume filling calculationformula,combined with compaction and shaking table test results,ensured the metamorphicsoft rock filling embankment compaction degree to meet the requirements of《Specificationsfor Design of Highway Subgrades》(JTGD30-2004), road roller vibration compaction energywould be greater than compaction energy (compaction work) and indoor vibrational energyper unit volume, through calculating vibratory compaction energy, and compared with theenergy value, then choosing the appropriate tonnage rolling machinery and strong vibrationcompaction parameters(loose lay thickness, rolling times, rolling speed and the wheel trackoverlap coefficient), through field test results verify the rationality and practicality of theformula calculation results, the formula provided a calculation method to select strongvibration compaction parameters.更多还原