【作者】 张永安；

【导师】 李峰；

【作者基本信息】 昆明理工大学 ， 地质工程， 2010， 博士

【摘要】 本文以安楚高速公路地区的滇中红层为研究对象,在广泛地质调研和工程地质研究的基础上,分析了滇中红层的分布范围、地质环境特征、工程地质特性、岩体结构特征,同时通过大量岩样的室内试验和现场试验,研究了红层的力学参数指标；并采用理论、数值分析方法对红层路堑边坡变形机理与稳定性进行了深入系统的研究；通过试验,研究了红层软岩土石混合料作为路堤填料的工程性能,并对红层高填路堤的稳定性及变形进行了分析,得出了红层路堤的稳定性和变形规律。通过现场调查、理论分析和试验研究,主要取得以下研究成果：(1)对滇中红层的分布、地质环境特征进行了系统的研究：滇中红层区出露的地层有下禄丰群、侏罗系和白垩系,侏罗系地层分布最广,岩性主要为泥岩及泥质岩类,其次为砂岩,多呈薄一中厚层状互层产出,局部夹泥灰岩；区内经向构造发育,构造带及其影响带岩体破碎,边坡稳定性差,破坏规模大；工程区岩体风化强烈,受岩性控制,具明显的不均匀性,表现为隔层风化、槽状风化发育；岩体卸荷在硬岩集中地段发育较强烈,区内地下水类型主要为基岩裂隙水和孔隙水。(2)对滇中红层的工程地质特征,包括物质组成、岩体构造、风化及水岩作用特征等进行了系统研究。滇中红层软岩的粘土矿物主要为伊利石／绢云母,有少量高岭石和绿泥石,矿物的微观结构呈不规则粒状和不规则片状叠聚体,泥岩的矿物成份和微观结构决定了其具有亲水性强、透水性弱、遇水易软化、泥化、蠕变及易崩解等特性；同时滇中红层多为软岩与硬岩相间,呈互层状产出,层间结合力弱,受区域构造影响,岩层扭曲褶皱强烈,多为中高倾角,结构面发育,多有泥化现象；红层软岩抗风化能力弱,岩体差异风化明显,泥岩崩解剥落速度快；软岩在饱水条件下强度降低,泥化面及层间夹泥在饱水条件下强度极低。(3)全面系统的对红层岩石包括砂岩、粉砂岩、泥质粉砂岩、粉砂质泥岩和泥岩进行了单轴压缩及三轴压缩条件下的强度与变形试验,对红层的强度及变形特征有了充分的了解,并得到了不同红层岩石的粘聚力与摩擦角等指标；在不同条件下的抗剪断和抗摩擦试验,给出了这些岩石的抗剪断和抗摩擦强度方程,试验发现红层的变形规律满足弹—塑性的本构关系,并按照弹—塑性理论给出红层的本构关系。对红层软弱夹层及张开少充填、闭合无充填、薄层充填、厚层充填结构面进行了系统的抗剪试验,取得了红层不同类型结构面的强度与变形参数,同时也研究了水对结构面强度与变形的影响。通过对红层泥岩及软弱夹层的蠕变试验,掌握了其长期的强度与变形特征。(4)通过试验,研究了红层软岩土石混合料作为路基填料的性能,主要包括红层填料的级配特性、击实特性、强度特性、变形特性及蠕变特征等,比较清楚地掌握了红层软岩土石混合料作为路堤填料的工程性能。(5)根据红层边坡的特性和岩体结构特征,对红层边坡的结构面和结构体进行了分级研究,根据岩层倾向和边坡倾向的关系及岩性特点,对滇中红层坡体结构类型进行归纳分类,滇中红层路堑边坡可划分为顺层、反倾、斜交、覆盖层及破碎带边坡五个大类十一种破坏类型。红层岩质边坡的坡体结构和稳定性,主要受岩层面和构造结构面综合控制,红层顺层边坡的主要破坏机制分为顺层—滑移型、滑移—拉裂型和滑移—弯曲型三种；斜交红层边坡的破坏机理可分为阶梯状顺层滑塌、阶梯状顺节理滑塌和楔形体破坏三种类型；反倾边坡产生弯曲—倾倒破坏和沿构造节理面滑塌；覆盖层边坡主要为沿岩层交界面滑动及覆盖层内圆弧滑动；破碎带边坡主要产生圆弧滑动。(6)选取典型工点,分别采用工程地质分析方法、极限平衡法、有限差分方法、有限元强度系数折减法等分析了顺层、反倾红层路堑边坡的稳定性及变形机理；对红层斜交边坡楔形体破坏模式边坡在两组结构面摩擦角不同的情况下稳定性系数的极限平衡法进行了分析。探讨了红层边坡的防护加固措施,提出了相应的防护加固建议。(7)研究了红层路堤各施工阶段及工后的稳定性、沉降变形及侧向位移等基本特征及其随时间的变化规律,同时也探讨了侧向变形对沉降的影响规律。更多还原

【Abstract】 Based on extensive geological investigation and analysis, deformation and failure mechanism and stability analysis of road cut slope in red beds are studied systematically and thoroughly in this paper. The author uses geological investigation, theoretic and numerical analysis to assist his research. Methods oriented by the typical projects of the red bed road cut slopes involved in the highway from Anning to Chuxiong in middle of Yunnan Province. The mechanic parameters of rock mass in red bed are simultaneously studied by using large numbers of laboratory test and field test. By the experiments through the soil work, Studying the red bed soft rock engineering function used to the embankment filler. The stability and setlement of the embankment have been analyzing,There by some factors that influence the stability and the setlement of the embankment have been got.The main results of this paper can be summed up as follows:(1) Studied the distribute and geology environment characteristic of red bed in middle of Yunnan Province, The strata of red bed in middle of Yunnan Province region are Cretaceous and Jurassic,the Cretaceous is distributing extensively, Rock mainly for the mudstone and the mudstone quality rock, secondly is sandstone, presenting by the layer form thin to middling and thick with each other, the part clips the marlite. The geologic conformation development, geologic conformation region and its influence region take the rock fell to pieces, the side slope stability became bad and break by large-scale. Rock airslake is very intensity, Performance for separate and trough figure, The rock unload consuming in the hard rock, The groundwater type mainly is the cranny water and lax hole water.(2) Studied the engineering geology characteristic of the red bed in middle of Yunnan Province, Include the characteristic of rock group, material constitute, conformation, airslake and water rock effect. the mainly soil mineral in red beds are illite/sericite, there is a small amount of kaolinite and chlorite, the micro-structure as irregular grains and irregular flakes stacked polymer,the mudstone mineral composition and microstructure of the decided its has strong hydrophilic, permeable weak and softening easily with water, argillation, plastic deformation and easy to collapse and other features;The red bed in the middle of YunNan is alternate for the soft rock and hard rock, in existence by alternating layers, the layer combines weak.had influenced by the regional structure,the layer has great torsion, fold and high angle fault with argillized phenomenon. The ability of red bed soft rock stick up to airslake is weak,has obvious differential airslake and the speed of disaggregation in mudstone is quick. the soft rock strength lowers and argillized seam is very lowe under the satisfied water condition.(3) Has systematic and general researched the red layer rock include the sandstone, powder sandstone and mire quality powder sandstone, the powder sand quality mire the rock and mire rock did single stalk compression the strength in appearance and transform experiment and under three stalk conditions strength with transform experiment, analyzed the strength characteristic of red layer and transform characteristic,got the Indicator of cohesive strength and frictional angle.Experiment discovered a transforming of the red layer soft rock the regulation is contented to elasticity-plasticity constitutive relation,can gived the constitutive relation and mohr-coulomb yielding function by elasticity-plasticity. The red layer structure noodles includes weak mezzanine, open a little fill and shut to match to have no fill structure noodles of fill, thin layer fill, thick layer carried on system to shear strength has experimented. Obtained the strength of the different type red layer structure noodles and transform parameter, Also studied water strength and the influence for transforming is to the structure noodles. Studied red layer soft rock and it weak mezzanine of the creep characteristic, Had clear understanding of long term strength and deformation of red layer and its weak mezzanine.(4) By the experimentation, studied the capability of red bed soft rock ground mixture as embankmen filler,Its mainly includes the characteristic of series design, hit close-grained, distortion and creep etc of red bed filling. Controling the characteristic of red bed soft rock ground mixture to anticipate embankment filler.(5) Bases the characteristic of geological engineering and rocks structure, Classed the quality classification of sturctural plane and polyhedron of red bed slope. Considering the relationship between the dip of bedding plane and the dip of slope, the dip red bed slope divided into five subgroupsand eleven kinds of damage type: consequent bedding rock slope, countertendency bedding slope and oblique crossing bedding slope. First, the deformation and failure mode consists of three types among consequent bedding rock slope:bedding sliding, sliding and fracturing, bending and fracturing. Secondly, the deformation and failure modes of coutertendency bedding slope are bending-toppling-sliding and slipe along the joint surface. Thirdly the failure modes of oblique crossing bedding slope consist of three types:ladder consequent bedding sliding, ladder consequent joint sliding, and wedge sliding. Fourthly the failure modes of caping layer slip along the interface and circular slide surface.(6) The author selected the typical slope engineering, Analysis the stability of the consequent bedding rock slope and countertendency bedding slope by the method such as Geology analogy, Limited-equilibrium Method, FLAC3D Fast Lagrangian Analysis for Continuum and shear strength reduction FEM method. the formula used to calculate stability factor of wedge failure with different friction angles on two structure planes using limit equilibrium method. Also discussed the reinforce method for differ failure style.(7) The character of settlement, lateral displacement, stability of embankment at different phases of construction have been studied. And also analyzed the rule of its with the variety regulation of time. Studied the settlement regulation influenced by the lateral displacement.更多还原