诸暨洞室工程稳定性评价

本文主要根据杭铁诸暨387洞室工程所取得的地质资料及室内岩石物理力学试验指标为依据,对该工程的围岩进行分类、並对围岩进行有限元方法的分析,及对围岩局部块体利用赤平极射投影方法进行稳定性验算,对该工程主体洞室的稳定性作出评价。     

水对受力岩石变形破坏宏观力学效应的实验研究

为了了解水对受力岩石的宏观力学效应,在MTS电液伺服材料试验系统上,对不同饱水度的砂岩、花岗闪长岩、灰岩和大理岩进行了单轴压缩试验,取得了这几种岩石的单轴抗压强度和弹性模量随饱水度变化的定量结果.结果表明,水对受力岩石的力学效应与岩石中的含水状态是密切相关的,自然状态的砂岩、花岗闪长岩浸水后,其峰值强度和弹性模量随饱水度的增加而迅速衰减,当饱水度达到某一定值时,这两种岩石的峰值强度和弹性模量基本稳定下来;文中用函数Y=Aexp（-Bx）+C对实验结果进行了最小二乘法拟合.实验中求得水饱和状态和自然状态砂岩的泊松比并没有明显差异,说明在宏观上水对该种岩石受力变形的作用是各向同性的.通过10^-5/s和10^-4/s两种不同应变率试验,发现水对受力岩石的力学效应具有时间依赖性,这一特点说明仅从有效应力原理来考虑水对受力岩石的力学效应是不够的,而应考虑应力腐蚀这样复杂的过程.此外,大理岩的试验结果表明,水对受力的碳酸盐类岩石的作用机理是一个值得进一步探讨的问题,它与水对受力的含SiO₂类岩石相比,可能存在差异.     

不等周期断层形变测量环境因子影响的研究

本文在研究和分析环境因子对断层测量年周变和季节性变化影响的基础上，归纳出断层形变测量年周变的变化规律，并针对不等周期观测资料，建立了形变测量的准线性动态数学模型，最后，对门源地震有异常的扁都口资料用上述模型进行了处理，结果是比较满意的。     

北秦岭—北祁连(天水—宝鸡)间早生古代火山岩系及其构造连接关系的研究

依据新发现的生物化石和同位素数据,将分布在陕、甘边界一带的原“牛头河群”哑岩系分解为元古代陇山群、秦岭群和早古生代葫芦河群与丹凤群(西延部分)。葫芦河群为北祁连加里东褶皱带的东廷部分,除局部为晚期宝鸡花岗岩侵位间隔外,基本上可与北秦岭地区的古生代斜峪关群相连接,在研究区内与北秦岭地区的奥陶纪草滩沟群,呈以寒武系为核心、两翼为奥陶系火山岩的复式背斜构造。解体后秦岭群呈断续相连的古老岩块,向西可与祁连中间隆起相衔接,丹风群向西延展可伸入祁连造山带的陇西一带,初步认为陇山群与走廊过渡带内的古老隆起相当。据早古生代葫芦河群及其火山岩系的研究,笔者发现从秦安至宝鸡,有近100km的基性枕状熔岩带,并依其相伴产出的超镁铁质-镁铁质(似)堆晶岩、辉绿岩墙及硅质岩等岩石组合单元,认为属与北祁连和北秦岭北带相当的蛇绿岩带。西延的丹凤群亦主要为火山岩(包括枕状熔岩)与超镁铁岩等岩石单元组成的蛇绿岩带。据此提出,北秦岭与北祁连不但是相互连接的,而且具有中间为古老隆起(秦岭群)岩块、两侧为早古生代火山岩(蛇绿岩)带的相同构造格架组合型式,同为我国华北与扬子板块间的碰撞拼合带产物。早古生代火山岩岩石学研究表明,各岩群皆以拉斑质(TH)+钙碱质(CA)岩石系列组合为主,部分岩群的钙碱系列呈双峰岩套特征,显示为岛弧或岛弧初期与裂谷末期阶段活动构造背景。依区内已知超镁铁岩体多呈断裂构造及其旁支系统产生情况,提出为岛弧根部或上地幔物质,受南、北板块碰撞挤压,沿断裂上升就位机制所形成。此外,对区内已知与火山岩有关的块状硫化物型矿床的矿床类型、特征和成矿规律等进行了研讨,提出它们的岩控和时控特征和一些发现新矿床可能性的远景地段。     

二红洼镁铁-超镁铁杂岩体特征及成因

新疆哈密二红洼镁铁-超镁铁杂岩体地表分南北两个岩体,深部可能连为一体,可划分为两个侵入期、四个岩相.第一侵入期构成岩体的主体部分,分异良好,由重力结晶分异形成自橄揽岩相、橄榄辉长岩相向含石英苏长辉长岩相的分异趋势,基性程度依次降低.岩浆多次贯入使得纵向上橄榄岩相和橄榄辉长岩相重复出现.第二侵入期辉长苏长岩相分异程度低,岩性稳定,为岩浆快速冷凝的产物.岩浆属于拉斑玄武岩系列,发生过金属硫化物熔离,有利于铜镍硫化物成矿.     

新疆准噶尔地区泥盆系火山碎屑岩中放射虫的发现及其地质意义

泥盆系课题组,在准噶尔地区发现20余层含放射虫的火山碎屑岩,放射虫均产于被化石证明了的下、中、上泥盆统中.在火山碎屑岩中产放射虫,国外已有报导,国内尚无正式报导.从而对该区岩相古地理提出了新认识.     

Static deformation of two welded half-spaces due to very long strike-slip dislocations

Closed form analytic expressions for displacement and stresses at any point of either of the two homogeneous, isotropic, perfectly elastic half-spaces in welded contact due to very long strike-slip dislocations are obtained. Both cases of vertical and horizontal strike-slip dislocations are discussed in detail. Variation of the displacement with horizontal distance from the fault and with vertical distance from the interface for a vertical strike-slip fault is studied numerically.     

Time-dependent behaviour of the rock mass

Summary The strength of intact rock and the rock mass is time-dependent. For intact rock experimental verification is available, for the rock mass the scale of time-dependence is a matter of judgement. Rock mass classifications do however emphasize the effect of time on tunnel stability. This paper examines the source of time-dependence in rocks and the rock mass and suggests a technique for estimating the long term strength. The long term strength of the rock mass is controlled by the time-dependent weakening of intact rock. Frictional resistance, a major source of rock mass strength, increases rather than decreases with time. Lifetime estimation for rocks can be accomplished phenomenologically or mechanistically. The first is a statistical process of wide applicability, the second is more restrictive in usage as its applies only to materials that suffer time-dependent strain (creep). Although the mechanistic route is more appealing, it has a major drawback as it concentrates on steady state creep. There is no strong evidence for steady state creep in rocks. The technique for long term prediction is developed through the analysis of the failure rate under constant load. The failure rate for a given load and environment is established from the frequency distribution of time-to-failure data as measured in static fatigue tests. As expected, the failure rate is strongly affected by both the loading and the environmental condition. The influence, however, is systematic and predictable.     

Research of pattern dynamics parameters of crustal deformation field in seismogenic process

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