斜井穿越饱和砂层旋喷围护结构设计及稳定性研究

发布时间：2018-02-28 05:54

本文关键词： 高压旋喷注浆饱和砂层斜井旋喷围护结构稳定性　出处：《煤炭科学研究总院》2017年硕士论文　论文类型：学位论文

【摘要】：煤炭资源在过去几十年以及可预见的短期内一直是我国国民经济与社会发展的重要物质基础。井工煤矿能否建成,首先取决于凿井技术,而斜井穿越饱和砂层建井技术一直是国内外的技术难题。旋喷注浆工艺因注浆效果可控、可靠且对井筒具有永久保护作用,因而,研究旋喷注浆形成围护结构掩护斜井穿越饱和砂层具有重要的理论指导意义和重大的实践推广意义。本文通过现场试验、室内试验、理论分析以及数值模拟的方法研究了斜井穿越饱和砂层旋喷围护结构的稳定性,初步形成了一套旋喷围护结构的设计方法及稳定性的判定标准,主要结论有:(1)通过室内试验,获得了陕北饱和砂土和旋喷固结体的物理、力学性质指标:砂土的含水率似、容重γs、土粒比重Gs以及邓肯-张模型参数;旋喷固结体的容重γs、单轴抗压强度σc、粘聚力c、内摩擦角φ、弹性模量Eav、泊松比μav。(2)通过理论分析,根据临界埋深将斜井分为浅埋段和深埋段两种情况进行研究。其中,浅埋段采用岩柱法计算围岩压力,深埋段经过分析比选,参考各种理论的作用机理、特点和适用范围后,最终确定使用《铁路隧道设计规范》计算围岩压力。(3)通过理论分析,建立了旋喷围护结构的力学模型,并给出浅埋段及深埋段旋喷围护结构顶板、底板以及两帮厚度的计算公式。其中,旋喷围护结构的受力形式按简支梁承受最大剪力的模型计算,两帮所受的力按最不利情况进行考虑。(4)根据实验结果,计算出浅埋段与深埋段厚度的设计值及变化规律。浅埋段厚度随埋深呈线性增长趋势,深埋段厚度不随埋深变化。(5)通过数值模拟,选择埋深16.6m、50m以及80m三个断面进行验证,证明了本文推导的旋喷围护结构厚度计算方法的正确性。研究表明,采用高压旋喷注浆工艺形成围护结构掩护斜井穿越饱和砂层是可行的,其理论分析手段与评价标准是适用和正确的,旋喷围护结构是稳定的。因此,本文得出的旋喷围护结构的力学模型及计算公式可作为饱和砂层斜井旋喷围护结构的设计方法及稳定性的判定标准。
[Abstract]:Coal resources have been an important material foundation for the national economy and social development in China in the past few decades and in the foreseeable short term. The construction technology of inclined well through saturated sand formation has always been a technical problem at home and abroad. Because the grouting effect is controllable, reliable and has permanent protection to the wellbore, the rotary jet grouting process has a permanent protective effect on the wellbore. It is of great theoretical significance and great practical significance to study the formation of cover inclined well with rotary jet grouting through saturated sand bed. In this paper, through field test, laboratory test, The theoretical analysis and numerical simulation method are used to study the stability of rotary jet retaining structure of inclined well through saturated sand bed, and a set of design methods and criteria for judging the stability of rotary jet enclosure structure are preliminarily formed. The main conclusions are as follows: (1) passing laboratory tests. The physical and mechanical properties of saturated sand and spouted consolidation body in Northern Shaanxi are obtained: the moisture content of sand is similar, the bulk density 纬 s, the specific gravity of soil grain Gs and the parameters of Duncan Chang model; The bulk weight 纬 s, uniaxial compressive strength 蟽 c, cohesive force c, angle of internal friction 蠁, modulus of elasticity Eavand Poisson's ratio 渭 av.t2) are studied by theoretical analysis. The inclined wells are divided into shallow buried section and deep buried section according to critical burying depth. The rock column method is used to calculate the surrounding rock pressure in the shallow buried section. After analyzing and selecting the deep buried section, referring to the action mechanism, characteristics and applicable range of various theories, it is finally determined to calculate the surrounding rock pressure by using "Railway Tunnel Design Code". The mechanical model of rotary jet enclosure is established, and the calculation formulas of roof, bottom plate and two sides thickness of shallow and deep burying section are given. The stress form of the rotary jet retaining structure is calculated according to the model of simply supported beam bearing the maximum shear force, and the force of the two bars is considered according to the most disadvantageous condition. (4) according to the experimental results, The design value and variation law of the thickness of shallow and deep buried section are calculated. The thickness of shallow section increases linearly with the depth of burial, and the thickness of deep section does not change with the depth of buried.) by numerical simulation, three sections of 16.6 mm-50m and 80m are selected for verification. It is proved that the calculation method of the thickness of rotary jet enclosure structure derived in this paper is correct. The research shows that it is feasible to use high pressure rotary jet grouting technology to form cover inclined well with enclosure structure through saturated sand layer. The theoretical analysis means and evaluation criteria are applicable and correct, and the rotary jet retaining structure is stable. In this paper, the mechanical model and calculation formula of the rotary jet enclosure can be used as the design method and the criterion of stability of the rotary jet retaining structure in the inclined well of saturated sand layer.
【学位授予单位】：煤炭科学研究总院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD262

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