共查询到20条相似文献，搜索用时 156 毫秒
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介绍了采用FLAC30内嵌功能较强的FISH语言对初始地应力场生成方法的改进,建立了三维非线性地应力反演分析数值模型.模拟了断层及裂隙密集带,并采用此方法构造神经网络样本,采用神经网络结构分析的方式,对不同深度的侧向系数进行反演.通过正分析的计算结果与现场实测值对比,满足精度要求,表明所获得的岩体地应力场是基本合理的. 相似文献
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《浙江大学学报(A卷英文版)》2016,(10)
目的:地下洞室群区域地应力分布繁杂多变,勘测点因数量有限难以反映初始地应力场空间分布特征。考虑工程区域内的地质构造、地形地貌及河谷的发育演化史等因素,提出综合反映工程区复杂地质条件及地层剥蚀过程的地应力场二次反演方法,揭示工程所在区域的三维地应力场分布特征,为地下工程的开挖加固设计提供更加准确的基础资料。创新点:1.基于地应力场反演基本理论,建立逐步回归-差异进化-支持向量机模型(SR-DE-SVM)的二次反演非线性模型;2.通过SR-DE-SVM算法计算流程,成功模拟工程区域地应力场分布。方法:1.通过工程勘测分析,推导出构造运动对工程区域地应力场分布产生的影响(表5和图13);2.基于智能反演方法,构建SR-DE-SVM的二次反演非线性模型(公式(10)),得到SR-DE-SVM算法的计算流程(图2);3.通过数值仿真模拟,结合地质历史的发展过程,验证所提出的二次反演方法的可行性和有效性(图10和11)。结论:1.工程区域内初始地应力水平属中等,主要受到岩体自重与构造运动的双重影响。2.SR-DESVM二次反演方法可更加清楚地明确初始地应力形成的主导成因,且更加准确、高效和真实地模拟工程区域三维地应力场的分布规律;3.围岩类别对黄登地下洞室群区域内的初始地应力场影响不大,仅在断层带及III、IV类凝灰岩夹层带切割部位有显著的应力释放效应。 相似文献
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樊锡君 《济南职业学院学报》1999,(1)
本文给出了有初始相干性注入的V型三能级系统理论模型,导出了在此系统中实现无粒子数反转激光的条件,分析了非线性增益大小跟驱动场和探测场Rabi频率、自发衰减率、原子注入速率比以及原子与探测激光场相互作用后从腔中排出速率之间的关系。 相似文献
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樊锡君 《济南教育学院学报》1999,(1):45-49
本给出了有初始相干性注入的V型三能级系统理论模型,导出了在此系统中实现无粒子数反转激光的条件,分析了非线性增益大小跟驱动场和探测场Rabi频率、自发衰减率、原子注入速率比以及原子与探测激光场相互作用后从腔中排出速率之间的关系。 相似文献
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基于煤层底板隐伏断层、陷落柱物理效应规律,以华北C-P型煤田水文地质结构和条件为背景,研制了能够进行煤层底板导水隐伏断层和陷落柱物理效应的三维沙槽实验平台,并对导水断层和陷落柱分别进行了水头、水温和浓度效应的三维实验。实验直观地反映了地下水流场、温度场、浓度场的分布规律,和矿区的实际情况吻合,和数值模拟计算结果吻合。经误差分析拟合度可达90%以上,说明实验模型及平台的设计是合理的。该实验平台能够实现对试验条件的稳定控制,对危险源效应的自动检测和高频采样,可以反映水害危险源的细微变化。为危险源的定位提供依据。 相似文献
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确定精细地球重力场在地球科学中具有重要意义.地球重力场结构由地球物质分布结构所决定,重力场信息反映地球内部密度分布信息.重力异常,即实际重力场与处于流体静力平衡理想地球体的正常重力场之差,揭示地球内部物质分布的非平衡状态,对应地球内部的密度异常,是地球内部动力学过程的动因.测定重力异常是目前探索地球内部结构的三种手段(包括地震波传播分析以及地磁场测定)之一,重力场提供了反映地球内部构造的"一面镜子".通过重力异常可反演密度异常,但这一反演问题不确定;目前地震波层析成像可提供地震波速度异常的三维图像,但直接由波速异常转换为密度异常还很困难.联合重力异常和三维地震层析成像,结合地球表面的形变和位移信息(由大地测量获得)以及对地幔物质物理化学性质的实验研究,加之地壳及岩石圈的磁异常信息,可以加深对地球内部密度异常结构及其动力过程的了解和认识. 相似文献
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地震反演中约束模型的建立,特别是多井、断裂发育区的三维复杂约束模型的建立,是地震波阻抗约束反演中的关键技术环节,对反演质量有着重要影响。本文运用地震、地质综合分析方法,系统地研究了测井资料垂向井孔轨迹约束、地质层位横向控制约束、断块约束、地层沉积模式和接触关系约束等三维约束模型的关键要素。通过对胜利油田胜坨地区三维复杂区块实际约束模型的建立和反演,证明了该方法行之有效,大大提高了反演结果的精度,取得了良好的应用效果。 相似文献
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煤田反演的声波测井曲线重构 总被引：6，自引：0，他引：6
声波测井作为测井和地震相结合的桥梁,作为测井约束反演的基础和核心,越来越得到广泛应用。在声波测井曲线品质不好或没有声波测井的地区,人们应用Gardner或Faust等经验公式构造声波测井曲线。这些经验公式砂、泥岩层比较适用,而对含煤地层则不适用。因此,本文提出声波测井曲线重构的方法,即密度、电阻率转换速度加权法,将密度、视电阻率等曲线转换成速度曲线再加权求和。该方法在煤田地震反演中应用,提高了反演的置信度。 相似文献
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NomenclatureV-Relative velocity vectorV′-Absolute velocity vectorω-Relative vorticity vectorω′-Absolute vorticity vectorR-Pipe radiusa-Radius of cylinder for helical vortex filament2πl-Pitch of i mage helical vortex filamentQ-Flowrate in pipe with an arbitrary cross-sectionΓ-Circulation of each helical vortex filamentV0-Constant transferal velocity of vortex filaments along thez-axisΩ-Constant angular velocity of vortex filaments around thez-axis(a,χ1) ,(a,χ2) -Relative helical … 相似文献
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Luquire et al.'s impedance change model of a rectangular cross section probe coil above a structure with an arbitrary number of parallel layers was used to study the principle of measuring thicknesses of multi-layered structures in terms of eddy current testing voltage measurements. An experimental system for multi-layered thickness measurement was developed and several fitting models to formulate the relationships between detected impedance/voltage measurements and thickness are put forward using least square method. The determination of multi-layered thicknesses was investigated after inversing the voltage outputs of the detecting system. The best fitting and inversion models are presented. 相似文献
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Ideas leading to the resolution of the problem of no-slip condition for fluid velocity at a solid surface are traced in this
concluding part of the article. In the continuum limit velocity slip being zero is established beyond any doubt now. Even
turbulent flows which have a large velocity gradient near a wall have to satisfy the no-slip condition at every instant. From
molecular considerations, on the other hand, we know that the velocity slip is proportional to the mean free path which may
not be negligible in rarefied gas flows. Experimental verification of no-slip has been only indirect and it is only recently
that slip velocity in non-wettable liquids has been measured directly. 相似文献
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光学空间滤波实验的微机模拟演示 总被引：1，自引：0，他引：1
陈城钊 《韩山师范学院学报》2005,26(6):33-36
提出了一种利用MATLAB和C移软件模拟演示空间滤波实验的新方法．用一维黑白光栅作为输入物，设计了能脱离MATLAB运行且界面友好的程序，模拟演示了高通、低通及衬比度反转等实验结果． 相似文献
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Theoretical Calculation and Analysis of Slip and Deformation for Concrete Sandwich Panels 总被引：1，自引：0，他引：1
Slip and deformation of concrete sandwich panels under uniformly distributed loads is concerned. The effect of slip on the deformation of concrete sandwich panels are studied,and the analytical expressions of slip and deformation for concrete sandwich panels is obtained. These formulae can describe the slip distribution and account for its effect on deformation. In order to restrict the bound of formula, the formula of crack moment is obtained. The results of theoretical calculation are compared with those of tests and finite element methods. The comparison shows that the results of theoretical calculation are in accord with those of tests and finite element methods. So the theoretical calculation can be used to calculate slip and deformation of concrete sandwich panels in practical projects. 相似文献
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The dynamic response of an infinite beam placed on a Pasternak foundation when the system was subjected to a moving load was investigated. We used the double Fourier transform and its inversion to solve the formulations of the problem. A closed form analytic solution of the beam was obtained by the theorem of residues. We selected a numerical example to illustrate the dynamic response of the beam on Pasternak and Winkler foundations, respectively. We discuss the effect of the moving load velocity on the dynamic displacement response of the beam. The maximum deflection of the beam increases slightly with increased load velocity but increases significantly with reduced shear modulus of subgrade at a given velocity. The maximum deflection of a beam resting on a Pasternak foundation is much smaller than that of a beam on a Winkler foundation. 相似文献
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Yun-guang Luan Hua-ming Wang Dong-biao Zhao Yang Wang Feng-hong Chen 《浙江大学学报(A卷英文版)》2017,18(10):831-840
A combustion-powered actuator has been proposed in our previous work (Wang et al., 2015), and it has shown great power hopping ability. To explore the hopping process and output performance of the actuator, the model of an actuator driving the hopping process is investigated through theoretical analysis and experimental validation. Firstly, the structure of the actuator and hopping process are described briefly, and the dynamic models of the process are constructed. Secondly, the thermodynamic model of the actuator is established by the Wiebe heat release function and the input energy density is computed by Chemkin for when propane and nitrous oxide with different equivalence ratios are injected into the chamber. Thus, the thermodynamic model is obtained by integrating dynamic and thermodynamic equations. After that, a few output performance parameters are identified to assess system performance. Lastly, the experimental rig of the combustion actuator is set up to test the displacement and pressure of the actuator driven hopping process. By solving the thermodynamic equations, the post-combustion pressure, the displacement and the velocity varying with time are computed, and are compared with the test results, indicating that the computational results match the experimental test well. At the end of the stroke, the velocities of the experiment and simulation are 6.5 m/s and 6.99 m/s, respectively. The hopping results are compared with the simulation when different pressures under equivalence ratio of 1 are injected, and the maximum and minimum deviations are 14.45% and 1.83%, respectively. 相似文献
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大型工程如坡体滑移、地基沉降等的变化都属于位移较大的移动。因此根据OTDR的弯曲损耗测试原理,设计了一种基于此原理的组合式光纤传感器,该传感器可以根据实际位移变化的需要改变量程的大小,并对单个该传感器进行了理论推导和试验测试,得出拟合公式。该实验结果可为弯曲损耗位移光纤传感器的开发研究作参考。 相似文献