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Support design method for deep soft-rock tunnels in non-hydrostatic high in-situ stress field
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作者 ZHENG Ke-yue SHI Cheng-hua +3 位作者 ZHAO Qian-jin LEI Ming-feng JIA Chao-jun PENG Zhu 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2431-2445,共15页
Due to the long-term plate tectonic movements in southwestern China,the in-situ stress field in deep formations is complex.When passing through deep soft-rock mass under non-hydrostatic high in-situ stress field,tunne... Due to the long-term plate tectonic movements in southwestern China,the in-situ stress field in deep formations is complex.When passing through deep soft-rock mass under non-hydrostatic high in-situ stress field,tunnels will suffer serious asymmetric deformation.There is no available support design method for tunnels under such a situation in existing studies to clarify the support time and support stiffness.This study first analyzed the mechanical behavior of tunnels in non-hydrostatic in-situ stress field and derived the theoretical equations of the ground squeezing curve(GSC)and ground loosening curve(GLC).Then,based on the convergence confinement theory,the support design method of deep soft-rock tunnels under non-hydrostatic high in-situ stress field was established considering both squeezing and loosening pressures.In addition,this method can provide the clear support time and support stiffness of the second layer of initial support.The proposed design method was applied to the Wanhe tunnel of the China-Laos railway in China.Monitoring data indicated that the optimal support scheme had a good effect on controlling the tunnel deformation in non-hydrostatic high in-situ stress field.Field applications showed that the secondary lining could be constructed properly. 展开更多
关键词 non-hydrostatic stress field high in-situ stress deep soft-rock tunnel squeezing pressure loosening pressure support design method
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Vertical two-dimensional non-hydrostatic pressure model with single layer
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作者 康玲 郭晓明 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2013年第6期721-730,共10页
The vertical two-dimensional non-hydrostatic pressure models with multiple layers can make prediction more accurate than those obtained by the hydrostatic pres- sure assumption. However, they are time-consuming and un... The vertical two-dimensional non-hydrostatic pressure models with multiple layers can make prediction more accurate than those obtained by the hydrostatic pres- sure assumption. However, they are time-consuming and unstable, which makes them unsuitable for wider application. In this study, an efficient model with a single layer is developed. Decomposing the pressure into the hydrostatic and dynamic components and integrating the x-momentum equation from the bottom to the free surface can yield a horizontal momentum equation, in which the terms relevant to the dynamic pressure are discretized semi-implicitly. The convective terms in the vertical momentum equation are ignored, and the rest of the equation is approximated with the Keller-box scheme. The velocities expressed as the unknown dynamic pressure are substituted into the continuity equation, resulting in a tri-diagonal linear system solved by the Thomas algorithm. The validation of solitary and sinusoidal waves indicates that the present model can provide comparable results to the models with multiple layers but at much lower computation cost. 展开更多
关键词 vertical two-dimensional model non-hydrostatic pressure single layer Thomas algorithm WAVE
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Ruby fluorescence pressure scale: Revisited 被引量:1
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作者 柳雷 毕延 徐济安 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第5期402-406,共5页
Effect of non-hydrostatic stress on X-ray diffraction in a diamond anvil cell (DAC) is studied. The pressure gradient in the sample chamber leads to the broadening of the diffraction peaks, which increase with the h... Effect of non-hydrostatic stress on X-ray diffraction in a diamond anvil cell (DAC) is studied. The pressure gradient in the sample chamber leads to the broadening of the diffraction peaks, which increase with the hkl index of the crystal. It is found that the difference between the determined d-spacing compressive ratio d/do and the real d-spacing compressive ratio dr/do is determined by the yield stress of the pressure transmitting media (if used) and the shear modulus of the sample. On the basis of the corrected experiment data of Mao et al. (MXB86), which was used to calibrate the most widely used ruby fluorescence scale, a new relationship of ruby fluorescence pressure scale is corrected, i.e., P = (1904/9.827)[(1 + △λ/λ0)9.827 - 1]. 展开更多
关键词 non-hydrostatic stress ruby fluorescence pressure scale diamond anvil cell
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Static solution on four-region spherial cavity expansion model in a pressure sensitive medium
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作者 于雪梅 唐立强 杨勇 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2010年第3期405-408,共4页
Spherical cavity expansion model is often used to study the mechanic characteristics of pressure sensitive mediums. The most important one we do in the paper is that we construct a four-region model with σθ≠0 in da... Spherical cavity expansion model is often used to study the mechanic characteristics of pressure sensitive mediums. The most important one we do in the paper is that we construct a four-region model with σθ≠0 in damage region,which is different from what Satapathy did before and is more reasonable. By adopting this model,different constitutive equations were constructed by different method-elastic mechanics in elastic region,damage mechanics and fracture mechanics in damage region,and macro-micro mechanics theory in plastic region. Then using Durban's self-similarity assumption,the control differential equations with boundary conditions were established,and the static numerical solution of stress field and displacement field in the three different regions of elastic,damage and plastic area were discussed respectively. Results showed that this four-region model can describe precisely the mechanic characteristics of pressure sensitive mediums under initial pressure. 展开更多
关键词 pressure-sensitive material SPHERICAL CAVITY expansion damage MECHANICS SELF-SIMILARITY assumption CONSTITUTIVE equation
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基于广义波阻抗理论的SHPB试验中弹性压缩阶段试件应力-应变曲线的应力波效应及其影响机理
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作者 高光发 《爆炸与冲击》 EI CAS CSCD 北大核心 2024年第9期98-111,共14页
定量研究分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)试验中弹性压缩阶段试件中的应力波效应是解耦准确材料弹性曲线的基础。在满足平面波假设的基础上,基于广义波阻抗理论,对杆与试件面积不匹配时试件弹性压缩阶段应力波... 定量研究分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)试验中弹性压缩阶段试件中的应力波效应是解耦准确材料弹性曲线的基础。在满足平面波假设的基础上,基于广义波阻抗理论,对杆与试件面积不匹配时试件弹性压缩阶段应力波演化造成的结构效应开展了定量理论研究,分析了不同情况下弹性阶段内试件唯象工程及实际材料应力-应变曲线的偏差特征与主要因素,并揭示了影响这种偏差的影响规律及其机理。研究表明:对于线性入射加载波,当无量纲时间为0.5的倍数时,即使其他参数改变,试件唯象与材料实际的应力-应变曲线仍对应相等;试件两端的应力差较大时,若应力差的变化趋于稳定,则试件唯象与材料实际的应力-应变曲线差异较小。计算了不同波动区间内试件的最大应力偏离值及其变化趋势和对应的无量纲时间,研究了入射波是双线性组合波时试件的应力-应变曲线。研究表明:双线性波入射时,2个线性区间可以独立分析,无论如何组合线性区间或应力差如何变化,只要试件两端应力差为近似恒定曲线,对应的试件唯象工程应力-应变曲线都是相对准确的。 展开更多
关键词 分离式霍普金森压杆 应力波效应 应力均匀性假设 动态应力-应变曲线
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Thermal behavior of friction clutch disc based on uniform pressure and uniform wear assumptions 被引量:8
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作者 Oday I.ABDULLAH Josef SCHLATTMANN 《Friction》 CSCD 2016年第3期228-237,共10页
关键词 dry friction clutch thermal analysis finite element analysis uniform wear assumption uniform pressure assumption
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基于Winkler地基的仰(俯)采采场顶板破断分析
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作者 温耀军 《山西焦煤科技》 CAS 2023年第8期22-27,共6页
基于Winkler地基假设,分析了仰(俯)采采场顶板破断机理,建立了仰(俯)采基本顶初次来压和周期来压的力学模型。运用ANSYS数值模拟软件对仰(俯)采采场顶板围岩应力分布进行数值模拟。通过理论分析、数值模拟和实例分析表明,仰斜开采和俯... 基于Winkler地基假设,分析了仰(俯)采采场顶板破断机理,建立了仰(俯)采基本顶初次来压和周期来压的力学模型。运用ANSYS数值模拟软件对仰(俯)采采场顶板围岩应力分布进行数值模拟。通过理论分析、数值模拟和实例分析表明,仰斜开采和俯斜开采的初次来压步距相同,但由于基本顶的断裂位置不同导致仰采的来压强度大于俯采的来压强度。其次,由于基本顶上的最大拉应力大小不等,导致仰采的周期来压步距小于俯采。与俯采相比,仰采的围岩活动剧烈,矿压显现程度严重。但俯采工作面上覆岩层垂直压应力大于仰采,俯采工作面的超前支承应力也大于仰采。综合分析,得出俯斜开采比仰斜开采优越。 展开更多
关键词 仰(俯)采 顶板破断机理 Winkler地基假设 矿压显现
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非静压假定的σ坐标下垂向二维浅水模型的应用研究 被引量:4
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作者 吴修广 沈永明 +2 位作者 王敏 郑永红 杨志峰 《水力发电学报》 EI CSCD 北大核心 2005年第1期93-97,112,共6页
本文采用σ坐标下的垂向二维自由表面流动的k -ε双方程湍流数学模型 ,加入动水压力项 ,采用有限体积法来离散 ,求解模型时利用SIMPLE算法。本模型通过带有槽沟的明渠水流资料进行验证 ,计算结果与实测结果吻合较好 ,在预测底部有潜堤... 本文采用σ坐标下的垂向二维自由表面流动的k -ε双方程湍流数学模型 ,加入动水压力项 ,采用有限体积法来离散 ,求解模型时利用SIMPLE算法。本模型通过带有槽沟的明渠水流资料进行验证 ,计算结果与实测结果吻合较好 ,在预测底部有潜堤明渠水流时 ,计算出潜堤后面有明显的回流。 展开更多
关键词 环境水力学 非静压假定 自由表面流动 SIMPLE算法 δ坐标
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等压假设下考虑化学反应动力学影响的约束爆炸准静态压力的计算 被引量:14
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作者 钟巍 田宙 《爆炸与冲击》 EI CAS CSCD 北大核心 2013年第4期375-380,共6页
为研究约束爆炸后爆炸产物与约束空间内的氧气发生化学反应对约束爆炸准静态压力的影响,从能量守恒和理想气体状态方程出发,基于爆炸后产物膨胀过程的等压假设模型,建立了约束爆炸准静态压力计算公式,并对TNT炸药爆炸后发生的化学反应... 为研究约束爆炸后爆炸产物与约束空间内的氧气发生化学反应对约束爆炸准静态压力的影响,从能量守恒和理想气体状态方程出发,基于爆炸后产物膨胀过程的等压假设模型,建立了约束爆炸准静态压力计算公式,并对TNT炸药爆炸后发生的化学反应与约束空间内准静态压力大小的关系进行分析。计算得到不同药量体积比下,TNT炸药约束爆炸后的准静态压力,计算结果与实验结果符合较好,可应用于其他类型炸药,并为预测约束爆炸后的准静态压力提供理论依据和估算方法。 展开更多
关键词 爆炸力学 准静态压力 等压假设 约束爆炸 药量体积比
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改进的浅埋隧道松动围岩压力计算方法 被引量:19
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作者 程小虎 《铁道学报》 EI CAS CSCD 北大核心 2014年第1期100-106,共7页
对浅埋隧道,松动围岩压力经典理论的计算结果差异显著,且在某些假定上存在不足。本文克服了经典理论假定上的不足,建立了实用的松动压力公式。该公式计算的松动压力随埋深、黏聚力、内摩擦角等参数的变化均符合一般规律。该公式随埋深... 对浅埋隧道,松动围岩压力经典理论的计算结果差异显著,且在某些假定上存在不足。本文克服了经典理论假定上的不足,建立了实用的松动压力公式。该公式计算的松动压力随埋深、黏聚力、内摩擦角等参数的变化均符合一般规律。该公式随埋深变化具有极大值,这一特征与岩柱理论、谢家烋公式类似。该公式可以用于内摩擦角φ≤45°的一般土质隧道,当φ≤10°时,该公式计算值与Terzaghi公式计算值差别微小。实测数据和对土柱的理论分析表明:松动压力的理论最大值为岩柱理论计算值。本文公式与Terzaghi公式计算值小于最大值,谢家烋公式计算值大于最大值。该公式对浅埋土质隧道和松散破碎的岩石隧道具有重要的参考价值。 展开更多
关键词 松动压力 浅埋隧道 拱效应 假定
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粒间吸引力对非饱和土变形及强度的影响分析 被引量:3
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作者 李顺群 肖成志 +1 位作者 吕毅兰 魏超5 《武汉理工大学学报(交通科学与工程版)》 2008年第6期1169-1172,共4页
基于球形颗粒理想化最松散堆积模型,研究了弹性条件下外加静水压力和粒间吸引力对非饱和土变形和强度的不同影响.研究表明,对于变形问题,外加静水压力引起的变形包括颗粒缺位体积和弹性变形2部分;粒间吸引力引起的变形只包括颗粒的弹性... 基于球形颗粒理想化最松散堆积模型,研究了弹性条件下外加静水压力和粒间吸引力对非饱和土变形和强度的不同影响.研究表明,对于变形问题,外加静水压力引起的变形包括颗粒缺位体积和弹性变形2部分;粒间吸引力引起的变形只包括颗粒的弹性变形.因此,在粒间吸引力作用下土体的体变要大大小于等值外加静水压力作用下产生的体变.对于强度问题,主要研究了摩擦力和咬合力.对于前者,2种加荷方式都有作用,但外加静水压力的作用要大于粒间吸引力的作用;对于后者,外加静水压力有增强作用而粒间吸引力则没有. 展开更多
关键词 非饱和土 Bishop假设 粒间吸引力 外加静水压力
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古典杨森散体压力理论的拓展及采矿工程中的应用 被引量:10
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作者 陈喜山 《岩土工程学报》 EI CAS CSCD 北大核心 2010年第2期315-319,共5页
在古典杨森垂直状态假设的基础上,导出了具有一定倾斜角度状态下的散体压力的新模型,拓展了古典杨森理论的描述范围,使其成为了新模型中倾角为90°的特例。同时,结合采矿工程薄矿脉开采的实际,提出了应用模拟实验对新模型进行修正... 在古典杨森垂直状态假设的基础上,导出了具有一定倾斜角度状态下的散体压力的新模型,拓展了古典杨森理论的描述范围,使其成为了新模型中倾角为90°的特例。同时,结合采矿工程薄矿脉开采的实际,提出了应用模拟实验对新模型进行修正的新方法,通过对新模型的实验修正得出了一个可以用于采矿工程中描述薄矿脉开采底部压力的半理论半经验公式。该研究成果无论是对古典杨森理论的发展和采矿工程的应用均具有实际意义。 展开更多
关键词 散体压力 基本假设 采矿工程 模拟实验
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提高2030平整机预测精度的实用方法 被引量:1
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作者 刘志亮 邱格君 《钢铁》 CAS CSCD 北大核心 2006年第7期61-64,共4页
根据轧件平整轧制时塑性变形量很小,变形沿带材高度不均匀分布的特点,采用沿高度应力均匀分布的平面假设将带来比较大的误差。在引入板形与力学性能综合控制目标函数的基础上,将带材的力学性能与外形质量结合来进行调整,经过大量的现场... 根据轧件平整轧制时塑性变形量很小,变形沿带材高度不均匀分布的特点,采用沿高度应力均匀分布的平面假设将带来比较大的误差。在引入板形与力学性能综合控制目标函数的基础上,将带材的力学性能与外形质量结合来进行调整,经过大量的现场试验与理论研究,通过轧制力设定,使得平整机既能保证伸长率精度又可以满足板形的要求,为此采用按接触表面边界条件方法计算以提高平整预测精度,并将其应用到宝钢2030连续退火平整机的生产实践,取得了良好使用效果。 展开更多
关键词 平整 轧制力 平面假设 预测精度
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确定地基土先期固结压力Pc试验方法的对比研究 被引量:1
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作者 吴会东 赵亚品 《铁道工程学报》 EI 北大核心 2007年第8期23-26,共4页
研究目的:通过2种试验方法的对比和综合分析,提出用非标准固结试验方法测定先期固结压力的修正方法,提高了试验的生产效率,与铁路客运专线勘察设计工期要求相适应。研究方法:通过对标准和快速固结试验结果分析对比,确定次固结修正法和K... 研究目的:通过2种试验方法的对比和综合分析,提出用非标准固结试验方法测定先期固结压力的修正方法,提高了试验的生产效率,与铁路客运专线勘察设计工期要求相适应。研究方法:通过对标准和快速固结试验结果分析对比,确定次固结修正法和K值修正法的修正方法,对修正后的结果与标准试验结果进行了误差分析,根据数理统计学原理进行检验分析。研究结果:对比试验数据表明,12 h快速固结试验经两种方法修正后,以95%置信度与标准固结试验所得结果无显著差异,试验工期由9 d可缩短为5 d。研究结论:对比试验研究提高了试验效率,缩短了试验工期,其结果已经纳入了《铁路工程土工试验规程》(TB 10102—2004),并被铁路勘察设计系统应用于铁路客运专线工程的土工试验中,有效地缓解了地质勘察设计的工期压力。 展开更多
关键词 地基土 先期固结压力 试验 对比 假设检验 次固结 修正
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Velocity and pressure distributions in discharge tunnel of rotary-obstruction composite inner energy dissipation 被引量:13
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作者 CAO ShuangLi 1,NIU ZhengMing 1,YANG Jian 2 & LU HongBo 1 1 Xi’an University of Technology,Xi’an 710048,China 2 China Water Resources Pearl River Planning,Surveying & Designing Co.Ltd,Guangzhou 510610,China 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第S1期111-117,共7页
On the basis of model test and theoretical analysis of velocity and pressure distributions,an hypothesis is presented that the distribution of tangential velocity in radial direction seems to be a combinational distri... On the basis of model test and theoretical analysis of velocity and pressure distributions,an hypothesis is presented that the distribution of tangential velocity in radial direction seems to be a combinational distribution of a quasi-free vortex and a quasi-forced vortex for the discharge tunnel of rotary-obstruction composite inner energy dissipation.The variations of corresponding parameters about the hypothesis are obtained under test conditions in this paper.The formula of pressure distribution in radial direction is deduced theoretically,and the theoretical values of pressure distribution computed by the formula are well consistent with the measured ones,showing that the formula is correct and can be applied to the computation and analysis of pressure distribution of this discharge tunnel. 展开更多
关键词 discharge tunnel rotary-obstruction COMPOSITE INNER energy dissipater model test assumption of velocity DISTRIBUTION the formula of pressure DISTRIBUTION
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A new depth-integrated non-hydrostatic model for free surface flows 被引量:3
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作者 GUO XiaoMing KANG Ling JIANG TieBing 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第4期824-830,共7页
A new depth-integrated model deploying a non-hydrostatic pressure distribution is presented.With the pressure divided into hydrostatic and dynamic components,the horizontal momentum equations were obtained by integrat... A new depth-integrated model deploying a non-hydrostatic pressure distribution is presented.With the pressure divided into hydrostatic and dynamic components,the horizontal momentum equations were obtained by integrating the Navier-Stokes equations from the bottom to the free surface.The vertical momentum equation,in which the convective and viscosity terms were omitted,was approximated by the Keller-box scheme.The model has two steps.First,the dynamic pressure gradient terms were discretized semi-implicitly and the other terms were in explicit scheme.Second,the velocities expressed as the unknown dynamic pressure were substituted into the continuity equation,resulting in a five-diagonal symmetric matrix linear system that was solved by the conjugate gradient method.The model was validated with the propagation of a solitary wave and sinusoidal wave,indicating that it can predict free surface flows well. 展开更多
关键词 depth-integrated free surface non-hydrostatic pressure WAVES
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Wind flow and wind loads on the surface of a tower-shaped building:Numerical simulations and wind tunnel experiment 被引量:1
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作者 JIANG YuJun LIU HuiZhi +3 位作者 ZHANG BoYin ZHU FengRong LIANG Bin SANG JianGuo 《Science China Earth Sciences》 SCIE EI CAS 2008年第1期103-113,共11页
Flow structure and wind pressure distribution caused by obtuse obstacles are usually the focuses in Computational Wind Engineer researches (CWE). By solving the non-hydrostatical dynamic equations, PUMA model (Peking ... Flow structure and wind pressure distribution caused by obtuse obstacles are usually the focuses in Computational Wind Engineer researches (CWE). By solving the non-hydrostatical dynamic equations, PUMA model (Peking University Model of Atmospheric Environment) was developed and applied to simulating the flow structure and wind pressure distribution around a tower-shaped building. Evaluation about the wind environment and wind loads around the building was obtained through the analysis of the numerical simulation results and wind tunnel data. Comparisons between the simulation and wind tunnel study indicate that numerical simulation results agree well in the flow field and wind pressure distribution around the tower-shaped building. On the other hand, the horizontal grid interval of 2 m and the vertical grid of 3 m were still too crude to simulate the flow structure and wind pressure distribution on the building surface more exactly in detail; and the absence of suitable pressure perturbation parameterization scheme between the solid and the adjacent space also limits the accuracy of the numerical simulation. The numerical simulation model can be used to evaluate the wind environment and wind load around high buildings. 展开更多
关键词 tower-shaped BUILDING WIND load WIND pressure COEFFICIENT non-hydrostatical numerical simulation model
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Dispersive Shallow Water Wave Modelling.Part II:Numerical Simulation on a Globally Flat Space
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作者 Gayaz Khakimzyanov Denys Dutykh +1 位作者 Oleg Gusev Nina Yu.Shokina 《Communications in Computational Physics》 SCIE 2018年第1期30-92,共63页
In this paper we describe a numerical method to solve numerically the weakly dispersive fully nonlinear SERRE-GREEN-NAGHDI(SGN)celebrated model.Namely,our scheme is based on reliable finite volume methods,proven to be... In this paper we describe a numerical method to solve numerically the weakly dispersive fully nonlinear SERRE-GREEN-NAGHDI(SGN)celebrated model.Namely,our scheme is based on reliable finite volume methods,proven to be very efficient for the hyperbolic part of equations.The particularity of our study is that we develop an adaptive numerical model using moving grids.Moreover,we use a special form of the SGN equations where non-hydrostatic part of pressure is found by solving a linear elliptic equation.Moreover,this form of governing equations allows to determine the natural form of boundary conditions to obtain a well-posed(numerical)problem. 展开更多
关键词 Nonlinear dispersive waves non-hydrostatic pressure moving adaptive grids finite volumes conservative finite differences
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土压力计算的讨论
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作者 凌云 袁维忠 《云南水电技术》 2008年第2期28-31,共4页
土压力计算在实际工程中是比较复杂的,一般均要进行简化处理。现在我们计算土压力常用的两种理论为朗肯土压力理论及库伦土压力理论,但两种土压力理论各有自己的假定及适用条件,在应用时需认真斟酌,选出与实际最接近的土压力理论进... 土压力计算在实际工程中是比较复杂的,一般均要进行简化处理。现在我们计算土压力常用的两种理论为朗肯土压力理论及库伦土压力理论,但两种土压力理论各有自己的假定及适用条件,在应用时需认真斟酌,选出与实际最接近的土压力理论进行计算土压力。 展开更多
关键词 土压力 朗肯土压力理论 库伦土压力理论 假定及适用条件 认真斟酌 选出土压力理论 计算土压力
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