检索结果-南通市图书馆

Comparative Study of the Rock-breaking Mechanism of a Disc Cutter and Wedge Tooth Cutter by Discrete Element Modelling

引用

Chinese Journal of Mechanical Engineering 2023年第3期36卷 269-285页

作者： Hua jiang Huiyan Zhao Xiaoyan Zhang yusheng jiang Yaofu Zheng School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China Beijing Urban Construction Group Co. Ltd.Beijing 100088China

The operation of a shield tunnel boring machine(TBM)in a high-strength hard rock stratum results in significant cutter damage,adversely affecting the thrust and torque of the cutter ***,it is very important to carry out the research on the stress characteristics and optimize the cutter parameters of cutters break high-strength hard *** this paper,the rock-breaking performance of cutters in an andesite stratum in the tunnel of Qingdao Metro Line No.8 was investigated using the discrete element method and theoretical *** rock-breaking processes of a disc cutter and wedge tooth cutter were simulated by software particle flow code PFC^(3D),and the rock-breaking degree,stress of the cutter,and rock-breaking specific energy were *** rock damage caused by the cutter in a specific section was divided into three stages:the advanced influence,crushing,and stabilizing *** rock-breaking degree and the tangential and normal forces of the wedge tooth cutter are larger than that of the disc cutter under the same *** disc cutter(wedge tooth cutter)has the highest rock-breaking efficiency at a cutter spacing of 100 mm(110 mm)and a penetration depth of 8 mm(10 mm),and the rock-breaking specific energy is 11.48 MJ/m^(3)(12.05 MJ/m^(3)).Therefore,two types of cutters with different penetration depths or cutter spacing should be *** number of teeth of wedge tooth cutters can be increased in hard strata to improve the rock-breaking efficiency of the *** research results provide a reference for shield cutterhead selection and cutter layout in similar projects.

关键词： Qingdao andesite Rock breaking with cutter Wedge tooth cutter Specific energy PFC^(3D)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental study on the influence of content and fineness of fly ash on the mechanical properties of grouting slurries

引用

Deep Underground Science and Engineering 2024年第4期3卷 467-480页

作者： Hua jiang Handong Zhang Xiaoyan Zhang Jinxun Zhang yusheng jiang School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijingChina Beijing Urban Construction Group Co. Ltd.BeijingChina

Excavation gaps around the front shield can be generated during shield construction,resulting in significant ground *** synchronous grouting slurries are unsuitable forfilling these gaps during tunneling under existing subway *** address this issue,experiments are conducted on mix characteristics and hardening properties of slurries with variations infineness and contents ofﬂy *** experimental and computed tomography scan results yield the followingfindings:(1)ﬂy ash with highfineness can effectively reduce the early strength of slurries and enhance their *** improves thefilling effect on micropores in the slurry and ultimately enhances thefinal hardening strength.(2)Fineness ofﬂy ash controls the process of slurry *** higher thefineness ofﬂy ash,the more visible the exothermic hydration of slurry and the earlier the highest temperature peak appears.(3)Fly ash with highfineness can effectively increase the density and consolidation rate of slurries,resulting in greater improvement in slurry strength,particularly when the ratio ofﬂy ash to cement(mf/mc)is 0.75.(4)Fly ash with highfineness can effectively decrease the likelihood of appearance of pores in the slurry,optimize the pore structure,and enhance the strength of slurries after consolidation.

关键词： content CT scan environmentally friendly fineness fly ash homogeneity hydration mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic evolution in mechanical characteristics of complex supporting structures during large section tunnel construction

引用

Deep Underground Science and Engineering 2022年第2期1卷 183-201页

作者： Hua jiang Jianhua Mu Jinxun Zhang yusheng jiang Chongyang Liu Xiaoyan Zhang School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijingChina Beijing Urban Construction Group Co. Ltd.BeijingChina

The shallow tunnelling method(STM)often uses temporary supports to divide large section tunnels into several closed or semiclosed sections so as to share the upper *** complex support system composed of primary and temporary supports can ensure safety during tunnel *** on the large section tunnel of Beijing Subway Line 12,the mechanical characteristics of support system by the double-side-drift method(DSDM)during excavation and demolition were analyzed through numerical simulation and *** study showed that the middle cave excavation was the most critical stage of the DSDM,during which the load on the supporting structure increased *** temporary vertical support bore most of the new load during middle cave *** the demolition stage,the load was redistributed,which caused arch settlement and section *** removal of the temporary vertical support exerted the greatest impact in this *** lateral temporary inverted arch changed from axial compression to axial tension after the middle and lower caves were *** on the mechanical characteristics of the support system,some engineering suggestions were proposed for large section tunnel *** research results can provide reference for the design and construction of similar large section tunnels.

关键词： large section tunnel mechanical characteristics on-site monitoring supporting structure the shallow tunnelling method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on the design method for uniform wear of shield cutters in sand-pebble strata

引用

Deep Underground Science and Engineering 2024年第2期3卷 216-230页

作者： Jinxun Zhang Bo Li Guihe Wang yusheng jiang Hua jiang Minglun Yin Zhengyang Sun Beijing Urban Construction Group Co. Ltd.BeijingChina China University of Geosciences BeijingChina China University of Mining and Technology BeijingChina

During shield tunneling in highly abrasive formations such as sand–pebble strata,nonuniform wear of shield cutters is inevitable due to the different cutting *** downtimes and cutter replacements have become major obstacles to long-distance shield driving in sand–pebble *** on the cutter wear characteristics in sand–pebble strata in Beijing,a design methodology for the cutterhead and cutters was established in this study to achieve uniform wear of all cutters by the principle of frictional *** applicability of the design method was verified through three-dimensional simulations using the engineering discrete element *** results show that uniform wear of all cutters on the cutterhead could be achieved by installing different numbers of cutters on each trajectory radius and designing a curved spoke with a certain arch height according to the shield *** the uniform wear scheme,the cutter wear coefficient is greatly reduced,and the largest shield driving distance is increased by approximately 47%over the engineering *** research results indicate that the problem of nonuniform cutter wear in shield excavation could be overcome,thereby providing guiding significance for theoretical innovation and construction of long-distance shield excavation in highly abrasive strata.

关键词： cutter wear EDEM model long-distance shield driving sand-pebble stratum shield tunnel uniform wear design method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical investigation on the spewing mechanism of earth pressure balance shield in a high-pressure water-rich sand stratum

引用

Deep Underground Science and Engineering 2023年第1期2卷 74-87页

作者： Zhiyong Yang Weiqiang Qi Yanjie Ding yusheng jiang Xinkang Yang Xing Yang Xiaokang Shao School of Mechanics and Civil Engineering China University of Mining and Technology‐BeijingBeijingChina China Railway First Survey and Design Institute Group Co. LtdXi'anChina

The spewing of a screw conveyor easily occurs from the earth pressure balance(called EPB)shield in a water-rich sand *** may lead to the collapse of the tunnel face and even serious subsidence of the ground *** understand the spewing mechanism of the shield screw conveyor and explore the critical hydraulic condition of soil spewing in a shield–soil chamber,a simplified theoretical model for the spewing of the screw conveyor was developed based on the equation of groundwater flow in the screw conveyor under turbulent ***,coupling Darcy's law with Brinkman's equation,this model was implemented within the COMSOL Multiphysics *** underground water flow in the shield screw conveyor was simulated so as to obtain its velocity and flow *** simulations show that the water pressure distribution is concentrated in the lower part of the soil chamber after the groundwater enters the soil *** the groundwater enters the screw conveyor,its pressure gradually decreases along the direction of the screw *** the water flow reaches the stratum–shield interface,the flow velocity changes markedly:first increases and concentrates at the entrance of the lower soil chamber,plummets and stabilizes gradually,and increases again at the *** soil chamber and screw conveyor are significantly *** is also found that the soil permeability coefficient can be reduced to k<2.6×10^(−4)cm/s through appropriate soil improvement,which can effectively prevent the occurrence of spewing disasters.

关键词： EPB shield multiphysical coupling permeability coefficient screw conveyor spewing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Effect of the Sinking of Isotope Grains in Water Injection Profile Logging

引用

Petroleum Science 2006年第1期3卷 45-49页

作者： Zhang yusheng jiang Quan Xia Yuanjian Tuha Business Division of China Petroleum Logging Co. Ltd. Shanshan Xinjiang 838202 China

In the process of oil field exploitation, radioactive isotope tracer water injection profile logging is a main method to determine the water-intake capacity of the target intervals. For those general water injection wells, whose perforated intervals are beyond the tubing shoe, the sinking speed of isotope grains is related to the density and salinity of the injection water and the tubing dimension. We studied the motion of the isotope grains in the water injection wells by both theoretical calculation and field experiment. The result shows that if the water injection quantity is over 20 m＆3/d, and the density of the isotope grains, whose diameter is 100-600 μm, is 1.06 g/cm^3, then the logging technique for this kind of water injection wells will be appropriate. Whether water injection profile logging is successful in the well, whose perforated intervals are beyond the tubing shoe, depends on the sinking speed of the tracer grains.

关键词： Isotope tracer logging injection water profile sinking calculation experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

北京地铁砂卵石地层盾构推力组成及可控因素敏感性研究

引用

现代隧道技术 2013年第4期50卷 109-114页

作者：江华张晋勋江玉生北京城建集团有限责任公司博士后工作站北京100088 中国矿业大学(北京) 力学与建筑工程学院北京100083

北京地铁盾构施工中穿越的砂卵石地层卵石含量高、粒径大，土体摩阻力大、流塑性差，给施工过程中盾构推力的控制带来了极大困难。为了降低盾构施工风险、提高掘进效率，文章着重在土压平衡盾构推力组成特征及主要可控因素等方面展开细... 详细信息

北京地铁盾构施工中穿越的砂卵石地层卵石含量高、粒径大，土体摩阻力大、流塑性差，给施工过程中盾构推力的控制带来了极大困难。为了降低盾构施工风险、提高掘进效率，文章着重在土压平衡盾构推力组成特征及主要可控因素等方面展开细致的研究；系统分析了土压平衡盾构掘进机理，推导了盾构推力的理论计算公式。根据砂卵石地层的力学特征，分析了砂卵石地层盾构推力的组成特征，并推导了简化的盾构推力计算公式。为了检验理论计算公式的合理性，以推导的盾构推力为研究对象，对刀盘开口率及碴土内摩擦角两大可控因素进行了敏感性统计分析。研究结果表明：（1）盾构推力与刀盘开口率成反比，刀盘开口率每增加10％，盾构推力约降低3％～5％；（2）盾构推力与碴土的内摩擦角成正比，内摩擦角每增加10。，盾构推力约增加6％～10％。同时以北京地铁十号线二期盾构工程为背景，开展盾构现场掘进试验，对理论研究成果进行了验证。研究成果为类似砂卵石地层盾构选型、设计与工程施工阶段土压平衡盾构推力的预测与控制提供依据，具有一定的理论意义与应用价值。

关键词：砂卵石地层盾构推力简化模型开口率内摩擦角

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于Timoshenko梁的盾构上跨对既有隧道纵向变形影响研究

引用

矿业科学学报 2021年第1期6卷 30-41页

作者：韦征江玉生中国矿业大学(北京)力学与建筑工程学院北京100083

采用修正的Loganathan理论研究了盾构上跨过程中土体损失引起的既有隧道纵向位移,考虑剪切变形的Timoshenko梁理论分析隧道内力变化及管片间错台量,基于弹性力学理论中的剪切效应建立了隧道纵向变形微分方程并求解,研究了隧道剪切刚度... 详细信息

采用修正的Loganathan理论研究了盾构上跨过程中土体损失引起的既有隧道纵向位移,考虑剪切变形的Timoshenko梁理论分析隧道内力变化及管片间错台量,基于弹性力学理论中的剪切效应建立了隧道纵向变形微分方程并求解,研究了隧道剪切刚度、土体损失率对隧道弯矩、剪力、管片间错台量变化规律。将计算结果与已发表监测数据对比,分析了Timoshenko梁发生弯曲变形后梁横截面不再与中性轴垂直,与不考虑剪切变形的Euler-Bernoulli梁的差异。研究表明:考虑剪切变形的理论解能准确预测隧道纵向变形,能矫正不考虑剪切变形条件下弯矩、剪力内力值过大以及无法计算管片错台量的缺陷。研究为预测盾构近距离上跨对既有隧道影响分析提供一种有效方法。

关键词： Timoshenko梁盾构上跨土体损失纵向变形

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

大直径土压平衡盾构始发与到达端头加固研究

引用

都市快轨交通 2013年第1期26卷 93-96页

作者：江玉生江华中国矿业大学(北京)力学与建筑工程学院北京100083 深部岩土力学与地下工程国家重点实验室北京100083

基于既有模型和改进模型,对粉质黏土、粉土、砂土及与砂卵石共4种地层进行端头加固统计计算,讨论纵向加固范围与盾构直径之间的关系,验证端头加固的尺寸效应,给出大小盾构分界的建议:在盾构始发与到达端头加固研究中,直径小于10 m和大于... 详细信息

基于既有模型和改进模型,对粉质黏土、粉土、砂土及与砂卵石共4种地层进行端头加固统计计算,讨论纵向加固范围与盾构直径之间的关系,验证端头加固的尺寸效应,给出大小盾构分界的建议:在盾构始发与到达端头加固研究中,直径小于10 m和大于10 m的盾构隧道端头土体纵向加固范围与直径的关系曲线表现出明显不同的变化特征,10 m直径可以作为大小盾构的有效分界线。对于直径大于10 m的盾构隧道,使用改进模型进行端头加固计算,更科学、更符合实际,结论更可靠。以北京地铁14号线大盾构始发与到达工程为背景,从强度、稳定性及渗透性3个方面分析大盾构端头加固方案的可行性。

关键词：城市轨道交通大盾构始发与到达端头加固尺寸效应尺寸界线

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

一种新的DV-Hop定位算法

引用

传感技术学报 2010年第12期23卷 1815-1819页

作者：江禹生冯砚毫重庆大学通信工程学院重庆400044

提出了一种新的基于非测距的DV-Hop高精度无线传感网节点定位算法。通过引入权重,改进计算未知节点平均跳距的方法,使计算出的平均跳距更加合理,用此平均跳距计算出的距离能更接近实际距离;通过引入共线性阈值NCD和跳数阈值THD,选择拓... 详细信息

提出了一种新的基于非测距的DV-Hop高精度无线传感网节点定位算法。通过引入权重,改进计算未知节点平均跳距的方法,使计算出的平均跳距更加合理,用此平均跳距计算出的距离能更接近实际距离;通过引入共线性阈值NCD和跳数阈值THD,选择拓扑关系好的且距离未知节点较近的锚节点组进行位置估计得出一系列位置;最后通过质心算法得出最终的位置坐标。仿真结果表明新算法能在不需要任何额外硬件的支持下,在降低算法复杂度的同时,能提供比DV-Hop算法更精确的位置估计。

关键词：无线传感网 DV-Hop定位算法平均跳距共线性定位精度

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：