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Information and knowledge behind data from underground rock grouting

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第6期13卷 1326-1339页

作者： Fei Xiao Qian Liu zhiye zhao Department of Civil Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016China School of Civil and Environmental Engineering Nanyang Technological University50 Nanyang Avenue639798Singapore

Data related to the pre-grouting work of a large underground project are systematically analyzed to reveal the mechanism behind,to shed some light on the execution of practical grouting,and to enrich the theory of engineering *** is generally taken as an effective way for controlling nonignorable water seepage during underground rock *** various models have been developed to guide grouting design or to specify criteria for grouting stop,it does not change the fact that grouting is still highly ***,explanation of the current situation due to grouting complexity is given through step-by-step data analysis,where the impact on grouting parameters from the geological and hydrogeological conditions is investigated,and the grouting features of two tunnels located at the same depth below the sea surface are compared and ***,the data from individual grout hole are used to construct the regional geological conditions via inverse *** is found that grouting of fractured rock masses is accompanied with great uncertainty,and field grouting data can contribute significantly to a better understanding of the regional geological conditions around an underground tunnel or rock cavern.

关键词： Field grouting data Water seepage Rock grouting Inverse modelling Data analytics Geological conditions

An improved three-dimensional spherical DDA model for simulating rock failure

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Science China(Technological Sciences) 2015年第9期58卷 1533-1541页

作者： JIAO YuYong HUANG GangHai zhao zhiye ZHENG Fei WANG Long State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences School of Civil and Environmental Engineering Nanyang Technological University

In this paper, a discontinuous numerical model, namely SDDARF3D(three-dimensional spherical discontinuous deformation analysis for rock failure), is proposed for simulating the whole process of rock failure. Firstly, within the framework of the classical discontinuous deformation analysis(DDA) method, the formulation of three-dimensional spherical DDA(3D SDDA) is deduced; secondly, a bonding and cracking algorithm is constructed and the SDDARF3 D model is proposed; thirdly, corresponding VC++ calculation code is developed and some verification examples are calculated. The simulated results can intuitively reproduce the failure phenomena of rock mass, indicating that the proposed SDDARF3 D numerical model is correct and effective.

关键词： rock failure three-dimensional spherical discontinuous deformation analysis crack propagation bonding and cracking algorithm

Numerical Simulations of the Richtmyer-Meshkov Instability of Solid-Vacuum Interface

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Advances in Applied Mathematics and Mechanics 2023年第5期15卷 1166-1190页

作者： Xiangyi Liu zhiye zhao Nansheng Liu Xiyun Lu Department of Modern Mechanics University of Science and Technology of ChinaHefeiAnhui 230026China

The Richtmyer-Meshkov instability of interfaces separating elastic-plastic materials from vacuum is investigated by numerical simulation using a multi-material solid mechanics algorithm based on an Eulerian *** research efforts are directed to reveal the influence of the initial perturbation and material strength on the deformation of the perturbed interface impacted by an initial *** varying the initial amplitude(kx0)of the perturbed interface and the yield stress(sY),three typical modes of interface deformation have been identified as the broken mode,the stable mode and the oscillating *** the broken mode,the interface width(i.e.,the bubble position with respect to that of the spike)increases continuously resulting in a final separation of the spike from the perturbed *** the stable mode,the interface width grows to saturation and then maintains a nearly constant value in the long *** the oscillating mode,the wavy-like interface moving forward obtains an aperiodic oscillation of small amplitude,namely,the interface width varies in time slightly around *** intriguing difference of the typical modes is interpreted qualitatively by comparing the early-stage wave motion and the commensurate pressure and effective ***,the subsequent interface deformation is illustrated quantitatively via the time series of the interface positions and velocities of these three typical modes.

关键词： Richtmyer-Meshkov instability elastic-plastic flow interface deformation mode

Improvement of contact calculation in spherical discontinuous deformation analysis

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Science China(Technological Sciences) 2017年第5期60卷 765-771页

作者： WANG Long JIAO YuYong HUANG GangHai ZHENG Fei zhao zhiye TAN Fei State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Department of Civil and Environmental Engineering University of California School of Civil and Environmental Engineering Nanyang Technological University

Discontinuous deformation analysis （DDA） method is a newly developed discrete element method which employs the implicit time-integration scheme to solve the governing equations and the open-close iteration （OCI） method to deal with contact prob- lem, its computational efficiency is relatively low. However, spherical element based discontinuous deformation analysis （SDDA）, which uses very simple contact type like point-to-point contact, has higher calculation speed. In the framework of SDDA, this paper presents a very simple contact calculation approach by removing the OCI scheme and by adopting the maximal displacement increment （MDI）. Through some verification examples, it is proved that the proposed method is correct and effective, and a higher computational efficiency is obtained.

关键词： 3D-DDA spherical element open-close iteration calculation efficiency

Micro-and macro-fractures of coarse granite under true-triaxial unloading conditions

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Mining Science and Technology 2011年第3期21卷 389-394页

作者： He Manchao Nie Wen zhao zhiye Cheng Cheng School of Mechanics and Civil Engineering China University of Mining ＆ Technology Beijing 100083 China State Key Laboratory of Geomechanics and Deep Underground Engineering Beijing 100083. China School of Civil and Environmental Engineering Nanyang Technological University Singapore

We studied the mechanical behavior of rock under different boundary conditions, based on the fractal characteristics of fractures in terms of microscopic and macroscopic investigations. Three rectangular granite specimens of similar dimensions were tested by a triaxial rock testing machine under uniaxial compression （UC）, confined compression （CC） and true-triaxial unloading conditions （RB） under rock burst boundary conditions. The failure processes of these specimens were investigated via examinations of their fracture behavior on a macro-scale by laser profilometers and on a micro-scale by a scanning electron microscopic （SEM） imaging technique. The SEM images, showing the spailing features of RB frag- ments, are compared with the grain dislocations under UC and CC conditions. Based on a variogram method, two fractal parameters, i.e., fractal dimensions （Dr^d） and the scale dependent fractal parameter Kv, were induced to present the surface roughness of scanning profiles in all directions. The fitted ellipses of Dr^d distribution show that RB surface has the smallest eccentricity, followed by the CC surface, while the UC surface had the largest eccentricity. As a result of this assessment, we conclude that rocks are affected by shear traction in an intermediate stress direction, which will cause fractures generated during rock bursts to twist rather than to tilt as shown in the uniaxial compression and the confined compres- sion tests.

关键词： Rock burstsSurface roughness Stress distribution Fractal dimension Coarse granite

Determination of hydraulic conductivity of fractured rock masses:A case study for a rock cavern project in Singapore

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Journal of Rock Mechanics and Geotechnical Engineering 2015年第2期7卷 178-184页

作者： Zhipeng Xu zhiye zhao Jianping Sun Ming Lu School of Civil and Environmental Engineering Nanyang Technological University Thomson Line Division of Rail Group Land Transport Authority

In order to reduce the risk associated with water seepage in an underground rock cavern project inSingapore, a reliable hydro-geological model should be established based on the in situ investigationdata. The key challenging issue in the hydro-geological model building is how to integrate limitedgeological and hydro-geological data to determine the hydraulic conductivity of the fractured rockmasses. Based on the data obtained from different stages （feasibility investigation stage, constructionstage, and post-construction stage）, suitable models and methods are proposed to determine the hydraulicconductivities at different locations and depths, which will be used at other locations in thefuture. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

关键词： Rock caverns Hydraulic conductivity Fractured rock masses Seepage analysis

Attenuation of rock blasting induced ground vibration in rock-soil interface

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第4期11卷 770-778页

作者： Bhagya Jayasinghe zhiye zhao Anthony Goh Teck Chee Hongyuan Zhou Yilin Gui School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijingChina School of Civil Engineering and Geosciences Newcastle UniversityNewcastle upon TyneUK

Blasting has been widely used in mining and construction industries for rock *** paper presents the results of a series of field tests conducted to investigate the ground wave propagation through mixed geological *** tests were conducted at a site in the northwestern part of Singapore composed of residual soil and granitic *** field test aims to provide measurement data to better understand the stress wave propagation in soil/rock and along their *** accelerometers were used for the free field vibration *** measured results are presented and discussed,and empirical formulae for predicting peak particle velocity (PPV) attenuation along the ground surface and in soil/rock were derived from the measured ***,the ground vibration attenuation across the soil-rock interface was carefully examined,and it was found that the PPV of ground vibration was decreased by 37.2% when it travels from rock to soil in the vertical direction.

关键词： Rock blasting Field tests Blast wave propagation Peak particle velocity (PPV) Rock-soil interface

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思想政治教育范式发展的六大问题研究

重庆大学学报（社会科学版） 2023年第2期29卷 140-152页

作者：赵志业西北农林科技大学马克思主义学院陕西杨凌712100

思想政治教育范式问题作为思想政治教育发展的重点和难点问题,已被学界关注多年,并产生了众多具有重大影响力的研究成果。但在部分研究中也存在“误用”“滥用”范式现象,甚至不同程度存在自说自话、低水平重复等混乱现象。究其根源,是... 详细信息

思想政治教育范式问题作为思想政治教育发展的重点和难点问题,已被学界关注多年,并产生了众多具有重大影响力的研究成果。但在部分研究中也存在“误用”“滥用”范式现象,甚至不同程度存在自说自话、低水平重复等混乱现象。究其根源,是对思想政治教育范式的基本问题缺乏深入研究,导致对思想政治教育范式其他层面的研究没有建立在相对统一且稳固的根基之上。因此,对于思想政治教育范式基本问题的研究就尤为重要。基于此,对思想政治教育范式的六大基本问题,即“内涵与结构问题”“形成与发展问题”“层次类型问题”“功能问题”“通约性问题”“转换与优化问题”进行探讨与研究,有利于为当前我国思想政治教育范式的高质量发展提供智力支持。针对思想政治教育范式六大基本问题进行研究,形成以下基本观点:第一,思想政治教育范式是指在思想政治教育理论研究与应用、实践研究与发展过程中形成和遵循的结构模型。思想政治教育范式结构是由科学共同体、框架体系、方法体系以及社会建制构成。第二,思想政治教育范式的形成是一个过程,在中国共产党的全面领导下,在理论工作者和实践工作者的共同努力下,当前我国思想政治教育范式已经初步形成。第三,思想政治教育范式的层次类型可以划分为思想政治教育研究范式、学科范式、理论范式及实践范式四种大类。这四类范式在结构上遵循着思想政治教育范式的基本规定,它们之间的关系是彼此交叉和部分重叠的,同时它们的侧重点有所不同。第四,当前思想政治教育范式的功能主要体现在培育思想政治教育科学共同体、划定界域并规范理论研究和实践、汇聚和整合各种资源和条件、传承和创造教育智慧等方面。第五,思想政治教育范式在形式上具有可通约性。不同国家、不同阶级、不同时代的思想政治教育范式一般是不可通约的,但可以进行交流互鉴。当前我国思想政治教育范式之间具有可通约性。第六,当前我国思想政治教育范式需要优化而不是转换,优化的路径是构建学科范式主导下的多范式发展格局,加强对思想政治教育范式结构各部分的优化。

关键词：思想政治教育思想政治教育范式范式结构范式功能范式通约性范式优化

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DDS桩在高速铁路复合地基工程中的适用性

铁道建筑 2020年第5期60卷 77-79页

作者：赵治冶山东铁路投资控股集团有限公司济南250102

结合铁路建设工程实际,选择不同地质和工况条件的施工区段,对DDS桩(全螺纹灌注挤土桩)和CFG桩(水泥粉煤灰碎石桩)进行复合地基载荷试验,对比分析2种桩在复合地基加固效果上的差异;对DDS桩进行实体取芯、局部开挖,研究其未达到预期效果... 详细信息

结合铁路建设工程实际,选择不同地质和工况条件的施工区段,对DDS桩(全螺纹灌注挤土桩)和CFG桩(水泥粉煤灰碎石桩)进行复合地基载荷试验,对比分析2种桩在复合地基加固效果上的差异;对DDS桩进行实体取芯、局部开挖,研究其未达到预期效果的原因.结果表明:地质条件、工装设备和工艺直接影响DDS桩的成桩质量和加固效果;桩底和桩身螺纹质量是保证复合地基处理效果的关键;在承载力以短桩端承力为主的加固区段不宜采用DDS桩技术进行复合地基处理;在承载力以长桩摩擦力为主的加固区段可采用DDS桩技术,但须采取改进措施.

关键词：高速铁路复合地基加固现场试验全螺纹灌注挤土桩适用性复合地基载荷