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周期性剪切应力作用下碎石的滑移特性

中山大学学报(自然科学版)(中英文) 2024年第5期63卷 131-139页

作者：廖纤陶康刘煜李舒彤党文刚中山大学土木工程学院弗莱贝格工业大学岩土工程研究所

为了研究碎石材料在周期性剪切荷载条件下的滑移特性，使用自主研发的多功能动剪试验机，对碎石试样施加恒定的法向应力，以及不同峰值、谷值和频率的水平方向周期性剪切应力，监测试样在加载过程中剪切位移随时间的变化情况，并分析剪... 详细信息

为了研究碎石材料在周期性剪切荷载条件下的滑移特性，使用自主研发的多功能动剪试验机，对碎石试样施加恒定的法向应力，以及不同峰值、谷值和频率的水平方向周期性剪切应力，监测试样在加载过程中剪切位移随时间的变化情况，并分析剪切位移增量的变化情况以及整个加载期内剪切应力对应的能量密度。研究结果表明：周期性剪切应力引起的滑移特征与其峰值、谷值和频率有关；周期性剪切应力会导致碎石材料的滑移跃变，且出现滑移跃变点的条件与加载期内的能量密度有关，可根据能量密度范围将试样的滑移状态划分为三个区域，即稳定区、过渡区和跃变区。

关键词：碎石路基周期性剪切应力多功能动剪试验机滑移特性剪切位移能量密度

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Frictional sliding of infilled planar granite fracture under oscillating normal stress

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International Journal of Mining Science and Technology 2023年第6期33卷 687-701页

作者： Kang Tao wengang dang Yingchun Li School of Civil Engineering Sun Yat-sen UniversityZhuhai 519086China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China Southern Marine Science and Engineering Guangdong Laboratory Zhuhai 519086China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

This paper investigates the frictional behavior of the infilled rock fracture under dynamic normal stress.A series of direct shear tests were conducted on saw-cut granite fractures infilled with quartz using a selfdeveloped dynamic shear apparatus,and the effects of normal load oscillation amplitude,normal load oscillation period and sliding velocity were *** test results reveal that the shear response can be divided into three stages over a whole loading-unloading process,characterized by different time spans and stress ***,a smaller oscillation amplitude,a longer oscillation period and a fast shear velocity promote the stability of the friction system,which is also confirmed by the Coulomb failure criterion calculated based on the observed periodic apparent friction *** dynamic strengthening/weakening phenomenon is dependent on the oscillation amplitude and product of sliding velocity and oscillation period(vT).Also,the rate and state friction law incorporating the parameter a that characterizes the normal stress variation is employed to describe the dynamic friction coefficient but exhibits an incompetent performance when handling intensive variation in normal ***,the potential seismicity induced by oscillating normal stress based on the observed stress drop is *** work helps us understand the sliding process and stability evolution of natural faults,and its benefits for relative hazard mitigation.

关键词： Granite fracture Quartz gouge Normal load oscillation Frictional stability Rate and state friction law

Frictional behavior of planar and rough granite fractures subjected to normal load oscillations of different amplitudes

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第3期14卷 746-756页

作者： wengang dang Kang Tao Xinfan Chen School of Civil Engineering Sun Yat-sen UniversityZhuhai519082China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou221116China Southern Marine Science and Engineering Guangdong Laboratory Zhuhai519082China

The dynamic frictional behaviors of natural discontinuities(joints,fractures,faults)play an important role in geohazards assessment;however,the mechanisms of the dynamic fault weakening/strengthening are still *** this paper,a dynamic shear box was used to perform direct shear tests on saw-cut(planar)and natural(rough)granite fractures,with different normal load oscillation *** on the recorded shear forces and normal displacements,the shear forces,apparent friction coefficients and normal displacements are found to change periodically with oscillated normal loads and are characterized by a series of time *** observed changing patterns are similar for the rough and planar *** with the test data under constant normal load(CNL),small/large normal load oscillation amplitude enhances/reduces the peak shear strength,with a critical *** magnitude of critical normal load oscillation for the rough fractures is smaller than the planer *** results imply that dynamic fault weakening/strengthening can be achieved by both normal load oscillation amplitudes and slip surface *** rough fractures with larger normal oscillation amplitude can easily cause frictional weakening under stress disturbance.

关键词： Direct shear test Normal load oscillation fracture roughness Critical oscillation amplitude Dynamic weakening/strengthening

Experimental study on the slip evolution of planar fractures subjected to cyclic normal stress

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International Journal of Coal Science & Technology 2023年第4期10卷 217-232页

作者： Kang Tao wengang dang Xian Liao Xingling Li School of Civil Engineering Sun Yat-sen UniversityZhuhai 519086China Southern Marine Science and Engineering Guangdong Laboratory Zhuhai 519086China

The frictional rupture mechanisms of rock discontinuities considering the dynamic load disturbance still remain *** paper investigates the transitional behaviors of slip events happened on a planar granite fracture under cyclic normal stress with diferent oscillation *** experimental results show that the activations of fast slips always correlate with unloading of normal ***,the intensive normal stress oscillation can weaken the shear strength which is recoverable when the normal stress return to *** rupture patterns are quantifed by stress drop,slip length and slip *** the efect of small oscillation amplitudes,the slip events show chaotic shapes,compared to the regular and predictable style under constant normal *** the amplitude is large enough,the big and small slip events emerge alternately,showing a compound slip *** amplitude of the cyclic normal stress also widens the interval diferences of the slip *** work provides experimental supports for a convincible link between the dynamic stress disturbance and the slip behavior of rock fractures.

关键词： Rock fracture Frictional rupture Cyclic normal stress Slip transition Rate and state friction law

Optimization of clay material mixture ratio and filling process in gypsum mine goaf

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International Journal of Mining Science and Technology 2013年第3期23卷 337-342页

作者： Liu Zhixiang dang wengang Liu Qingling Chen Guanghui Peng Kang School of Resources and Safety Engineering Central South University

Because there is neither waste rock nor mill tailings in the gypsum mine, and the buildings on the goaf of gypsum mine are needed to be protected, the research proposed the scheme of the clay filling technology. Gypsum, cement, lime and water glass were used as adhesive, and the strength of different material ratios were investigated in this study. The influence factors of clay strength were obtained in the order of cement, gypsum, water glass and lime. The results show that the cement content is the determinant influence factor, and gypsum has positive effects, while the water glass can enhance both clay strength and the fluidity of the filing slurry. Furthermore, combining chaotic optimization method with neural network, the optimal ratio of composite cementing agent was obtained. The results show that the optimal ratio of water glass, cement, lime and clay (in quality) is 1.17:6.74:4.17:87.92 in the process of bottom self-flow filling, while the optimal ratio is 1.78:9.58:4.71:83.93 for roof-contacted filling. A novel filling process to fill in gypsum mine goaf with clay is established. The engineering practice shows that the filling cost is low, thus, notable economic benefit is achieved.

关键词： Mining engineering Filling Material mixture ratio Neural network Chaotic optimization Filling process

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采区“Z”型巷道布置

辽宁工程技术大学学报（自然科学版） 2011年第4期30卷 485-488页

作者：党文刚刘志祥刘青灵中南大学资源与安全工程学院湖南长沙410083

为了实现煤矿无煤柱开采,以矿压关键层理论为基础,结合充填开采技术提出了采区"Z"型巷道布置新工艺,并对巷旁充填体力学进行力学分析。研究结果表明,巷旁充填体塑性区的宽度比例随时间变化逐渐减小最终趋于一稳定值,并且受充填体的弹性... 详细信息

为了实现煤矿无煤柱开采,以矿压关键层理论为基础,结合充填开采技术提出了采区"Z"型巷道布置新工艺,并对巷旁充填体力学进行力学分析。研究结果表明,巷旁充填体塑性区的宽度比例随时间变化逐渐减小最终趋于一稳定值,并且受充填体的弹性模量、硬化阶段斜率等物理性质影响,对于巷旁充填,充填体弹性模量增大并不一定真正有利于充填体的稳定性。采区"Z"型巷道布置使采区工作面采煤与区段巷道准备一体化,减少了采矿中专门的机掘工作,具有提高煤炭资源采出率、取消孤岛工作面及缩短搬家时间、延长矿井服务年限等优点。

关键词：采区“Z”型巷道绿色开采关键层理论力学分析巷旁充填采出率沿空留巷塑性区

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不同稳定化处理对青稞籽粒储藏稳定性的影响

食品科技 2024年第3期49卷 173-182页

作者：党斌景孝男张杰张文刚杨希娟青海大学青海西宁810016 青海省青藏高原农产品加工重点实验室青海西宁810016 北京红星股份有限公司北京101400

为明确不同稳定化处理对青稞籽粒储藏特性的影响,以未处理青稞为对照,通过比较过热蒸汽、远红外和微波3种方式处理的青稞籽粒在储藏过程中脂肪酶活性、脂肪酸值、过氧化值、丙二醛值等的变化,明确不同稳定化处理效果之间的差异,确定稳... 详细信息

为明确不同稳定化处理对青稞籽粒储藏特性的影响,以未处理青稞为对照,通过比较过热蒸汽、远红外和微波3种方式处理的青稞籽粒在储藏过程中脂肪酶活性、脂肪酸值、过氧化值、丙二醛值等的变化,明确不同稳定化处理效果之间的差异,确定稳定化处理青稞的方式。结果表明,过热蒸汽处理条件为温度190℃,时间为70 s;远红外处理条件为面火、底火均为150℃,烘烤40 min;微波处理条件为功率800 W,时间为150 s。在以上条件下青稞籽粒脂肪酶活力下降至较低水平。在加速储藏过程中,对照和稳定化处理后青稞含水量在前30 d内水分含量会逐渐升高,30 d以后水分含量逐渐下降并趋于平衡,脂肪酶的活性、脂肪酸值及菌落总数和霉菌总数均呈升高趋势,且对照青稞脂肪酸值显著上升(P0.05),对照在20 d后丙二醛含量开始迅速上升。过热蒸汽处理抑制青稞籽粒脂肪酶活性、脂肪氧化及减菌效果相对较好,远红外、微波次之。因此,确定过热蒸汽处理(190℃、70 s)为青稞籽粒稳定化的有效方式。此结果为提高青稞籽粒储藏稳定性提供了参考。

关键词：青稞过热蒸汽远红外微波储藏稳定性

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不同品种藜麦营养成分分析及品质综合评价

青海农林科技 2024年第2期 15-25,103页

作者：张玲党斌张杰张文刚青海大学农牧学院青海西宁810016 青藏高原种质资源研究与利用实验室青海西宁810016 青海省青藏高原农产品加工重点实验室青海西宁810016

以大白藜、贡扎4号和青藜2号为原料,探究品种对藜麦成分的影响,并对藜麦品质进行综合评价。结果表明:大白藜粗蛋白、总氨基酸、总淀粉含量最高,贡扎4号灰分和脂肪含量最高,而青藜2号粗纤维、支链淀粉和酚类物质含量最高。贡扎4号必需氨... 详细信息

以大白藜、贡扎4号和青藜2号为原料,探究品种对藜麦成分的影响,并对藜麦品质进行综合评价。结果表明:大白藜粗蛋白、总氨基酸、总淀粉含量最高,贡扎4号灰分和脂肪含量最高,而青藜2号粗纤维、支链淀粉和酚类物质含量最高。贡扎4号必需氨基酸含量和氨基酸评分值最优。藜麦不饱和脂肪酸主要为油酸和亚油酸,饱和脂肪酸主要为棕榈酸,贡扎4号Ω-6/Ω-3比例最接近最佳比例,而大白藜的致动脉粥样硬化指数(AI)和血栓形成指数(TI)指数相对最低。藜麦主要矿物质为K、Mg、Ca,且大白藜更为丰富。青藜2号酚类物质含量及抗氧化能力最高。不同品种藜麦品质特征在PCA图中可以明显区分。本研究可为藜麦的品质评价、资源筛选及加工应用提供理论参考。

关键词：藜麦营养成分氨基酸评价

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软土地区强夯石渣桩地基的有限元分析

公路工程 2020年第6期45卷 44-51页

作者：刘智陈仕文唐昌意党文刚李栋珠海市规划设计研究院广东珠海519000 中山大学土木工程学院广东珠海519000

根据实际工程建立有限元基准模型分析了软土地区强夯石渣桩地基道路在施工及运营过程中静力性能,并展开了道路沉降影响因素分析。结果表明:强夯石渣桩作为良好的排水通道能够促使超静孔隙水压力的消散和有效应力的增长;强夯石渣桩道路... 详细信息

根据实际工程建立有限元基准模型分析了软土地区强夯石渣桩地基道路在施工及运营过程中静力性能,并展开了道路沉降影响因素分析。结果表明:强夯石渣桩作为良好的排水通道能够促使超静孔隙水压力的消散和有效应力的增长;强夯石渣桩道路的桩土差异沉降及桩土应力比均较小,但运营期间总沉降和桩土应力比都会明显增大。参数分析结果表明:在研究的参数范围内,道路高度和地基土渗透性对总沉降影响最大,而道路高度和填石厚度及桩径对差异沉降影响最大。

关键词：数值模拟强夯超静孔隙水压力沉降