Testing Studies on Rock Failure Modes of Statically Loads Under Dynamic Loading

By means of the improved split Hopkionson pressure bar(SHPB) with axial pre-pressure and confined pressure, two series of experiments on sandstone are carried out to research the failure mode of rock during the course of exploitation of resources in deep. One is under the conditions that the con-fining pressure is fixed and the axial pressure is changeable. The other is under the conditions that the confining pressure becomes and the axial pressure is fixed. It is found that samples break up evenly after impacting when axial static pressures are low, there is great disparity in size of fragments when axial static pressures are high, and the main bodies of samples after the tests under the combination of dy-namic and static loads frequently show the type of V or X. The samples are more close-grained at the elastic stage and impacts make many cracks be generated and developed, as makes samples more crackable. At the initial phase of damage stage, the static pressures make some cracks in the samples which are undeveloped and the impacts′ role is similar to that at the elastic stage. At the metaphase or anaphase of damage stage, these cracks in the samples develop adequately and the impacts mainly accelerate samples′ failure. The main bodies of samples show the type of V or X after impacting due to the confining pressures′ restraining samples′ lateral formation at the elastic stage or the initial phase of damage stage, the main bodies of samples have almost formed at the stage loading static pressures and the results after impacting usually are similar to those under the axial pressures tests.

Rock burst mechanism analysis in an advanced segment of gob-side entry under different dip angles of the seam and prevention technology

In order to investigate the frequent occurrences of rock burst in gob-side entry during the mining process of the mining zone No. 7, the mechanical model of main roof of fully-mechanized caving mining before breaking was established by the Winkler foundation beam theory, and the stress evolution law of surrounding rock with different dip angles of the seam during the mining process was analyzed by using FLAC3 D. The results show that: with the dip angle changing from 45° to 0°, the solid-coal side of gobside entry begins to form an L-shaped stress concentration zone at a dip angle of 30°, and the stress concentration degree goes to higher and higher levels. However, the stress concentration degree of the coalpillar side goes to lower and lower levels; the influence range and peak stress of the abutment at the lateral strata of adjacent gob increase with dip angle decreasing and reach a maximum value at a dip angle of 0°, but the tailgate is not affected; the abutment pressure superposition of two adjacent gobs leads to stress concentration further enhancing in both sides of gob-side entry. With the influence of strong mining disturbance, rock burst is easily induced by dynamic and static combined load in the advanced segment of gob-side entry. To achieve stability control similar to that in the roadway, the key control strategy is to reinforce surrounding rock and unload both sides. Accordingly, the large-diameter drilling and high-pressure water injection combined unloading and reinforced support cooperative control technology was proposed and applied in field test. The results of Electromagnetic Emission(EME) and field observation showed that unloading and surrounding rock control effect was obvious.

Mechanism of rock burst caused by fracture of key strata during irregular working face mining and its prevention methods

To study the occurrence mechanism of rock burst during mining the irregular working face,the study took irregular panel 7447 near fault tectonic as an engineering background.The spatial fracture characteristic of overlying strata was analyzed by Winkler elastic foundation beam theory.Furthermore,the influence law of panel width to suspended width and limit breaking span of key strata were also analyzed by thin plate theory.Through micro-seismic monitoring,theoretical analysis,numerical simulation and working resistance of support of field measurement,this study investigated the fracture characteristic of overlying strata and mechanism of rock burst in irregular working face.The results show that the fracture characteristic of overlying strata shows a spatial trapezoid structure,with the main roof being as an undersurface.The fracture form changes from vertical‘‘O-X"type to transverse‘‘O-X"type with the increase of trapezoidal height.From the narrow mining face to the wide mining face,the suspended width of key strata is greater than its limit breaking width,and a strong dynamic load is produced by the fracture of key strata.The numerical simulation and micro-seismic monitoring results show that the initial fracture position of key strata is close to tailgate 7447.Also there is a high static load caused by fault tectonic.The dynamic and static combined load induce rock burst.Accordingly,a cooperative control technology was proposed,which can weaken dynamic load by hard roof directional hydraulic fracture and enhance surrounding rock by supporting system.

Application of high-pressure water jet technology and the theory of rock burst control in roadway

This paper puts forward using high-pressure water jet technology to control rock burst in roadway, and analyzes the theory of controlling rock burst in roadway by the weak structure zone model. The weak structure zone is formed by using high-pressure water jet to cut the coal wall in a continuous and rotational way. In order to study the influence law of weak structure zone in surrounding rock, this paper numerically analyzed the influence law of weak structure zone, and the disturbance law of coal wall and floor under dynamic and static combined load. The results show that when the distance between high-pressure water jet drillings is 3 m and the diameter of drilling is 300 mm, continuous stress superposition zone can be formed. The weak structure zone can transfer and reduce the concentrated static load in surrounding rock, and then form distressed zone. The longer the high-pressure water jet drilling is, the larger the distressed zone is. The stress change and displacement change of non-distressed zone in coal wall and floor are significantly greater than that of distressed zone under dynamic and static combined load. And it shows that the distressed zone can effectively control rock burst in roadway under dynamic and static combined load. High-pressure water jet technology was applied in the haulage gate of 250203 working face in Yanbei Coal Mine, and had gained good effect. The study conclusions provide theoretical foundation and a new guidance for controlling rock burst in roadway.

Influence of static cartoons combined with dynamic virtual environments on preoperative anxiety of preschool-aged children undergoing surgery

BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.

黔西南金矿砂岩动静组合加载岩石力学特性研究

为探究巷道开挖后围岩不同深度切向应力不同程度的增加对围岩动力学性能的影响,采用改进的分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)试验系统,对黔西南金矿砂岩试件在0,10,20,30,40MPa的轴压下进行动静组合加载试验,旨在分析砂岩在不同轴压下的力学行为、变形特征与能量演化规律。研究发现:动静组合加载试样应力-应变曲线分为压密阶段、弹性阶段、塑性破坏和峰后阶段;轴压使得峰值应变逐渐增加,极限应变逐渐降低;动态弹性模量、动态抗压强度、应变率及各能量的演化规律均呈现以10MPa为转折点的变化规律。

三维动静加载下煤的本构模型及卸荷破坏特征

为研究非静水压条件下煤体动力学性能及动力扰动后卸荷破坏特征,在三维动静加载实验的基础上,研究了卸荷方式对动力扰动后卸荷煤样宏观破坏特性的影响。首先,采用Ф50 mm的分离式霍普金森压杆系统,开展三维动静加载下煤样的动力学实验,研究轴压、应变率对煤样动力学响应规律的影响;其次,基于响应曲面理论,借助中心复合试验法,构建考虑因素交互作用的回归模型,并分析单因素及因素交互作用的显著性;然后,结合因素交互作用、Weibull分布、Drucker-Prager准则,修正煤的强度型统计损伤本构模型,对比理论与实验结果,验证模型可靠性;最后,借助加卸荷电液伺服装置,探究轴压、冲击气压、卸荷方式对煤样破坏特征的影响及作用机制。结果表明,构建的强度型统计损伤模型,相关系数R~2≥0.88,可表征煤样动力学响应行为。冲击后同步卸荷的煤样多呈层裂破坏,拉伸界面随轴压增大而后移直至消失,无法形成层裂破坏;非同步卸荷下煤样破坏形式主要包括整体完整、层裂、压剪破坏,而当冲击气压0.4~0.6 MPa,轴压14.5 MPa时,表现为“层裂+压剪”混合破坏。

Xgadget:基于动静结合的二进制Gadget搜索

代码复用技术一直以来都是软件安全研究领域的热点,ROP(return-oriented programming)、JOP(jump-oriented programming)和DOP(data-oriented programming)技术是典型代表。Gadget搜索是代码复用的基础,针对现有静态搜索算法存在支持的Gadget类型不多,不能同时搜索动态链接库等问题,提出了基于动静结合的二进制Gadget搜索方法,基于此开发了搜索工具Xgadget。利用动态映像级插桩,对所有函数进行反汇编;设计了Token级和指令级有穷自动机,实现了基于自动机的静态搜索算法;在五款应用程序中对其进行了测试与评估。实验结果表明,算法支持ROP、JOP、DOP等多种Gadget类型的搜索,能够同时对目标程序动态链接库进行搜索,搜索数量是ROPgadget的12.5倍,单位指令搜索时间较之降低32.1%。算法为不同需求的代码复用提供更为广泛的支持,且输出结果是二进制Gadget,后续复用更直接,有利于代码复用自动化利用。

基于“动静结合”理论探讨中医治疗儿童肱骨髁上骨折的优势

“动静结合”是中医骨伤科治疗疾病的重要指导原则。肱骨髁上骨折是儿童最为常见的肘关节骨折,其并发症多,康复治疗缺乏一定的规范,容易出现肘关节功能障碍等严重后果。根据临床实践及文献阅读,从“动静结合的理论溯源”“儿童肱骨髁上骨折的治疗现状及困境”“动静结合的思想内涵与科学论证”“动静结合在临床中的具体应用“”动静结合理论在儿童肱骨髁上骨折治疗中的优势”5个方面探讨基于“动静结合”理论下中医药治疗儿童肱骨髁上骨折的优势,以期丰富中医“动静结合”思想内涵,为中医药治疗儿童肱骨髁上骨折提供理论基础。

粉煤灰改良粉砂土动静力学特性研究

为探究不同粉煤灰掺量粉砂土的动力特性和粉煤灰改良粉砂土的改性机理,以绥化—大庆高速公路路基填土为研究对象,开展无侧限压缩试验和动三轴试验,分析粉煤灰掺量对粉砂土静力学特征影响情况,以及围压、动荷载加载次数和粉煤灰掺量对改良粉砂土动强度的影响规律。结果表明:围压相同的情况下,土体的无侧限压缩强度和动强度,均随粉煤灰掺量增加先升高后降低;加载次数相同时,围压越大,土体动强度越大;选取加载次数为100次动强度进行拟合分析,得出粉煤灰掺入量与动剪切强度对应关系的经验公式。为改善路基强度,加快粉煤灰综合利用进程,结合试验结果与数据分析,建议在粉砂土路基掺加质量比15%粉煤灰进行路基施工。15%粉煤灰掺入量的改良粉砂土对比素土,存在颗粒紧凑,孔隙更小,结构相对致密,骨架更强等优点,可为东北地区粉砂土改良等工程建设提供参考。

温建民教授中西医结合微创治疗拇外翻学术思想总结

阐述温建民教授中西医结合微创治疗拇外翻的学术思想。温老师治疗拇外翻的核心思想来源于中医的阴阳理论、筋骨理论及天人合一的整体观念,在此基础上凝练出“筋骨并重”“动静结合”及“内外兼治”3条治疗大法,涵盖了微创截骨手法整复、裹帘法外固定、中药内服外用、中西医结合康复调护4个操作环节。温老师传承经典,融贯中西,从中西医结合的角度贡献了“筋”与“骨”伤病的独家治疗经验和学术思想。

计及组合区间不确定性分析的光伏出力动静态赋权搜索预测模型

针对目前光伏出力确定性预测缺乏考虑不确定性信息导致预测精度受限的问题,提出了一种计及组合区间不确定性分析的光伏出力动静态赋权搜索预测模型。首先分别构建卷积神经网络(convolutional neural network,CNN)-注意力机制(attention)-双向长短期记忆网络(bidirectional long-short term memory,BiLSTM)(CNN-Attention-BiLSTM)和自然梯度提升(natural gradient boosting,NGBoost)模型进行确定性预测;然后通过分析2个模型的确定性预测值和真实值的分布揭示了组合区间相对可靠性规律,基于该规律提出一种动静态赋权搜索预测模型,利用NGBoost模型进行不确定性预测,并根据所提供的概率分布信息,动态区分确定性预测结果的重要性,结合模型历史静态的指标评价信息,实现组合区间内搜索预测结果;最后采用澳大利亚沙漠知识太阳能中心和宁夏某光伏电站的数据集进行仿真研究,验证了该文方法的有效性和适用性,可为光伏出力确定性组合预测提供新的研究思路。

快掘扰动下巷道围岩变形控制技术研究

针对黄陵一号煤矿快掘扰动下巷道围岩变形及其控制问题,采用现场调研与监测、理论计算等手段,在厘清632回风平巷受快掘扰动情况的基础上,分析了围岩水平应力与支承应力分布演化特征。632回风平巷自然平衡拱高度为1.048 m。提出临时支护与永久支护相结合的支护措施,在632回风平巷顶板采用锚杆+锚索梁+金属网联合支护,两帮采用锚杆+塑钢网联合支护。借助原位监测技术验证了围岩控制方案的可行性,快掘扰动下巷道围岩变形得到控制。

一维动静组合加载下灰岩力学特性及能量耗散分析

为改善灰岩的破岩效率及能耗,采用分离式霍普金森压杆开展围岩一维动静组合加载试验研究,分析不同应变率、轴压梯度对灰岩的动态抗压强度、能量利用率以及破坏的影响。结果表明,当轴压一定时,灰岩试样在冲击荷载条件下的动态抗压强度随着应变率的增大呈线性增加趋势;相同应变率条件下,灰岩动态抗压强度随着轴压的增大而增大,但轴压超过一定的阈值之后,强度开始减小;不同轴压下灰岩的透射比率随着入射能的增加均呈现出指数减少趋势;轴压一定时,加载应变率越高,能耗密度越大,灰岩的变形越迅速,二者呈现出线性增加关系。在应变率相近的条件下,适当地增加轴压会使能耗密度明显降低,但过大轴压会加大能耗密度,因此破碎灰岩时,应考虑轴压和冲击荷载的综合作用。

动针静灸法联合自制上肢训练器对脑卒中患者上肢运动功能、生活质量及S100β、NO、CGRP的影响

目的:本研究旨在探讨动针静灸法联合自制上肢训练器对脑卒中患者上肢运动功能、生活质量及S100β、NO、CGRP的影响。方法:选取2022年6月~2023年1月在我院康复医学科就诊的脑卒中上肢功能障碍患者62例为研究对象,随机分为观察组和对照组,对照组在常规治疗基础上,采用自制上肢训练器进行功能训练。观察组在对照组基础上,加用动针静灸法。即施术者先实施“静灸”,即在进行隔药饼灸的同时,患者进行运动想象疗法;其后采用运动针法,即患者在接受针刺的同时,进行自制上肢训练器训练。2组连续治疗4周。治疗前后,评估Fugl-Meyer上肢评定量表(Fugl-Meyer assessment-upper extremities,FMA-UE)、改良的Ashworth量表(Modify Ashworth Scale,MAS)、脑卒中专用生活质量量表(Stroke Specific Quality of Life Scale,SS-QOL),实验室指标[S100β蛋白(S100β)、一氧化氮(NO)、降钙素基因相关肽(CGRP)]。结果:在量表评估,治疗前2组在FMA-UE、MAS、SS-QOL评分比较均无统计学意义(P>0.05);治疗4周后,2组3项指标均优于治疗前,差异有统计学意义(P<0.05);而观察组在FMA-UE和SS-QOL评分均高于对照组,在MAS评分低于对照组,差异均有统计学意义(P<0.05)。在实验室检查,治疗前2组S100β、NO、CGRP比较均无统计学意义(P>0.05);干预4周后,2组S100β、NO、CGRP水平均优于治疗前,差异有统计学意义(P<0.05);而观察组在S100β低于对照组,在NO、CGRP高于对照组,差异均有统计学意义(P<0.05)。结论:动针静灸法联合自制上肢训练器可以改善偏瘫患者上肢运动功能、降低肌张力,改善实验室指标,值得进一步推广。

动静结合按揉天宗穴治疗颈型颈椎病的临床疗效

目的:观察动静结合按揉天宗穴治疗颈型颈椎病的疗效。方法:选取开封市中医院2020年6月至2022年6月就诊的60例颈型颈椎病患者,随机分为对照组与观察组,每组30例。对照组患者采用传统推拿手法治疗,观察组患者在传统推拿手法治疗后予以动静结合按揉天宗穴治疗,比较两组患者治疗前后视觉模拟评分法(VAS)评分、颈椎功能障碍指数(NDI)、治疗效果和预后情况。结果:治疗后,两组患者VAS评分均降低,且观察组患者VAS评分均低于对照组,差异具有统计学意义(P<0.05);治疗后,两组患者NDI评分均降低,且观察组患者NDI评分均低于对照组,差异具有统计学意义(P<0.05);观察组患者总有效率高于对照组,差异具有统计学意义(P<0.05)。结论:动静结合法按揉天宗穴可有效缓解患者疼痛症状,改善生活质量,达到颈型颈椎病快速康复的目的。

小庄煤矿冲击地压分源解危措施及效果分析

针对冲击地压难以精准防治的问题,结合动静组合叠加理论,开展了分源监测,提出了冲击地压危险源层次化监测和分源解危措施,即对煤岩破断之后所萌生的动载荷监测工作,需要借助微震法对全矿井实施监测。同时借助地音法对重点工作面实行监测,借助应力在线监测的方法以及钻屑法抽样监测的方法,实现局部危险区域内的煤体静载荷全面监测。基于检测结果,制定了针对掘进工作面迎头及顶煤的冲击地压解危方案并在现场进行了实施。结果表明:采掘扰动是诱发冲击地压发生的重要因素,采用冲击地压解危方案后,钻屑平均值分别由卸压前的2.44、2.26 kg/m降低至1.98、1.87 kg/m,起到了明显的卸压效果,为合理防治冲击地压提供了思路。

“Second quantitative characterization”and its application in fractured-vuggy carbonate reservoirs

The Ordovician fracture-vug carbonate reservoirs of Tarim Basin,are featured by developed vugs,caves and fractures.The strong heterogeneity results in huge uncertainty when these reservoirs are quantitatively characterized using merely static seismic data.The effective quantitative characterization of the reservoirs has been an urgent problem to be solved.This study creatively proposes the"second quantitative characterization"technique with the combination of dynamic and static data based on the primary static quantitative characterization and fully considering lots of key influence factors when conducting characterization.In this technique,dynamic analysis methods such as well testing,production rate transient analysis,dynamic reserve evaluation and dynamic connectivity evaluation are used to get understandings on this kind of reservoir.These understandings are used as statistical parameters to constrain the inversion of seismic wave impedance to improve the relationship between wave impedance and porosity and determine the fracture-vug morphology,calculate dynamic reserves,and then a more accurate fracture-vugmodel can be selected and used to calculate the oil-water contact inversely based on the results of"second quantitative characterization".This method can lower the uncertainties in the primary quantitative characterization of fracture-vug reservoirs,enhance the accuracy of characterization results significantly,and has achieved good application results in the fracture-vug carbonate reservoirs of Tarim Basin.

缝洞型油藏原始油水界面刻画新方法——以哈拉哈塘油田为例

哈拉哈塘油田奥陶系发育孔、洞、缝储集体,该储集体是由不同压力系统和不同油水关系的缝洞单元在空间上相互叠加形成的复杂油气藏,具有多压力系统、多油水关系、多开发动态特征并存的特点。错综复杂的油水关系加大了开发难度,导致钻井成功率较低。同时,由于该类油藏的特殊性,储层存在大量放空漏失段,传统的直接预测法或监测手段识别油水界面分布及变化规律难度较大、可靠性低。为此,笔者创新性地采用缝洞型碳酸盐岩油藏不确定性地质建模技术和油藏产量不稳定分析法分别计算缝洞体静态体积、动态油体积和水体积,在动、静态储集体体积一致的基础上,逐渐调整模型油水界面,实现静态模型法刻画油、水体积与动态评价结果一致,从而确定该井原始油水界面,由井点及面推至全区,利用地质规律及生产、钻井测试等分析结果综合修正原始油水界面位置。新方法为缝洞型油藏预测原始油水界面、预留避水高度提供了新思路,也为油田进一步调整开发措施奠定基础,后期可通过加密井网、侧钻注气等措施挖潜。

基于道家养生思想的中国武术养生文化研究

道家养生思想深刻影响了习武者的思维方式、价值取向与行为实践,为中国武术养生文化的发生发展提供了理论支撑和智力支持。采用学科交叉研究思路,运用历史分析、逻辑演绎等研究方法,深刻阐释道家养生思想的主要内涵及其文化特质,并以之为理论支撑,系统剖析中国武术养生文化的理论内涵、练养方法、时代价值。研究认为,道家“静”“动”“志”“顺”“节”“德”等养生思想,推动了中国武术守静养神文化特色的生成、以动养形炼养方法的丰富、内外兼修锻炼形式的践行、天人合一实现方式的塑造、寡欲戒劳养生理念的调摄、修德益寿养生实践的规制,为中国武术养生文化提供了理论源泉与实践指引。新时代,道家养生思想视域下中国武术养生文化的创造性转化与创新性发展,亟须把握文化强国、体育强国与健康中国建设的时代机遇,构建富有中国文化精神的中国武术养生体系。同时,可坚守中华文化立场,推动文化自信自强,助力新时代中国特色社会主义文化发展与完善,为全面建设社会主义文化强国提供有力支撑。