检索结果-南通市图书馆

FRAGILITY ANALYSIS OF STRUCTURES WITH TUNED VISCOUS MASS DAMPERS UNDER NEAR-FAULT PULSE-TYPE GROUND MOTIONS

Gongcheng Lixue/engineering Mechanics 2024年第6期41卷 212-223页

作者： Zhang, Li-Li Han, Jian-Ping Li, Da-Wei Ma, Lian-Sheng key laboratory of disaster prevention and mitigation in civil engineering of Gansu province Lanzhou University of Technology Lanzhou 730050 China Western engineering Research Center of disaster mitigation in civil engineering of Ministry of Education Lanzhou University of Technology Lanzhou 730050 China School of Science Lanzhou University of Technology Lanzhou 730050 China

A series of incremental dynamic analysis (IDA) were conducted on 6-storey 3-bay steel frames subjected to selected near-fault pulse-type ground motions. The frames are installed with tuned viscous mass dampers (TVMDs), viscous dampers (VDs) or no dampers, respectively. The seismic fragility curves corresponding to different damage states were obtained based on IDA results. The comparison of the seismic fragility of structures between TVMDs and VDs shows that the reliabilities of the main structure against different damage states are improved significantly with the addition of inerter element. Given the same damping ratio, the structure with TVMDs exhibits excellent improvement in seismic resistant capacity and low damage failure probability of the main structure against different damage states. With the increase of mass ratio, the improvement in structural performance due to TVMD does not decrease with the increase of nonlinearity. And the seismic mitigation effect of the structure is stable during the whole process including elasticity, elastic-plasticity and collapse. Furthermore, three sets of near-fault ground motion records with different pulse periods were selected for time history analysis, and the seismic mitigation effect of TVMD under near-fault pulse-type ground motions was discussed. The results show that under the near-fault pulse-type ground motions, TVMD does not always achieve the damping enhancement of the damping element, and the performance of the damper is related to the characteristics of ground motions. Compared with the enhanced structure with VDs and the original benchmark model, TVMD system reduces the input energy of the main structure when T1/Tp≥2. However, it has lower capacity of energy dissipation and the effect of damping enhancement could not be realized. When T1/Tp © 2024 Tsinghua University. All rights reserved.

关键词： Energy dissipation

来源：博看期刊评论

在线全文

博看期刊

学校读者我要写书评

暂无评论

Development and application of novel high‐efficiency composite ultrafine cement grouts for roadway in fractured surrounding rocks

引用

Deep Underground Science and engineering 2024年第1期3卷 53-69页

作者： Maolin Tian Shaojie Chen Lijun Han Hongtian Xiao shandong key laboratory of civil engineering disaster prevention and mitigation Shandong University of Science and TechnologyQingdaoChina College of civil engineering and Architecture Shandong University of Science and TechnologyQingdaoChina College of Energy and Mining engineering Shandong University of Science and TechnologyQingdaoChina State key laboratory for Geomechanics and Deep Underground engineering China University of Mining and TechnologyXuzhouChina

The fractured surrounding rocks of roadways pose major challenges to safe mining.Grouting has often been used to reinforce the surrounding rocks to mitigate the safety risks associated with fractured rocks.The aim of this study is to develop highly efficient composite ultrafine cement(CUC)grouts to reinforce the roadway in fractured surrounding rocks.The materials used are ultrafine cement(UC),ultrafine fly ash(UF),ultrafine slag(US),and additives(superplasticizer[SUP],aluminate ultrafine expansion agent[AUA],gypsum,and retarder).The fluidity,bleeding,shrinkage,setting time,chemical composition,microstructure,degree of hydration,and mechanical property of grouting materials were evaluated in this study.Also,a suitable and effective CUC grout mixture was used to reinforce the roadway in the fractured surrounding rock.The results have shown that the addition of UF and US reduces the plastic viscosity of CUC,and the best fluidity can be obtained by adding 40%UF and 10%US.Since UC and UF particles are small,the pozzolanic effect of UF promotes the hydration reaction,which is conductive to the stability of CUC grouts.In addition,fine particles of UC,UF,and US can effectively fill the pores,while the volumetric expansion of AUA and gypsum decreases the pores and thus affects the microstructure of the solidified grout.The compressive test results have shown that the addition of specific amounts of UF and US can ameliorate the mechanical properties of CUC grouts.Finally,the CUC22‐8 grout was used to reinforce the No.20322 belt roadway.The results of numerical simulation and field monitoring have indicated that grouting can efficaciously reinforce the surrounding rock of the roadway.In this research,high‐performance CUC grouts were developed for surrounding rock reinforcement of underground engineering by utilizing UC and some additives.

关键词： broken surrounding rock composite ultrafine cement(CUC)grouts grouting material grouting performance grouting reinforcement

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

Layered metastructure containing freely-designed local resonators for wave attenuation

引用

Defence Technology（防务技术） 2024年第2期32卷 23-31页

作者： Yu Li Huguang He Jiang Feng Hailong Chen Fengnian Jin Hualin Fan State key laboratory for disaster prevention&mitigation of Explosion&Impact Army Engineering University of PLANanjing 210007China Rocket Force University of engineering Xi'an 710025China Henan International Joint laboratory of Dynamics of Impact and disaster of engineering Structures Department of Civil EngineeringNanyang Institute of TechnologyNanyang 473004China Guangxi key laboratory of disaster prevention and engineering Safety and Key Laboratory of Disaster Prevention and Structural Safety of Ministry of EducationCollege of Civil Engineering and ArchitectureGuangxi UniversityNanning 530004China Research Center of Lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Mechanical StructuresNanjing University of Aeronautics and AstronauticsNanjing 210016China

Combining periodic layered structure with three-dimensional cylindrical local resonators,a hybrid metastructure with improved wave isolation ability was designed and investigated through theoretical and numerical approaches.The metastructure is composed of periodic rubber layers and concrete layers embedded with three-dimensional resonators,which can be freely designed with multi local resonant frequencies to attenuate vibrations at required frequencies and widen the attenuation bandgap.The metastructure can also effectively attenuate seismic responses.Compared with layered rubber-based structures,the metastructure has more excellent wave attenuation effects with greater attenuation and wider bandgap.

关键词： Layered metastructure Local resonator Wave attenuation

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

Accurate Analysis of Multi-Mode Interferometric Optical Fiber Sensor

引用

Photonic Sensors 2024年第1期14卷 48-58页

作者： Lijun LI Congying JIA Qian MA Tianzong XU College of Electronic and Information engineering Shandong University of Science and TechnologyQingdao 266590.China State key laboratory of Mining disaster prevention and Control Co-Founded by shandong province and the Ministry of Science and Technology Qingdao 266590China

In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and experimentally.The suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,respectively.This method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis methods.At the same time,this method is also beneficial to solve the repetitive problem of such sensors.

关键词： Window function FFT optical fiber interferometric sensor analysis method

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Three-dimensional limit variation analysis on the ultimate pullout capacity of the anchor cables based on the Hoek-Brown failure criterion

引用

Journal of Mountain Science 2024年第3期21卷 1036-1047页

作者： ZUO Shi ZHAO Lianheng HU Shihong College of civil engineering Changsha UniversityChangsha 410022China Hunan Provincial key laboratory for disaster prevention and mitigation of Rail Transit engineering Structure Key Laboratory of Heavy-Haul Railway Engineering StructureMinistry of EducationCentral South UniversityChangsha 410075China College of civil engineering Central South UniversityChangsha 410075China

Only simplified two-dimensional model and a single failure mode are adopted to calculate the ultimate pullout capacity(UPC)of anchor cables in most previous research.This study focuses on a more comprehensive combination failure mode that consists of bond failure of an anchorage body and failure of an anchored rock mass.The three-dimensional ultimate pullout capacity of the anchor cables is calculated based on the Hoek-Brown failure criterion and variation analysis method.The numerical solution for the curvilinear function in fracture plane is obtained based on the finite difference theory,which more accurately reflects the failure state of the anchor cable,as opposed to that being assumed in advance.The results reveal that relying solely on a single failure mode for UPC calculations has limitations,as changes in parameter values not only directly impact the UPC value but also can alter the failure model and thus the calculation method.

关键词： Anchor cable Ultimate pullout capacity(UPC) Failure model Variation analysis Hoek-Brown failure criterion

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

Stability analysis of intermittently jointed rock slopes based on the stepped failure mode

引用

Journal of Mountain Science 2024年第3期21卷 1019-1035页

作者： LI Dejian FU Junwen LI Hekai CHENG Xiao ZHAO Lianheng ZHANG Yingbin PENG Xinyan School of civil engineering Southwest Jiaotong UniversityChengdu 610031China Institute for disaster Management and Reconstruction College of Architecture&EnvironmentSichuan UniversityChengdu 610065China School of civil engineering Key Laboratory of Heavy-Haul Railway Engineering StructureMinistry of EducationHunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering StructureCentral South UniversityChangsha 410075China

In practical engineering,due to the noncontinuity characteristics of joints in rock slopes,in addition to plane failure,stepped sliding failure may occur for intermittently jointed rock slopes.Especially for intermittently bedding jointed rock slopes,the correlation and difference in strength parameters between joints and rock bridges,along with the various failure modes and intermittency of rock bridges,contribute to the complexity of stepped failure modes and the unpredictability of failure regions.Based on the upper-bound limit analysis method and multi-sliders step-path failure mode,considering the shear and tensile failure of rock bridges and the weakened relationship between the strength parameters of rock bridges and jointed surfaces,by introducing the modified M-C failure criterion and the formula for calculating the energy consumption of tensile failure of rock bridges,two failure mechanisms are constructed to obtain the safety factor(F_(s))of intermittently jointed rock slopes.The sequential quadratic programming method is used to obtain the optimal upper-bound solution for F_(s).The influence of multiple key parameters(slope height H,horizontal distance L,Slope angleβ,shear strength parameters of the rock bridgeφr and cr,Dimensionless parameter u,weakening coefficients of the internal friction angle and cohesion between the rock bridges and joint surfaces Kφand Kc)on the stability analysis of intermittently jointed rock slopes under the shear failure mode of rock bridges as well as under the tensile failure mode is also explored.The reliability of the failure mechanisms is verified by comparative analysis with theoretical results,numerical results,and landslide cases,and the variation rules of F_(s)with each key parameter are obtained.The results show that F_(s) varies linearly withφr and cr of the rock bridge and with K_(φ)and K_(c),whereas F_(s)changes nonlinearly with H and L.In particular,with the increase in Kφand Kc,Fs increases by approximately 52.78%and 171.02%on average,respectively.For rock b

关键词： Jointed rock slopes Stepped sliding failure Weakening characteristics Modified M‒C failure criterion

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

真三轴应力状态下含预制裂隙煤系泥岩强度与破坏特征

引用

Journal of Central South University 2024年第1期31卷 196-209页

作者：李文帅蒋邦友李兆霖王连国杨旭旭 shandong key laboratory of civil engineering disaster prevention and mitigation Shandong University of Science and TechnologyQingdao 266590China College of Energy and Mining engineering Shandong University of Science and TechnologyQingdao 266590China State key laboratory of Mining Response and disaster prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China State key laboratory for Geomechanics and Deep Underground engineering China University of Mining and TechnologyXuzhou 221116China

对一系列含有预制缺陷的煤系泥岩试样进行了真三轴试验(TTT),即中间主应力(σ_(2))平行于预制缺陷的试样(TTT-Flaw-2)和最小主应力平行于预制缺陷的试样(σ_(3))(TTT-Flaw-3),研究σ_(2)加载方向和预制缺陷的位置对试样强度和破坏模式... 详细信息

对一系列含有预制缺陷的煤系泥岩试样进行了真三轴试验(TTT),即中间主应力(σ_(2))平行于预制缺陷的试样(TTT-Flaw-2)和最小主应力平行于预制缺陷的试样(σ_(3))(TTT-Flaw-3),研究σ_(2)加载方向和预制缺陷的位置对试样强度和破坏模式的影响。结果表明,完整试样和含预制缺陷试样的峰值强度随σ_(2)的增加先增大后减小,符合Mogi-Coulomb准则。在相同的应力条件下,完整试样的强度明显大于含预制缺陷试样的强度,且TTT-Flaw-2试样的强度最低。CT扫描结果显示,在常规三轴试验条件下,含预制缺陷试样中的裂纹并不总是沿着预制缺陷尖端形成,而是随机分布在试样内部;在TTT-Flaw-2试样中,反翼型裂纹从预制缺陷尖端附近开始形成,最终主要分布在σ_(2)加载方向上;而在TTT-Flaw-3试样中,在σ_(2)加载方向上出现剪切裂纹,而在σ_(3)加载方向上几乎没有观察到反翼型裂纹。

关键词：真三轴试验煤系泥岩预制缺陷强度破裂模式

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

Ballistic performance of spaced multi-ply soft fabrics: Experimental and numerical investigation

引用

Defence Technology（防务技术） 2024年第4期34卷 143-155页

作者： Zhongwei Zhang Xiaoning Yang Yuan Lin Ziming Xiong Yuhang Xiang Yi Zhou Mingyang Wang State key laboratory of Explosion&Impact and disaster prevention&mitigation Army Engineering University of PLANanjing 210007China School of Mechanical engineering Nanjing University of Science&TechnologyNanjing 210007China State key laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200China Postdoctoral Station of civil engineering Army Engineering University of PLANanjing 210007China

It has been reported that the ply gap influences the ballistic resistance of spaced multi-ply fabric systems,but its working mechanism was not well-understood. This paper reports the experimental and numerical approaches and results of an investigation on the mechanisms that enable the improved ballistic performance of spaced multi-ply systems. Penetration tests were performed over a range of impact velocities ranging from 200 m/s to 400 m/s. The results confirmed that the ply gap is beneficial to the energy absorption capability of the systems. This is because the front plies tend to absorb more energy when they are not immediately constrained by the rear plies. During a ballistic event, the gap relieves the reflection of the compressive pulse, prolonging the projectile engagement time with the front plies;on the other hand, the rear plies become increasingly less active in dissipating energy as the gap increases.When the gap is sufficiently widened to avoid any interference between the plies before the failure of the front ply, the responses of the whole system no longer vary. It was also found that the ballistic performance of the spaced systems is influenced by ply thickness, impact velocity, and the stacking order of the ply gap.

关键词： Energy absorption capability Ply gap Ballistic performance The front ply The rear ply

来源：

维普期刊数据库博看期刊

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

Effect of trigger system on experimental dispersion characteristics of active surface wave testing

引用

Earthquake engineering and engineering Vibration 2024年第2期23卷 311-318页

作者： Lin Shibin Jeramy C.Ashlock Zhu Liming Qin Zexiang Li Bo Zhu Xingji Zhai Changhai State key laboratory of Precision Blasting Jianghan UniversityWuhan 430056China Hubei key laboratory of Blasting engineering Jianghan UniversityWuhan 430056China Department of civil Construction&Environmental EngineeringIowa State UniversityAmesIA 50010USA Wuhan Airport Road Development Co. Ltd.Wuhan 430065China School of civil and Environmental engineering Harbin Institute of TechnologyShenzhen 518055China key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of TechnologyHarbin 150090China key Lab of Smart prevention and mitigation of civil engineering disaster of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin 150090China

A trigger system is typically employed in active seismic testing to trigger and synchronize multichannel surface wave data acquisition.The effect of the trigger system on the dispersion image of surface waves is empirically known to be negligible,however,theoretical explanation regarding the effect of the trigger system is insufficient.This study systematically examines the theory for surface wave dispersion analysis and proves that the effect of the trigger system on a dispersion image is negligible via a solid theoretical explanation.Subsequently,based on the new theoretical explanation,an alternative method that uses only the relative phase difference between sensors to extract dispersion characteristics with better conceptual clarity is proposed.Two active surface wave testing cases are considered to validate the theory and method.The results indicate that(1)an accurate trigger system is not necessary for surface wave data acquisition,and(2)it is unnecessary to assume that the impact point is the generation point of the surface waves for the experimental dispersion analysis.

关键词： site investigation surface waves data acquisition dispersion

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

Energy mechanism of bolt supporting effect to fissured rock under static and dynamic loads in deep coal mines

引用

International Journal of Mining Science and Technology 2024年第3期34卷 371-384页

作者： Deyuan Fan Xuesheng Liu Yunliang Tan Xuebin Li Shenglong Yang College of Energy and Mining engineering Shandong University of Science and TechnologyQingdao 266590China State key laboratory of Mining disaster prevention and Control Shandong University of Science and TechnologyQingdao 266590China National Energy Group Ningxia Coal Industry Co. Ltd.Yinchuan 753001China

The stability control of fissured rock is difficult,especially under static and dynamic loads in deep coal mines.In this paper,the dynamic mechanical properties,strain rate evolution and energy dissipation of fissured and anchored rocks were respectively obtained by SHPB tests.It was found that bolt can provide supporting efficiency-improving effect for fissured rock against dynamic disturbance,and this effect increased quadratically with decrease in anchoring angles.Then,the energy dissipation mechanism of anchored rock was obtained by slipping model.Furthermore,bolt energy-absorbing mechanism by instantaneous tensile-shear deformation was expressed based on material mechanics,which was the larger the anchoring angle,the smaller the energy absorption,and the less the contribution to supporting efficiency improvement.On this basis,the functional relationship between energy dissipation of anchored rock and energy absorption of bolt was established.Taking the coal-gangue separation system of Longgu coal mine as an example,the optimal anchoring angle can be determined as 57.5°–67.5°.Field monitoring showed fissured rock with the optimal anchoring angle,can not only effectively control the deformation,but also fully exert the energy-absorbing and efficiency-improving effect of bolt itself.This study provides guidance to the stability control and supporting design for deep engineering under the same or similar conditions.

关键词： Static and dynamic loads Anchored rock Energy absorption Anchoring angle engineering verification

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：