检索结果-南通市图书馆

shear behavior and off-fault damage of saw-cut smooth and tension-induced rough joints in granite

Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1216-1230页

作者： Fanzhen Meng Feili Wang Louis Ngai Yuen Wong Jie Song Muzi Li Chuanqing Zhang Liming Zhang College of Science Qingdao University of TechnologyQingdao266033China Department of Earth Sciences The University of Hong KongPokfulamHong KongChina State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Cooperative Innovation Center of Engineering Construction and Safety Shandong Peninsula Blue Economic Zone Qingdao266033China

The damage of rock joints or fractures upon shear includes the surface damage occurring at the contact asperities and the damage beneath the shear surface within the host *** latter is commonly known as off-fault damage and has been much less investigated than the surface *** main contribution of this study is to compare the results of direct shear tests conducted on saw-cut planar joints and tension-induced rough granite joints under normal stresses ranging from 1 MPa to 50 *** shear-induced off-fault damages are quantified and compared with the optical microscope *** results clearly show that the planar joints slip stably under all the normal stresses except under 50 MPa,where some local fractures and regular stick-slip occur towards the end of the *** post-peak stress drop and stick-slip occur for all the rough *** residual shear strength envelopes for the rough joints and the peak shear strength envelope for the planar joints almost *** root mean square(RMS)of asperity height for the rough joints decreases while it increases for the planar joint after shear,and a larger normal stress usually leads to a more significant decrease or increase in ***,the extent of off-fault damage(or damage zone)increases with normal stress for both planar and rough joints,and it is restricted to a very thin layer with limited micro-cracks beneath the planar joint *** comparison,the thickness of the damage zone for the rough joints is about an order of magnitude larger than that of the planar joints,and the coalesced micro-cracks are generally inclined to the shear direction with acute *** findings obtained in this study contribute to a better understanding on the frictional behavior and damage characteristics of rock joints or fractures with different roughness.

关键词： Planar joint Rough joint shear behavior Off-fault damage Micro-cracks

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

shear behavior of ultra-high-performance concrete beams prestressed with external carbon fiber-reinforced polymer tendons

引用

Frontiers of Structural and Civil Engineering 2021年第6期15卷 1426-1440页

作者： Li JIA Zhi FANG Maurizio GUADAGNINI Kypros PILAKOUTAS Zhengmeng HUANG College of Civil Engineering Hunan UniversityChangsha 410082China Key Laboratory for Wind and Bridge Engineering of Hunan Province Changsha 410082China Department of Civil and Structural Engineering The University of SheffieldSheffield S13JDUK Guizhou Transportation Planning Survey and Design Academe Co.Ltd. Guiyang 550003China

The ultra-high-performance concrete(UHPC)and fiber-reinforced polymer(FRP)are well-accepted high-performance materials in the field of civil *** combination of these advanced materials could contribute to improvement of structural performance and corrosion ***,only limited studies are available for shear behavior of UHPC beams reinforced with FRP bars,and few suggestions exist for prediction methods for shear *** paper presents an experimental investigation on the shear behavior of UHPC beams reinforced with glass FRP(GFRP)and prestressed with external carbon FRP(CFRP)*** failure mode of all specimens with various shear span to depth ratios from 1.7 to 4.5 was diagonal tension *** shear span to depth ratio had a significant influence on the shear capacity,and the effective prestressing stress affected the crack *** experimental results were then applied to evaluate the equations given in different codes/recommendations for FRPreinforced concrete structures or UHPC *** comparison results indicate that NF P 18-710 and JSCE CES82 could appropriately estimate shear capacity of the slender specimens with a shear span to depth ratio of ***,a new shear design equation was proposed to take into account the effect of the shear span to depth ratio and the steel fiber content on shear capacity.

关键词： beam external prestressing ultra-high-performance concrete fiber-reinforced polymers shear behavior design equation

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

shear behavior of AZ80 Mg alloy using experimental, theoretical and numerical techniques

引用

Transactions of Nonferrous Metals Society of China 2018年第12期28卷 2427-2439页

作者： A.BANAFSHI F.FERESHTEH-SANIEE Department of Mechanical Engineering Faculty of Engineering Bu-Ali Sina University

The shear punch test(SPT)is a suitable experiment for characterizing the shear behavior of various materials,especially where there are volume *** the present investigation,the relations among various parameters such as clearance,die diameter and sample thickness,and the yield and ultimate shear strengths of AZ80Mg alloy were ***,based on the Mohr-Coulomb theory,relatively optimum conditions were introduced for the shear punch *** this regard,a range of2%-10%is found to be suitable for the clearance/sheet thickness *** provide a simple shear stress state during a shear punch test,it is also necessary to select the die diameter/sheet thickness ratio between2:1and10:*** on the predictions of the Mohr-Coulomb theory,it is better to conduct a room-temperature shear punch test with a sample thickness of0.5mm,a clearance of25μm and a die diameter ***,the mean conversion factors to gain the tensile and compressive yield strengths of the cast AZ80from its shear one are found to be1.70and3.09,respectively.

关键词： shear punch test Mohr-Coulomb theory shear behavior AZ80 Mg alloy numerical simulation

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

shear behavior of Novel Prestressed Concrete Beam Subjected to Monotonic and Cyclic Loading

引用

Transactions of Tianjin University 2014年第4期20卷 257-265页

作者：余芳姚大立贾金青吴锋 State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology School of Architecture and Civil Engineering Shenyang University of Technology School of Civil and Safety Engineering Dalian Jiaotong University

Prestressed steel ultrahigh-strength reinforced concrete(PSURC) beam is a new type of prestressed concrete beam, which not only has a considerable compressive strength attributed to the ultrahigh strength concrete, but also ensures a certain degree of ductility at failure due to the existence of structural steel. Five of these beams were monotonically tested until shear failure to investigate the static shear performance including the failure pattern, loaddeflection behavior, shear capacity, shear crack width and shear ductility. The experimental results show that these beams have superior shear capacity, crack control ability and shear ductility. To study the shear performance under repeated overloading, seven PSURC beams were loaded in cyclic test simultaneously. The overall shear performance of cycled beams is similar to that of uncycled beams at low load level but different at high load level. The shear capacity and crack control ability of cycled beams at high load level are reduced, whereas the shear ductility is improved. In addition, the influences of variables including the degree of prestress, stirrup ratio and load level on the shear performance of both uncycled and cycled beams were also discussed and compared, respectively.

关键词： prestressed concrete beam structural steel ultrahigh strength concrete shear behavior cyclic loading

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

A numerical analysis of the shear behavior of granular soil with fines

引用

Particuology 2015年第4期13卷 160-172页

作者： Beibing Dai Jun Yang Xiaodong Luo Research Centre of Geotechnical Engineering and Information Technology Sun Yat-sen University Department of Civil Engineering The University of Hong Kong

shear behavior of granular soil with fines is investigated using the discrete element method （DEM） and particle arrangements and inter-particle contacts during shear are examined. The DEM simulation reveals that fine particles play a vital role in the overall response of granular soil to shearing. The occurrence of liquefaction and temporary reduction of strength is ascribed mainly to the loss of support from the fine particle contacts （S-S） and fine particle-to-large particle contacts （S-L） as a consequence of the removal of fine particles from the load-carrying skeleton. The dilative strain-hardening response following the strain-softening response is associated with the migration of fine particles back into the load-carrying skeleton, which is thought to enhance the stiffness of the soil skeleton. During shear, the unit normal vector of the large particle-to-large particle （L-L） contact has the strongest fabric anisotropy, and the S-S contact unit normal vector possesses the weakest anisotropy, suggesting that the large particles play a dominant role in carrying the shear load. It is also found that, during shear, fine particles are prone to rolling at contacts while the large particles are prone to sliding, mainly at the S-L and L-L contacts.

关键词： Granular soil Fine particle shear behavior Discrete element method Fabric anisotropy Coordination number

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

Loading direction-dependent shear behavior at different temperatures of single-layer chiral graphene sheets

引用

Acta Mechanica Sinica 2018年第3期34卷 542-548页

作者： Yang Zhao Shuhong Dong Peishi Yu Junhua Zhao Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology Jiangnan University

The loading direction-dependent shear behavior of single-layer chiral graphene sheets at different temperatures is studied by molecular dynamics （MD） simulations. Our results show that the shear properties （such as shear stress-strain curves, buckling strains, and failure strains） of chiral graphene sheets strongly depend on the loading direction due to the structural asymmetry. The maximum values of both the critical buckling shear strain and the failure strain under positive shear deformation can be around 1.4 times higher than those under negative shear deformation. For a given chiral graphene sheet, both its failure strain and failure stress decrease with increasing temperature. In particular, the amplitude to wavelength ratio of wrinkles for different chiral graphene sheets under shear deformation using present MD simulations agrees well with that from the existing theory. These findings provide physical insights into the origins of the loading direction-dependent shear behavior of chiral graphene sheets and their potential applications in nanodevices.

关键词： Chiral grapheme shear behavior Buckling strain Wrinkles

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

Effect of a filter cake on shear behavior of sand-concrete pile interface

引用

Journal of Central South University 2022年第6期29卷 2019-2032页

作者： CHEN Chen LENG Wu-ming YANG Qi DONG Jun-li XU Fang RUAN Bo Department of Civil Engineering Central South UniversityChangsha 410075China MOE Key Laboratory of Engineering Structures of Heavy Haul Railway Changsha 410075China Hunan Tieyuan Civil Engineering Testing Co. Ltd.Changsha 410075China

A filter cake is often formed between soil and concrete during casting concrete in the ground,such as constructions of diaphragm walls and bored *** present study aims to investigate the effect of the filter cake on the shear behavior of the sand-concrete pile interface.A series of sand-concrete interface direct shear tests were performed with a large-direct shear apparatus while considering different roughness(I=0,10,20 and 30 mm)and filter cake thickness(Δh=0,5 and 10 mm).For a smooth interface without a filter cake,the shear stress-horizontal displacement curves showed a“softening”*** peak shear strength and friction angle decreased exponentially with increasing theΔ***,for a rough interface withΔh=5 or 10 mm,the shear stress-horizontal displacement curves presented a“hardening”*** peak strength,as well as friction angle,decreased linearly with increasing theΔ***,a critical roughness I_(cr)of 10 mm was observed in the tests without a filter *** interface shear strength initially increased with increasing I but gradually decreased when the I exceeded I_(cr).In addition,the filter cake could reduce the roughness sensitivity on shear strength.

关键词： filter cake sand-concrete pile interface large scale direct shear test shear behavior critical roughness

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

Degradation of joint surface morphology, shear behavior and closure characteristics during cyclic loading

引用

Journal of Central South University 2018年第3期25卷 653-661页

作者： FAN Wen-chen CAO Ping LONG Long School of Resources and Safety Engineering Central South UniversityChangsha 410083China Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal Mines Hunan University of Science and TechnologyXiangtan 411201China

In order to investigate the failure mechanism of rock joint,a series of laboratory tests including cyclic direct shear tests under constant normal load(CNL)conditions were *** parameters of the rock joint surface were precisely calculated by means of a three-dimensional laser scanning *** test results were analyzed to investigate the shear behavior and normal displacement behavior of rock joints under CNL *** of rock joint surface during cyclic shear tests was also *** comparison results of the height parameters and the hybrid parameters of the joint surface during cyclic tests show that the degradation of the surface mostly happens in the first shear and the constant normal loads imposed on the joints have significant promotion effects on the morphology *** cyclic shear tests,joints surfaces evolve from rough state to smooth state but keep an overall *** of rock joints degrades with the degradation of joint surface and the increase of normal *** closure deformation of joint is larger than that of the intact rock,and the normal stiffness increases with the increase of shearing times.

关键词： rock joint constant normal load condition surface morphology degradation shear behavior joint closure characteristic

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

Macro and meso characteristics evolution on shear behavior of rock joints

引用

Journal of Central South University 2015年第8期22卷 3087-3096页

作者：李凯辉曹平张科钟涌芳 School of Resources and Safety Engineering Central South University School of Civil Environmental and Mining Engineering the University of Western Australia

Direct shear tests were conducted on the rock joints under constant normal load(CNL), while the acoustic emission(AE) signals generated during shear tests were monitored with PAC Micro-II system. Before and after shearing, the surfaces of rock joints were measured by the Talysurf CLI 2000. By correlating the AE events with the shear stress-shear displacement curve, one can observe four periods of the whole course of shearing of rock joints. By the contrast of AE location and actual damage zone, it is elucidated that the AE event is related to the morphology of the joint. With the increase of shearing times, the shear behavior of rock joints gradually presents from the response of brittle behavior to that of ductile behavior. By combining the results of topography measurement, four morphological parameters of joint surface, S p(the maximum height of joint surface), N(number of islands), A(projection area) and V(volume of joint) were introduced, which decrease with shearing. Both the joint roughness coefficient(JRC) and joint matching coefficient(JMC) drop with shearing, and the shear strength of rock joints can be predicted by the JRC-JMC model. It establishes the relationship between micro-topography and macroscopic strength, which have the same change rule with shearing.

关键词： rock joint shear behavior surface morphology acoustic emission joint roughness coefficient (JRC) joint matchingcoefficient (JMC)

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

Effect of rock joint roughness on its cyclic shear behavior

引用

Journal of Rock Mechanics and Geotechnical Engineering 2017年第6期9卷 1071-1084页

作者： S.M.Mahdi Niktabar K.Seshagiri Rao Amit Kumar Shrivastava Department of Civil Engineering Indian Institute of Technology Delhi Department of Civil Engineering Delhi Technology University

Rock joints are often subjected to dynamic loads induced by earthquake and blasting during mining and rock cutting. Hence, cyclic shear load can be induced along the joints and it is important to evaluate the shear behavior of rock joint under this condition. In the present study, synthetic rock joints were prepared with plaster of Paris(Po P). Regular joints were simulated by keeping regular asperity with asperity angles of 15°-15° and 30°-30°, and irregular rock joints which are closer to natural joints were replicated by keeping the asperity angles of 15°-30° and 15°-45°. The sample size and amplitude of roughness were kept the same for both regular and irregular joints which were 298 mm×298 mm×125 mm and 5 mm, respectively. shear test was performed on these joints using a large-scale direct shear testing machine by keeping the frequency and amplitude of shear load under constant cyclic condition with different normal stress values. As expected, the shear strength of rock joints increased with the increases in the asperity angle and normal load during the first cycle of shearing or static load. With the increase of the number of shear cycles, the shear strength decreased for all the asperity angles but the rate of reduction was more in case of high asperity angles. Test results indicated that shear strength of irregular joints was higher than that of regular joints at different cycles of shearing at low normal stress. shearing and degradation of joint asperities on regular joints were the same between loading and unloading, but different for irregular joints. shear strength and joint degradation were more significant on the slope of asperity with higher angles on the irregular joint until two angles of asperities became equal during the cycle of shearing and it started behaving like regular joints for subsequent cycles.

关键词： Cyclic shear test shear behavior shear strength Regular joint Irregular joint Joint dilation Asperity degradation

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：