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Some contributions to mechanical behaviors of lacustrine deposit in Bogota, Colombia 预览
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作者 Bernardo Caicedo Cristhian Mendoza +1 位作者 Arcesio Lizcano Fernando Lopez-Caballero 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第4期837-849,共13页
This paper presents the mechanical behaviors of the lacustrine deposit,a representative soil in Bogota,Colombia.Initially,the physical characterization of the deposit is performed via laboratory tests (grain size dist... This paper presents the mechanical behaviors of the lacustrine deposit,a representative soil in Bogota,Colombia.Initially,the physical characterization of the deposit is performed via laboratory tests (grain size distribution,scanning electron microscopy,Atterberg limits and water content).This characterization intends to explain the special characteristics of the mechanical behaviors of this soil.Then,various triaxial tests are carried out with controlled loading path,strain rate change,relaxation,extensile stress,and cyclic loading.The test results reveal the shape of the yield curve for Bogotá soil (in a natural state),and also show that an increasing effect of the strain rate depends on the liquid limit.This effect is also preserved with extensile stresses (which are poorly studied in soil mechanics).Finally,other effects,such as the loss of structure in the reconstituted samples and the effect of shear modulus at low strains,are studied for Bogota soil. 展开更多
关键词 Cyclic TRIAXIAL tests TRIAXIAL compression test TIME-DEPENDENT response LACUSTRINE soils Soil COMPRESSIBILITY Yield CURVE
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基于三轴漏磁检测的管道缺陷量化方法 预览
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作者 杨亮 徐春风 +4 位作者 宋云鹏 诸海博 王宇楠 郭晓婷 宋华东 《管道技术与设备》 CAS 2019年第4期29-31,共3页
文中主要介绍了一种基于三轴漏磁检测技术的管道缺陷几何特征量化方法——灰度图像法。利用三轴漏磁信号绘制的缺陷轮廓灰度图能够清晰直观地对缺陷几何形状进行显示,并便于直接读出缺陷轮廓信息。对两个不同大小缺陷进行灰度图显示,结... 文中主要介绍了一种基于三轴漏磁检测技术的管道缺陷几何特征量化方法——灰度图像法。利用三轴漏磁信号绘制的缺陷轮廓灰度图能够清晰直观地对缺陷几何形状进行显示,并便于直接读出缺陷轮廓信息。对两个不同大小缺陷进行灰度图显示,结果表明:大面积缺陷较小面积缺陷灰度图像轮廓清晰度高;灰度图像的缺陷轮廓轴向方向准确度较高,而周向方向存在增量误差,且误差程度随缺陷面积减小而增大。 展开更多
关键词 管道检测 三轴 漏磁 数字传感 灰度图 缺陷量化
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New shakedown criterion and permanent deformation properties of unbound granular materials 预览
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作者 Ali Alnedawi Kali Prasad Nepal Riyadh Al-Ameri 《现代交通学报:英文版》 2019年第2期108-119,共12页
Unbound granular material specifications for road pavements in Australia are primarily based on physical material specification rather than mechanical characterisation. This simplified approach does not reflect the ac... Unbound granular material specifications for road pavements in Australia are primarily based on physical material specification rather than mechanical characterisation. This simplified approach does not reflect the actual material performance under repeated dynamic traffic loads. There is a little information available on the influence of the local crushed rock properties and compacted layer properties on permanent deformation (PD). This study aims to characterise the local unbound granular materials in Victoria according to their PD behaviour under repeated loads and to develop a suitable shakedown criterion that could describe the PD of the tested materials to simplify the flexible pavement design. Repeated-load triaxial tests were conducted over several samples with a range of moisture contents, gradations, densities, and stress conditions. The laboratory test results showed that PD behaviour was influenced by several factors. In addition, the tested subbase-specified unbound granular materials reflect high PD resistance that is almost equivalent to basequality unbound granular materials. This may indicate that current requirements for the subbase-quality unbound granular materials are over-prescribe. Moreover, as the existing shakedown criterion was not applicable for the multi-stage repeated-load triaxial test and the local tested materials, a new shakedown criterion and new boundaries are proposed based on the PD behaviour. In the proposed criterion, the shakedown ranges are identified based on the curve angle of the PD vs. logarithm of the number of loading cycles, and this new criterion was validated using several materials from existing literature. The local tested base and subbase materials can be assigned as Range A when PD\1%, Range B when 1%\PD\3%, and Range C when PD[3%. The proposed criterion could provide a useful and quick approach to assess the PD of the unbound granular materials with both single and multistages of stresses. 展开更多
关键词 Flexible PAVEMENT Unbound GRANULAR materials Repeated load TRIAXIAL test PERMANENT deformation SHAKEDOWN theory
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Rock mechanics for design of Brisbane tunnels and implications of recent thinking in relation to rock mass strength 预览
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作者 L.B.McQueen A.Purwodihardjo S.V.L.Barrett 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第3期676-683,共8页
This paper explores the potential implications of recent thinking in relation to rock mass strength for future tunnelling projects in Brisbane,Australia,particularly as they are constructed within deep horizons where ... This paper explores the potential implications of recent thinking in relation to rock mass strength for future tunnelling projects in Brisbane,Australia,particularly as they are constructed within deep horizons where the in situ stress magnitudes is larger.Rock mass failure mechanisms for the current tunnels in Brisbane are generally discontinuity controlled and the potential for stress-induced failure is relatively rare.For the road tunnels which have been constructed in Brisbane over the last 12 years,the strength of the more massive rock masses for continuum analysis has been estimated by the application of the Hoek-Brown(H-B)failure criterion using the geological strength index(GSI)to determine the H-B parameters mb,s and a.Over the last few years,alternative approaches to estimating rock mass strength for‘massive to moderately jointed hard rock masses’have been proposed by others,which are built on the work completed by E.Hoek and E.T.Brown in this area over their joint careers.This paper explores one of these alternative approaches to estimating rock mass strength for one of the geological units(the Brisbane Tuff),which is often encountered in tunnelling projects in Brisbane.The potential implications of these strength forecasts for future tunnelling projects are discussed along with the additional work which will need to be undertaken to confirm the applicability of such alternative strength criteria for this rock mass. 展开更多
关键词 Rock mass strength Hoek-Brown(H-B)failure criterion Triaxial testing BRITTLE FAILURE BRISBANE TUFF
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Shear behavior of ultrafine magnetite tailings subjected to freeze-thaw cycles 预览
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作者 Chong Wei Derek B.Apel Yunhai Zhang 《矿业科学技术学报:英文版》 CSCD 2019年第4期609-616,共8页
To study the shear behavior of the ultrafine magnetite tailings subjected to freeze-thaw cycles,unconsolidated-undrained shear tests were conducted on ultrafine-grained tailings that were subjected to 1-11 cycles of f... To study the shear behavior of the ultrafine magnetite tailings subjected to freeze-thaw cycles,unconsolidated-undrained shear tests were conducted on ultrafine-grained tailings that were subjected to 1-11 cycles of freeze-thaw and defined as a type of clayey silt under confining pressures of 100,200,and 300 kPa.Taking the number of freeze-thaw cycles,cooling temperature,initial dry density,and moisture content as the four main influencing factors of shear behavior of the tailings samples,the shear stress-strain curve,compression modulus,failure strength,cohesion,and internal friction angle were measured.The results show that the freeze-thaw cycle has an obvious weakening effect on the shear behavior of the tailings material,and the shear mechanical parameters are affected by a combination of confining pressure,freeze-thaw cycle condition,and initial physical-mechanical properties of the tailings samples.Through the microstructural analysis of the tailings samples subjected to freeze-thaw cycles,it shows that the freeze-thaw cycle mainly affects the porosity,bound water,and arrangement of the tailings particles.Subsequently,the macroscopic changes in shear strength indexes emerge,and then the stability of the tailings dam will decrease. 展开更多
关键词 Ultrafine magnetite tailings(UMT) Freeze-thaw cycle Shear behavior Triaxial shear test
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Numerical solutions of rotational normal modes of a triaxial two-layered anelastic Earth
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作者 Wenbin Shen Zhuo Yang +1 位作者 Zhiliang Guo Wenying Zhang 《大地测量与地球动力学:英文版》 2019年第2期118-129,共12页
The Earth’s rotational normal modes depend on Earth model used, including the layer structures,principal inertia moments of different layers and the compliances. This study focuses on providing numerical solution of ... The Earth’s rotational normal modes depend on Earth model used, including the layer structures,principal inertia moments of different layers and the compliances. This study focuses on providing numerical solution of the rotational normal modes of a triaxial two-layered anelastic Earth model without external forces but with considering the complex forms of compliances and the electromagnetic coupling between the core and mantle. Based on the present knowledge of the Chandler wobble(CW) and Free Core Nutation(FCN), we provide a set of complete compliances which could be used for reference in further investigations. There are eight rotational normal mode solutions, four of which might exist in nature. However, in reality only two of these four solutions correspond to the present motion status of the prograde CW and the retrograde FCN. On one hand, our numerical calculations show that the periods and quality factors(Qs) of CW and FCN are respectively 434.90 and 429.86 mean solar days(d) and 76.56 and 23988.47 under frequency-dependent assumption, and the triaxiality prolongs CW about 0.01 d and has hardly effect on FCN. On the other hand, we analyze the sensibility of compliances and electromagnetic coupling parameter on the periods and Qs of CW and FCN and find the sensitive parameters with respect to them. 展开更多
关键词 EARTH ROTATION TRIAXIAL two-layered anelastic EARTH model Compliances ROTATIONAL normal MODES Numerical solution
冲击载荷下三轴煤体动力学分析及损伤本构方程 预览
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作者 王恩元 孔祥国 +3 位作者 何学秋 冯俊军 鞠云强 李金铎 《煤炭学报》 EI CAS CSCD 北大核心 2019年第7期2049-2056,共8页
为研究冲击载荷下三轴煤体的动力学特征,建立了三轴分离式霍普金森压杆(SHPB)试验系统,开展了轴向静载、围压和冲击载荷随机组合的动态冲击试验,研究了三轴煤体在冲击载荷下的动力学特性。实验结果表明:冲击载荷下三轴煤体动态应力应变... 为研究冲击载荷下三轴煤体的动力学特征,建立了三轴分离式霍普金森压杆(SHPB)试验系统,开展了轴向静载、围压和冲击载荷随机组合的动态冲击试验,研究了三轴煤体在冲击载荷下的动力学特性。实验结果表明:冲击载荷下三轴煤体动态应力应变曲线无压密阶段,轴向预静载有助于使煤体原生裂隙闭合,初始加载就表现出完整弹性体的特征;当应力达到峰值强度的60%~85%阶段时,应力应变曲线呈现“跃进”现象,可能与碳在晶体微破裂中的作用有关;当应力超过煤体动态强度,试样破坏,应力降低。冲击载荷下三轴煤体动态强度和破坏应变与平均应变率高度线性相关,应变率效应明显,应变率效应使得不同轴向静载、围压和冲击载荷因素对煤体动态强度和破坏应变的影响具有可比性。基于岩石力学强度理论和统计损伤理论,建立了冲击载荷下三轴煤体动态损伤本构模型,该模型综合考虑了轴向静载、围压和冲击载荷等因素,明确地反映了3种因素对煤体动力学特征的影响,轴向静载会劣化煤体,造成动态强度降低,围压和冲击载荷有助于提高煤体的动态强度,理论模型反映的特征与试验结果相吻合,并通过建立的本构模型和试验应力应变数据拟合了理论应力应变曲线,其与试验应力应变曲线基本重合,且应变率越高,一致性越好。 展开更多
关键词 冲击载荷 动力学特征 煤体 三轴 损伤
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Phenomenological behavior of rock salt:On the influence of laboratory conditions on the dilatancy onset 预览
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作者 A.Rouabhi P.Labaune +2 位作者 M.Tijani N.Gatelier G.Hevin 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第4期723-738,共16页
Recently,stress-based dilatancy criteria have become essential tools to design underground facilities in salt formations such as gas storage caverns.However,these criteria can depend critically on the volumetric strai... Recently,stress-based dilatancy criteria have become essential tools to design underground facilities in salt formations such as gas storage caverns.However,these criteria can depend critically on the volumetric strain measurements used to deduce the dilatancy onset.Results from conventional triaxial compression tests can show different volumetric behavior depending on the loading conditions,as well as on the measurement techniques.In order to obtain a quantitative understanding of this problem,an experimental program was carried out and the testing procedure was investigated numerically under homogeneous and heterogeneous stress states.The experimental results showed that the deviatoric stress corresponding to the dilatancy onset was significantly dependent on the measurement techniques.With a heterogeneous stress state,the simulation results revealed that the strain measurements at different scales (referred to as local,hybrid or global) can provide different volumetric results with moderate to significant deviations from the idealized behavior,and hence different onsets of dilatancy.They also proved that,under low confinement,tensile stresses can take place within the compressed specimen,leading to a great deviation of the dilatancy onset from the idealized behavior.From both experimental and numerical investigations,the difference in sensitivity to the measurement techniques between the deviatoric and the volumetric behaviors is explained by the relatively small values of the volumetric strain.The non-ideal laboratory conditions have more impact on this strain than on the deviatoric one.These findings can have implications for the interpretation of the dilatancy behavior of rock salt,and hence on the geomechanical design aspects in salt formations. 展开更多
关键词 Rock salt TRIAXIAL tests DILATANCY ONSET End RESTRAINT VISCOPLASTICITY
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Effect of vertical stress rest period on deformation behaviour of unbound granular materials:Experimental and numerical investigations 预览
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作者 Ali Alnedawi Kali Prasad Nepal +1 位作者 Riyadh Al-Ameri Mohanad Alabdullah 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第1期172-180,共9页
Repeated load triaxial test is used to assess the deformation behaviour of unbound granular materials(UGMs)in flexible road pavements.Repeated load pulse characteristics(i.e.shape,loading period and rest period)are th... Repeated load triaxial test is used to assess the deformation behaviour of unbound granular materials(UGMs)in flexible road pavements.Repeated load pulse characteristics(i.e.shape,loading period and rest period)are the stress configurations used in the experimental set-up to simulate the passing axle loads.Some researchers and standard testing protocols suggest a rest period of varying durations after a loading phase.A thorough review of existing literature and practises has revealed that there is no agreement about the effect of the rest period of vertical stress pulse on the deformation behaviour of the UGMs.Therefore,the main objective of this study is to investigate the effect of repeated stress rest period on the deformation behaviour of UGMs experimentally.Experiments are conducted,both with and without rest period,using basalt and granite crushed rocks from Victoria,Australia.Furthermore,in order to gain insight into the effect of the rest period,finite element modelling is also developed.Both the experimental and modelling results show that the rest period has a noticeable effect on both resilient and permanent deformation behaviours of UGMs.It is,therefore,recommended to take extra precautions while adopting a particular standard testing protocol and to supplement the results by additional tests with different loading configurations. 展开更多
关键词 Flexible PAVEMENT Unbound GRANULAR materials(UGMs) Repeated load TRIAXIAL test Resilient MODULUS PERMANENT deformation Finite element modelling
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Influence of stress and high temperature treatment on the permeability evolution behavior of sandstone 预览
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作者 Peng Xu Sheng-Qi Yang 《力学学报:英文版》 SCIE EI CAS CSCD 2019年第2期419-432,共14页
Permeability is an important property of rock in gas and oil exploration engineering, environment temperature and geo-stress have great influence on it. This paper aims to analyze the influence of thermal treatment on... Permeability is an important property of rock in gas and oil exploration engineering, environment temperature and geo-stress have great influence on it. This paper aims to analyze the influence of thermal treatment on the permeability of sandstone under triaxial compression. Based on the gas seepage tests on a sandstone specimen after different thermal treatment temperatures with different gas pressures, hydrostatic stresses and deviatoric stresses, the thermal effect on physical property of sandstone is firstly analyzed. The results show that the mass of the sandstone specimen decreases with the increase of temperature, some spalling damage and tensile crack occur on the lateral surface of the specimen at 400℃. According to the seepage test results with various gas pressures, an exponential relationship has been found between the permeability coefficient and temperature. The permeability coefficient is approximately 100 times as large as the initial value when the temperature increases from 20℃ to 800℃. The permeability evolution of the heated sandstone under hydrostatic and deviatoric compression has also been analyzed. A simplified double pore texture model is proposed which can well describe the permeability evolution of sandstone under compression with hydrostatic stress and deviatoric stress, it can be helpful to estimate the permeability of thermal treated sandstone under elastic triaxial compression. 展开更多
关键词 SANDSTONE TRIAXIAL compression PERMEABILITY Thermal treatment Double PORE TEXTURE model
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A simple permanent deformation model of rockfill materials 预览
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作者 De-gao Zou Jing-mao Liu +2 位作者 Xian-jing Kong Chen-guang Zhou Qing-po Yang 《水科学与水工程:英文版》 EI CAS CSCD 2018年第4期302-309,共8页
Existing experimental results have shown that using a semi-log linear relationship between the permanent volumetric strain and cyclic number underestimates the volumetric deformation of rockfill materials with a large... Existing experimental results have shown that using a semi-log linear relationship between the permanent volumetric strain and cyclic number underestimates the volumetric deformation of rockfill materials with a large cyclic number, and that the error increases with the confining pressure. The existing permanent deformation models are not suitable for the seismic safety analysis of high dams during strong earthquakes. In this study, a series of large-scale triaxial cyclic loading tests of rockfill materials were performed, and a new permanent deformation model of rockfill materials was developed and validated with three kinds of rockfill materials. The results show that the proposed model can properly reflect the general features of the permanent deformation of rockfill materials. The main features of the model are as follows:(1) relations between the cyclic number and permanent volumetric/shear strain are described by hyperbolic functions, which can avoid underestimating the volumetric deformation occurring during strong earthquakes;(2) the model can capture the effect of the mean effective stress on the permanent volumetric strain, with greater confining pressure correlating to greater permanent volumetric deformation, and the permanent volumetric strain under low confining pressure near the dam crest can be well represented;and (3) the model can reflect the effect of the consolidation stress ratio on the permanent shear strain. 展开更多
关键词 ROCKFILL materials PERMANENT DEFORMATION TRIAXIAL test CYCLIC loading CONSOLIDATION stress ratio
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Mechanical properties of gas hydrate-bearing sediments during hydrate dissociation 预览
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作者 X.H.Zhang D.S.Luo +2 位作者 X.B.Lu L.L.Liu C.L.Liu 《力学学报:英文版》 SCIE EI CAS CSCD 2018年第2期266-274,共9页
The changes in the mechanical properties of gas hydrate-bearing sediments(GHBS)induced by gas hydrate(GH)dissociation are essential to the evaluation of GH exploration and stratum instabilities.Previous studies presen... The changes in the mechanical properties of gas hydrate-bearing sediments(GHBS)induced by gas hydrate(GH)dissociation are essential to the evaluation of GH exploration and stratum instabilities.Previous studies present substantial mechanical data and constitutive models for GHBS at a given GH saturation under the non-dissociated condition.In this paper,GHBS was formed by the gas saturated method,GH was dissociated by depressurization until theGHsaturation reached different dissociation degrees.The stress–strain curves were measured using triaxial tests at a same pore gas pressure and different confining pressures.The results show that the shear strength decreases progressively by 30%–90%of the initial value with GH dissociation,and the modulus decreases by 50%–75%.Simplified relationships for the modulus,cohesion,and internal friction angle with GH dissociated saturation were presented. 展开更多
关键词 Gas hydrate-bearing SEDIMENTS Dissociation MECHANICAL properties Shear strength Triaxial test
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三轴不同加载路径下花岗岩Kaiser效应试验研究 预览
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作者 魏筱乐 宦秉炼 +1 位作者 余贤斌 鲁会军 《中国钨业》 2018年第1期45-48,70共5页
为了解不同加载路径三轴预加载对花岗岩Kaiser效应的影响,先对花岗岩进行三轴预加载试验,再进行单轴压缩试验并采集声发射信息,据此分析预加载对声发射特征的影响。研究表明,预加载时轴压和围压的加载顺序及大小对于Kaiser效应有明显的... 为了解不同加载路径三轴预加载对花岗岩Kaiser效应的影响,先对花岗岩进行三轴预加载试验,再进行单轴压缩试验并采集声发射信息,据此分析预加载对声发射特征的影响。研究表明,预加载时轴压和围压的加载顺序及大小对于Kaiser效应有明显的影响。先加围压可以抑制轴向加载损伤的产生,导致Kaiser点提前。先加轴压,后加较小围压对Kaiser点影响可忽略;后加围压如果较大,则会加大花岗岩所受损伤,导致Kaiser点延后。如果轴压围压同步加载,则会大幅度影响Kaiser点的准确性,甚至完全观察不到预加载的影响。该试验研究方法和结果可为岩石Kaiser效应理论研究提供参考。 展开更多
关键词 岩石力学 声发射 KAISER效应 加载路径 预加载 三轴
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Triaxial strength behaviour of rockmass satisfying Modified Mohr-Coulomb and Generalized Hoek-Brown criteria 预览
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作者 Saurav Rukhaiyar Narendra Kumar Samadhiya 《矿业科学技术学报:英文版》 CSCD 2018年第6期901-915,共15页
The triaxial strength of twenty rockmass types was predicted using two non-linear triaxial strength criteria for rockmass i.e.Modified Mohr-Coulomb(MMC)criterion and Generalized Hoek-Brown(GHB)criterion.Four different... The triaxial strength of twenty rockmass types was predicted using two non-linear triaxial strength criteria for rockmass i.e.Modified Mohr-Coulomb(MMC)criterion and Generalized Hoek-Brown(GHB)criterion.Four different rockmass classification systems were used for the calculation of MMC criterion parameters while only GSI classification system has been used for calculation of GHB parameters.The representative value of the uniaxial compressive strength and elastic modulus of rockmass have been estimated using probabilistic approach.A hypothetical case of an unsupported tunnel has been analyzed considering both MMC and GHB criteria.The analysis was done using the convergence-confinement method with two different approaches.The first approach predicts the tunnel response using GHB criterion directly.The second approach predicts the tunnel response using equivalent Mohr-Coulomb parameters obtained by linearization of triaxial data points obtained from MMC and GHB criteria.The tunnel response has been estimated in terms of radius of plastic zone,tunnel convergence and tunnel convergence strain.For very poor rockmasses the tunnel response predicted by MMC criterion is less than that predicted by GHB criterion.For poor and fair rockmass,the tunnel response estimated considering both the criteria are comparable except for few cases.Squeezing condition in rockmass has been also evaluated. 展开更多
关键词 TRIAXIAL STRENGTH MODIFIED MOHR-COULOMB CRITERION Generalised HOEK-BROWN CRITERION Convergence-confinement method
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软岩卸荷流变及非线性本构模型研究 预览
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作者 穆红文 赵栋 +2 位作者 刘亚峰 胡瑞民 刘力波 《甘肃科学学报》 2017年第6期95-99,共5页
为模拟隧洞开挖过程中围岩应力调整所产生的问题,对贵州某电站引水隧洞泥质粉砂岩进行了恒定轴压下的围压卸荷试验。结果表明:在一定偏应力的影响下,试样表现出了明显的流变力学特性;降低围压时,随着偏应力增大,试样轴向变形速率每级... 为模拟隧洞开挖过程中围岩应力调整所产生的问题,对贵州某电站引水隧洞泥质粉砂岩进行了恒定轴压下的围压卸荷试验。结果表明:在一定偏应力的影响下,试样表现出了明显的流变力学特性;降低围压时,随着偏应力增大,试样轴向变形速率每级增长幅度在11%~34%之间,横向变形速率每级增长幅度在8%~27%之间,表明围压卸荷能够减弱对岩石内部颗粒滑移的束缚,从而增大变形速率。在三维Burgers模型的基础上,通过引入流变加速阶段的损伤修正系数,建立了软岩非线性阶段的本构模型,并与试验结果进行拟合分析,发现该模型能够很好地反映流变非线性阶段。 展开更多
关键词 泥质粉砂岩 卸荷流变 三轴 BURGERS模型 损伤
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不同泥质含量砂岩三轴渗透试验研究 预览 被引量:2
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作者 周祥 《水文地质工程地质》 CAS CSCD 北大核心 2017年第1期84-90,共7页
为探讨三向应力状态下不同泥质胶结物含量砂岩渗透力学性能的异同,对泥质含量分别为4%、15%、24%、31%的4组不同泥质含量砂岩进行了三轴压缩渗透试验。试验结果表明:砂岩的强度和弹性模量随着泥质胶结物的增加呈幂函数型减小,随围压的... 为探讨三向应力状态下不同泥质胶结物含量砂岩渗透力学性能的异同,对泥质含量分别为4%、15%、24%、31%的4组不同泥质含量砂岩进行了三轴压缩渗透试验。试验结果表明:砂岩的强度和弹性模量随着泥质胶结物的增加呈幂函数型减小,随围压的升高而增大,内摩擦角和黏聚力随含泥量增加而逐渐减小;相同围压和泥质含量下,渗透性随加载应力的增大呈先减小后增大、再略微减小的整体趋势,渗透系数在峰值应力附近达到最大值;相同围压和偏应力下,渗透系数随泥质胶结物含量的升高而呈线性减小;同等泥质含量和偏应力下,砂岩的渗透性随围压的升高呈对数型函数减小。基于试验结果,分析得到了一种综合考虑围压、孔隙度以及泥质含量影响的砂岩综合渗透模型,并通过理论与试验数据对比分析验证了模型的合理性。 展开更多
关键词 砂岩 泥质含量 三轴 渗透 模型
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含杂质盐岩三轴蠕变特性试验研究 预览 被引量:2
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作者 吴池 刘建锋 +4 位作者 周志威 徐慧宁 吴斐 卓越 王璐 《四川大学学报:工程科学版》 CSCD 北大核心 2017年第S2期165-172,共8页
针对杂质盐岩蠕变力学特性问题,利用大型程控流变仪,对两种不同杂质盐岩进行分级加载下的三轴蠕变试验。试验结果表明:围压和杂质含量不同,盐岩破坏形态及力学参数均有差异。围压小于临界围压,盐岩呈剪切破坏;围压大于临界围压,盐岩呈... 针对杂质盐岩蠕变力学特性问题,利用大型程控流变仪,对两种不同杂质盐岩进行分级加载下的三轴蠕变试验。试验结果表明:围压和杂质含量不同,盐岩破坏形态及力学参数均有差异。围压小于临界围压,盐岩呈剪切破坏;围压大于临界围压,盐岩呈大变形鼓状破坏。围压和杂质含量一定,岩盐稳态速率随偏应力增加呈指数增长;偏应力和杂质含量一定,蠕变速率随围压增大而降低,长期强度有所增大;偏应力和围压一定,低杂质(ω=2.1%)盐岩稳态蠕变速率高于高杂质(ω=46.8%)盐岩。体积变形经历了压密期-平静期-扩容期3个阶段,高杂质盐岩体积应变低于低杂质盐岩。将不溶物杂质含量与应力敏感性常数n的关系同分数阶蠕变本构方程进行耦合,建立耦合杂质的盐岩分数阶非定常蠕变模型;将理论模型与试验数据对比分析证实了该模型的合理性。 展开更多
关键词 三轴 蠕变 杂质 盐岩 体积变形 分数阶本构模型
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Laboratory Study of Geotextiles Performance on Reinforced Sandy Soil
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作者 Brahim Abdelkader Arab Ahmed +1 位作者 Belkhatir Mostefa Shahrour Isam 《地球科学学刊:英文版》 SCIE CAS CSCD 2016年第6期1060-1070,共11页
这份报纸论述为对压力紧张和增强的沙的土壤的容量的变化行为的 geotextiles 的影响的调查进行的 triaxial 测试的结果。测试在松开的沙的土壤上被执行。试验性的节目在与 geotextiles 层(Ng ) 和限制压力的不同价值增强的样品上包括排... 这份报纸论述为对压力紧张和增强的沙的土壤的容量的变化行为的 geotextiles 的影响的调查进行的 triaxial 测试的结果。测试在松开的沙的土壤上被执行。试验性的节目在与 geotextiles 层(Ng ) 和限制压力的不同价值增强的样品上包括排干的压缩测试(<sub > c </sub>) 。准备的二个方法被使用:让 pluviation (AP )(MT ) 并且潮湿的捣实通风。测试结果证明 geotextiles 在增强的沙在压力 deviator (q) 和体积收缩导致伪线性的增加。准备的方法显著地影响 shear 力量;空气 pluviation 方法准备并且动员了 deviator 压力的样品比那些由潮湿的捣实准备方法的显著地高。Geotextiles 限制增强的沙的土壤的膨胀并且因而,收缩增加。有增加的动员磨擦角度增加层数,有增加起始的限制的减少迫使。潮湿的捣实准备的样品比那些坐飞机准备 pluviation 方法的介绍显著地低的动员磨擦角度。为空气 pluviation 方法,在 <sub>1</sub>=1% 的正割模量和 5% 减少与增加 geotextile 层准备的样品;潮湿的捣实方法,在 <sub>1</sub>=1% 的正割模量和 5% 增加与增加准备的那些限制压力的 geotextile 层沙数。从 10% 轴的紧张,正割模量与增加 geotextile 层的包括增加。 展开更多
关键词 沙质土壤 实验项目 土工布 织物性能 制备方法 土工织物 样品制备 钢筋
带上下反压功能的土体渗流试验系统的研制 预览
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作者 路东辉 商首兴 田萍 《工程与试验》 2016年第2期59-61,共3页
本机是一种可对土体在三轴应力作用下的渗流性能进行测试的试验机,由轴向压力加载系统、围压室、围压加载系统、上反压加载系统、下反压加载系统、轴向测控系统、围压测控系统、孔隙水反压测控系统和数据处理系统等几部分组成。本机的... 本机是一种可对土体在三轴应力作用下的渗流性能进行测试的试验机,由轴向压力加载系统、围压室、围压加载系统、上反压加载系统、下反压加载系统、轴向测控系统、围压测控系统、孔隙水反压测控系统和数据处理系统等几部分组成。本机的最大特点是可对试样施加上下不同的压力并进行渗流量测量。本机可对试样进行恒载荷或恒变形控制,还可对试样施加特定频率和振幅变化的动态载荷。 展开更多
关键词 土体 三轴 渗流
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Triaxial high-g accelerometer of microelectro mechanical systems 预览
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作者 HE Xu ZHANG Zhen-hai +1 位作者 LI Ke-jie LIN Ran 《北京理工大学学报:英文版》 EI CAS 2015年第4期427-431,共5页
A triaxial high-g accelerometer of microelectro mechanical systems(MEMS)has a structure of multi-chips combination and will be used in aerospace field,civil and military fields.The accelerometer can measure the accele... A triaxial high-g accelerometer of microelectro mechanical systems(MEMS)has a structure of multi-chips combination and will be used in aerospace field,civil and military fields.The accelerometer can measure the acceleration of the carrier.The chips with island-membrane structures on its back surfaces are made by MEMS dry processing.The chip is reasonable and can work well under high impact load;Titanium alloy base is also stronger in high shock environment,these are proved by finite element analysis.Finally,the MEMS combined triaxial high-g accelerometer is validated by high impact calibration experiments in order to get a key performance index,including range,sensitivity and transverse sensitivity and so on.These data can satisfy the need of design but some problems remain,these will be eliminated by improvement of the processing technology and materials. 展开更多
关键词 自动化元件 发送器 分配器 配电器
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