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Three independent parameters to describe conventional triaxial compressive strength of intact rocks 被引量:11
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作者 Mingqing You 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2010年第4期350-356,共7页
The strengths of 12 rocks cited from literatures increase in a nonlinear way with increasing confining pressure against the Coulomb criterion. The criteria with power forms like the generalized Hoek-Brown criterion ar... The strengths of 12 rocks cited from literatures increase in a nonlinear way with increasing confining pressure against the Coulomb criterion. The criteria with power forms like the generalized Hoek-Brown criterion are not available for describing the strength properties in the whole test range for Indiana limestone, Yamaguchi marble and Vosges sandstone, of which the differential stresses are approximately constant at high confining pressures. The exponential criterion with three parameters fits the test data of those 12 rocks well with a low misfit. The three parameters are independent of the uniaxial compressive strength (UCS), the initial increasing rate of strength with confining pressure, and the limitation of differential stress. 展开更多
关键词 strength criteria criterion parameters exponential criterion intact rocks
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Dynamic strength of rocks and physical nature of rock strength 被引量:6
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作者 Qihu Qian Chengzhi Qi Mingyang Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2009年第1期1-10,共10页
Time-dependence of rock deformation and fracturing is often ignored.However,the consideration of the time-dependence is essential to the study of the deformation and fracturing processes of materials,especially for th... Time-dependence of rock deformation and fracturing is often ignored.However,the consideration of the time-dependence is essential to the study of the deformation and fracturing processes of materials,especially for those subject to strong dynamic loadings.In this paper,we investigate the deformation and fracturing of rocks,its physical origin at the microscopic scale,as well as the mechanisms of the time-dependence of rock strength.Using the thermo-activated and macro-viscous mechanisms,we explained the sensitivity of rock strength to strain rate.These mechanisms dominate the rock strength in different ranges of strain rates.It is also shown that a strain-rate dependent Mohr-Coulomb-type constitutive relationship can be used to describe the influence of strain rate on dynamic rock fragmentation.A relationship between the particle sizes of fractured rocks and the strain rate is also proposed.Several time-dependent fracture criteria are discussed,and their intrinsic relations are discussed.Finally,the application of dynamic strength theories is discussed. 展开更多
关键词 rock dynamics deformation and fracturing TIME-DEPENDENCE dynamic strength criteria of fracturing
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Numerical evaluation of strength and deformability of fractured rocks 被引量:9
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作者 Majid Noorian Bidgoli Zhihong Zhao Lanru Jing 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2013年第6期419-430,共12页
Knowledge of the strength and deformability of fractured rocks is important for design, construction and stability evaluation of slopes, foundations and underground excavations in civil and mining engineering. However... Knowledge of the strength and deformability of fractured rocks is important for design, construction and stability evaluation of slopes, foundations and underground excavations in civil and mining engineering. However, laboratory tests of intact rock samples cannot provide information about the strength and deformation behaviors of fractured rock masses that include many fractures of varying sizes, orientations and locations. On the other hand, large-scale in situ tests of fractured rock masses are economically costly and often not practical in reality at present. Therefore, numerical modeling becomes necessary. Numerical predicting using discrete element methods(DEM) is a suitable approach for such modeling because of their advantages of explicit representations of both fractures system geometry and their constitutive behaviors of fractures, besides that of intact rock matrix. In this study, to generically determine the compressive strength of fractured rock masses, a series of numerical experiments were performed on two-dimensional discrete fracture network models based on the realistic geometrical and mechanical data of fracture systems from feld mapping. We used the UDEC code and a numerical servo-controlled program for controlling the progressive compressive loading process to avoid sudden violent failure of the models. The two loading conditions applied are similar to the standard laboratory testing for intact rock samples in order to check possible differences caused by such loading conditions. Numerical results show that the strength of fractured rocks increases with the increasing confning pressure, and that deformation behavior of fractured rocks follows elasto-plastic model with a trend of strain hardening. The stresses and strains obtained from these numerical experiments were used to ft the well-known Mohr-Coulomb(MC) and Hoek-Brown(H-B) failure criteria, represented by equivalent material properties defning these two criteria. The results show that both criteria can provide fair estimates of the compressive strengths for all tested numerical models. Parameters of the elastic deformability of fractured models during elastic deformation stages were also evaluated, and represented as equivalent Young’s modulus and Poisson’s ratio as functions of lateral confning pressure. It is the frst time that such systematic numerical predicting for strength of fractured rocks was performed considering different loading conditions, with important fndings for different behaviors of fractured rock masses, compared with testing intact rock samples under similar loading conditions. 展开更多
关键词 strength Deformability Fractured rocks Discrete element methods(DEM) Failure criteria
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Basic characteristics and development of yield criteria for geomaterials 被引量:7
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作者 Maohong Yu Gulyun Xia Vladimir A Kolupaev 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2009年第1期71-88,共18页
The yield criteria of geomaterials play a crucial role in studying and designing the strength of materials and structures.The basic characteristics of yield criteria for geomaterials need to be studied under the frame... The yield criteria of geomaterials play a crucial role in studying and designing the strength of materials and structures.The basic characteristics of yield criteria for geomaterials need to be studied under the framework of continuum mechanics.These characteristics include the effects of strength difference(SD) of materials in tension and compression,normal stress,intermediate principal stress,intermediate principal shear stress,hydrostatic stress,twin-shear stresses,and the convexity of yield surface.Most of the proposed yield criteria possess only one or some of these basic characteristics.For example,the Tresca yield criterion considers only single-shear stress effect,and ignores the effect of SD,normal stress,intermediate principal stress,intermediate principal shear stress,hydrostatic stress,and twin-shear stresses.The Mohr-Coulomb yield criterion accounts for the effect of SD,normal stress,single-shear stress and hydrostatic stress,but disregards the effect of intermediate principal stress,intermediate principal shear stress,and twin-shear stresses.The basic characteristics remain to be fully addressed in the development of yield criterion.In this paper,we propose a new yield criterion with three features,that is,newly developed,better than existing criteria and ready for application.It is shown that the proposed criterion performs better than the existing ones and is ready for application.The development of mechanical models for various yield criteria and the applications of the unified strength theory to engineering are also summarized.According to a new tetragonal mechanical model,a tension-cut condition is added to the unified strength theory.The unified strength theory is extended to the tension-tension region. 展开更多
关键词 yield criteria failure criteria unified strength theory tension cut-off orthogonal octahedral element geomaterial beauty of a strength theory
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Prediction of the Biaxial Failure Strength of Composite Laminates with Unit Cell Analytic Model
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作者 赵琳 ZHANG Boming QING Xinlin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第5期923-927,共5页
A new method to predict the ultimate strength of fiber reinforced composites under arbitrary load condition is introduced. The micromechanics strength theory is used to perform the final failure prediction of composit... A new method to predict the ultimate strength of fiber reinforced composites under arbitrary load condition is introduced. The micromechanics strength theory is used to perform the final failure prediction of composite laminates. The theory is based on unit cell analytic model which can provide the ply composite material properties by only using the constituent fiber and matrix properties and the laminate geometric parameters without knowing any experimental information of the laminates. To show that this method is suitable for predicting the strength of composite laminates, the micromechanics strength theory is ranked by comparing it with all the micro-level and the best two macro-level theories chosen from the World Wide Failure Exercise. The results show that this method can be used for predicting strength of any composite laminates and provide a direct reference for composite optimum design. 展开更多
关键词 COMPOSITES strength failure criteria unit cell analytic model
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Application of strength reduction method to dynamic anti-sliding stability analysis of high gravity dam with complex dam foundation 被引量:3
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作者 Deng-hong CHEN Cheng-bin DU 《Water Science and Engineering》 EI CAS 2011年第2期212-224,共13页
Considering that there are some limitations in analyzing the anti-sliding seismic stability of dam-foundation systems with the traditional pseudo-static method and response spectrum method, the dynamic strength reduct... Considering that there are some limitations in analyzing the anti-sliding seismic stability of dam-foundation systems with the traditional pseudo-static method and response spectrum method, the dynamic strength reduction method was used to study the deep anti-sliding stability of a high gravity dam with a complex dam foundation in response to strong earthquake-induced ground action. Based on static anti-sliding stability analysis of the dam foundation undertaken by decreasing the shear strength parameters of the rock mass in equal proportion, the seismic time history analysis was carried out. The proposed instability criterion for the dynamic strength reduction method was that the peak values of dynamic displacements and plastic strain energy change suddenly with the increase of the strength reduction factor. The elasto-plastic behavior of the dam foundation was idealized using the Drucker-Prager yield criterion based on the associated flow rule assumption. The result of elasto-plastic time history analysis of an overflow dam monolith based on the dynamic strength reduction method was compared with that of the dynamic linear elastic analysis, and the reliability of elasto-plastic time history analysis was confirmed. The results also show that the safety factors of the dam-foundation system in the static and dynamic cases are 3.25 and 3.0, respectively, and that the F2 fault has a significant influence on the anti-sliding stability of the high gravity dam. It is also concluded that the proposed instability criterion for the dynamic strength reduction method is feasible. 展开更多
关键词 dynamic anti-sliding stability complex dam foundation dynamic strength reduction method instability criteria elasto-plastie model dynamic time history analysis gravity dam
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Strength Prediction of Cruciform Specimen Under Biaxial Loading
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作者 Weng Jingmeng Wen Weidong Xu Ying 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2017年第3期286-295,共10页
In order to achieve a better understanding of failure behavior of cruciform specimen under different biaxial loading conditions,a three-dimensional finite element model is established with solid and interface elements... In order to achieve a better understanding of failure behavior of cruciform specimen under different biaxial loading conditions,a three-dimensional finite element model is established with solid and interface elements.Maximum stress criterion,two Hashin-type criteria and the new proposed criteria are used to predict the strength of plain woven textile composites when biaxial loading ratio equals 1.Compared with experimental data,only the new proposed criteria can reach reasonable results.The applicability of the new proposed criteria is also verified by predicting the tensile and compressive strength of cruciform specimen under different biaxial loading ratios.Moreover,the introduction of interface element makes it more intuitive to recognize delamination failure.The shape of the predicted delamination failure region in the interface layer is similar to that of the failure region in neighboring entity layers,but the area of delamination failure region is a little larger. 展开更多
关键词 woven compressive tensile intuitive verified recognize specimen Prediction neighboring loaded
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基于混凝土水化热效应的高地温水工隧洞衬砌结构温控防裂研究
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作者 李飞飞 姜海波 +1 位作者 项鹏飞 魏纲 《隧道建设(中英文)》 CSCD 北大核心 2024年第6期1262-1273,共12页
为分析高地温水工隧洞衬砌结构温度应力特性,基于拉普拉斯变换推导出衬砌结构瞬态温度场的解析解,并借助弹性抗力法推导出衬砌结构的弹性温度应力分量。依托新疆布伦口水电站监测数据对衬砌结构瞬态温度场及应力场进行计算分析,并采用... 为分析高地温水工隧洞衬砌结构温度应力特性,基于拉普拉斯变换推导出衬砌结构瞬态温度场的解析解,并借助弹性抗力法推导出衬砌结构的弹性温度应力分量。依托新疆布伦口水电站监测数据对衬砌结构瞬态温度场及应力场进行计算分析,并采用抗拉强度准则和裂缝尖端强度因子对衬砌结构破坏进行分析,提出合理的温控防裂措施。结果表明:1)衬砌温度场前期整体温度迅速上升,在第7天左右达到最大值,其中衬砌内壁温度可达到37℃,外壁温度可达到56℃。2)衬砌结构外墙环向应力可达到2.2 MPa,体现为拉应力状态;径向应力可达到2.7 MPa,呈现为压应力状态。3)衬砌结构强度的破坏主要受温度及结构本身稳定性2方面影响,可通过采用低热水泥、控制混凝土的入模温度以及严格监控施工过程来提高衬砌的稳定性。其中,采用低热水泥可降低衬砌结构的温升值,混凝土的最终水化热每降低50 k J/kg,衬砌结构内外壁的温差可降低1.85℃左右;适当提高入模温度可缩短水化热的放热周期及降低衬砌内外壁温差。 展开更多
关键词 水工隧洞 拉普拉斯变换 弹性抗力法 抗拉强度准则 尖端强度因子 温控防裂
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基于贝叶斯方法的混凝土强度接收准则研究 被引量:1
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作者 蒋利学 郑士举 王卓琳 《结构工程师》 2024年第5期102-113,共12页
以一次计量抽样检验理论为依据,综合平衡生产方风险和使用方风险,并适当考虑保护生产方利益,提出无论对于标准差已知统计方法还是标准差未知统计方法,混凝土强度平均值的评定系数k均应对应于90%的等效保证率(0.9分位值);并以贝叶斯理论... 以一次计量抽样检验理论为依据,综合平衡生产方风险和使用方风险,并适当考虑保护生产方利益,提出无论对于标准差已知统计方法还是标准差未知统计方法,混凝土强度平均值的评定系数k均应对应于90%的等效保证率(0.9分位值);并以贝叶斯理论为依据确定了标准差未知统计方法的抽样方案。样本容量很小时,以平均质量标准差为依据建立了非统计方法的接收准则,并根据一次计数抽样检验理论提出最小值接收准则,并作为平均值接收准则的补充。采用贝叶斯方法,将前一检验周期内的样本和本次抽样样本合并,通过扩大样本容量,提高了标准差已知统计方法接收准则的检验功效;同时采用贝叶斯方法,综合考虑平均质量标准差和实测样本标准差,提高了非统计方法接收准则的检验功效。本文建议的接收准则具有更明确的统计学依据,通过采用统一的等效保证率使各种方法保持了较接近的检验功效,并用贝叶斯方法将各种方法统一于标准差未知统计方法。实例分析表明,本文建议的接收准则总体上略比GB/T 50107—2010严格,但变动幅度在可接受范围;采用合理的先验标准差后,本文建议的贝叶斯改进方法可以得到科学合理的评定结果。 展开更多
关键词 贝叶斯方法 混凝土强度 接收准则 检验功效 标准差
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基于断裂能的混凝土弹塑性损伤本构模型和尺寸效应研究 被引量:2
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作者 江婷 杜效鹄 +2 位作者 沈振中 张宏伟 许峙峰 《水电能源科学》 北大核心 2024年第1期79-83,共5页
为研究混凝土断裂特性与尺寸效应,引入断裂能和等效应变表示混凝土的损伤演化规律,结合混凝土塑性变形特征,提出基于断裂能的混凝土弹塑性损伤本构模型,并建立相应的数值计算模型。为验证数值计算结果的合理性,引入改进的能量尺寸效应... 为研究混凝土断裂特性与尺寸效应,引入断裂能和等效应变表示混凝土的损伤演化规律,结合混凝土塑性变形特征,提出基于断裂能的混凝土弹塑性损伤本构模型,并建立相应的数值计算模型。为验证数值计算结果的合理性,引入改进的能量尺寸效应公式进行对比分析。通过对三点弯曲梁的有限元数值模拟和断裂参数敏感性分析发现,尺寸较小的梁失效时,断裂过程区未扩展至特征长度,限制了能量耗散,从而提高了梁的抗断裂能力,增强了梁的名义强度;随着尺寸增大,失效时的断裂过程区逐渐接近特征长度,梁的名义强度逐渐减小;当断裂过程区达到特征长度后,结构名义强度不再随梁尺寸的增大而减小。 展开更多
关键词 混凝土 能量准则 断裂特性 尺寸效应 结构名义强度 三点弯曲梁
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建筑用金属面绝热夹芯板耐久性试验研究 被引量:1
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作者 徐凯 房跃 +4 位作者 白静国 郭万江 姚正迎 朱长禹 武新航 《新型建筑材料》 2024年第3期91-95,129,共6页
建筑用金属面绝热夹芯板广泛应用于工业与民用建筑的屋面和墙体。现行的国家标准中没有建筑用金属面绝热夹芯板耐久性试验方法及评价指标的要求。根据金属面夹芯板实际用途,选择3种不同芯材的金属面夹芯板,在4种不同环境条件下进行耐久... 建筑用金属面绝热夹芯板广泛应用于工业与民用建筑的屋面和墙体。现行的国家标准中没有建筑用金属面绝热夹芯板耐久性试验方法及评价指标的要求。根据金属面夹芯板实际用途,选择3种不同芯材的金属面夹芯板,在4种不同环境条件下进行耐久性试验,并对芯材的密度、质量吸湿率、导热系数以及金属面夹芯板的粘结强度进行测试。通过对试验数据的分析,找出影响试验数据的主要因素,并对金属面夹芯板耐久性评价指标的确定提出建议。 展开更多
关键词 耐久性试验 环境条件 粘结强度 导热系数 评价指标
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基于强度折减法下不同失稳判据对边坡稳定性的影响
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作者 戴文文 汪兵 《昆明冶金高等专科学校学报》 CAS 2024年第4期9-14,31,共7页
为了充分了解不同失稳判据准则下强度折减法对分析边坡稳定性的影响,解决有关边坡失稳的问题,利用ABAQUS有限元软件平台开展了不同失稳判据准则下有限元强度折减法对分析均质土坡稳定性影响的研究。详细分析了在不同失稳判断准则下,利... 为了充分了解不同失稳判据准则下强度折减法对分析边坡稳定性的影响,解决有关边坡失稳的问题,利用ABAQUS有限元软件平台开展了不同失稳判据准则下有限元强度折减法对分析均质土坡稳定性影响的研究。详细分析了在不同失稳判断准则下,利用强度折减法所得到的边坡安全系数之间存在差异性;并对不同失稳判据下土体强度参数的变化将对边坡稳定性所产生的影响进行了分析。研究结果显示:不同的失稳判据下利用强度折减法所得的安全系数之间存在一定的差异性,但其影响程度由土体强度参数在一定范围内的变化所决定;与此同时,土体粘聚力、内摩擦角和泊松比等参数的变化对于边坡临界状态时内部的塑性区的发展和滑动面的形状还存在一定的影响。 展开更多
关键词 失稳判据 强度折减法 边坡稳定性 安全系数
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永磁同步电动机转子冲片强度分析
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作者 郝玉涛 王亚杰 罗英露 《电工材料》 CAS 2024年第3期9-12,17,共5页
针对永磁同步电动机转子冲片强度分析,应用有限元法仿真计算电机转子冲片强度,建立基于FKM强度准则的冲片局部应力超屈服状态下的静强度评估方法。结果表明,基于线弹性有限元分析的局部应力计算值超屈服后,转子冲片仍具备一定承载能力... 针对永磁同步电动机转子冲片强度分析,应用有限元法仿真计算电机转子冲片强度,建立基于FKM强度准则的冲片局部应力超屈服状态下的静强度评估方法。结果表明,基于线弹性有限元分析的局部应力计算值超屈服后,转子冲片仍具备一定承载能力。基于FKM强度准则的静强度评估方法可有效评估转子冲片局部应力超屈服强度下的安全裕量,为永磁电机冲片强度设计提供参考。 展开更多
关键词 转子冲片 强度评估 局部应力 FKM准则
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动车组受电弓布置准则及连接强度研究
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作者 赵刚 贾亚丽 《智慧轨道交通》 2024年第5期6-9,共4页
受电弓作为动车组高压供电系统中的关键部件,其布置方式将影响弓网关系协调、受流稳定和减阻降噪等性能,动车组高速运行时,受电弓与支持绝缘子的连接强度将承受到严峻的考验。文章对动车组受电弓的布置准则进行了分析和总结,包括受电弓... 受电弓作为动车组高压供电系统中的关键部件,其布置方式将影响弓网关系协调、受流稳定和减阻降噪等性能,动车组高速运行时,受电弓与支持绝缘子的连接强度将承受到严峻的考验。文章对动车组受电弓的布置准则进行了分析和总结,包括受电弓的间距、定位、开闭口和高度,为动车组受电弓的集成方案设计提供了有效参考。通过分析受电弓在动车组高速运行中各工况下的受力情况,计算了受电弓与支持绝缘子连接螺栓的极限载荷和最小预紧力,然后结合最小预紧力和工作拉力进一步校核了螺栓强度,证明了所用螺栓规格符合使用要求。根据连接螺栓的工作拉力和许用应力,计算了连接螺栓的最大预紧力,并确定了合理的拧紧扭矩,为受电弓与支持绝缘子连接螺栓的选型和扭矩取值提供了正确指导。 展开更多
关键词 动车组 受电弓 布置准则 强度校核 预紧力 扭矩
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路基改良土循环加/卸载试验能量演化研究
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作者 牛洪军 张俊武 +1 位作者 章希伦 赵嘉 《路基工程》 2024年第4期69-76,共8页
通过循环加/卸载试验,分析公路路基改良土受载时的各能量参数转化规律。结果表明:不同围压下路基改良土的能量转化近似,都呈现峰前能量聚集,破坏能量耗散,峰后残余强度能量重新积聚,但效率和总量低于峰前;围压对峰前路基改良土能量参数... 通过循环加/卸载试验,分析公路路基改良土受载时的各能量参数转化规律。结果表明:不同围压下路基改良土的能量转化近似,都呈现峰前能量聚集,破坏能量耗散,峰后残余强度能量重新积聚,但效率和总量低于峰前;围压对峰前路基改良土能量参数影响较小,但少量提升了残余强度时能量聚集的作用;峰前能耗比K随轴向应变的增加而缓慢减小,当土体强度失效时,能耗比K产生突变;能耗比K突变点与应力-时间曲线拐点相对应,说明能耗比可以作为路基改良土三轴应力状态下循环加/卸载作用时的强度失效特征,也可以从能量的角度解释路基改良土的演化破坏规律。 展开更多
关键词 路基改良土 循环加/卸载 径向应变 能量演化 参数比例 强度失效判据
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基于残余位移增量判据的土石围堰边坡稳定性分析 被引量:1
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作者 孙士国 周鑫 彭是焱 《水电能源科学》 北大核心 2024年第2期81-84,共4页
针对有限元强度折减法在复杂水文地质环境下土石围堰边坡稳定性评价中效果欠佳的问题,引入残余位移增量判据,基于有限元强度折减法,考虑深厚覆盖层土石围堰不同水位下的渗流特征,通过计算坡面节点平均残余位移增量,获取边坡稳定系数,进... 针对有限元强度折减法在复杂水文地质环境下土石围堰边坡稳定性评价中效果欠佳的问题,引入残余位移增量判据,基于有限元强度折减法,考虑深厚覆盖层土石围堰不同水位下的渗流特征,通过计算坡面节点平均残余位移增量,获取边坡稳定系数,进一步通过位移增量分布图,探讨了围堰边坡潜在滑面位置及其形成机制。结果表明,在复杂水文地质环境下的土石围堰边坡稳定性评价中,残余位移增量判据相较经典失稳判据适用性更强。研究结果能够为工程实践提供指导。 展开更多
关键词 土石围堰边坡 有限元强度折减法 残余位移增量判据 失稳判据
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冻土的蠕变及蠕变强度 被引量:37
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作者 马巍 吴紫汪 盛煜 《冰川冻土》 CSCD 北大核心 1994年第2期113-118,共6页
基于试验,本文讨论分析了冻土三轴蠕变规律及温度和围压对冻土蠕变强度的影响,给出了冻土蠕变及蠕变强度随时间降低的方程式。进而提出了冻土蠕变强度的抛物型屈服准则。通过改变参数可将冻土的瞬时强度准则与冻土的蠕变强度准则统一... 基于试验,本文讨论分析了冻土三轴蠕变规律及温度和围压对冻土蠕变强度的影响,给出了冻土蠕变及蠕变强度随时间降低的方程式。进而提出了冻土蠕变强度的抛物型屈服准则。通过改变参数可将冻土的瞬时强度准则与冻土的蠕变强度准则统一为同一个方程描述。 展开更多
关键词 蠕变 蠕变强度 冻土
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冻融循环后在三向受压荷载下混凝土性能的试验研究 被引量:16
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作者 商怀帅 宋玉普 +1 位作者 覃丽坤 于长江 《水利学报》 EI CSCD 北大核心 2006年第7期874-879,885,共7页
本文对经过0、255、0、75次快速冻融循环作用的混凝土试件进行了三个方向均为压荷载时的力学性能测试,观察了试件的破坏形态以及裂缝的走向特征,测得了试件的强度和应变,并采集到了应力-应变关系曲线。根据试验结果,讨论了冻融循环次数... 本文对经过0、255、0、75次快速冻融循环作用的混凝土试件进行了三个方向均为压荷载时的力学性能测试,观察了试件的破坏形态以及裂缝的走向特征,测得了试件的强度和应变,并采集到了应力-应变关系曲线。根据试验结果,讨论了冻融循环次数及中间应力对峰值应力及其所对应的应变的影响,建立了冻融循环后试件应变与中间应力比的关系式。 展开更多
关键词 混凝土 三向受压 冻融循环 破坏准则
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节理的剪切力学性质与含三维形貌参数的剪切强度准则比较研究 被引量:21
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作者 唐志成 刘泉声 刘小燕 《岩土工程学报》 EI CAS CSCD 北大核心 2014年第5期873-879,共7页
利用水泥砂浆材料浇注3组不同表面形貌的节理试件,由常法向应力下的直剪试验研究节理的剪切力学性质,并分析法向应力、三维形貌特征对抗剪强度的影响。直剪试验结果表明:峰值剪胀角与法向应力成反变化关系,与粗糙程度呈正变化关系;峰值... 利用水泥砂浆材料浇注3组不同表面形貌的节理试件,由常法向应力下的直剪试验研究节理的剪切力学性质,并分析法向应力、三维形貌特征对抗剪强度的影响。直剪试验结果表明:峰值剪胀角与法向应力成反变化关系,与粗糙程度呈正变化关系;峰值抗剪强度与法向应力、粗糙程度均呈正变化关系。分析了JRC-JCS准则计算值偏低于试验值的原因,根据试验现象建议采用三维形貌参数、抗拉强度描述节理的剪切强度。对比分析了含三维形貌参数的峰值抗剪强度准则,建议低法向应力水平下采用双曲线形式的峰值剪切强度准则估算岩石节理的峰值抗剪强度。 展开更多
关键词 节理 三维形貌参数 抗拉强度 抗剪强度准则
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岩石软弱面产状对井壁稳定性的影响 被引量:18
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作者 刘向君 陈一健 肖勇 《西南石油学院学报》 CSCD 2001年第6期12-13,20,共3页
在连续介质力学井壁稳定性分析的基础上 ,采用简化的岩石软弱面地质模型和力学模型 ,计算分析了岩石软弱面倾角和倾斜方位角改变对直井、斜井井壁稳定性的影响。结果表明 :相同作业条件下 ,岩石软弱面的稳定性明显低于基质岩块的稳定性 ... 在连续介质力学井壁稳定性分析的基础上 ,采用简化的岩石软弱面地质模型和力学模型 ,计算分析了岩石软弱面倾角和倾斜方位角改变对直井、斜井井壁稳定性的影响。结果表明 :相同作业条件下 ,岩石软弱面的稳定性明显低于基质岩块的稳定性 ,当井周围存在裂缝或节理等软弱面时 ,井壁的稳定性将受到软弱面的影响而明显降低 ;斜井条件下 ,井壁失稳的位置和失稳的程度与软弱面的产状密切相关 ;直井条件下 ,井壁垮塌的方位将可能偏离原地最小水平主应力的方位 ,而主要取决于岩石软弱面的倾角和倾斜方位角。 展开更多
关键词 岩石软弱面 井壁稳定性 强度准则 直井 斜井 油气井
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