板弯曲弹塑性分析拟协调元     

孙建刚 《地震工程与工程振动》1996,16(1):110-115

本文从拟协调元列式出发，建立板弯曲弹塑性分析单元，给出了分层和不分层的板弹塑性问题的Ｔｒｅｓｃａ屈服准则下，由切线刚度法进行求解的方法。  相似文献   

The influence of stiffness of the true triaxial testing machine on the rupturing and acoustic emission of rocks and its correlation with seismic activities     

Zhaoyong Xu  Shirong Mei  Cantao Zhuang  Peilin Li 《地震学报(英文版)》1992,5(2):367-379

This paper introduces how the ratioR of the characteristic stiffness of rock samplevs. the stiffness of testing machines would influence the rupturing process and the acoustic emission (AE) on the part of the tested rock samples. Result of the experiment shows: WhenR>0.20, the rock sample would rupture abruptly; whereas whenR<0.20, the rock samples would rupture slowly. When the samples rupture abruptly, the time-dependent variation of the AE rate takes such a pattern:peak value—stable low values—rises to the maximum value (concentration)—drops back to the minimum value (quiescence)—(rises again)—ruptures. Moreover, smallerR-value tends to be associated with longer quiescence and vice versa. WhenR>1.50, no pre-failure quiescence is detected. When the rock samples rupture slowly, the variation pattern of the AE rate (after the stress has increased to more than 50% of the rupturing stress) is as the following:stable low (or high) values—rises (or drops) to its maximum (or minimum) values and then continues for some time—ruptures. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 223–233, 1991. This study is supported by the Chinese Joint Seismological Science Foundation.  相似文献   

Influence of viscoelastic coupling on the axial rotation of the Earth and its fluid core     

M. Lefftz  H. Legros 《Geophysical Journal International》1992,108(3):725-739

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岩石粘滑的自锁模型及数值模拟     

陈铁民  陶振宇 《地震工程学报》1993,15(1):39-44

本文根据岩石摩擦的自锁模型,通过数值模拟讨论了围压和围压介质刚度对粘滑及其应力降的影响。结果表明:围压的增大有利于发生粘滑;粘滑应力降随围压的增大而增大;天然地震应力降低于室内粘滑应力降是由围压介质刚度引起的。  相似文献   

Implementation of configuration dependent stiffness proportional damping for the dynamics of rigid multi-block systems     

Yun?Byeong?Chae  Jae?Kwan?KimEmail author 《地震工程与工程振动(英文版)》2003,2(1):87-97

The distinct element method (DEM) has been used successfully for the dynamic analysis of rigid block systems. One of many difficulties associated with DEM is modeling of damping. In this paper, new procedures are proposed for the damping modeling and its numerical implementation in distinct element analysis of rigid multi-block systems. The stiffness proportional damping is constructed for the prescribed damping ratio, based on the non-zero fundamental frequency effective during the time interval while the boundary conditions remain essentially constant. At this time interval, the fundamental frequency can be estimated without complete eigenvalue analysis. The damping coefficients will vary while the damping ratio remains the same throughout the entire analysis. A new numerical procedure is developed to prevent unnecessary energy loss that can occur during the separation phases. These procedures were implemented in the development of the distinct element method for the dynamic analyses of piled multi-block systems. The analysis results for the single-block and two-block systems were in a good agreement with the analytic predictions. Applications to the seismic analyses of piled fourblock systems revealed that the new procedures can make a significant difference and may lead to much-improved results.  相似文献   

云南兰坪—思茅盆地中轴构造带的特征及其研究意义   总被引：9，自引：1，他引：9       下载免费PDF全文

管 烨王安建  李朋武曹殿华 刘俊来 《中国地质》2006,33(4):832-841

笔者利用云南西部已有的DSS地震测深、石油反射地震资料的再解释,并通过地球物理、地球化学以及矿产等资料的综合分析,对滇西兰坪—思茅盆地内的中轴构造带的构造特征进行了深入分析。研究结果表明兰坪—思茅盆地内的中轴构造带是一条近南北走向的集断裂带、伸展构造、深部隆起为一身的大型构造带。地震测深的速度结构及反射地震剖面表明,中轴构造带在思茅盆地南部存在有深部地幔的上隆现象,该构造带内的断裂系统倾向在盆地南北有差异。研究发现该构造带与矿床、侵入碱性岩体及区域地化异常分布有密切的关系。结合地质构造分析研究,表明该构造带是一多期活动的重要构造带,具有伸展走滑的性质;中轴构造带在形成、演化过程中被近东西向的多条直线型断裂所错断,从构造形态上看与大洋中脊有相似的展布特征。该构造带对盆地的构造演化以及矿产形成具有重要控制作用。  相似文献   

节理裂隙边坡锚注加固机制及特性研究   总被引：6，自引：0，他引：6  

许万忠  彭振斌  袁海平 《水文地质工程地质》2006,33(5):30-33

本文通过对节理裂隙边坡锚注加固模型的力学推导，得出锚注加固工法可以提高岩石边坡弱面抗剪强度和抗剪刚度的结论；指出锚注结构可以充分发挥锚杆和注浆体各自的材料潜能，从而避免锚杆单独作用所存在的弊端；结合某高速公路边坡加固工程，阐述了锚注加固工法的技术特点及工艺流程，指明压力注浆可以针对边坡岩体的薄弱环节，直接进行有效的处理，使边坡的稳定性得以提高，并就边坡锚注加固施工中存在的技术问题，提出相应的处理措施。  相似文献   

中(下)承式拱桥吊杆静张力分析方法的改进   总被引：3，自引：0，他引：3  

杜思义  殷学纲  陈淮 《世界地震工程》2006,22(4):99-103

在中(下)承式拱桥的有限元模型中,引入了由于施工中吊杆长度调整而产生的几何刚度矩阵,用一阶矩阵摄动理论,导出了相应的吊杆系静张力分析的相关公式。对一实际中承式拱桥的数值计算分析表明,使用本方法可有效地提高中(下)承式拱桥的吊杆静张力分析的准确性。  相似文献   

A Combined-Power Model for the Distribution of Axial Force in Shaft Anchor along Its Length   总被引：1，自引：0，他引：1  

卫军  周锡武朱玉 罗昕 《中国地质大学学报(英文版)》2006,17(1):89-94

INTRODUCTIONThe anchorage of geomaterial , including shaftanchors and prestressed tendons ,is usually used ingeotechnical engineering. Owing to various advanta-ges ,these two anchorage types are widely used instructures in China ( Cao et al ., 2003 ; Fu et al .,1999 ;Lu et al .,1998 ; Li et al .,1995) . Shaft an-chors can be classifiedinto three kinds by the forceinthe shaft and cement grout :tensile ,press ,and sheartype (Lu et al .,1998) . The tensile type is the mostpopular in China…  相似文献   

型钢高强混凝土柱轴压比限值的试验研究   总被引：2，自引：0，他引：2  

李俊华  薛建阳  王新堂  赵鸿铁 《世界地震工程》2007,23(2):154-160

通过20个型钢高强混凝土柱的低周反复加载试验对其受力性能进行了研究，分析了剪跨比、轴压比、配箍率以及混凝土强度对型钢高强混凝土柱延性的影响，提出了不同剪跨比、不同配箍率的型钢高强混凝土柱的轴压比限值。其中，剪跨比大于2．0的型钢高强混凝土柱的轴压比限值由大、小偏心界限破坏时力的平衡条件并结合试验结果确定，而剪跨比小于2．0的型钢高强混凝土柱的轴压比限值则通过与剪跨比大于2．0的型钢高强混凝土柱的延性对比加以确定。  相似文献