Fractographic determination of joint length distribution in chalk     

Dov Bahat 《Rock Mechanics and Rock Engineering》1988,21(1):79-94

Summary Measurements of fracture joint distribution combined with determinations of plume length and orientation on a vertical section of a single chalk layer near Beer Sheva, Israel, reveal that joints marked by unilateral and circular plumes are skewed towards the shorter sizes while joints decorated by bilateral plumes are skewed towards the longer sizes. The mean lengths of the unilateral and bilateral joints are 66.5 cm and 155.6 cm, with standard deviations of 30 cm and 60.6 cm, respectively. These results as well as joint length observations from other areas seem to suggest a bimodal length distribution. However, since the minor maximum is generally very weak, and due to some additional uncertainties, further confirmation of the present observations is needed.  相似文献   

Shear resistance of jointed rock masses and stability calculation of rock slopes     

Xing Zhang 《Geotechnical and Geological Engineering》1993,11(2):107-124

Summary Based on an extension to a model originally proposed by Zhang (1990), a method for estimating the shear strength of a jointed rock mass containing two joint sets is developed. Compared to the original method in which only a single en-echelon joint set was considered, the new method has the following advantages: (1) it allows a much more realistic joint pattern to be incorporated; (2) the effects of joint connectivity and intersection angle between joint sets on shear strength are included. Use of the new method is demonstrated by application to the calculation of the stability of slopes in jointed rock. The importance of joint connectivity, joint persistence and joint set intersection angle on slope stability, as predicted by the model, is revealed.  相似文献   

Tomographic determination of 3-D crustal structure — Joint inversion of explosion and earthquake data     

Xian-Kang Zhang  Zhuo-Xin Yang  Yu-Chun Yang  Jian Yang  Jian-Li Song  Ping Zhao 《地震学报(英文版)》1995,8(4):519-529

In this paper, the theory and method, obtaining the tomographic determination of three-dimensional velocity structure of the crust by use of the joint inversion of explosion and earthquake data, are given. The velocity distribution of the crust is regarded as a continuous function of the spatial coordinates without parametrization of the velocity model ahead, so that the inversion solution would not be influenced by different parametrization procedures. The expressions of integration kernels, which relates the two kinds of data sets, are also given. The authors have processed the observed data in Tangshan earthquake region by the method proposed in this paper, and obtained the tomographic results of the middle and upper crust structures in this region. The comparison of these results with the result obtained only by the explosion data, has also been made.  相似文献   

填充墙与钢框架协同工作性能非线性分析   总被引：5，自引：2，他引：5  

戴绍斌  余欢  黄俊 《地震工程与工程振动》2005,25(3):24-28

在试验研究的基础上，运用ANSYS有限元中的接触单元建模，对加气混凝土填充墙钢框架的结构性能进行了研究，同时与纯钢框架结构在强度、刚度、以及延性等方面进行了对比分析，结果表明：填充墙与钢框架协同工作能够改善钢框架结构的受力性能和抗震能力，这为钢结构及其围护体系的研究与推广应用提供了一定的理论依据。  相似文献   

半刚性连接钢管混凝土框架剪力墙结构的动力特性分析   总被引：1，自引：1，他引：1  

孙修礼  梁书亭  王群依  蒋永生  李玉莹 《地震工程与工程振动》2005,25(3):93-97

将钢管混凝土框架剪力墙结构作为连续弹性无限自由度结构，建立自由振动方程，分析了半刚性连接对结构自振周期和频率的影响，推导出半刚性连接框剪结构自振周期系数的计算公式。使用通用有限元程序ANSYS进行结构的模态分析，有限元分析结果和公式计算结果吻合良好。结果表明，半刚性连接使得结构自振周期增大，半刚性连接对高阶振型自振周期的影响很小。提出了地震区钢管混凝土框剪结构体系的设计建议，可供工程设计人员参考使用。  相似文献   

拱形波纹钢屋盖动力特性测试及分析   总被引：2，自引：0，他引：2  

王小平蒋沧如  胡春宇李桂青 《地震工程与工程振动》2005,25(5):112-116

拱形波纹钢屋盖是一种新颖的金属拱形薄壳结构，在我国已经得到了广泛的应用。由于结构的复杂性，目前有关的理论研究尚不够深入，动力研究还很少有人涉及。以18m和30m两种跨度的W666型拱形波纹钢屋盖为研究对象，测试了拱在竖向平面内振动时的频率、振型及阻尼。在所提简化计算模型的基础上，采用有限元方法计算了结构的动力特性，其结果与试验数据符合较好。测试和分析结果为该结构的动力反应研究提供了方便。  相似文献   

油气储运系统钢结构设备地震火灾效应研究   总被引：3，自引：0，他引：3  

李天祺  赵振东 《地震工程与工程振动》2005,25(6):118-121

预防和减轻油气储运系统地震火灾危险性是防震减灾中的重要课题。本文论述了油气储运系统的地震火灾特征及防火要求，对钢结构的防火涂料在遭到破坏和平时情况下的抗火性能进行了对比分析，并应用有限元法对油气储运系统中典型钢结构设备在地震火灾荷载作用下的抗火性能进行了数值模拟。研究结果表明，防火涂料遭到强地震荷载破坏后，钢结构的抗火性能大大降低。  相似文献   

Centrifuge Modeling of Rock Slopes Susceptible to Block Toppling   总被引：2，自引：0，他引：2  

J. H. Zhang  Z. Y. Chen  X. G. Wang 《Rock Mechanics and Rock Engineering》2007,40(4):363-382

Summary This paper presents the results of centrifuge tests that were aimed at validating the Goodman-Bray method for rock slope toppling analysis. The Goodman-Bray method was extended by the authors to accommodate non-persistent basal planes of rock columns. Two gypsum column models, with and without anchors were used to represent the failure modes. Measured critical centrifuge accelerations were in agreement with the results obtained from numerical modeling. A background of the toppling slope failures associated with a large hydropower project in China instigated the need for the centrifuge study. The centrifuge model tests used an artificial rock. The observed failure mode did not follow a straight failure plane as proposed by Goodman and Bray. The failures revealed a bi-planar slip surface with a deep-seated portion near the toe of the slope. The outcomes of the centrifuge tests illustrated the need to search for the critical failure surface when performing a toppling analysis. The search technique is similar to that usually performed in a conventional sliding analysis.  相似文献   

Nonlinear aspects of energy dissipation in wood-panel joints     

Sara Casciati 《地震工程与工程振动(英文版)》2007,6(3):259-268

The joints connecting vertical and horizontal elements are the "weak link" in structural systems assembled from wood panels. If they are too weak, local failures may occur, resulting in performance that is significantly below expectations. If they are too resistant, the joints may be unable to dissipate energy during vibrations, thus possibly initiating a fast progressive failure. This paper re-processes and re-elaborates the results of shaking table tests previously carried out by the author and other co-workers. The goal is to assess the feasibility of a joint which is able to dissipate energy during vibration, without degrading the connection performance.  相似文献   

钢骨混凝土结构抗震研究综述     

吴平川  张令心  杨克勇 《世界地震工程》2007,23(4):13-18

介绍了钢骨混凝土结构的特点以及抗震研究发展现状，指出了这种结构在抗震研究中存在的主要问题和今后需要进一步研究的方向。  相似文献