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针对目前地震区多层房屋设计和施工中存在的不合理因素,从结构选形,节点的设计与施工等方面进行了综合分析,并对砖混结构中构造柱和女儿墙的设计提供了改进建议。 相似文献
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阐述了土木工程专业《结构力学》课程教学改革应遵循的原则,在此基础上针对新形势下《结构力学》教学内容提出了合理、有效的改革措施,从而提高《结构力学》的教学质量。 相似文献
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Viscoelasto-plastic rheological experiment under circular increment step load and unload and nonlinear creep model of soft rocks 总被引:4,自引:3,他引:1
The viscoelastic-plastic creep experiments on soft ore-rock in Jinchuan Mine III were performed under circular increment step
load and unload. The experimental data were analyzed according to instantaneous elastic strain, visco-elastic strain, instantaneous
plastic strain and visco-plastic strain. The result shows that instantaneous deformation modulus tends to increase with the
increase of creep stress; soft rocks enhance the ability to resist instantaneous elastic deformation and instantaneous plastic
deformation during the multi-level of load and unload in the cyclic process. In respect of specimen JC1099, the ratio of visco-elastic
strain to visco-plastic strain varies from 3.15 to 6.58, and the ratio has decreasing tendency with stress increase as a whole;
creep deformation tends to be a steady state at low stress level; soft rocks creep usually embodies accelerated creep properties
at high stress level. With the damaging variable and the hardening function introduced, a nonlinear creep model of soft rocks
is established, in which the decay creep is described by the nonlinear hardening function H of viscidity coefficient. The model can describe the accelerated creep of soft rocks since the nonlinear damaging evolvement
variable D of deformation parameter of rocks is introduced. Three stages of soft rocks creep can be described with the uniform creep
equation in the nonlinear creep model. With this nonlinear creep model applied to the creep experiments of the ore-rock of
Jinchuan Mine III, the nonlinear creep model’s curves are in good agreement with experimental data.
Foundation item: Project(2007CB209400) supported by the Major State Basic Research and Development Program of China; Project(50774093) supported
by the National Natural Science Foundation of China; Project(200801) supported by Open Research Fund of Hunan Provincial Key
of Safe Mining Techniques of Coal Mines 相似文献
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针对预应力锚杆复合土钉支护基坑内部整体稳定的可靠性计算问题,以边坡极限平衡理论与圆弧滑动面法为基础,应用扰动力法建立了基坑内部整体稳定性分析的功能函数与最危险滑动面的计算模型.通过SLP优化法与单形调优法实现了最危险滑动面的优化搜索.以土体的抗剪强度指标作为随机变量,应用AFOSM(2)法计算了基坑内部整体稳定可靠性指... 相似文献
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在建立双重介质热-水-力耦合微分控制方程的基础上,提出了高温岩体地热开发系统热-水-力耦合的双重介质模型,对不同的介质分别建立以结点位移、水压力和温度为求解量的三维有限元格式,提出了该数学模型的求解策略与方法,开发了双重介质热-水-力耦合分析的的三维有限元计算程序DTHM.for,对地下-6km的高温岩体地热开发进行了详细的数值分析,结果表明:随地热提取,岩体裂缝法向应力逐渐降低、裂缝宽度成非线性增长;开始运行阶段,拟连续基岩介质内水压上升滞后,1a左右,整个系统水压保持稳定,以固定的压力梯度流动,在注入井和生产井附近区域水压力梯度较大,达0.046MPa/m,而在中间区域相对平缓,平均水压梯度约0.011MPa/m;在地热开采过程中,温度整体呈下降趋势,在生产井附近区域,温度呈非线性降低,与时间呈负指数关系下降趋势,而在注入井附近区域温度呈线性下降. 相似文献
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软岩黏弹塑性流变特性及非线性蠕变模型 总被引:3,自引:0,他引:3
采用分级增量循环加卸载方式,对金川有色金属公司Ⅲ矿区软弱矿岩进行流变试验,探讨了软弱矿岩的黏弹塑性变形特性.建立了软岩的非线性蠕变模型.结果表明:分级增量循环加卸载下软岩有明显的瞬时应变硬化趋势,软弱矿岩JC1099试件的黏弹性应变分量与黏塑性应变分量之比为3.15~6.58,随应力水平的增加蠕应变中黏塑性应变占的份量总体上有增加走势;在低应力水平下,蠕变变形趋于稳定状态,在高应力水平下,软岩蠕变往往表现出加速蠕变特性.建立的非线性蠕变模型可以用统一的蠕变方程来描述软岩蠕变的3阶段,将该模型应用于金川Ⅲ矿区矿岩蠕变试验,蠕变试验曲线与理论曲线较为吻合. 相似文献
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采用有限元分析方法对全钢载重子午线轮胎六角形钢丝圈与圆形钢丝圈进行结构和性能对比分析.结果表明,圆形钢丝圈及其底部胶料在轮胎中受力和非受力状态下的应力变化率小于六角形钢丝圈,其在受力作用时的变形量也较小,更有利于将轮胎束紧在轮辋上,可有效预防胎体钢丝断爆现象. 相似文献
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