Tunnel reinforcement via topology optimization     

Luzhong Yin  Wei Yang  Tianfu Guo 《国际地质力学数值与分析法杂志》2000,24(2):201-213

Anchoring is a fundamental method for supporting tunnels. It reinforces the original rock mass and reduces the deformation along the tunnel surface. The topological complexity of its layouts renders a design methodology difficult. A numerical approach to reinforce the host ground becomes desirable. The present paper proposes a topology optimization method based on a two‐phase cell model and finite‐element discretization of the host ground. The element consists of the original rock and the reinforcing material. The design issue involves the distribution of the reinforcing materials. The relative ratios of the two phases in various elements will be optimized to reduce the compliance of the tunnel. The method enables the computer‐aided design for the support of underground structures. The capabilities of the method are demonstrated by the designs to support a deep tunnel under various in situ stresses. The results indicate that oriented reinforcement is needed along the direction of the largest absolute value of the principal stress. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Vertical vibration of an elastic strip footing on saturated soil     

Y. Q. Cai  Y. M. Cheng  S. K. Alfred Au  C. J. Xu  X. H. Ma 《国际地质力学数值与分析法杂志》2008,32(5):493-508

Based on Biot's dynamic coupled equations, the vertical vibration of an elastic strip footing on the surface of saturated soil is studied. Utilizing the Fourier transform, the governing dynamic differential equations for saturated poroelastic medium are solved. Considering the mixed boundary value conditions at the bottom of the foundation, a pair of dual integral equations about the vertical vibration of an elastic strip footing is derived, which can be converted to a set of linear equations by means of infinite series of orthogonal functions. The relation between the dynamic compliance coefficients and the dimensionless frequency tends to be gentle with decreasing footing rigidity, while the dimensionless frequency has only small effect on the dynamic compliance coefficients. When the dynamic permeability is large, its effect on the dynamic compliance coefficients should be taken into consideration. Furthermore, the dynamic compliance coefficients are found to be not sensitive to Poisson's ratio of the soil for footing on saturated soil. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

粘弹性体力学模型的判别准则及在岩石试验中的应用   总被引：3，自引：2，他引：3  

薛琳 《岩土力学》1996,17(1):9-15

从粘弹性介质的蠕变柔量出发，推导出粘弹性体力学模型的判别准则。并通过单轴压缩条件下４种岩石的蠕变试验，讨论了判别准则实用化中的两个问题，解的存在条件问题，多解性及解的唯一性问题。  相似文献   

广义地应力及其强度理论     

薛琳 《岩土力学》1997,18(1):16-24

根据岩体力学位移理论，将广义地应力理论与岩体介质蠕变柔量理论相结合，建立了广义地应力的强度理论，并讨论了它在岩体工程中的应用。  相似文献   

A review of shear wave splitting in the crack-critical crust   总被引：7，自引：0，他引：7  

Stuart Crampin  Sebastien Chastin 《Geophysical Journal International》2003,155(1):221-240

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The sensitivity of seafloor compliance measurements to sub-basalt sediments   总被引：1，自引：0，他引：1  

Wayne C. Crawford 《Geophysical Journal International》2004,157(3):1130-1145

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Management measures and fishers' commitment to sustainable exploitation: a case study of Atlantic salmon fisheries in the Baltic Sea     

Haapasaari  P.; Michielsens  C. G. J.; Karjalainen  T. P.; Reinikainen  K.; Kuikka  S. 《ICES Journal of Marine Science》2007,64(4):825-833

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节理岩体蠕变特性研究   总被引：13，自引：3，他引：10  

杨松林  张建民  黄启平 《岩土力学》2004,25(8):1225-1228

在已知岩石和节理蠕变规律的前提下,推导了节理岩体蠕变模型的一般表达式。假定岩石体积变形和节理法向压缩变形为弹性变形,忽略节理的剪胀现象,认为只有岩石畸变和节理剪切滑移与时间有关,从而推导了含三组相交节理的岩体蠕变模型及其参数。根据反演出的岩石和节理蠕变模型,计算了含三组相交节理的岩体在单轴应力作用下一些节理参数对岩体单轴蠕变的影响。分析表明,节理间距、剪胀系数以及节理夹角都对岩体的单轴蠕变变形有明显影响。节理间距越大,剪胀系数越大,节理夹角越小,节理岩体的单轴蠕变柔量也就越小,岩体的蠕变变形也越小。  相似文献   

Corruption and regulatory compliance: Experimental findings from South African small-scale fisheries     

Aksel Sundström 《Marine Policy》2012

Although corruption is often mentioned as an obstacle to fisheries management, its negative effects have seldom been investigated empirically in a systematic manner. This article examines the impact of corruption on regulatory compliance among South African small-scale fishermen. Results from scenario experiments with 181 participants confirm that perceived corruptibility of the enforcing authority corrodes the willingness to comply with regulations. Both grand and petty types of corruption have significant effects. Attitudes related to moral support of the regulations, perceived inclusion in the decision making leading to regulations and an individual record of law breaking all affect the willingness to comply. However, these effects are trumped by the relative size of the negative impact of corruption. These findings underline the importance of curbing corruption involving public officials in the small-scale fisheries sector.  相似文献   

饱和地基上条形弹性基础的摇摆振动     

马晓华  蔡袁强  徐长节 《岩土力学》2010,31(7):2164-2172

基于Biot动力方程,研究了饱和均质弹性半空间上弹性条形基础的摇摆振动问题。通过Fourier积分变换求解了饱和土的动力控制方程,然后结合基础底部为混合边界的条件得到了弹性条形基础的摇摆振动对偶积分方程,利用正交多项式将对偶积分方程转化为求解一组线性代数方程组,同时利用复合Simpson法则,得到了动力柔度系数的表达式,通过算例得出了不同参数时地基动力柔度系数随无量纲频率的关系曲线。  相似文献