岩质边坡楔形体锚索加固方向角三维优化设计     

安彩龙  梁烨  王亮清  邓姗  孙自豪  范斌强  郑罗斌 《岩土力学》2020,41(8):2765-2772

以岩质边坡中常见的楔形体滑动为研究对象,研究其最优锚固方向角的计算方法。将锚索自由段单位长度能提供的最大抗滑增量作为目标控制变量,将坡面和两组滑动面的特征参数与锚索设计参数作为优化控制自变量,通过坐标系转换建立线性方程组对锚索的预拉力进行分解,得到用于锚固方向角三维优化的新计算方程。在该方程的基础上,借助导数法和Matlab软件中的fmincon函数分别对锚索加固方向与坡面走向垂直的二维优化方式和锚索加固方向不受限制时的三维优化方式下的锚固方向角进行了优化。最后通过算例与工程实例分析相结合,证明了推荐的最优锚固方向角计算方法的有效性与先进性。新方法可进一步提高锚索的锚固效益,减少锚索的总用量,降低边坡的支护费用。  相似文献   

The distribution of solute processes on an acid hillslope and the delivery of solutes to a stream: II. Exchangeable Al3+     

S. J. Park  T. P. Burt 《地球表面变化过程与地形》1999,24(10):851-865

In order to identify the distribution of aluminium (Al) within an acid hillslope and its release to a stream, the spatial distribution of acid ammonium oxalate extractable Al (Al_o) and exchangeable Al³⁺ have been investigated on a podzolized hillslope in Bicknoller Combe, Somerset, UK. The eluviated Al from topsoils is mainly deposited in the lower soil horizons forming podzolic B horizons, but some Al flows downslope carried by lateral throughflow. Al oxides may provide the main source of exchangeable Al³⁺ on the study slope due to high soil acidity. Examination of the spatial distribution of exchangeable Al³⁺ suggests that the slope hollow, where active convergent throughflow occurs, and the saturation wedge at the base of the slope are the main delivery routes of dissolved Al³⁺ to the stream. Divalent base cations (Ca²⁺ and Mg²⁺), supplied from atmospheric input and organic decomposition and carried by throughflow, exchange Al³⁺ via cation exchange reactions under high water content. Laterally illuviated Al oxides in the lower hollow adjacent to the saturation wedge probably provide a pool for continuous delivery of Al either as soluble or complexed forms to the stream via the saturated wedge. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

南海东北部陆坡与恒春海脊天然气水合物分布的地震反射特征对比   总被引：3，自引：0，他引：3  

尚继宏  李家彪 《海洋学研究》2006,24(4):12-20

对“探宝号”调查船2001年8月在南海东北部陆坡及台湾南部恒春海脊海域采集的多道地震剖面资料进行了地震反射波数据分析、解释和研究,并对南海北部陆坡、陆隆及其东侧俯冲带等区域天然气水合物矿藏的成藏规律及分布特征作了初步的分析与探讨,结果表明:(1)南海东北部陆坡和台湾南部恒春海脊海域地震剖面上均显示有BSR,但两区域构造成因、形式和相关地质环境的不同造成了天然气水合物的成因及过程不同。(2)南海东北部陆坡区域的天然气水合物形成与该区广泛发育的断裂带、滑塌构造体及其所形成的压力场屏蔽环境有关,而台湾南部恒春海脊海域天然气水合物的形成则与马尼拉海沟俯冲带相关的逆冲推覆构造、增生楔及其所对应的海底流体疏导体系有关。(3)南海陆缘区域广泛发育有各种断裂带、滑塌构造体、泥底辟、俯冲带、增生楔等,且温压环境合适,是天然气水合物矿藏极有可能广泛分布的区域。  相似文献