某尾矿库渗流及动静力稳定性研究

尾矿坝与水库水工坝不同,其施工过程也是矿山企业的生产过程,所以渗流作用、动静力对坝体稳定性的影响具有特殊性。文中为了清楚反映计算分析剖面与尾矿库工程的位置关系,建立了尾矿库的三维地质及三维渗流场模型,通过野外特征、原位测试、室内常规试验、直剪试验、静三轴试验等多种手段获取各土层物理力学性质指标,确定坝坡稳定计算所需的计算参数,进行渗流及动静力稳定性分析。研究结果表明,最终坝高洪水运行工况浸润线最小埋深满足要求,浸润线不会从坝面上溢出,不会产生管涌和流土等现象;采用瑞典圆弧法对坝体稳定性进行计算分析,现状坝高及最终坝高剖面的坝坡稳定最小安全系数均能满足规范要求,但是坝体在地震运行工况下富余度不大。

柔性加固失稳重力式挡土墙的动静力稳定性分析

针对地震区重力式挡土墙地震后多数出现不稳定的现象和由于挡土墙工作条件改变产生失稳的事故,采用框架预应力锚杆柔性加固技术对失稳重力式挡土墙进行加固是一种非常有效的加固方法;但是,由于该加固方法系作者首先提出并在工程中使用,其稳定性分析方法,特别是地震动力稳定性分析方法是迫切需要解决问题。该文以极限平衡理论为基础,对柔性加固后重力式挡土墙进行整体静力稳定性分析,推导出挡土墙的抗倾覆稳定性和抗滑移稳定性计算公式;通过分析给出了地震动力计算模型,分析了地震动力作用,采用振型分解法给出地震动力作用下地震作用和锚杆拉力计算公式,并采用极限平衡法给出动力稳定性计算公式。

Study of the aerostatic and aerodynamic stability of super long-span cable-stayed bridges

With the increase of span length, the bridge tends to be more flexible, and the wind stability be- comes an important problem for the design and construction of super long-span cable-stayed bridges. By taking a super long-span cable-stayed bridge with a main span of 1 400 m as example, the aerostatic and aerodynamic stability of the bridge are investigated by three-dimensional nonlinear aerostatic and aerodynamic stability analy- sis, and the results are compared with those of a suspension bridge with a main span of 1 385 m, and from the aspect of wind stability, the feasibility of using cable-stayed bridge in super long-span bridge with a main span above l 000 m is discussed. In addition, the influences of design parameters including the depth and width of the girder, the tower structure, the tower height-to-span ratio, the side-to-main span ratio, the auxiliary piers in the side span and the anchorage system of stay cables, etc on the aerostatic and aerodynamic stability of su- per long-span cable-stayed bridges are investigated numerically; the key design parameters are pointed out, and also their reasonable values are proposed.