基于不同方法的滑坡滑带力学参数敏感性分析

滑坡参数敏感性分析是滑坡机理分析和定量评价的基础。滑坡参数敏感性分析有多种方法,然而采用不同方法所得的分析结果是否一致,目前尚不清楚。本文以具有流变特征的甘肃省舟曲县泄流坡滑坡为例,采用敏感性系数法、敏感度函数法和正交试验法等3种最常用方法分析滑坡位移速率对滑带力学参数的敏感性。对比分析发现,3种方法识别出的最敏感参数均为Maxwell黏度,而滑坡对其他参数的敏感性排序却不尽相同。由于敏感性系数法和敏感度函数法适用于参数较少的情况,所以对于受多个流变力学参数控制的缓慢活动性滑坡,基于正交试验法所得的敏感性分析结果相对更为合理。

基于传递系数法边坡滑带力学参数反演分析

黏聚力及内摩擦角是评价滑坡变形稳定的重要力学参数。基于刚体极限平衡理论,采用传递系数法对冷家山H2滑坡进行黏聚力与内摩擦角参数反演及敏感性分析。根据参数反演结果,对比分析了参数反演与室内试验结果间差异,计算得到不同工况下坡体稳定性。计算分析结果表明,黏聚力与内摩擦角为2个相关参数,需在同一滑坡截取两处均处于极限状态的地质断面联立进行参数反演计算。与参数反演结果相比,冷家山H2滑坡室内试验黏聚力偏低10.26%,内摩擦角偏高5.68%。坡体稳定系数对内摩擦角的敏感性大于黏聚力,在滑坡稳定性评价及其工程处治设计中,岩土体强度参数应将两者对比分析,合理地取值。

里坞矿区降雨型滑坡勘察与评价

矿区受开挖和降雨的影响,极易形成滑坡,本文通过里坞水泥矿区的滑坡勘察实例,在查明滑体现状同时采用极限平衡法反求其岩土参数,利用有限元方法进行稳定性验证。考虑到地下水位、渗流路径和岩土参数的复杂性,采用非饱和土力学理论,根据实测水位和泉眼出露情况,进行降雨条件下滑坡渗流场及应变场模拟,较为准确地模拟出滑坡的形成过程。

Parametric analysis of mixed lubrication characteristics in work zone of strip rolling

A theoretical model for mixed lubrication with more accurate contact length has been developed based on the average volume flow model and asperity flattening model,and the lubricant volume flow rate and outlet speed ratio are determined by integrating differential equations based on rolling parameters.The lubrication characteristics at the roll-strip interface with different surface roughness,rolling speed,reduction and lubricant viscosity are analyzed respectively.Additionally,the average volume flow rates of lubricant under different rolling conditions are calculated and used to explain the change rule of lubrication characteristics.The developed scheme is able to determine the total pressure,lubricant pressure,film thickness and real contact area at any point within the work zone.The prediction and analysis of mixed lubrication characteristics at the interface is meaningful to better control the surface quality and optimize the rolling process.