尾矿坝液化判别简化方法研究

在现有尾矿坝液化判别研究成果的基础上,提出利用尾矿坝在不同深度和不同沉积滩距离处的放大系数和折减系数来计算动剪应力的方法。该方法可以考虑尾矿坝坝体的刚度和距离对液化特性的影响。结合大量的现场标贯试验和室内动三轴试验,研究细粒含量对尾矿材料液化特性的影响,并提出细粒含量对尾矿材料液化特性影响的修正公式。通过考虑上覆有效应力、钻孔直径、钻杆长度、落锤条件以及细粒含量等影响因素,对尾矿材料的抗液化强度进行修正。结合抗液化安全系数的概念,比较动剪应力和抗液化强度,判别尾矿材料的液化程度。使用Visual Fortran语言,编制与提出的尾矿坝液化判别方法相应的液化判别程序,便于该方法在尾矿坝液化判别方面的推广和应用。

STUDY ON A SIMPLIFIED PROCEDURE FOR EVALUATING LIQUEFACTION POTENTIAL OF TAILINGS DAM

Based on the present study results of evaluating liquefaction potential of tailings dam,a method considering the effect of amplification coefficient and reduction coefficient at different distances and different stiffness is presented to calculate the dynamic shear stress.Through a lot of in-situ standard penetration tests(SPT) and dynamic triaxial testst,he effect of fine content on dynamic liquefaction property is studied.A formula is given to modify the effect of the fine content on the liquefaction strength.By considering effective overburden stress,diameter of boreholer,od length,hammer type and fine contentt,he corresponding correction factors are calculated by the given formulas.Comparing the dynamic shear stress with the liquefaction resistance,the anti-liquefaction safety factor is used to evaluate the liquefaction degree.At last,a simplified procedure is presented to evaluate the liquefaction potential of tailings dam by taking plenty of correction factors into account.The given method is programmed with Visual Fortran language in order to spread the method more conveniently.