循环爆破扰动下含软弱夹层岩质边坡动力失稳灾变机制

The dynamic stability of rock slope with weak interlayer is one of important issues in rock mechanic and engineering. The dynamic instability catastrophe of rock slope with weak interlayer under cyclical blasting disturbance are key study objects in this research. The research system of dynamic instability catastrophe mechanism of rock slope with weak interlayer under cyclical blasting disturbance will be set up by combining with experimental study, theory analysis and numerical simulation organically, where cumulative damage effects of weak interlayer soil under cyclical dynamic loading are taken as the important foundation and ligament. First, the intensity parameters degradation and deformation accumulation evolvement law of weak interlayer soil under cyclical dynamic loading can be obtained by dynamic triaxial test. Second, the theory analysis method of instability of rock slope with weak interlayer under cyclical blasting disturbance will be founded by catastrophic theory and Newmark slider displacement method based on experiment research results. Last, the dynamic instability process of rock slope with weak interlayer under cyclical blasting disturbance will be studied systemically combining with some typical engineering cases by FLAC3D numerical simulation based on already obtained research results, considered multi factors and conditions. The complex mechanism of dynamic instability catastrophe of rock slope with weak interlayer under frequent blasting disturbance will be revealed by this research. And the research results have important theoretic and practical significance for prevention and treatment of dynamic instability disaster of rock slope with weak interlayer.

含软弱夹层岩质边坡动力稳定性问题是岩石力学与工程研究的难点与热点之一。本项目以循环爆破扰动下含软弱夹层复杂岩质边坡动力失稳灾变为研究对象，将试验研究、理论分析与数值模拟有机结合，以循环动荷载作用下软弱夹层土的累积损伤效应为基础和纽带，建立循环爆破扰动下含软弱夹层岩质边坡动力失稳灾变机制研究体系。首先，通过动三轴试验，探寻循环动荷载作用下软弱夹层土的强度参数劣化和变形累积演化规律；其次，基于试验研究成果，利用突变理论和Newmark滑块位移法建立循环爆破扰动下含软弱夹层岩质边坡失稳的理论分析方法；最后，结合典型工程，基于已有研究成果，利用FLAC3D数值模拟方法系统研究多因素和多工况条件下循环爆破扰动诱发含软弱夹层岩质边坡动力失稳灾变过程。本项目研究可深层次揭示循环爆破扰动诱发含软弱夹层岩质边坡失稳灾变的复杂机理，研究成果对于含软弱夹层岩质边坡动力失稳灾害防治具有重要的理论和实际意义。

循环动荷载下软弱夹层动力响应特性及其诱发复合岩体动力失稳灾变的内在机制及其演化过程十分复杂，有待深入探索和进一步研究。.本项目以循环爆破扰动下含软弱夹层复杂岩质边坡动力失稳灾变为研究对象，将试验研究、理论分析与数值模拟有机结合，以循环动荷载作用下软弱夹层土的动力响应为基础和纽带，建立循环爆破扰动下含软弱夹层岩质边坡动力失稳灾变机制研究体系。首先，通过动三轴试验，探寻循环动荷载作用下软弱夹层土的强度参数劣化和变形累积演化规律；其次，利用Newmark滑块位移法建立循环爆破扰动下含软弱夹层岩质边坡失稳分析方法；再次，根据软弱夹层发育特征，建立含软弱夹层复合岩体质量分级评价方法；最后，利用FLAC3D数值模拟方法系统研究多因素和多工况条件下含软弱夹层岩质边坡稳定性。.研究结果表明：（1）软弱夹层累积应变规律具有破坏型特征，随含水率和黏粒含量增大而增大，随围压增大先减小后增大；动弹性模量随围压增大单调递增，随循环周次和含水率增大单调递减。（2）软弱夹层的动强度受主要黏土矿物成分和黏粒含量共同影响；动粘聚力与主要黏土矿物成分的工程性质优劣呈正相关；而动内摩擦角随软弱夹层黏粒含量的增大单调递减。（3）基于最大应变法表征损伤量，用低周疲劳损伤演化模型描述软弱夹层在循环动荷载下的累积损伤机理与特征是合理的。（4）对于规模相对较小的软弱夹层（厚度小于10cm），可将其作为折减因素，建立了含软弱夹层的层状复合岩体质量分级修正BQ方法。（5）基于强度折减法，利用FLAC3D分析了不同倾角、厚度、含水率、粘粒含量等软弱夹层发育条件下岩质边坡稳定性，研究表明对岩质边坡稳定性影响程度依次为：软弱夹层的倾角、粘粒含量、含水率和厚度。（6）建立了爆破扰动下含软弱夹层岩质边坡的物理模型和滑块力学模型，通过能量守恒原理给出了多次爆破振动下滑坡的总位移量表达式。.研究成果可为预防循环动荷载扰动作用下含软弱夹层复杂岩质边坡动力失稳灾害提供科学指导和技术支撑。