含水状态对红层软岩力学特性影响机理

发布时间：2018-01-16 23:29

本文关键词：含水状态对红层软岩力学特性影响机理　出处：《煤炭学报》2017年08期 　论文类型：期刊论文

【摘要】：饱水状态下,红层软岩力学特性的劣化直接影响相关工程的变形稳定。考虑干燥、自然和饱水3种状态,对红层软岩抗压和抗拉强度特性、变形破坏特征及微观结构特征进行了比较系统的试验和检测分析。研究表明:①饱水状态下红层软岩的软化特征明显,破坏时的延性特征更加明显,不同围压下岩样的抗压强度软化系数为0.36~0.65,相对于干燥状态,弹性模量和变形模量逐渐降低分别降低了35.60%~75.53%,44.57%~69.64%,而且围压越小,抗压强度和模量降低趋势越明显;②相对干燥状态,饱水状态下岩样的黏聚力、内摩擦角分别下降了47.77%和12.68%,岩样的黏聚力对含水状态更为敏感;③饱水状态下岩样抗拉强度软化系数为0.40,加载线附近局部破坏特征明显;④岩样内部矿物颗粒间泥质胶结物的溶解破坏,伊利石、蒙脱石等黏土矿物吸水膨胀、分解,使得岩体结构由相对密实状态逐渐变得多孔、松散,而且孔隙多被水充填,这些微观结构的改变直接导致了红层软岩力学性质的劣化。
[Abstract]:The saturation condition, deterioration of mechanical properties of soft rock of red layer directly affect the deformation and stability of related engineering. Considering the natural dry and water saturated 3 kinds of state of red layer soft rock compressive strength and tensile strength characteristics, deformation characteristics and microstructure characteristics were compared with the test system and test analysis. The results show that the water saturated softening characteristics of soft rock of red layer obviously, ductility failure is more obvious, the compressive strength under different confining pressure rock softening coefficient is 0.36~0.65, relative to the dry state, elastic modulus and deformation modulus decreases respectively decreased 35.60%~75.53%, 44.57%~69.64%, pressure is small and round, and the compressive strength the modulus decreased more obviously; the relatively dry, water saturated rock cohesion, internal friction angle decreased by 47.77% and 12.68%, the cohesion of rock is more sensitive to water content; the water saturated state The softening of rock tensile strength coefficient is 0.40, the loading line in the vicinity of the local damage characteristics; the dissolved rock mineral particles argillanceous cement damage, illite, montmorillonite clay mineral swelling, decomposition, making the rock mass structure by relatively dense state gradually become porous, loose and porous water filling, these the change of microstructure directly leads to the deterioration of red layer soft rock mechanical properties.

【作者单位】：三峡大学三峡库区地质灾害教育部重点实验室;
【基金】：国家自然科学基金资助项目(51679127);国家自然科学基金重点资助项目(51439003) 水利部公益基金资助项目(201401029)
【分类号】：TU45
【正文快照】： 红层软岩作为一类特殊的岩体,遇水易产生膨胀变形,甚至崩解破坏,在各类岩土工程中普遍存在,往往对边坡、坝基以及地下洞室的变形稳定性起着控制性作用[1]。较多学者对红层软岩的物理力学特性进行了理论和试验研究。孙乔宝[2],万宗礼等[3]对红层软岩结构构造及岩体结构特征进行

【相似文献】