颗粒材料黏滑运动特征与颗粒黏结试验研究

发布时间：2018-06-01 00:11

本文选题：土工试验 + 黏滑运动　；参考：《岩石力学与工程学报》2016年09期

【摘要】：为了研究饱和颗粒材料的黏滑运动特征与颗粒表面黏结机制,采用钠钙玻璃珠,开展颗粒材料的固结排水三轴试验、单颗粒压缩试验、固结试验和热熔试验。三轴试验结果表明:饱和、密实的颗粒材料在高围压条件下具有黏滑运动特征,并且随着有效围压的增大,平均偏应力降幅呈指数增长。试样在滑动瞬间,偏应力骤降,体积突然收缩。试样在黏滞阶段,偏应力逐渐增长,表现为应变硬化;试样体积首先收缩到最小点,然后才开始膨胀。黏滑运动过程中,偏应力变化与围压变化的一致性要好于与孔隙水压力变化的一致性,说明围压监测精度较高。单颗粒压缩试验、固结试验和热熔试验表明,在常温条件下颗粒表面黏结形态与高温条件下的热熔黏结形态完全不同。这是因为常温条件下,颗粒在压力作用下互相接触、压缩,在水的作用下表面逐渐溶解,并在颗粒表面再沉淀导致颗粒黏结,其黏结强度较低且颗粒表面形态变化较小。
[Abstract]:In order to study the characteristics of viscosity and slip motion and the mechanism of surface adhesion of saturated granular materials, the consolidation and drainage triaxial tests, single particle compression tests, consolidation tests and hot melt tests were carried out with sodium calcium glass beads. The results of triaxial test show that the saturated and dense granular materials have the characteristics of viscous and slip movement under high confining pressure, and the decrease of average deviant stress increases exponentially with the increase of effective confining pressure. At the moment of sliding, the deflection stress drops and the volume shrinks suddenly. In the viscous phase, the strain hardening of the specimen increases gradually, and the specimen volume first shrinks to the minimum point and then begins to expand. The variation of deflection stress and confining pressure is better than that of pore water pressure in the process of visco-slip movement, which indicates that the precision of confining pressure monitoring is higher. The single particle compression test, consolidation test and hot melt test show that the surface bonding morphology of particles at room temperature is completely different from that at high temperature. This is because under normal temperature the particles contact with each other under pressure compress the surface dissolve gradually under the action of water and precipitate on the surface of the particles lead to particle bonding. The bonding strength of particles is lower and the change of particle surface morphology is small.
【作者单位】：中国地质大学工程学院;中国地质大学教育部长江三峡库区地质灾害研究中心;奥地利维也纳农业大学;
【基金】：国家自然科学基金资助项目(41002102,41272308)~~
【分类号】：TU411

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