清水及硫酸溶液浸泡下花岗岩残积土强度演化特征研究

Strength Evolution Characteristics of Granite Residual Soil Immersed in Distilled Water and Sulfuric Acid Solution

为了揭示不同浸泡环境下花岗岩残积土的强度演化特征,考虑到花岗岩残积土的结构损伤与介质溶解,以不同硫酸溶液浓度和浸泡时间作为试验变量,开展清水及硫酸溶液浸泡下试样的波速测试、快剪试验以及质量测试。研究表明:试样浸泡在清水中时,其黏聚力、内摩擦角和纵波波速均随浸泡时间增加呈指数衰减,28 d^40 d后稳定,硫酸溶液中则随硫酸浓度增加呈指数衰减,浓度增加到5%后趋于稳定;分别以黏聚力、内摩擦角和纵波波速的定义损伤变量,在清水浸泡下随浸泡时间增长而增大,浸泡28 d^40 d后稳定,在硫酸溶液浸泡下随硫酸浓度增加而增大,浓度增加到5%后趋于稳定;黏聚力和纵波波速演化特征相似,可通过纵波波速推算黏聚力。

In order to reveal the strength evolution characteristics of the granite residual soil under different immersing environment. By considering the structural damage and medium dissolution of the granite residual soil, this paper took the different sulfuric acid solutions concentration and immersing time as the variables, the wave velocity test, fast shear test and quality test of the sample immersed in clear water and sulfuric acid solutions were carried out. The results show that: cohesion, internal friction angle and P-wave velocity of granite residual soil samples decreased exponentially with the increase of immersion time when immersed in clear water, and are stable after 28~40 days. In sulfuric acid solution, they decreased exponentially with the increase of sulfuric acid concentration immersed, and stabilized after the concentration increased to 5%. The deterioration variables are defined by cohesion, internal friction angle and longitudinal wave velocity, they increase with the increase of immersion time and then became stable after 28~40 days in clear water. When immersed in sulfuric acid solutions, they increased with the increase of sulfuric acid concentration, and then tended to be stable after the concentration increased to 5%. The evolution characteristics of cohesion and P-wave velocity are similar, it is feasible to calculate cohesion by P-wave velocity. With the increase of sulfuric acid concentration, the loss rate of soil mass gradually increases.