降雨环境下块度对泥质岩崩解能量特征的影响

Influence of Lumpiness on Energy Characteristics of Disintegration of Mudstone in Rainfall Environment

为了研究块度不同对泥质岩崩解特性的影响,采用自行设计的试验装置模拟自然界中降雨的实际环境,对江西省赣南地区的泥质岩制成80~70、70~60、60~50、50~40 mm 4种不同块度的试样,开展了模拟降雨与干燥条件下的崩解试验,并对其崩解的能量特征进行研究。结果表明,在试样各粒组百分含量关系曲线中,不同循环次数条件下,曲线都存在一个明显的峰值,曲线基本表现出先增加至峰值而后减小的变化趋势,且随着循环次数的增加,峰值逐渐向粒径减小的方向发生移动。在峰值前,随着循环次数的增加,曲线的位置逐渐向下移动;而在峰值后,随着循环次数的增加,曲线的位置则逐渐向上移动。随着循环次数的增加,各粒组百分含量曲线之间的间距逐渐减小,且最后4次干湿循环条件下各粒组百分含量曲线非常接近,表明泥质岩的崩解逐渐趋于稳定。分析了岩石崩解过程累计新增比表面积与循环次数的变化关系,随着循环次数的增加,各试样累计新增比表面能在循环次数较小时先迅速增大,在第2次干湿循环之后增速逐渐放缓,最后基本达到稳定。随着试样块度的逐渐增加,试样累计新增表面能逐渐减小。基于最小二乘法原理,求得了累计新增比表面能与循环次数的关系式,并验证了计算模型的正确性。

In order to study the influence of different lumpiness on the disintegration characteristics of mudstone,a self-designed test device was used to simulate the actual environment of rainfall in the natural world.The mudstone in the Weinan area of Jiangxi Province was made into 80~70,70~60,60~50 and 50~40 mm,the samples of different lumpiness were tested in the laboratory disintegration under the action of dry and wet cycles.The relationship between the cumulative specific surface energy and cycle numbers in the rock disintegration process was analyzed.Based on the principle of least squares method,the relationship between the cumulative new surface energy and the cycle numbers was obtained,and the correctness of the calculation model was verified.Results show that,in the curve of the percentage of each particle group,there is a significant peak in the curve under different cycles.The curve basically shows increasing to the peak first,then decreasing.And with the cycle numbers increasing,the peak gradually moves toward the direction in which the particle diameter decreases.Before the peak,as the cycle numbers increases,the position of the curve gradually moves downward;and after the peak,as the cycle numbers increases,the position of the curve gradually moves upward.With the increase of the cycle numbers,the gap between the percentage curves of each group gradually decreased,and the curve under the last four dry and wet cycles was very close,indicating that the disintegration of mudstone gradually becomes stable.With the increase of cycle numbers,the cumulative specific surface energy of each sample increases rapidly when the number of cycles is small,and after the second cycles the growth rate gradually slowed down and finally stabilized.As the lumpiness increases gradually,the cumulative surface energy of the sample gradually decreases.