摘要
针对贺兰口岩画赋存区域坡面泥石流和危岩等地质灾害频发的问题,通过对区域内灾害发育特征和岩性条件的详细调查与定性分析得出地质灾害频发的问题是由薄、厚互层浅变质砂岩差异损伤造成。以前期研究为依据,设置不同化学环境两种岩石长龄期的冻融和干湿循环实验,初步揭示了其损伤机制。结果表明:薄层浅变质砂岩试样在所设任意相同劣化条件下的质量损失率、黏聚力与内摩擦角的衰减速率、孔洞数量与面积的增长速率、长石类矿物转化率与损伤变量的变化率均明显高于厚层浅变质砂岩试样,而导致上述差异的原因在于薄层浅变质砂岩中较高的长石类矿物的含量、隐伏层面的存在以及填隙物以泥质为主,三方面的共同作用使薄层浅变质砂岩在相同劣化条件下的矿物水解和溶蚀反应的剧烈程度、胶结的失效程度明显高于厚层浅变质砂岩。
In view of the frequent occurrence of geological disasters such as slope debris flow and dangerous rock in the rock painting area of Helankou,through the detailed investigation and qualitative analysis of the disaster development characteristics and lithologic conditions in the region,it is concluded that the problem of frequent geological disasters is caused by the differential damage of thin and thick interbedded low-grade metamorphic sandstone.Based on previous research,freeze-thaw and dry-wet cycle experiments of two kinds of rocks in different chemical environments were set up,and the damage mechanism was preliminarily revealed.The results showed:The mass loss rate,the attenuation rate of cohesion and internal friction angle,the growth rate of the number and area of pores,the conversion rate of feldspar minerals,and the change rate of damage variable of thin low-grade metamorphic sandstone samples are significantly higher than those of thick low-grade metamorphic sandstone samples under any same deterioration conditions.The reason for the difference is that the thin low-grade metamorphic sandstone has a high content of feldspar minerals,the existence of latency layers,and interstitial material that is mainly argillaceous.The joint action of these three aspects makes the intensity of mineral hydrolysis and dissolution reaction and the degree of cementation failure of thin low-grade metamorphic sandstone significantly higher than that of thick low-grade metamorphic sandstone under the same deterioration conditions.
作者
崔凯
陈一凡
吴国鹏
裴强强
CUI Kai;CHEN Yifan;WU Guopeng;PEI Qiangqiang(Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province Lanzhou University of Technology,Lanzhou 730050,China;National Ancient Mural Protection Engineering Technology Research Center,Dunhuang 736200,China)
出处
《工程地质学报》
CSCD
北大核心
2024年第6期1988-2002,共15页
Journal of Engineering Geology
基金
国家自然科学基金项目(资助号:42107206,U22A20599)
中国博士后科学基金项目(资助号:20023MD734145)
甘肃省自然科学基金项目(资助号:22JR5RA292)。
关键词
薄厚互层
损伤特征
损伤变量
差异风化
隐伏层面
Sandstone interbeds
Damage feature
Damage variable
Differential weathering
Latency layer
