兰州市红圈沟黄土裂缝群成因分析  

FRACTURE GROUP IN HONGQUANGOU GULLY OFLANZHOU

作　　者：付东林 王志强 FU Dong-in;WANG Zhi-qiang(Gansu Institute of Geo-environmental Monitoring,Lanzhou 730020,China)

机构地区：[1]甘肃省地质环境监测院,甘肃.兰州730050

出　　处：《甘肃地质》2024年第4期41-46,共6页Gansu Geology

摘　　要：在兰州市皋兰县水阜乡红圈沟自然地质环境条件、黄土裂缝群基本特征概述基础上,选取8#裂缝勘查与岩土试验;通过湿陷性计算与评价和近十余年的宏观地貌变化观测,判定黄土裂缝群已经基本趋于稳定;提出干旱古气候条件下形成的地质环境条件使得全新世地质历史上的地下水位线处于一个较低水平状态,灌溉工程实施以后形成了一个现代较高水平的地下水位线,地下水侧向浸润、渗透,粘性土持水、滞水,丘陵、阶地土体发生自重湿陷,受丘陵土体中裂隙、节理等切割作用,遂形成黄土裂缝群。对比黄土丘陵沟谷中冲洪积层与坡体上风积层,易溶盐总量减少0.01%~0.05%;易溶盐组分是原状土体结构的重要组成部分,遇水后易溶解流失。黄土地区在斜/边坡失稳监测中在充分注重大气降水监测的同时,强烈建议加强人工用水过程和用水强度、用水频次、总用水量等的预设计、监测和管理。另外,结合多年实践,建议从填筑体的结构组成改良上入手,进一步加强地表、地下排水方法的研究与运用,为黄土地区工程建设起到有力的地质科技支持。Based on the natural geological environment conditions and the basic characteristics of Loess Fracture Group in Hongquangou gully,Shuifu Township,Gaolan County,Lanzhou City,we finished the 8th fracture's exploration and geotechnical test.According to the calculation and evaluation of collapsibility and the observation of macroscopical geomorphologic change in recent ten years,it is concluded that the Loess Fracture Group has basically become stable.It is pointed out that the geological environment conditions formed under the arid and paleoclimate conditions resulted in a lower level of groundwater level in the Holocene geological history,and a modern higher level of groundwater level was formed after the implementation of irrigation project,and then the Loess Fracture Group is formed by the side infiltration of groundwater,water holding and stagnant of clayey soil,the self-weight collapse of Hill and terrace soil and the soil cracks and joints cutting action of it etc.Compared with the alluvial-diluvial layer and the Eolian layer on the slope in the loess hilly-gully region,the total amount of soluble salt decreased by 0.01%~0.05%.The soluble salt component is an important part of the original soil structure,which is easy to dissolve and flow away when exposed to water.In the monitoring of slope/slope instability in loess area,while paying full attention to the atmospheric precipitation monitoring,it is strongly suggested to strengthen the pre-design,monitoring and management of artificial water use process,water use intensity,water use frequency and total water use.In addition,combined with the practice for many years,we proposed that we should strengthen the research and application of surface and underground drainage methods from the improvement of the structure composition of the filling body,so as to provide the strong geological scientific and technological support for the engineering construction in the loess area.

关 键 词：兰州市皋兰县 黄土裂缝群 勘查及岩土试验 稳定性及形成机理 黄土地区用水管理 

分 类 号：TU475[建筑科学—结构工程] P642.2[建筑科学—土工工程]