补水压力对土体冻胀的影响  

Experimental study on the effect of boundary hydraulic pressure on frost heaving of soil

作　　者：郝小云 冯文杰 马巍 温智 张莲海 王永瑞 申明德 黄永庭 HAO Xiaoyun;FENG Wenjie;MA Wei;WEN Zhi;ZHANG Lianhai;WANG Yongrui;SHEN Mingde;HUANG Yongting(State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Geological Hazards Prevention,Gansu Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]甘肃省科学院地质自然灾害防治研究所,甘肃兰州730000

出　　处：《冰川冻土》2022年第2期708-716,共9页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41871061,41971087);国家自然科学基金重点项目(41630636);中国科学院重点部署项目(ZDRWZS-2020-1)资助。

摘　　要：为了研究冷端温度、土质和补水压力对土体冻胀影响的强弱以及现行评价土体冻胀敏感性的方法在土体有压补水冻结时的适用性,开展了三因素三水平的冻胀正交试验。基于灰色关联度法得到的结果表明,影响土体冻胀率的因素由强到弱依次为补水压力、冷端温度和土质。补水压力、冷端温度与冻胀率的关联度较大,土质与冻胀率的关联度较小。在较高的补水压力作用下,非冻胀敏感性的砂类土产生了明显的冰透镜体,且部分砂类土的冻胀率超过了黏质土的冻胀率。发现仅凭细粒含量评价水压作用下砂类土的冻胀敏感性存在缺陷,应根据土体所处的实际环境进行综合评估。通过讨论冻胀敏感性、融沉敏感性与冻害敏感性之间的关系,提出受水压影响的寒区工程构筑物须通过设置隔水和排水设施以及使用换填法来综合防治冻害的方法,可为相关工程的设计及安全运营提供参考。In order to study the influence of cold-end temperature,soil group and boundary hydraulic pressure on soil frost heave and the applicability of the current methods on assessing frost heave susceptibility of soils.Three factors and three levels of orthogonal experiments are carried out. The sequence of influencing frost heave ratio of soils is obtained by using the gray correlation method. The results show that the correlation among boundary hydraulic pressure,cold-end temperature and frost heave ratio is relatively larger,and the correlation between soil group and frost heave ratio is relatively smaller. Therefore,the factors affecting the frost heave ratio of soil from strong to weak are boundary hydraulic pressure,cold-end temperature and soil group. The ice lenses are formed in sandy soil samples during freezing under boundary hydraulic pressure,and the frost heave ratio of some sandy soil samples were larger than that of silty clay samples. Therefore,it can be concluded that it is not reasonable to assess the frost heave sensitivity of soil under the condition of boundary hydraulic pressure by fine particle content,and the frost heave susceptibility of soils should be assessed according to the actual situation. It is generally believed that the influence of soil group on frost heaving is strong,while it is found that the effect of soil on frost heaving is the weakest under boundary pressure. The relationship among frost heave susceptibility,thaw weakening susceptibility and frost susceptibility were discussed. It is found that although the sandy soil can frost heave under boundary hydraulic pressure,it can rapidly discharge water during thawing,which can reduce the frost damage caused by soil thawing. Therefore,coarse-grained soil should be replaced with fine-grained soil when treating the frost damage. In order to ensure the safe operation of engineering structures in cold regions under boundary hydraulic pressure,it is proposed that the effect of boundary hydraulic pressure on soil should be solved firstly.

关 键 词：冻胀 冻胀敏感性 水分迁移 补水压力 土质 冷端温度 

分 类 号：P642.14[天文地球—工程地质学]