共和-玉树高速公路多格茸段冻胀丘与公路路基的相互影响  

Interaction effect of frost mounds and embankment in section Duogerong Basin along Gonghe-Yushu Highway

作　　者：吴吉春 盛煜 WU Jichun;SHENG Yu(State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese 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

出　　处：《冰川冻土》2021年第2期453-462,共10页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41171058,41271084);冻土工程国家重点实验室自主研究项目(SKLFSE-ZE-11)资助。

摘　　要：冻胀丘是土层中水分向冻结锋面大量迁移集聚,并且冻结膨胀使地面隆起呈丘状的一类冰缘地貌。冻胀丘的本质特征是存在纯冰核或高含冰地层,冻胀丘地表的隆起高度即代表了地下冰层的累计厚度,在工程建设中一般采用避让措施。在我国冻土区公路建设中,过去尚未遇到道路穿越冻胀丘的先例,正在建设中的青海省共和-玉树高速公路(简称共玉高速)在玛多县多格茸盆地横跨几个冻胀丘,对公路建成以后安全运营造成潜在威胁。以共玉高速建设里程K430+070处道路所跨的冻胀丘为例,基于地温监测数据和冻胀丘钻探资料,探讨公路建设对冻胀丘下覆冰层的影响及由此带来的路基稳定性问题。监测发现目前路基下多年冻土上限已经下降至冻胀丘高含冰地层位置,由于沥青路面的强吸热性,未来冻胀丘路段将发生持续沉降。如果多年冻土完全融化,该段路基有可能发展成热融湖塘。A frost mound is any mound-shaped landform produced by ground freezing combined with groundwater movement or the migration of soil moisture. It is characterized by massive ice or ice bounded strata underneath. The height of frost mound that upheaved from ground surface reveals the accumulative thickness of ground ice. So we should avoid frost mounds while engineering constructing. In course of highway building in permafrost regions in China,it was not experienced that highway embankment cut across the frost mound. But this case has encountered by Gonghe-Yushu building highway in Duogerong basin,and it would have threatened embankment stability potentially. In this work,we explore embankment stability and influence of highway constructions on ground ice under frost mound which site at mile K430+070 along Gonghe-Yushu Highway. Employing ground temperature and drilling core,we found that permafrost table under embankment has dropped to interface of ground massive ice along the section of highway cut across frost mound. The embankment would be settled consecutively because of intensely absorbing heat by black asphalt pavement in future. Where would change into thermokarst lake if permafrost has thawed completely.

关 键 词：冻胀丘 多年冻土 地下冰 公路施工 路基稳定 共玉高速 

分 类 号：P642.14[天文地球—工程地质学]