高原冻土区地质条件复杂，冻土地基的差异性冻胀和融沉变形威胁着工程的长期稳定性和服役性能。为满足工程基础的工后沉降与沉降差要求，同时减少对下部冻土的扰动，以多年冻融区过渡段某富水场地为例，开展地基处理现场试验，对比块石抛填和块石抛填+换填两种地基处理施工方案。结果表明，针对包括淤泥质泥岩、粉砂质土、中粗砂、冻融区过渡带四种工程地质条件，采用块石抛填方案均出现翻浆、冒泥等现象，无法碾压达成地基处理要求，而采用块石抛填+换填处理方案，经8~10遍碾压后，压实度均能达到要求。

The engineering geological conditions in high-altitude permafrost regions are complex, and the differential frost heave and thaw settlement of permafrost foundations threaten the long-term stability and service performance of engineering structures. In order to meet the requirements of post construction (differential) settlement of foundation and reduce disturbance to underlying permafrost, a field test on foundation treatment is carried out at a water rich site in transition section of freeze-thaw zone. A comparative study is conducted on two construction schemes for foundation treatment, namely, “stone throwing and filling” and “stone throwing and filling + replacement”. The results show that for four types of engineering geological conditions, including muddy mudstone, sandy soil, medium coarse sand, and transition section of freeze-thaw zones, direct use of “stone throwing and filling” has resulted in phenomena such as mud overturning and mud seepage, which makes it impossible to meet the requirements. However, the use of “stone throwing and filling + replacement” can achieve the compaction requirements after 8~10 passes of rolling.

U416

中国电建集团西南指挥部科技项目（XNZ/2020/KK-1-2）