软土地层中水平冻结施工对上方运营地铁车站影响监测分析

Monitoring and Analysis of Impact of Horizontal Freezing Construction on Operation of Subway Stations above in Soft Soil Strata

摘要:

为研究近接隧道水平冻结对上部运营车站冻胀变形的规律，以上海市18号线国权路站在建隧道下穿10号线上部运营车站冻结法施工为工程背景，通过监测数据分析研究冻结温度和车站沉降变形规律。分析结果表明：土体温度随着冻结天数增加，先急后缓地下降，并于50 d后低于-10℃，在隧道周围形成2 m厚的冻结壁。随着冻结程度的增强，冻结中心区域冻胀变形显著，其中侧墙初始沉降为2 mm，后持续增加到5 mm，并保持稳定；车站道床初始隆起为3 mm，后增加到10 mm，并达到稳定状态；车站立柱初始隆起为5 mm，后显著增加到23 mm，后期保持稳定。

Abstract:

To study the law of horizontal freezing close to the tunnel on the frost heave deformation of the upper operating station, relying on the freezing process construction of the tunnel under construction of the Shanghai Metro Line 18 Guoquan Road Station underpassing the upper operating station of Metro Line 10, the monitoring data are used to analyze and study the laws of freezing temperature and station settlement and deformation. The analysis result shows that the soil temperature decreases rapidly and then slowly with the increase of freezing days, and after 50 days, it drops below -10 ℃, forming a 2 m-thick frozen wall around the tunnel. As the degree of freezing increases, the frost heave deformation in the frozen center area is significant. The initial settlement of the side wall is 2 mm, which continues to increase to 5 mm and remains stable. The initial uplift of the station track bed is 3 mm, which later increases to 10 mm and reaches a stable state. The initial uplift of the station pillars is 5 mm, which significantly increased to 23 mm and remained stable in the later stage.