兰州市地铁1号线穿黄段工程综合勘察方法与评价

Study on General Investigation Methods and Assessment of Crossing Works under Yellow River,Metro Line 1 in Lanzhou City

兰州市城市轨道交通1号线奥体中心-世纪大道以及迎门滩-马滩区间2次穿越黄河,穿越长度近300 m,穿越黄河段主要地层为卵石地层,其中上部全新统(Q4)卵石地层为第四系全新统,下更新统(Q1)卵石地层为下更新统冲积卵石,有胶结现象。为查清穿黄段区间卵石的工程地质特性以及施工过程中采用盾构法穿越卵石地层的风险,采用了钻探、原位测试、抽水试验、大型剪切试验等多种综合勘察方法,查明了穿黄段卵石地层的地质特征以及物理力学性质,为穿黄段工程的设计、施工提供了详细的物理力学参数及工程措施建议,为兰州地铁1号线穿黄段顺利施工提供了基础保证。

Section Olympic Center to Shiji Avenue and Section Yingmentan to Matan of the urban rail transit Line 1 in Lanzhou city cross twice under the Yellow River with crossing length of 300 m nearly. The crossing section of the Yellow River features cobble in stratum. Among it, the cobble stratum of the upper Holocene Series （Q4） is of the Quaternary brand-new series and the cobble stratum of the lower Pleistocene system （Q1）, alluvial cobble of the lower Pleistocene system with cementation. To know clearly the engineering geological characteristics of the cobble in the sections and risks in the cobble stratum while shield tunneling method is applied in construction, a couple of investigation methods are applied such as drilling, in situ tests, pumping test and large shear tests, etc. . The geological characteristics and physical-mechanic properties of the cobble stratum in the crossing sections are investigated. These provide design and construction of the crossing works with detailed physical-mechanic parameters and engineering measures / comments as well as the successful construction of the crossing works of metro Line 1 in Lanzhou with fundamental assurance.