Geological and geotechnical characteristics of Xiaolangdi dam, Yellow River, China

In order to construct a 154 m high, 1,650 m long earth filled dam across the Yellow River at Xiaolangdi, China, site investigations including in situ and laboratory tests, Landsat imaging, geological mapping, geophysical survey and drilling were undertaken. Two special investigation techniques were employed. To ensure full recovery of the intercalated clays and siltstones in the Permian and Triassic deposits, a sleeve drilling technique was introduced while to establish the long-term stress conditions in the tunnels, radial resistance testing was undertaken. The paper focuses on the geotechnical characteristics of the Quaternary sands and gravels, which in the channel of the valley are up to 70 m thick, and discusses the influence of the Triassic and Permian bedrock.