Research on Support Technology of a Soil-Rock Combination Deep Excavation in Qingdao

다국어 초록 (Multilingual Abstract)

Based on a deep excavation engineering in Qingdao, which is one of the largest or deepestsoil-rock combination excavations in China, the design parameters and calculation results aregiven for excavation retaining and protection. The excavation on-site test data are provided,including the anchor axial force and pile top displacement, and a comprehensive analysis iscarried out. Using numerical simulation, the distribution of anchor axial force is analyzedunder different working conditions, as same as pile body deformation and slope bodydisplacement are analyzed. Retaining and protection structure can be calculated in four stagesby the elastic foundation beam method. Results: when the lower rock mass is calculated assoil by equivalent internal friction angle, the retaining and protection structure designparameters deviate from the actual needs with working conditions. The ratio of tested anddesigned axial force of anchor in soil layer is generally greater than the ratio in rock layer.
Whether above the soil-rock interface or the pit base, the measured horizontal compositeforce of anchors is between the calculated active earth pressure and the static earth pressure.
Anchorage section length is recommended 2.0 m in the medium or slightly weathered rock.