为探讨RPC材料应用于隧道管片结构中的可行性,文章通过22根活性粉末混凝土(PRC)构件的大偏心受压试验,确定了不同截面尺寸、配筋率以及有无钢纤维条件下RPC偏心受压构件的承载特性,得到了各级荷载条件下试验柱的整个截面的应变分布特征。研究结果表明,偏心荷载作用下RPC偏心受压试件截面应变符合平截面假定,采用RPC材料制作隧道管片结构时,其厚度可有较大幅度的降低;试件截面厚度对其承载力的影响最为显著;由于RPC材料本身的抗拉、压强度较高,钢筋在RPC偏压结构中所起的作用逐渐减弱,RPC结构可适当减少其配筋量。
Taking an urban underground bored road tunnel as an example, a three-dimensional numerical simula- tion of dynamic excavation using the CRD and cross diaphragm with step methods is conducted based on the finite- element theory. A contrastive analysis of the deformation and force characteristics of the rock mass and support structure of the tunnel constructed by the above two methods is carried out and an optimization of the cross dia- phragm with step method is performed based on the results of numerical calculations. A comparison between the two construction methods is performed in terms of the advantages and disadvantages regarding construction safety, quali- ty, progress and cost. The research and practice indicate that the two construction methods can both meet the re- quirements for rock mass and support structure stability, but the cross diaphragm with step method is superior to the CRD method in respect to construction progress and cost and produces better economic benefits in practice.