混凝土条形基础设计研究

Research on the design of strip footing with concrete

混凝土条形基础受力类似于悬臂梁,墙或基础梁是其嵌固端,而向上的土压力则是作用在梁上的荷载。结合现行《建筑地基基础设计规范》和《混凝土结构设计规范》的规定,对条形基础的剪切承载力、内力臂系数、钢筋充分利用点等关键问题进行研究。研究表明,无筋条形基础在满足抗弯承载力的前提下可不必验算抗剪承载力,而钢筋混凝土条形基础的内力臂系数可取0.95,二分之一钢筋的理论切断点可偏于安全取为距端部的0.58倍悬挑长度处,研究成果为此类基础设计和规范修订提供参考。

The concrete strip footing behaves similarly to a cantilever beam,where the cantilever extends out from the wall or foundation beam and is loaded in an upward direction by the soil pressure. Based on the China Code GB50007--2011 and GB50010--2010, some key questions such as load-carrying capacity and cut-off are studied. It is found that the flexure is more important than the shear in checking of load-carrying capacity for a wall footing with plain concrete. The lever-arm and theoretical cut-off with half of reinforcements are deduced. The results may be as reference in footing design and code revising.