荷载、强度和结构安全

资料简介：

　　Loads, Strength, and Structural Safety
　　A. Loads
　　Loads that act on structures are usually classified as dead loads or live loads. Dead loads are fixed in location and constant in magnitude throughout the life of the structure. Usually the self-weight of a structure is the most important part of the dead load. This can be calculated closely, based on the dimensions of the structure and the unit weight of the material. Concrete density varies from about 90 to 120 pcf ( 14 to 19 kN/m3) for lightweight concrete, and is about 145 pcf (23 kN/m3) for normal concrete. In calculating the dead load of structural concrete, usually a 5 pcf ( 1 kN/m3) increment is included with the weight of the concrete to account for the presence of the reinforcement.
　　荷载、强度和结构安全
　　一、荷载
　　作用在结构上的荷载通常分为恒载或活载。恒载在结构整个使用寿命期间的位置是固定的，其大小是不变的。通常，结构的自重是恒载是最重要部分。它可以根据结构的尺寸和材料的单位重量进行精确计算。混凝土的密度是变化的，对于轻质混凝土大约从90至120pcf(14至19KN/M3)的增加量。活载就是如人群、雪、风和车辆荷载或地震力等荷载。他们可能全部或部分地出现，或者根本不出现。这些荷载的位置是变化的。